Class Rules

Micro
Tracey Carpenter

Classroom Behavior
While we will have some very fun times discussing the material there are some rules
NO ARGUEING
If I am lecturing, no side discussions
You give me respect in the class, I will give it to you

Objectives
You will be able to:
Match terms related to microbiology with their correct definitions
Research the causes and preventions of human disease
Select factors influencing the occurrence of infection
Describe means of controlling the transmission of infection

Evaluation
Professionalism 10%
Tests 20%
Attendance 10%
Homework 10%
Research Paper 10%
Midterm 20%
Final 20%
You must make a 70% on the final to pass the class

Final
Sorry to say that the final is to be comprehensive
This is a mandate from administration
Don’t worry, we will review

Attendance
You know the rules by now
The Texas Board of Education regulates attendance
NOT THE SCHOOL
If you miss school you will be counted absent
Attending class late adds up fast
Be on time
Again you know the rules if you need a refresher see the syllabus
Remember
If you miss 6 classes you will be dropped from the course
If you do miss and have mitigating circumstances turn it in to Mr. E
You will be dropped from the course after 7 absences with mitigating circumstances
You have two weeks to challenge attendance
After that it sticks

Remember
This class will not be offered again for two quarters
If you must miss make it count

Tests
If you miss a test for any reason, you can make it up on the assigned test make up day noted on the syllabus
If you don’t take it on that day, it will be a zero

Class Rules
Turn in assignments on time
I will not take late work
If you are late and come in after I call for it, I WILL NOT TAKE IT
No food or drink
covered drinks are okay
No Children
Turn cell phones on silent
If you’re expecting an important call, take it in the hall
Phones will be put away during class time

Cheating
Will not be tolerated!
This is an ethical issue
Do you want someone operating on you that is not ethical?

Research Assignment
Choose an organism, any organism
Write as if you are the organism
Tell your life story
Where do you live
What do you eat
What do you like to do
Are you mean or friendly?
Give yourself a nickname

Paper Requirements
Cover page
Name of the paper, your name, my name
Centered on page
At least 2 pages
1 inch margins all the way around
I do own a ruler 
Double spaced
12pt Times New Roman

Work Cited Page
You do not need one!

I will be able to read your paper and know how much you have put into it
Be thorough, let me know that you know what you are talking about
Grammar will not be counted
Although full sentences and punctuation will
Have fun with it!
Be creative!
It will be due, at the beginning of class, by Week 7
Late papers will not be taken!
Remember this is 10% of your grade
That can equal a whole grade point!
You can turn them in early

Do
Pay attention to the parameters of the paper
Example - If the first page is not centered – points off
I am looking to see how well you pay attention to the rules, can you follow direction

Don’t
Wait till the last minute
No excuses
Examples:
The printer is not working right
I left it at home

Presentation
Can add up to 10pts with AV
Just reading your paper gets 2pts
Presentation with a poster gets up to 6pts
Presentation with Power Point gets up to 10 pts
Keep a copy of you paper
When you turn in your paper it is mine
Do not expect me to bring it to you for your presentation

Notes for the class
http://vcmicronotes.blogspot.com/
Be prepared beforehand
Don’t leave the class to print the notes
You will be counted late

Intro to Microbiology

Microbiology
for the Surgical Technologist
History
1665 - 1884
Robert Hooke
Marked the beginning of Cell Theory
Anton Van Leeuwenhoek
Rudolf Virchow
Proposed the theory of Biogenisis
Louis Pasteur
established the Germ Theory of Fermentation
And the process of Pasteurization
Edward Jenner
Ignaz Semmelweis
Joseph Lister
Established some of the first principles of Aseptic Technique
Robert Koch
Hans Gram
Chemotherapeutic Agents
Chemotherapy
is the treatment of disease with chemical substances
Antibiotics
are naturally produced by bacteria and are used against other microbes
Twentieth Century Advances
Paul Ehrilich - 1910
Discovered SALVARSAN
Rebecca Lancefield - 1933
Alexander Fleming – late 1930’s
Discovered PENICILLIN by accident
Interferon discovered – 1960
Avery, MacLeod, and McCarty - 1944
Lederberg and Tatum – 1946
Discovered CONJUGATION
Watson and Crick – 1953
Robert Gallo – Late 1970’s
AIDS discovered - 1981

Nomenclature
Binomial System
Genus then Species
Example: Homo sapien or Homo sapien
H. sapien
Means wise man
The Five-Kingdom System
Procaryotae
Protista
Fungi
Plantae
Animalia
Units of Measure
Meter – (m) 1 m =
Decimeter – (dm) 10 dm =
Centimeter – (cm) 100 cm =
Millimeter – (mm) 1000 mm =
Micrometer – (m) 0.000001 m =
Nanometer – (nm) 0.000000001 m =
Angstrom – (Å) 0.0000000001 m

Sizes of Microbes
Bacteria
From 3 m to as small as 0.2 m
Erythrocytes (red blood cells)
About 7 m
Viruses
From 10 to 300 nm
Large protozoa
Can be 2000 m, or 2 mm in length

Microscopes
Compound (bright-field) Microscope
Two lenses with a light source
Objective lens
Ocular lens
Magnifies from 40x to 1000x
Oil immersion objective
Condenser
Resolution


Dark Field Microscope
Uses a dark field condenser
Phase-Contrast Microscope
Used to visualize the internal structures of a microbe
Fluorescence Microscope
Flurochromes
Electron Microscope
Used to visualize viruses
Uses electrons instead of light

Transmission Electron Microscope (TEM)
Focused beam of electrons
Drawbacks
Limited penetration of electrons
Special preparation of specimen
Cannot view in 3D
Scanning electron Microscope (SEM)
3D surface view of specimen
Primary and secondary electrons
Staining Methods
Preparing for staining
Smear
Simple stain
Single stain used
Common stains used are
Methylene blue
Carbolfuchsin
Safranin
Crystal violet
Viewed with immersion oil
Differential Stains
Gram Stain
Gram-positive
Turns purple
Gram negative
Turns red
Acid-Fast
Identifies Mycobacterium


Special Stains
Negative staining for capsules
Capsule
Protects the cell
Determines Virulence
Soluble in water
Utilizes India Ink and a simple stain
Halo effect

Spore Staining
Spores are difficult to stain
Stained with malachite green, then safranin
Appears green within a red cell

Flagella Staining
Enlarges flagella so that it can be seen
Culture Mediums
Culture
Microbes that grow and multiply in or on a culture medium
Agar
Solid medium used in petri dishes
Enriched media
Added nutrients so that FASTIDIOUS organisms will grow
Blood agar and Chocolate agar
Selective Media
MacConkey agar
both a selective and differential medium
Gram-negative culturs
Salmonella
PEA agar (Phenylethyl alcohol)
Blood agar with inhibitors
Gram-positive cultures

Differential Media
distinguish specific colonies of bacteria from other colonies that are growing on the same dish.
Reducing media
Anaerobic cultures

Words of Wisdom
The future is whatever you want it to be.
Gerladine A. Ferraro

Cell structure

Cell structure
Chapter 2
Microbiology for the Surgical Technologist
Eukaryotic and Prokaryotic Cells
Prokaryotes
Simple cell structure such as bacteria
Eukaryotes
Complex cells
Include protozoa, fungi, algae, some plant and all animal cell, including human cells
Eukaryotic Cells
Range in size from 10-100 μm
Have a true nucleus that is enclosed within a membrane
Contain organelles
Plasma Membrane
Also called the cell membrane
Hold internal structures of the cell in place
Encloses cytoplasm and forms outer boundary of the cell
Composed of large molecules of phosphate-containing fat lipids called phospholipids and protein
Also contains cholesterol, another lipid, that stabilizes and fortifies the other phospholipids
Plasma Membrane - continued
The protein adds structural support and protection
The membrane functions to create selective permeability
Only certain substances are allowed to enter and leave the cell
Responsible for managing the inflow and outflow of nutrients, waste, and other types of cell secretions
Plasma Membrane
Plasma Membrane - continued
Two ways that materials cross the plasma membrane
Passive
Substances move through the membrane from an area of high concentration to an area of low concentration without the cell using any ATP.
ATP is the cells store of energy
Active
The cell uses ATP to move substances from a low area of concentration to a high area
Osmosis
Passive process
Three types of osmotic solutions
Isotonic
Hyoptonic
Hypertonic
Isotonic solution
The concentration of the solution outside the cell equal the solution inside the cell
Hypotonic solution
The concentration of the solution outside the cell is lower that the solution inside the cell
Hypertonic solution
The concentration of the solution outside the cell is higher than the solution inside the cell
Nucleus
A small spherical structure in the center of the cell
Is the control center for all cell activity
Surrounded by a nuclear membrane that encloses the neoplasm
Neoplasm
Contains two important structures
The nucleolus
The chromatin granules
Nucleolus
Designs and oversees the construction of ribosomes
The ribosomes then migrate out of the nuclear membrane into the cytoplasm and are responsible for the production of protein
Chromatin granules
Made of protein and DNA
Deoxyribonucleic acid
Double stranded
Contains genetic information
Cytoplasm
Semifluid nutrient solution within the cell membrane
Organelles are contained in it
The portion of the cell where the most work is performed
Organelles
Endoplasmic Reticulum (ER)
A system of membranes that form a series of tubules that twist through the cytoplasm
Responsible for the transport of nutrients to the nucleus
The majority is rough ER
It appears rough because ribosomes are attached to it
Smooth ER
Has no ribosomes
Responsible for the manufacture of fats, carohydrates, and proteins that make up the cell membrane
Golgi complex
Connects and communicates with the ER
Look like small flattened sacs stacked on top of each other like pancakes
Process protein from the ER into vesicles (small sacs) that are sent to the cell membrane where they attach then open and release their contents into the interstitial fluid of the membrane
Lysosomes
Small vesicles created by the Golgi complex
Contain the enzyme lysozyme
That lyses or destroys foreign substances ingested by the cell
Uses the process of phagocytosis with a particular leukocyte called a phagocyte
If the enzymes escape from the lysosomes into the cytoplasm, they can destroy the cell itself

Mitochondria
Are the power plant of the cell, create the energy
Produces ATP (adenosine triphosphate) by way of cellular respiration
Energy is released from glucose molecules by enzymes utilizing oxygen to provide energy for the other cellular functions
Centrioles
Form spindle fibers to aid in cell division
Eukaryotic cell division is called mitosis
The cell divides and the resulting daughter cell has the same number of chromosomes as the parent
May also me responsible for the manufacture of Eukaryotic flagella and cilia, because their protein composition is the same
Flagella and Cilia
Eukaryotic flagella are more complex than those of prokaryotic cells
Consist of microtubules
Move back and forth in a wavelike motion
Prokaryotic Cells
Range in size from 0.2 to 2.0 μm
Have no true nucleus
Not enclosed in a membrane
Cell walls are chemically complex
All bacteria are prokaryotes
Reproduce by binary fission
Cell Wall
Rigid and gives shape to the cell
Main component is peptidoglycan
Thickness varies in Gram-positive and Gram-negative
Gram-positive have thicker walls
Gram-negative have thin walls
Cytoplasmic (Cell) Membrane
Surrounds cytoplasm just inside cell wall
Protects cell from external substances
Functions in the synthesis and secretion of bacterial toxins
Used for flagellar propulsion
Contains mesosomes
Embedded in membrane and produce ATP for cell function
Capsules
Some bacteria have capsule on the outside of the cell wall
Called the slime layer if loosely attached
Provide the cell the ability to move on solid surfaces
Allow cells to anchor to the surface of teeth and mucous membranes so they cannot be washed away
Cytoplasmic Particles
The cytoplasm is gelatinous
Contains particles
Majority are ribosomes that perform the same protein synthesis as in eukaryotic cells, only smaller
Chromosomes
No nuclear membrane
Not stable shape
Contain a single strand of DNA
To control the function of the cell only
Guides the process of binary fission
Flagella
Mostly found on Gram-negative bacillus
Extend from the cytoplasmic membrane
Classification can be determined by the number of flagella
There are four classifications…
Pili
Singular – pilus
Hairlike structures mainly on Gram-negative bacteria
Thinner than flagella, more rigid
Do not provide motility
Pili
(continued)
Serve three functions
Serve as a site for the attachment of particular types of other bacteria
Provide bacteria that have a sex pilus the ability to transfer genetic material to another bacteria through the process of conjugation
Provide the bacteria the ability to attach to other bacteria or surfaces, such as the lining of the intestine
Endospores
Several types of bacteria can form spores known as sporulation
When conditions do not allow the organism to survive it forms an endospore as a means of survival
Contains the genetic material, and is resistant to heat, dry conditions, and many chemicals
Can survive long periods of time
Spores are used to test the various methods of sterilization

Classification of Organisms

Major Classifications of Organisms
Microbial Relationships
Independence
two different kinds of organisms live independently without affecting the other
Symbiosis
Close relationship
Mutualism – derives some
benefit from each other
Commensalism – one organism
derives benefit but does not
hurt the other
Parasitism – one organism
derives benefit from the other,
at the other’s expense
Antibiosis
One organism produces substances or causes conditions which are lethal for the other
There are five major classes of organisms
Protozoa
Fungi
Bacteria
Rickettsia
Viruses
Protozoa
Unicellular
Simplest form of animal life
Microscopic
Consume solid food particles
Can reproduce sexually or asexually by fission
Become inactive in adverse conditions
Protozoan Disease
Amebic dysentery
Caused by Entamoeba histolytica
Symptoms: intense diarrhea with bloody, mucous-filled stools
Occurs following fecal contamination of food or drink
Malaria
Caused by a parasite of the Plasodium genus
Transmitted by the female Anopheles mosquito or by contaminated needle or blood transfusion
Characterized by chills and fever
Protozoan Disease
(continued)
Trichomonas infection
Caused by Trichomonas vaginalis
Characterized in women by vaginitis with a profuse, cream-colored, foul smelling discharge. Can be misdiagnosed as a yeast infection.
Transmitted by sexual intercourse, contaminated examination equipment and contaminated towels
Fungi
Are of the plant kingdom
Lack chlorophyll
Over 100,000 species
Include yeasts and molds
Some fungi are common on stale bread, rotten fruit, or damp leather
Have to exist as either
Parasite – existing on another living organism
Saprophyte – living on dead matter
Some like mushrooms are visible to the naked eye
Most medically important fungi are microscopic
Yeast
Are unicellular, microscopic organisms
Reproduce by budding
Some are used commercially in preparing beer, wine, and breads
A common yeast mycosis is Candida infection caused by Candida albicans
Infects mucous membranes of the mouth and is known as thrush
Infects female genitalia and is known as vulvovaginitis or vaginal thrush
Note: Thrush is seen commonly in newborns infected by the mother
Molds
Are multicellular
Are characterized by a fuzzy growth of interlacing filaments called hyphae
Reproduce by spores
Some may be seen on foods such as bread and cheese
Ringworm of the scalp (Tinea capitis) and ringworm of the foot (Tinea pedis – athlete’s foot) are common mycoses caused by molds
Bacteria
Are unicellular
Are simple plant organisms
Ordinarily do not contain chlorophyll
Approx. 2000 know species and are found everywhere
Only about 100 species produce disease in humans
Two classifications
Pathogenic – produce toxins which cause many diseases such as syphilis, gonorrhea, tuberculosis, typhoid and paratyphoid fevers, and whooping cough
Nonpathogenic – essential for life, assist in decomposition of matter, and aid in production of some foods and chemicals such as cheeses, sauerkraut, cultured milk products, and lactic acid
Reproduce asexually by binary fission
Have rigid cell wall which blocks entrance of certain substances
Morphology
Three basic shapes
Coccoid (Cocci)
Round
Bacillus (Bacilli)
Rod
Spiral
Curved or spiral
Mycoplasmas
No cell wall
Growth Rate
Refers to the increase in the number of microbes
Motility
The ability to move
Flagella
Axial filaments
Moisture
Drying may kill some bacteria
Note: There are some bacteria that can withstand drying for a long period of time and become active again.
Food
Autotrophic bacteria use carbon dioxide and other inorganic compounds for food and are nonpathogenic
Heterotrophic bacteria require living or dead organic matter for food and are pathogenic
Parasites utilize living organic matter for food
Saprophytes utilize dead organic matter for food
Examples: tetanus, gas gangrene, and botulism
Two classifications
Aerobic
Need oxygen
Examples: Staphylococcus aureus (responsible for skin and wound infections)
Anaerobic
Cannot live with oxygen
Examples: Clostridium sp.(causes tetanus, gas gangrene, and botulism
Anaerobes
Three types of anaerobes
Obligate
Will not grow in any oxygen
Facultative
Able to survive with or without oxygen
Aerotolerant
Do not need oxygen, grow better without
Can survive in CO2 environment
Moderate temperature
High heat destroys most bacteria
Pre-vacuum steam autoclaves enables the heat to penetrate resistant strains
Freezing does not always destroy bacteria, but does reduce growth
Darkness
Most bacteria are killed by direct sunlight
Spore formation is stimulated by sunlight (because the bacterium is stressed)
Neutral pH
Most bacteria grow best close to the neutral point on the pH scale or slightly on the alkaline side
Both acids and alkalis are harmful to bacteria
Pathogenicity and Metabolism
Their ability to cause disease
Endotoxins
Contained in the cell wall
Released when cell dies
When released it produces symptoms
Examples: typhoid fever and bacillary dysentery
Exotoxins
Most potent toxins known
Secreted out of the intact cell into the surrounding tissue
Will produce the symptoms and lesions of the disease
Example: Tetanus, gas gangrene, diphtheria, and scarlet fever
Eukaryotic and Prokaryotic Cells
Eukaryotes
Prokaryotes
Simple cell structure such as bacteria
Bacteria and the diseases
they cause
Cocci
Certain strains of Staphylococci
Food poisoning
Staphylococcus aureus
Most post-operative wound infections
Neisseria gonorrhoeae
Gonorrhea
Neisseria meningitis
Bacterial (meningococcal) meningitis
Bacilli
Salmonella typhi - typhoid fever
Shigella dysenteriae – bacterial dysentery
Escherichia coli – gastroenteritis, UTI, epidemic diarrhea in newborn nurseries
Clostridium tetani – tenanus (lock jaw)
Clostridium perfringens – gas gangrene
Clostridium botulinum – botulism
Pseuomonas aeruginosa – severe wound infections, , osteomyelitis, meningitis, and septicemia when resistance of host is especially low, such as in burn patients.
Spiral Shaped bacteria
Spirochete – Treponema pallidum – causes syphilis
Vibrio – Vibrio cholerae – causes cholera
Rickettsia
Are much smaller than bacteria, but larger than viruses
Are obligate intracellular parasites
Meaning that they can only reproduce and thrive within the cell of the host
Transmitted to humans through the bites of mite and ticks, or the feces of lice and fleas
Typhus Group
Rickettsia prowazekii – epidemic typhus (old world)
Transmitted by the bite or feces of human body lice
Cause high fever, rash, chills, delirium vomiting and shock
Mortality rate can reach up to 30% if left untreated
Can remain dormant in lymph nodes for years
Scrub Typhus Group
Caused by Rickettsia tsutsgamushi – scrub typhus
Transmitted by a mite that normally live on rodents
Similar syptoms as epidemic typhus with an addition of a red nodule that turns into a black scab
Mortality can reach 40% if untreated
Found in Japan, Southeast Asia, and the Southwest Pacific
No vaccine
Spotted Fever Group
Rickettsia akarii - rickettsialpox
Rickettsia rickettsii – Rocky mountain spotted fever
Transmitted by American dog tick and other tick species
Found mostly in southeastern and south central US
Symptoms include sudden high fever, severe headache, fatigue, muscle pain, chills, and rash
Q fever group
Coxiella burnetii – Q fever
Transmitted to humans through animals that have been bitten by an infected tick.
Can be transmitted through milk, products of conception, or animal excrement
Especially in sheep, cattle or goats
If left untreated can lead to bacterial endocarditis or atypical pneumonia
Viruses
Smallest organism known: can only be seen with the aid of an electron microscope
Approx 2500 viruses could fit on the tip of a pin
Intracellular parasites
Shapes vary
Viruses of humans and animals are spherical
Viruses of plants are rod-shaped or many-sided
Viruses that attack bacteria are known as bacteriophages and are rod shaped
Viruses have no metabolic function: they borrow the ribosomes of the host cell to make new viruses
Inclusion bodies are found in host cells that have been affected by a virus
Their presence helps the pathologist diagnose a viral disease
They are transmitted by both direct and indirect contact
Relationship between viruses and interferon
Interferon is a protein produced by a normal body cell that is being attacked by a virus
It blocks the effect of the virus and is part of the body’s defense against a viral infection
Research is being done into “interferon inducers”, substances that stimulate the cell to produce interferon, which would help to expand our control over viral diseases
Viral Diseases
There are five types of viruses
Dermotrophic
Pneumotrophic
Neurotrophic
Viscerotrophic
Immunotrophic

Dermotrophic

Affect skin and mucous membranes
Smallpox – Variola virus
Chickenpox – Varicella virus
Measles - Rubeola virus
German measles – Rubella virus
Fever blisters (cold sores) – Herpes simplex virus
Shingles (Herpes zoster) – Varicella-zoster virus
Pneumotrophic
Affects the respiratory tract
Common cold (coryza)
Influenza
Infectious mononucleosis
Viral pneumonia
Neurotrophic
Affects the central nervous system
Poliomyelitis
Rabies
Encephalitis
Viscerotrophic
Affects a specific organ
Hepatitis
Immunotrophic
Affects the immune system
AIDS
Hepatitis
Chemically induced
Caused by chemical toxins including alcohol
Not infectious
Viral
Caused by primary or secondary viruses
Very contagious
Two herpes viruses can result in secondary hepatitis
Presently there are five hepatrophic viruses that can cause hepatitis

HAV (HepA)
Primarily transmitted by the fecal-oral route
Also found in semen and blood
More prevalent in developing and third world countries than in US due to required vaccination of school children.
HBV (HepB)
Acquired Parenterally through blood transfusions and contaminated needles.
Causes jaundice, weakness, fever, and nausea
1 in 20 infections result in Chronic hepatitis
Persistent hepatitis six months after the onset of the illness
Chronic HBV can be benign with normal liver tests or may be an aggressive inflammatory process that can lead to cirrhosis (hardening of the liver).
The vaccine consists of three injections and is highly recommended for OR personnel.
HCV (HepC)
Acquired parenterally and sexually
Mode of transmission is unknown in 20% of cases
Produces flu like symptoms without jaundice. Because the liver enzymes are not tested for these symptoms, the infection may not be detected for many years.
Chronic HCV occurs in 50-60% of cases, and most carriers remain contagious for life.
Many develop aggressive hepatitis and eventually cirrhosis and liver failure, requiring liver transplant.
HDV (Delta Virus)
Infects only those liver cells that are already infected with HBV.
Uses the HBV enzyms for replication and the acquisistion of a protein coat that allows it to survive outside of the liver
Those infected develop super infections that can be fatal, neither interferon or transplant is effective.

Human Immunodeficiency Virus
Although AIDS (acquired immunodeficiency syndrome) was discovered by the CDC in 1981, the virus that causes it, HIV, was not discovered until 1983
The chief routes of transmission are blood, sexual contact, and mother to child.
The main target cell for the virus is CD4 T lymphocytes (T-cells)
Of the 28 million that had HIV in 1997, it is estimated that 8 million will acquire AIDS. By 2000, 36 million were infected and to date approx 20 million have died.
Patients infected may be asymptomatic for many years before they are diagnosed with AIDS.
It weakens the immune system and allows opportunistic infections, malignancies and neurological diseases to occur.
Example: Kaposi’s sarcoma, lymphoma of the brain, Pheumocystis carinii pneumonia, etc.
There is a new class of antiretroviral drugs that have been developed called protease inhibitors (PI) that inhibit the maturation and replication of the virus, but
AIDS is a fatal disease, there is no cure
Implications for the STSR
STSRs are frequently exposed to blood-borne pathogens
Vaccination for HBV is strongly recommened
Universal precautions should be used on all surgical procedures
All surgical patients should be treated as if they are infected

Protective eyewear should be worn in all cases and double gloving is recommended to help prevent needle sticks
Always wear gloves when handling contaminated items
Needles should not be recapped to prevent needle sticks
Homework
Matching 1 and 2

The Infectious Process

The Infectious Process
Skin
Portals of Entry
Skin –the first line of defense
The skin must be broken to act as an entry portal
Including surgical skin incision, burns, cuts, scratches
Sebaceous glands - Secrete sebum (fatty acids)
Prevent bacterial and fungal infections
Low PH – inhibits microbes
The first line of defense – continued
Sweat glands – secrete perspiration
Has lysozyme – breaks down gram-positive bacterial cell walls
Also found in tears, saliva, and other tissue fluids
Common organisms entering the skin cause tetanus, gas gangrene, staphylococcal infection, and streptococcal infection
Note: Generally, these are opportunistic microorganisms which pose no threat of infection unless the skin is broken
Mucous Membranes
Line the respiratory tract
Easiest route of entry
They have specialized cells called goblet cells that secrete mucous
Including nasal secretions, tears, and saliva
Line nose, nasal passages, trachea, bronchi
Contain cilia that catch microbes and don’t allow them to penetrate furthered
Common organisms
Tuberculosis, pneumonia, common cold, measles (rubeola), German measles (rubella), scarlet fever, and smallpox

Gastrointestinal tract (Alimentary tract)
Include the mouth, esophagus, stomach, intestines
Enteric microorganisms enter through this route
Common organisms that enter through this route are
Typhoid fever, HEP A, HEP E, bacillary and amebic dysentery, and cholera.
Genitourinary tract
Kidney, ureters, bladder, urethra, vagina, uterus, penis
Infections are usually contracted sexually
Common organisms
All of the sexually transmitted diseases including HIV (AIDS)
Note: urinary infections are usually the result of the migration of microorganisms from the rectal area.

Placenta
There are certain microorganisms from the pregnant mother will penetrate the placenta and infect the fetus
These include: HIV (AIDS), smallpox, and German measles
Circulatory system
Organisms develop in one area then enter by invading the bloodstream
Example: an infection can start on the skin and the microorganism is picked up by the blood and spreads to other areas of the body
A tooth infection can enter the heart and cause endocarditis
Or they can be transmitted by contaminated blood transfusions, needle sticks, or cuts from sharp objects which are contaminated
Common organisms are HEP B and HIV
FYI: HIV can not transmitted through insect bites
Second Line of Defense
Phagocytes
They are called leukocytes (white blood cells)
Phagocytosis
The process where the leukocytes surround and ingesting a microbe or foreign particle and destroy it

Inflammation
A local response to infection
Includes pain, heat, redness and swelling (edema)
Vasodilation
Refers to the increase in diameter of blood vessels, which increases the blood flow to the area

Fever
A systemic reaction
Can be caused by a bacterial or viral infection
The infection produces prostaglandins from the hypothalamus, in the brain, which aid in the production of phagocytes aiding in phagocytosis
Interferons
What do interferons do?

Human Portals of Exit
A portal of exit is the pathway by which microorganisms leave the body
This depends largely on the part of the body affected by the disease.
Body secretions and excretions are potential portals of exit if they contain any component of blood
The main substances are blood, respiratory secretions, urine and feces

Blood
Include organisms causing HEP B and HIV
These are “blood-borne pathogens”
A major concern to health care professionals.
Fecal matter (feces)
Can include microorganisms causing hepatitis, polio and dysentery
Urine
Can include organisms causing typhoid fever
In the majority of cases urine is considered sterile when infection is not present
Respiratory secretions (sputum)
Can includes organisms causing tuberculosis, pneumonia, the common cold, or respiratory flu

Saliva
Includes organisms causing strep throat and may have the organism causing the common cold.
HIV will be transmitted in saliva only if it contains blood
Rabies: transmitted primarily by the saliva of an infected animal.
Tears
Can include organisms causing conjunctivitis
Semen and vaginal secretions
Can include organisms causing HIV (AIDS) and other sexually transmitted diseases

Other body fluids that may contain infectious blood cells include
Cerebrospinal fluid
Synovial fluid, found in the joints
Pericardial fluid
Peritoneal fluid
Amniotic fluid
Breast milk
Transmission of Pathogens
Direct contact
Patient to Worker/Worker to Patient
Can also include direct animal to person contact
Patient to Patient
Worker to Worker
Indirect Contact
The spread of contagious disease by some other medium than direct touching of infected person
Contaminated Food or water
Fomites
Inanimate objects
Example: bedpans, sheets, drinking cups, tables
Vectors
Examples: Flies, ticks, mosquitoes, mites
Vectors may carry pathogens inside their bodies and transfer this biologically through a bite as in Rocky Mountain spotted fever, or they may carry pathogens on their bodies and simply mechanically transfer these organisms as when flies land on food.
Dirt or dust
Air molecules

Factors Influencing Infection
Portal of entry
Most organisms will cause infection only when they enter a particular pathway
Example: swallowing malarial organisms would not cause the disease; they must enter through the bloodstream
Number of organisms
The normal body defenses can usually control a few organisms, but when large numbers are introduced, they usually cause infection

Virulence of the organism
Organisms are more virulent if they produce hemolysins, coagulase, enzymes, endotoxins, or exotoxins
The presence of a capsule also increases the virulence
Resistance of host
Resistance determines whether or not infection will take place and the severity of the disease.
Types of infection
Primary infection
The first or original infection
Secondary infection
One which follows or complicates the original disease
Latent infection
One which is inactive or hidden
Mixed infection
One caused by more than one organism
Examples: Appendicitis, wound infections
Acute and Chronic Infections
Acute
Runs a rapid and severe course terminating abruptly
Example: a cold or the flu
Chronic
Runs a slow course over a long period of time: may last from weeks to years
Example: Tuberculosis, syphilis, fungal infections

Stages of Infection
Incubation
Period between entrance of organisms to the body and onset of symptoms
Prodromal
Short period, usually a day or less, when symptoms are vague or cause only mild discomfort
Acute
Period of actual illness with symptoms, may have a degree of fever or not
The length of time depending on the disease, condition of patient, and the treatment

Convalescent
The beginning of the decline of the acute symptoms and fever (if present)
The length of time depends on the severity of the acute stage, the treatment of the pt, and their general health
Controlling Transmission
Portals of entry
Hand washing
Place sterile bandages over wounds
Wear masks over nose and mouth
Wearing protective eyewear
All of these can protect you or the pt
Use of insect repellent
Do not eat/drink contaminated food or beverage

Use only sterile supplies for invasive procedures (injections, surgery, etc.)
Cleansing (prepping) the proposed incision site
Providing sterile supplies and a sterile surgical environment
Properly clean hands after using the restroom
Get your required vaccination

Controlling transmission
Continued
Vectors, fomites, air
Sterilize or disinfect fomites
Used dust control measures
Don’t shake towels or drapes
Disinfect air
Properly handle food, water, and milk
Control insects
Vaccinate household pets
Words of Wisdom
There is no such thing as a great talent without great will-power.
Honore De Balzac
(1799 – 1850)

Immunology

Immunology
Body Defense Against Disease
Antigens
An antigen is any foreign substance that enters the body and stimulates the production of antibodies.
They have one or more sites called antigenic determinants that antibodies and/or lymphocytes can bind to.
Components of the Immune System\Types of Antibodies
Lymphocytes (white blood cells)
Three types
B cells
T cells
NK (natural killers) cells
Develop from lymphoid stem cells in the bone marrow
B cells
Migrate to the lymphoid regions of the intestine and liver
Produce antibodies that circulate in the lymph system and blood stream
Provide Humoral immunity
Only live one to two weeks
Quickly mass produce antibodies
T Cells
Migrate to the Thymus gland to differentiate into four types:
Helper T cells
Suppressor T cells
Cytotoxic T cells
Delayed-hypersensitivity T cells
NK (Natural Killer) cell
Destroy tumor cells and virally infected cells
Antibodies
Are glycoproteins produced by B cells
Y-shaped
Bind to the receptor site(s) of the specific antigen that stimulated their production
Placed in a class of proteins called immunoglobulins (Ig)
Found in lymph fluid, colostrum, tears, and saliva
Antibodies
Immunity Response
Lag Phase
After a person is exposed to an antigen, there is a delayed response in the production of antibodies called the lag phase.
The antigen is involved with macrophages, T cells, and B cells.
Some antigens only require B cells.
Eventually some of the B cells turn into larger plasma cells that can produce antibodies by protein synthesis.

The first step of the immune response is called the primary response.
When the number of antigens declines, the number of antibodies in the bloodstream also declines as the plasma cells die
Secondary Response
Other B cells become memory cell to protect against future infection
The production of the antibodies after re-exposure is called the secondary response
This is why titers are drawn to check the level of antibody concentration in the blood
Types of Immune Responses

Cell-mediated immune response (CMI)
Antibodies cannot enter cells, even those with intracellular pathogens
Mainly used against viral antigens
Uses Macrophages and T cells to control chronic infections
CMI controls but does not eliminate the cause of infection.
Example: Herpes
Types of Immune Responses
(Continued)
Humoral Immunity
Involves Helper T cells and B cells in the production of antibodies
T cells stimulate the production of antibodies from B cells
They do not produce antibodies themselves
Some B and T cells remain as memory cells to protect against future invasion of the same antigen
Types of Immunity
Genetic (inborn) Immunity
Is programmed into one’s genetic makeup
Does not involve antibodies
Varies between individuals, nationalities, racial groups, and species
Example: Ebola
Types of Immunity
(continued)
Acquired Immunity
Involves the use of antibodies
May be naturally acquired or actively acquired
May be active or passive
Types of Immunity
(continued)
Active immunity
The body produces its own antibodies in response to antigens
Naturally Acquired Active Immunity
Individual contracts disease, and then produces own antibodies and long term memory cells to that specific disease
Artificially Acquired Active Immunity
Individual is administered a vaccine, then the body produces antibodies to the antigen
Although this produces
long term immunity,
booster shots may be
needed to maintain
antibody levels.
Passive Immunity
Antibodies from an outside source are introduced into the body; body does not produce its own antibodies
Naturally Acquired Passive Immunity
Mother’s antibodies pass through placenta to fetus or through breast milk to infant
Artificially Acquired Passive Immunity
Antibodies produced elsewhere are injected in the form of immune serums
Artificially Acquired Passive Immunity
(continued)
Immune serums may be prepared in animals, other humans, or in the lab.
They only provide short-term immunity with no memory against future invasions.
Example: Immune globulin (gamma globulin) contains special antibodies and is commonly given to boost immunity when exposed to HepA

Allergic Response
Hypersensitivity Reactions
Hypersensitivity Reactions
Represent an immune response that is abnormal and can be mild to life threatening.
Instead of providing protection, the antibodies damage cells of the body.
Can be dangerous and life threatening
Symptoms can be from localized itching to anaphylactic shock
Hypersensitivity Reactions
(continued)
Is brought on by allergens which cause altered reactions in the body tissue of sensitized individuals but which produce no effect in non-allergic individuals.
Does not occur on first contact because antibodies have not been produced yet
It may occur on the second contact or take several contacts to produce enough antibodies to trigger a response.

Hypersensitivity Reactions
(continued)
Common allergens include:
Inhalants such as dust, pollen, and perfume
Foods such as wheat, eggs, milk, chocolate, and strawberries
Drugs such as aspirin and various antibiotics and serums
Other contactants such as animals, plants, hair, and fur
Anaphylactic Shock
A severe allergic reaction to a drug such as penicillin or a foreign protein such as insect venom
Body produces histamine or a histamine-like substance causing vasodilation, hypotension, and bronchiolar constriction.
Anaphylactic Shock
(continued)
Early reactions occur suddenly and include
Itching
Ringing in ears
Metallic taste in mouth
Difficulty breathing (larygospasm/brochospasm)
Elevated blood pressure (hypertension)
Increased heart rate
restlessness
Anaphylactic Shock
(continued)
Late symptoms
Rapid decrease in BP (hypotension)
Tachycardia
Nausea and vomiting
Confusion and inability to mentally focus
Respiratory failure
Death usually results from bronchiospasm
Individuals with prior anaphylaxis should always wear medical alert tags.

Anaphylactic Shock
(continued)
Treatment
100% O2
Epinephrine: causes bronchodilation, reduces laryngeal spasm, elevates blood pressure
Steroids: slows chain reaction taking place
IV fluids to maintain fluid volume
Levophed, a vasopressor agent used to increase blood pressure.
Hemolytic Transfusion Reaction
From blood transfusions that are not properly matched to the patient’s blood type
Symptoms of the awake patient include:
Lack of energy
Shortness of breath
Rapid pulse
Hemolytic Transfusion Reaction
(continued)
Surgical patients receiving general anesthesia do not display these signs.
The only noticeable signs may be diffuse loss of blood at the surgical site and decrease in O2 saturation (SaO2) due to the inability of the erythrocytes to carry oxygen.
In some cases pts must undergo dialysis in order to remove the mismatched blood.
Autoimmune Disease
Caused by the person’s immune system not recognizing certain tissues as a normal part of the body.
The body actually attempts to destroy the tissue because it is perceived as foreign.
Example:
Rheumatoid arthritis
Rejection Syndrome
May occur following transplantation of an organ or tissue.
Every organism has a natural tendency to reject foreign substances, especially tissues from another person or animal.
Tissue and organs are cross-matched much in the same way as blood.
Drugs that suppress antibody formation are used to decrease tissue rejection.

Wound Healing

Wound Healing
And Microorganisms
Types of Wound Healing
1st Intention
2nd Intention
3rd Intention
First Intention
Has no postoperative swelling
No serous discharge or local infection
No separation of wound edges
Minimal scar formation (hairline scar)
Heals by primary union
Second Intention
Infection, excessive trauma, loss of tissue or poorly approximated tissue is present
Healing is by process of granulation from the bottom up
Wound is not closed (sutured)
Granulation tissue forms in the gap of the wound and closes it by contraction
Healing takes longer than first intension because more area must be filled in.
Scar formation is excessive
Healing may produce a weak union, which may be conducive to incisional herniation (rupture) later
Risk of a secondary infection is proportional to amount of necrotic tissue present.
Third Intention
Similar to second intention except wound is sutured, either delayed or secondary
When wound is infected at time of surgery, suturing is delayed until infection subsides
When sutured wound becomes very infected after surgery, the primary sutures are removed and secondary sutures are put in later
During the period of waiting for infection to subside, wound has begun to heal by granulation
Healing takes longer than second intention
A deeper and wider scar usually results
Healing may produce a weak union, which may result in incisional herniation later.

Phases of 1st Intention Wound Healing
Lag (substrate) phase (days 1-6)
Exudates containing blood, lymph, and fibrin begins clotting and loosely binds the cut edges together.
Fibrin, clotting blood, and serum protein dry out, forming a scab which seals the wound
Leukocytes remove bacteria and damaged tissue debris
Healing (proliferative) Phase (days 6-14)
Fibroblasts multiply rapidly bridging wound edges, and secrete collagen which forms fibers
Tensile strength grows rapidly because of collagen.
New cells are formed.
Maturation (remodeling) Phase (days 14-21)
Scar forms
Collagen reforms into cross-links which increase tensile strength.
As collagen density increases, vascularity decreases and scar grows pale

Types of Wounds
Chronic wounds
Wounds that will not heal by 2nd intention
Examples: ulcerations, pressure sores, sinus tracts
Traumatic wounds
When a chemical, thermal, or other extrinsic agent has injured living body tissue
Surgical incisions
When a surgeon cuts through intact tissue using aseptic technique
Classes of Traumatic Wounds
Closed Wounds
Open Wounds
Closed wounds

The skin is intact, but the underlying tissue is injured
Example: simple fractures, torn ligaments, blister
Open Wounds
The skin is broken – 4 classifications
Simple – the skin is interrupted but the without loss or destruction of underlying tissue
Complicated – the skin and underlying tissues are injured or destroyed by crushing, burning, or implantation of a foreign object
Clean – the object or conditions surrounding the injury were relatively clean. Wound is cared for within 6 hours. Heals with 1st intention
Contaminated – the conditions and/or object surrounding the injury are obviously not clean; or the wound is over 6 hours old. Heals by 2nd intention
Types of Traumatic Wounds
Abrasion, Avulsion
Contusion, Crush
Incised, Laceration
Puncture, Perforation
Abrasion
Wound caused by mechanical irritation such as boot rubbing, scraping or being injured with sand paper.
Avulsion
A portion of the skin and soft tissue is partially or completely torn away.







Partial Complete
Contusion
A bruise that may be caused by a blunt instrument in which skin is not broken, the tissues below the surface are damaged, and the blood vessels have ruptured causing discoloration.
Crush Injury
A wound that has been squeezed or forced by pressure so as to alter or destroy the tissue structure.
Incised
A wound with smooth edges that is made by a cutting instrument; may be contaminated (glass) or clean (scalpel)
Laceration
A torn wound with irregular edges
Puncture
A wound made by a sharp, pointed instrument.
Perforation
A wound in which the vulnerating body (such as a bullet, knife or pipe) both enters and emerges from the tissue.
Classifications of Surgical Wounds
Class I - Clean
Class II - Clean-contaminated
Class III - Contaminated
Class IV - Dirty/Infected
Class I - Clean
Expected infection rate: 1% to 5%
Elective procedures – wound made under ideal conditions
Primary closure, no drain
No breaks in aseptic technique
No inflammation present
Alimentary, genitourinary, respiratory tracts or oropharyngeal cavity not entered
Class II - Clean-contaminated
Expected infection rate: 8% to 11%
Primary closure, wound drained
Minor breaks in aseptic technique occurred
No inflammation present
Alimentary, genitourinary, or respiratory tract or oropharyngeal cavity entered under controlled conditions – without unusual contamination or spillage.
Includes hysterectomies, appendectomy, cholecystectomy, and face lift.
Class III - Contaminated
Expected infection rate: 15% to 20%
Open fresh traumatic wound less than 4 hours old
Major break in aseptic technique
Acute, non-purulent inflammation present
Gross spillage/contamination from gastrointestinal tract
Entry into biliary or genitourinary tracts with infected bile or urine present
Class IV - Dirty/Infected
Expected infection rate: 27% to 40%
Old traumatic wound over 4 hours old from a dirty source or the presence of necrotic tissue, foreign body, or fecal material
Microbial contamination is present in the operative field before the procedure
Acute bacterial inflammation is present, may be purulent or there is a known clinical infection

Factors Influencing Healing
Type of wound
Operative technique
Physical condition of Patient
Physical Condition of Patient
and Wound Healing
Age, Weight, and general health
Nutrition
Immune response
Drug therapy
Radiation Therapy
Postoperative complications
Age, weight ,and general health
Skin tone and muscle tone decrease with age
Excess fat causes difficulty in confining and securing good closure, and is most vulnerable of all tissues to trauma and infection
Associated diseases such as diabetes, anemia, cirrhosis delay wound healing
Malignancies, debilitating injuries, and systemic or localized infections can also adversely affect wound healing
Adequate nutrition
Wound healing is impaired by deficiencies in zinc, protein, carbohydrates, and vitamins A, B, C and E
Protein provides essential amino acids for new tissue construction
C permits collagen formation and also aids in the production of connective tissue and a strong scar
B is necessary for carbohydrate metabolism
E is necessary for softening tissue to produce less scarring
Immune Response
Normal immune response speeds tissue healing
Abnormalities in immune responses such as allergic reactions can contribute to delayed wound healing
A person with an immunosuppressed or compromised immune system condition can be life threatening
Drug Therapy
Since wound healing is basically collagen synthesis, any agent that interfere with cellular metabolism such as steroids have a potentially negative effect on the healing process
Radiation Therapy
Healing is delayed if the patient has had radiation in large doses preoperatively
The blood supply in irradiated tissue is decreased
However little change from the normal healing pattern occurs if radiation has been given in low doses
Postoperative complications
Edema, vomiting, or coughing can place stress on the healing wound before fibroblasia takes place
Complications in other parts of the body, far from the site of operation, such as pneumonia or embolus formation, can inhibit oxygen supply to the wound site.
Physical Activity

Very Important!
Early ambulation speeds up circulation and decreases post operative complication
Operative Technique and Healing
Aseptic Technique
Hemostasis
Tissue handling
Tissue Approximation
Wound Closure
Aseptic Technique
Must be followed by every member of the surgical team
It is less expensive to change out a whole set up than it is to treat an infection
A little embarrassment on your part is not as important as the well being of the patient
Hemostasis
Must be achieved to prevent loss of the patient’s blood and to provide as bloodless a field as possible for accurate dissection and to prevent hematoma formation.
Tissue Handling
All tissues should be handled as gently as possible
Incisions should be just long enough to be able to perform the procedure
Laparoscopies are used more often because they cause minimal trauma and heal quickly
Retractors are placed for exposure and should not be pulled so hard that they cause tissue damage
Tissue Approximation
Tissue edges should be brought together precisely, avoiding strangulation and eliminating dead space
Too tight a closure under tension causes ischemia
Serum or blood collect in dead spaces
Drains and pressure dressings are placed to help decrease dead spaces
Wound Closure
The suture material provides all of the strength of the wound immediately after closure
Closely spaced sutures give a stronger suture line
The strength of the suture should not be stronger than the tissue that it is used on

Complication in Wound Healing
Dehiscence, Evisceration
Adhesions, Herniation
Fistula, Sinus tract
Keloid Scarring, Infection

Dehiscence
Partial or total separation of the layers of a surgical wound
Evisceration
Extrusion of internal organs or viscera resulting from a wound dehiscence. The wound totally separates.
Adhesions
Abnormal attachment of two surfaces or structures that are normally separate

Herniation
The result of wound dehiscence and could cause incarceration of the bowel
Fistula
A tract between two epithelial surfaces, open at both ends
Sinus tract
A tract between two epithelial surfaces, open at one end
Keloid scarring
A hypertrophic scar formation that mainly occurs in dark-skinned individuals
Characteristics of Wound Disruption
May occur in a small percentage of clean, surgical, abdominal wounds
Usually happens between 4th and 6th postoperative days
Symptoms
Patient feels something give way
There may be a lot of drainage on dressing
The contour of the abdomen may change or spillage of abdominal contents
Causes of Wound Disruption
Infection
Abdominal distention
Type and direction of incision
Nutritional status of the patient
Coughing, straining, unusual activity
Obesity
Diseases
Infectious Process
Sepsis
The invasion of the body of a microorganism or their toxins
Involves three phases
Invasion
Localization
Recovery
Infectious Process
(continued)
Most wound infections present in the first postoperative week
Factors in recovery
Identification of organism
Administration of antibiotic
Virulence and drug resistance of the microbe
Health of the patient
Infectious Process
(continued)
If the body cannot contain a localized infection it becomes a regional infection.
The lymph nodes become responsible for trying to contain it.
If the lymph nodes cannot contain the infection it becomes a systemic infection.
Infectious Process
(continued)
Septicemia (systemic infections)
Are very dangerous
Symptoms include
Fever, chills
Elevated metabolic rate placing stress on vital organs
Toxicity
Elevated cardiac output (approx 60% above normal resting value)
If there are multiple infection sites and shock is present, the prognosis is poor
Septicemia
Nosocomial Infections
An infection that develops while a patient is in the hospital
Two types
Exogenous
Acquired from source outside the patient’s body
Endogenous
Acquired from source within patient’s body
Approximately 35% of nosocomial infections occur in surgical patients.
Postoperative Wound Infections
Two types
Incisional infection
Penetrates the skin, subcutaneous tissue and muscle
May require I&D
Deep-tissue
Involves layers under fascia or peritoneum
Requires I&D
Increased risk of dehiscence
If it occurs around implants, such as plates or screws, they may have to be removed
Postoperative Wound Infections (continued)
Burn and trauma patients are at high risk of developing viral, bacterial and fungal infections
Common bacterial infections in burn patients:
Streptococcus pyogenes
Staphylococcus aureus
Pseudomonas aeruginosa
Common fungal infections:
Candida
Postoperative Wound Infections (continued)
Common pathogens acquired from the OR
Aerobic
Staphylococcus aureus
Most common
Pseudomonas aeruginosa
Found in water, soil, and GI tract
Has a smelly odor and a blue-green color
Postoperative Wound Infections (continued)
Anaerobic
Clostridium perfringens
Causes gas gangrene
High mortality rate
Clostridium tetani
Introduced by penetrating wound with soil or fecal matter
Causes tetanus
Postoperative Wound Infections (continued)
Infections will appear within a week of surgery
If infection occurs after a week it indicates that the contamination did not happen int the operating room.
The skin is the most likely source of contamination
If the patient is not the source, it is likely contamination from the hair or nares of the surgical personnel
Peri-operative Precautions
Careful shaving of the patient’s skin
No nicks or cuts
Skin prep
Meticulous draping procedures
Proper aseptic technique
Use of PPE’s
Hair covering, protective eyewear, mask, sterile gown and gloves
Homework
Questions for further study
Page 382
#3, 5, and 8

Staphylococcus/Streptococcus

Staphylococcus/Streptococcus
And Aerobic Gram-positive Cocci
Chapters 9 & 10
Microbiology for Surgical Technologists

Review
Staphylococcus
And Aerobic Gram-positive Cocci
Staphylococcus
Clusters of spherical organisms
Two bacteria to be discussed
Staphylococcus aureus
Staphylococcus epidermidis
Both are Gram-positive
Stain purple in Gram stain test
Nosocomial Infections
Hospital-acquired infection
$$$
Types of patients that are prone
Immunologically suppressed
Surgical pts
Areas of the body that are susceptible:
UTI, surgical sites, URS and the blood
Staphylococcus aureus
Termed a “super bug”
Common in boils, impetigo, TSS, osteomyelitis, and postoperative wound infections
Usually localized
Controlled by host defenses
Portals of entry
Brake in skin
Respiratory tract
Serious infection can follow prosthetic placement

Staphylococcus aureus
(continued)
Initial response
Inflammation, heat, swelling, and pus
Fibrin clot may form to protect the infection
Abscess
Can become systemic and cause recurring boils (carbuncles)
If it becomes systemic the septicemia can be fatal
Second most common type of nosocomial infections
Staphylococcus aureus
(continued)
Facultative anaerobe
aerobic on skin
Anaerobic in the pores
Primarily colonizes in the nasal passages
Multiplies rapidly in moist places
Nose, axilla, anus
Lab culture is yellow

Staphylococcus aureus

Staphylococcus aureus
(continued)
Antibiotic Resistance
90% of nosocomial infections are untreatable with penicillin
MRSA (methicillin-resistant S.aureus)
Represents about 45% of nosocomial infections
Resistant to most antibiotics
Vancomycin is drug of choice
No longer restricted to hospitals
Resistant strains are considered a medical emergency
Staphylococcus aureus
(continued)
Virulence Factors
Some release exoenzymes
Increase the ability of the pathogen to invade tissue
The exoenzyme produces coagulase
Clots plasma to form a coat of fibrin for protection
Staphylococcus aureus
(continued)
Diseases
Food poisoning
Caused by the enterotoxins
Symptoms usually appear in 2 to 6 hours
Lives on skin and mucous membranes
Result of improper food handling and storage
Cannot be killed by cooking
Food looks and smell normal
Cannot be treated by antibiotics
Prevention is the key
Staphylococcus aureus
(continued)
Toxic Shock Syndrome (TSS)
Caused by exotoxin (a superantigen)
Commonly infects menstruating women
Can also be caused by pneumonia, wound infection and abscess
Toxin producing strains are part of normal flora of the vagina
If left untreated, can be fatal
Nafcillin is drug of choice
Staphylococcus aureus
(continued)
Impetigo
Highly contagious superficial skin infection
Nonbullous
Small red macules that turn into pus filled vesicles that break open
Forms thick yellow crust
Bullous
Vesicle is thin walled and ruptures
Forms thin clear crust
Treated with cephalosporins or erythormycin
Impetigo
Staphylococcus aureus
(continued)
Folliculitis
Infection of the hair follicle that causes pustules
Can lead to furunculosus and carbuncles
Furunculosis
Found on faces of men with beards, eyelids (styes), and arms and legs of children
Hard painful pustules that rupture and spread the disease
Folliculitis
Staphylococcus aureus
(continued)
Osteomyelitis
Chronic bone and bone marrow infection
Occurs at one site and travels to bone
Long bones in children
Vertebrae and pelvis in adults
Pt’s have persistent localized pain that increases
Treated with bed rest and IV antibiotics
In some cases an I&D is performed to remove necrotic bone
Osteomyelitis
Staphylococcus aureus
(continued)
Endocarditis
Travels from initial site, through bloodstream, to endocardium and heart valves
Destroys valve tissue
Symptoms – heart murmur, chronic fever, splenomegaly, and embolism
Treatment
IV penicillin, cephalosporin, or gentamicin
Sometimes may require valve replacement
Staphylococcus epidermidis
Lab culture is white
Found on the skin, but can be found in eyes, ears, mouth and nose
Most frequent cause of IV catheter infections, urinary infections, prosthetic infection and subacute bacterial endocarditis
Can be introduced in surgery
Staphylococcus epidermidis
(continued)
Signs and symptoms of endocarditis often do not develop for up to one year after surgery
The percentage of reinfection in artificial joints is high
Most strains are methicillin resistent (MRSE)
75% of S. epidermidis infections are caused by MRSE
Vancomycin is the drug of choice
Streptococcus
And Aerobic Gram-positive Cocci
Streptococcus
Streptococcus
Gram-positive
Non-motile
Non-spore forming
Facultative or obligate anaerobe
Identified by sensitivity to optochin
Causes cell to lyse
Streptococcus
(continued)
Classifications
Beta hemolytic (β-hemolytic)
Complete lysis of erythrocytes
Alpha hemolytic
Partial lysis of erythrocytes
Gamma hemolytic
Do not lysis erythrocytes
Streptococcus
(continued)
Groups
Group A streptococci
Beta hemolytic
Spread by respiratory secretions and fomites
Group B streptococci
Gamma hemolytic
Normal vaginal flora
Streptococcus pneumoniae
In the eyes, ears, mouth, and nose
Causes:
Pneumonia, meningitis, and otitis media
Most common cause of bacterial pneumonia
One of three most common causes of bacterial meningitis
Streptococcus pneumoniae
(continued)
Two pneumonia causing strains
Capsulated
Shiny, mucoid appearance
More virulent
Non-capsulated
Dry pitted appearance
Frequent cause of pneumonia in children and elderly
Streptococcus pneumoniae
(continued)
Diseases
Pneumococcal pneumonia
Caused by inhaling infected droplets
To not produce toxins, bacterial cells cause inflammation
Becoming more virulent over time
Resistant to many antibiotics
Vaccine – Pneumovax
Protects from 23 of the 84 known strains
The 23 strain account for 90% of the known virulent strains that cause the infection
Streptococcus pneumoniae
(continued)
Bacterial ear infection
Responsible for most cases of otitis media
Most occur in children ages 1 – 8
Usually in conjunction with cold, nose or throat infection
Treatment
Penicillin, amoxicillin, or erythromycin
Myringotomy
Otitis media
Streptococcus pneumoniae
(continued)
Meningitis
S. pneumoniae is the primary cause in the elderly
Is also common cause in children
Symptoms similar to cold
Cause death if untreated
5% to 10% will die anyway
Can cause permanent brain damage
Streptococcus pyogenes
Group A, beta hemolytic
Causes strep throat, rheumatic fever, scarlet fever, and necrotizing fasciitis (the flesh eating disease)
Cell envelope contain antigenic protein M
Prevents phagocytosis
Help to adhere to pharyngeal cells
Identified with fluorescent staining
Streptococcus pyogenes
(continued)
Diseases
Streptococcal pharyngitis
Pharyngitis is strep throat
Causes fever, pain, difficulty swallowing, and inflammation of the tonsils and pharynx
Streptococcal pharyngitis
Streptococcus pyogenes
(continued)
Scarlet fever
Associated with strep throat
The pathogen is invaded by a bacterial virus that deposits it’s genetic information into it
This strain produces erythrogenic toxin
The toxin causes a red skin rash, and red spots on the tongue
The skin and tongue eventually shed their cells
Streptococcus pyogenes
(continued)
Necrotizing Fasciitis
The cell surface is mucoid and has a large amount of M protein
Infects the fascia and may penetrate the underlying muscle
Produces an enzyme called protease, that destroys proteins
Also produces a pyrogenic toxin, that causes a type of TSS
Streptococcus pyogenes
(continued)

Necrotizing Fasciitis (continued)
The disease has been around for a while, but the number of cases has increased in recent years
Treatment
Heavy doses of penicillin, cephalosporin, or vancomycin
Surgical I&D of necrotized flesh to pervent secondary infections
Necrotizing Fasciitis
Streptococcus agalactiae
Better known as group B strep (GBS)
Found in lower GI tract, GU tract and vagina
20% of women have GBS
Naturally acquired antibodies protect the host

Streptococcus agalactiae
(continued)
Neonate born without the antibodies 1% -2% are at risk of contracting systemic infections
Can be contracted in utero, during birth or during the first few weeks of life
Early onset – infection occurs in within seven days
Late onset – infection occurs from one week to three months
Streptococcus agalactiae
(continued)
Pregnant women are at risk of developing UTIs, amnionitis, endometritis, and wound infections
Men and non pregnant females develop skin infections, bacteremia, and pneumonia
Cancer, alcoholism and diabetes predispose individuals to infection
Treated with penicillin and vancomycin
Streptococcus viridans
Similar to S. pyogenes
Alpha hemolytic
Named for the green colonies that grow in the lab
Viridis is Latin for green
Normal flora of the upper respiratory tract, GI and GU tracts
Streptococcus viridans
(continued)
Cause subacute endocarditis, dental caries, and suppurative abdominal infections
Adhere to tooth enamel and heart valves that have already been damaged by rheumatic fever
Treated with penicillin

Aerobic G+ bacilli, Coccobacilli, and Coreform bacilli

Aerobic Gram-Positive Bacilli, Coccobacilli, and Coryneform Bacilli
Chapter 11
Microbiology for Surgical Technologists
Bacillaceae
Bacillaceae
Endospore forming bacteria
51 species are classified as genus Bacillus
Few cause human disease except one
All are aerobic or facultative anaerobes
Are Gram-positive or Gram-variable
Most are motile
Found abundantly in soil
Can live for years in adverse conditions
Are saprophytes
Bacillus anthracis
Clinical diagnosis
Culture characteristics
Sticky adherence of the colonies
Chains of bacilli
Nonmotility
Absence of hemolysis
Virulence
Spore forming
Antiphagocytic capsule
Edema factor – produces profuse swelling
Lethal factor
Contributes to death by oxygen depletion, shock, respiratory failure, and cardiac failure

Bacillus anthracis
(continued)
Each of the virulence factors alone are ineffective, but when combined they are lethal
Anthrax toxins are also antiphagocytic and blocks the activities of leucocytes
The capsule is important in the first part of the disease, then the toxin dominates
Bacillus anthracis
(continued)
Acquired by exposure to contaminated animals or direct contact (biological weapons)
Majority of infections result from exposure to spores
Can be contracted through the skin, inhalation and ingestion
Person to person transmission has not happened and is not likely to occur
Bacillus anthracis
(continued)
Cutaneous Anthrax
Enter through a cut or other break in skin
Usually from handling horses, sheep or goats
Starts as a painless bump and turns into a necrotic ulcer in 1 to 2 days
If not treated promptly, can be fatal
Cutaneous Anthrax
Bacillus anthracis
(continued)
Inhalation Anthrax
Rapidly progressive pulmonary disease that leads to respiratory failure
Mortality rate is high even with treatment early in course of disease
Incubation is about 7 days and death usually results in 1 to 3 day after symptom start
Bacillus anthracis
(continued)
Gastrointestinal Anthrax
Acquired by eating contaminated meat
Causes inflammation of the mucous membrane of the GI tract
Symptoms include nausea, vomiting, high fever, and loss of appetite
Pts experience abdominal pain, severe diarrhea, and vomiting blood
Becomes systemic with a high mortality rate
Bacillus anthracis
(continued)
Control and Treatment
Penicillin, erythromycin, and tetracycline
Effective if administered before the onset of lymphatic spread or septicemia
Animal control
Vaccinations
Infected animals should be cremated
Bacillus anthracis
(continued)
Human vaccine developed in 1970
93%effective
Vaccine is cell free
Does not contain either live or dead bacteria
Consists of three shots given 2 weeks apart
Followed by three more shots given at 6, 12 and 18 months
Annual boosters are recommended
Only given to healthy adults 18 to 65
Bacillus anthracis
(continued)
Nonendospore cells can be killed by 0.05% hypochlorite solution
1 tablespoon bleach per gallon of water
Spores can only be killed by steam or gas sterilization, or boiling at 100 degrees C for 30 minutes
Bacillus cereus
Found in soil
Gram-positive, facultative aerobic
Motile and hemolytic
the Bacillus subtilits var. niger strain globingi is used for biological indicator tests for (EtO) gas sterilization
Causes ocular infection, IV catheter sepsis, and gastroenteritis (from food poisoning)
Bacillus cereus
Bacillus cereus
(continued)
Two types of gastroenteritis from two enterotoxins
The emetic form
Results from eating contaminated rice
Enterotoxin produced by bacteria is not killed in cooking process
Symptoms – nausea, vomiting, and abdominal cramps
Begins in 1 to 6 hours and lasts for 24 hours
Bacillus cereus
(continued)
The diarrheal form
Results from eating meat, milk, fish or vegetables
Enterotoxin produces symptoms of diarrhea, nausea, and abdominal cramps
Lasts for more than 24 hours

Bacillus cereus
(continued)
Ocular infections are caused by three toxins
Causes rapid destruction of the tissue of the eye by the combination of toxins
Usually attributed to a traumatic puncture wound
Causes Bacillus panophthalmitis
100% rate of losing light perception within 48 hours
Bacillus cereus
(continued)
Septicemia infection are primarily introduced with contaminated IV catheters
Can cause endocarditis
CNS infection can be contracted after the insertion of ventriculoperitoneal and ventriculoatrial shunt used to treat hydrocephalus
Listeria Species
Listeria Species
Listeria monocytogenes is the only one of 6 species that causes disease in humans
Listeriosis
Non-spore forming, facultative anaerobe
Causes meningitis, food poisoning and bacteremia
Motile at room temperature but not at 37ºC
Most likely to cause disease in immunocomprimised, elderly and pregnant pts
Listeria monocytogenes
Found in water, soil, plants, and animals
1% to 5% of healthy people are known to be fecal carriers
Fourth most common causes of community-acquired meningitis
Approx 2000 will be infected this year, of them 500 will die
1/3 of those infected are pregnant women
20 times more likely to get listeriosis
Peaks during warmer months

Listeria monocytogenes
(continued)
Majority of cases are food borne
20% to 30% mortality rate
Refrigeration slows, but does not stop the growth rate
Vegetables become contaminated from soil and manure fertilizer
Animals are carriers
Listeria is killed by pasteurization
Listeria monocytogenes
(continued)
Two forms of neonate disease
Early onset – granulomatosis
Caused by the mother eating contaminated food while pregnant
Cells are transferred to the fetus either through the placenta or after ROM at birth
Can cause spontaneous abortion or still births
Causes abscesses and granulomas in the infants internal organs
Infant mortality is high
Listeria monocytogenes
(continued)
Late onset
Occurs two to three weeks after delivery
Causes meningitis or meningoencephalitis with septicemia
Listeria monocytogenes
(continued)
Treatment
Penicillin and ampicillin, either alone or in combination with gentamicin
Erythromycin is used for those with PCN allergy
Control
Avoid eating raw animal foods, cheeses, and unwashed raw vegetables
A vaccine is not available
Erysipelothrix rhusiopathiae
The only member of the Erysipelothrix genus
Gram_positive, non spore forming
Widespread in both wild and domestic animals
Causes disease mostly in pigs
Not common in humans
Occupational disease
Butchers, farmers, vets, etc.
Erysipelothrix rhusiopathiae
(continued)
Three forms of the disease
Localized skin infection (erysiploid)
Lesion with raised edges that increases in size
Edemic, painful, and pruritic
Usually resolves on it’s own, meds speed the process

Erysipelothrix rhusiopathiae
(continued)
Generalized cutaneous infection
Rare
Localized infection that spreads to the cutaneous tissue
Septicemia
Causes endocarditis
Attacks HEALTHY heart valves
Erysipelothrix rhusiopathiae
(continued)
Treated with PCN, cephalosporins, clindamycin and erythromycin
A vaccine is used to control the disease in pigs
No human vaccine
Patients that have been infected do not develop immunity
Relapse can occur
Lactobacillus Species
Lactic acid producing bacteria (homolactic)
Facultative or strictly anaerobic
The lactic acid can spoil food but is important in the food industry
Creating pickles, sauerkraut, and yogurt
Lactobacillus Species
(continued)
In humans lactobacillus is part of the normal flora of the oral cavity, GI tract and vagina
Causes endocarditis
Is dangerous because it is resistant to Vancomycin and other types of antibiotics only inhibit its growth
Corynebacterium Species
Also produce lactic acid
Aerobic or facultative anaerobe
Non spore forming, non motile
Normal flora of the skin, GI and GU tracts, and upper respiratory tract
Corynebacterium Species
(continued)
Corynebacterium diphtheriae
Diphtheria
The first clinical description was by Hippocrates in the 4th century B.C.
In the 1920’s 150,000 cases with 13,000 deaths
In the 1980’s only 24 cases were reported
Due to vaccinations
Corynebacterium diphtheriae
(continued)
Diphtheria is found worldwide
Particularly in overcrowded, poor urban areas
Immunity is low because of the lack of vaccination
Humans are the only known reservoir for the bacteria
Transmitted by skin contact or respiratory droplets
Primarily a disease that affects children
Corynebacterium diphtheriae
(continued)
Three strains
Gravis – most sever
Intermedius
Mitis – least severe
Diphtheria toxin is an exotoxin that is secreted by the bacteria at the site of infection
Once the toxin enters the cell, it is irreversible and cell death occurs
Corynebacterium diphtheriae
(continued)
Diseases
Respiratory Diphtheria
Incubation period of 2 to 6 days
Attach to the epithelial cells of the pharynx
A lesion develops and necrosis begins
Blood plasma leaks and a fibrin network forms
The fibrin network becomes a pseudomembrane
Composed of bacteria, dead cells, plasma cells, and lymphocytes
Corynebacterium diphtheriae
(continued)
Respiratory Diphtheria (continued)
The pseudomembrane covers the uvula, tonsils, and palate and extends into the nasopharynx and into the larynx
It adheres to the underlying tissue and is difficult to remove due to bleeding
Disease lasts about a week
Pts that recover will expectorate the membrane
Corynebacterium diphtheriae
(continued)
Respiratory Diphtheria (continued)
Complications – breathing and respiratory problems, cardiac arrhythmia, neurologic symptoms, and possibly coma
Death can result
Treatment
Administer antitoxin before pseudomembrane forms
PCN and erythromycin
Isolation
Corynebacterium diphtheriae
(continued)
Respiratory Diphtheria
Immunization
Beginning at three to four months of age
Three injections, once a month, for 3 months
Booster at one year
Recommendation for booster every 10 years
The vaccine contains diphtheria toxoid, pertussis vaccine, and tetanus toxoid
DPT
Corynebacterium diphtheriae
(continued)
Cutaneous Diphtheria
Acquired through skin contact with infected person
Gains access through a break or cut in skin
Papule that progresses to an ulcer with a grayish-colored membrane covering
Corynebacterium jeikeium
Well known in the medical community
Very rare
As many as 40% of hospitalized pts are colonized
Affects immunocomprimised pts with IV access
Very resistant to antibiotics
Corynebacterium urealyticum
Also very rare
Causes urinary infections
Produces urease, an enzyme that decomposes urine to ammonia and carbon dioxide
Can lead to the formation of calculi (stones) in the kidney, ureter, and bladder
Resistant to most antibiotics except vancomycin

Neisseria/other G- bacilli

Neisseria
And Aerobic Gram-negative Cocci

Microbiology for Surgical Technologists
Chapter 12
Neisseriaceae
Gram-negative
Aerobic
Consists of ten species, two of which are human pathogens
Virulence factors
Both have pili, allows them to move through tissue and are not easily removed
They are encapsulated
Neisseria gonorrhoeae
Gonorrhea
Also called the clap or the drips

Fastidious, gram-negative diplococcus
Reached epidemic status in US
Due to a promiscuous, mobile society
The use of birth control in women changes the microbial environment of the vagina, making them more susceptible to the disease
Due to careless use of PCN, it has mutated into resistant strains known as penicillinase-producing N. gonorrgoeae (PPNG)
An estimation of 80% women and 20% men are asymptomatic
Attaches to the epithelial cells of the GU tract, rectum, and throat
Then passes to the sub-epithelial space and becomes established
Initial phase can last several months and damage and scar reproductive organs
Symptoms then appears as localized pain
Infections in males occur primarily in the urethra
Displays with a urethral discharge and dysuria (painful urination)
Primary site of infection in females is the cervix
It cannot infect the epithelial cells of the vagina
Displays symptoms of dysuria, abdominal pain and vaginal discharge
A serious complication in women is Pelvic Inflammatory Disease (PID)
An acute infection of the abdomen
Can cause salpingitis ( infection of the fallopian tubes
If left untreated, can cause sterility due to scarring and adhesions
Can be contracted orally and present as only a sore throat for a short duration
Can be passed to fetus at birth
Treatment
CDC remommends ceftiaxone, cefixime, ciprofloxacin for uncomplicated cases
In patients with dual infections with chlamydia, one of the above is combined with doxycyline or azithromycin
Neisseria meningitidis
An encapsulated, Gram-negative diplococci
Only found in humans
Colonizes the nasopharynx
Second most common cause of community-acquired meningitis in adults
If untreated, mortality rate is 100%
When the bacteria invade the bloodstream through the nasopharynx epithelium it is Meningococcemia
Pt can have it with or without meningitis
Life threatening
Symptoms include skin lesions and petechial skin patches
The petechial skin patches will combine to form larger hemorrhagic lesions
Acute fulminating meningococcemia (Waterhouse-Friderichsen syndrome) a serious disease that involves multiorgan systems of the body
Has a high mortality rate
In just a few hours the pt becomes restless, apprehensive, and delirious
Petechial patches appear all over the body with no signs of meningitis
Results in disseminated intravascular coagulation (DIC), and shock
DIC is a condition where the pts blood will no longer clot properly
An extreme emergency in surgical pts
Majority of pts expire within 24 hours despite treatment
A vaccine has been developed
Only used for military personel and in hyperendemic* regions of the world
A region that has epidemics that are cyclic
Transmitted through respiratory droplets
Most common during dry months
In US causes endemic outbreaks and seldom causes epidemics
The sub-Saharan area of Africa is referred to as the “meningitis belt”
Epidemics occur every ten years
Moraxella
Gram-negative, nonmotile, cocci
Strictly aerobic
Are coccobacilli
Their shape is between a cocci and rods
Moraxella lacunata
Colonizes the eyes
Is thought to be a cause of conjunctivitis in humans
Moraxella catarrhalis
Common cause of otitis media in children, adult sinusitis, bronchitis, and bronchopneumonia
The elderly with chronic obstructive pulmonary disease (COPD) are very susceptible
Is resistant to PCN, but cephalosporins, erythromycin, tetracycline, ampicillin, and sulfa drugs are effective
Moraxella catarrhalis
Estimated to be normal flora in 40% to 50% of school age children
The third most common cause of otitis media
The third most common cause of sinusitis in adults
Pts with COPD will often develop emphysema and chronic bronchitis which leads to life threatening pneumonia
Other Gram-negative Bacilli and Coccobacilli
Chapter 13

Microbiology for Surgical Technologists
Pasteurellaceae
Gram-negative
Nonmotile
Nonspore forming
Either aerobic or facultative anaerobic
Pasteurella
Named after Louis Pasteur
Are pleomorphic
Range from bacilli to cocci
Facultative anaerobic
Infection transmitted to humans from animals through an opening in the skin or from a bite
Pasteurella multocida
Four forms of the infection
Localized
Cellulitis, lymphdenitis, and pain from the bite
Respiratory
Increased pulmonary complication with pts that already have pulmonary disease
Septicemia
Spreads either through circulatory system or lymphatic system
Endocarditis

Pasteurella multocida
(continued)
Domestic animals harbor the bacteria in their respiratory tract
Pass it on to humans through bites and scratches
Domestic animal bites are responsible for 1% of all emergency room admission
If not cleaned and treated can result in serious infection.
Pasteurella multocida
(continued)
Virulence factors
Antiphagocytotic capsule
Endotoxin that contributes to tissue damage and chronic abscesses
Lab cultures emit a foul odor
Easily treated with antibiotics
Brucella
Nonmotile, Gram-negative, nonencapsulated coccobacilli
Four of the six species are human pathogens and cause brucellosis
Named for the animal in which it is commonly found:
B. abortus (cattle)
B. canis (dogs)
B. melitensis
B. suis (swine)
Brucella
(continued
Virulence
Resistant to phagocytosis
The phagocytes take the bacteria in and then they are transported to the kidneys, spleen, lymph nodes, and bone marrow
Cause granulomas in these structures and will destroy the organ tissue
Result from the consumption of unpasteurized milk and dairy products
Brucella
(continued
Of the 100 to 200 cases reported in the US annually, most are from Texas and California
Can also occur from direct contact with animals or through infectious aerosols
Other routes of infection are breast milk and sexual contact with an infected person
Incidence is low now due to vaccination and destruction of infected animals
Brucella
(continued
Dogs and cows produce a mild form of the disease
Swine and goats produce the more severe form
Produces undulant fever
Intermittent fever
In severe cases recovery can take a few weeks to several months
Bordetella
Gram-negative, strickly aerobic coccobacilli
Virulence:
Surface protein on the cell wall called filamentous hemagglutinin
Aids in the ability of the organism to adhere to the cilia of the respiratory tract
Secretion of pertussis toxin
An exotoxin that increases the release of histamine
Bordetella
(continued)
Virulence (continued)
Secretion of adenylate cyclase
A compound that inhibits phagocytosis
Tracheal cytotoxin
An exotoxin that destroys the tissue of the respiratory tract
Bordetella pertussis
Whooping
Cough
Bordetella pertussis
(continued)
Acquired by inhaling the cough droplets of an infected person
Highly communicable
In 1934 265,000 cases were reported
5 of every 1000 children died
Once the vaccine was developed the cases dramatically decreased
Bordetella pertussis
(continued)
Three stages of the disease
Prodromal stage
Begins with nonspecific cold-like symptoms that progress to a cough
Paroxysmal stage
Frequent, violent coughing attacks that cause the patient to gasp for breath
Resulting in the characteristic sound for which the disease is named for
Convalescent stage
Resolution of symptoms and disease
Bordetella pertussis
(continued)
The bacteria attach to the cilia of the respiratory tract and prevent their movement and progressively destroy them
This prevents the mucous that collects to be swept forward and eliminated
The patient attempts to cough up the mucous, with increased violence of the coughing spells
Bordetella pertussis
(continued)
Complications
Occur during second stage (paroxysmal)
Broken ribs (especially in children)
Inguinal hernia (primarily in men)
Rectal prolapse
Severe difficulty breathing requiring intubation and ventilation
Otitis media in children
Bordetella pertussis
(continued)
A culture is obtained by placing a swab, on the end of a wire, through the nose into the nasopharyngeal tract and left in place while the pt coughs
A more recent method is with aspiration of the nasopharyngeal tract
Bordetella pertussis
(continued)
Treatment
Erythromycin is given, but only to lessen symptoms by destroying some of the organisms
By the time pertussis is diagnosed the toxins have already caused extensive damage
Supportive measures are taken, but the disease has to run it’s course
Bordetella pertussis
(continued)
Treatment
(continued)
Convalescence depends on the cilia’s ability to regenerate
The most effective treatment is prevention with the vaccine (DPT)
Pts who have had the disease will develop immunity for a number of years

Gardnerella vaginalis
Non-motile
Non-spore forming
Non-capsulated
Facultative anaerobe
The cell wall allows adherance to epithelial cells
Normal vaginal flora in 50% to 70% of women
Gardnerella vaginalis
(continued)
The pathogenic role of the organism causes vaginosis
Since inflammation is not present, the term vaginosis is used instead of vaginitis
Can be transmitted sexually
Although men are only carriers and show no sign of disease
Increases the normal pH level of the vagina
Changes the normal environment throwing the balance off
Gardnerella vaginalis
(continued)
Risk factors for developing vaginosis
Invasive procedures
Hysterectomy, endometrial biopsy, and implantation of IUD
Change in sexual partners
Menopause
Diabetes
Immunocompromised pts
Poor hygiene
Gardnerella vaginalis
(continued)
Can cause
Postpartum bacteremia, postpartum endometriosis, premature birth, low birth weight, and neonatal septicemia
Symptoms
Copious gray-white discharge with a foul “fish-like” smell
Caused by amines putrescine and cadaverine, found in rotting fish
Gardnerella vaginalis
(continued)
Standard treatment is the antibiotic Flagyl
Kills the anaerobes and allows the normal lactobacilli to multiply back to their normal population and decreasing pH

Haemophilus & other enteric bacilli

Haemophilus

Chapter 14
Microbiology for Surgical Technologists
Haemophilus
Nonmotile
Gram-negative rods
Facultative anaerobe, but prefer an aerobic environment
Grow in pairs or short chains
Found in the mucous membranes of the respiratory and genital tracts of humans
Haemophilus
(continued)
Means blood-loving
Require one or two factors that are present in blood
Specifically heme (the old name is the “X” factor)
Contracted through droplet inhalation or sexual contact
Haemophilus influenzae
6 serotypes – a through f
Type b is most virulent
Virulence factors
Antiphagocytic
Peptidoglycan – in cell wall, damages the blood-brain barrier
Exotoxin – inhibits the movement of respiratory cilia
Fimbriae – aids cell adherence to tissue
Adhesins - aids cell adherence to tissue
Haemophilus influenzae
(continued)
Type b can spread from the respiratory tract to the sinuses and middle ear
It is the most common cause of septic arthritis and cellulitis in children 2 and under
Can lead to pneumonia and meningitis
Can be deadly in small children and elderly
Haemophilus influenzae
(continued)
Neurological conditions that can occur following recovery from H. influenzae meningitis are:
Hearing loss, blindness, chronic convulsions, hydrocephaly, and developmental disabilities
Since the introduction of the conjugated vaccine, the US has seen an almost 100% reduction in the incidence of H. influenzae type b
Haemophilus influenzae
(continued)
Treatment
Antibiotic therapy
Clinical trials are being done in infant to include dexamethasone (a steroidal anti-inflammatory drug).
It has been very successful in reducing meningeal swelling and the incidence of hearing loss
Haemophilus influenzae
biotype aegyptius
Causes pinkeye
A highly contagious purulent conjunctivitis
Infection can range from mild to severe
Mild – involving only the blood vessels of the eye
Severe – with lacrimation, swelling and photophobia
It can cause an even more severe form called Brazilian purpuric fever
Haemophilus ducreyi
Endemic in some parts of the world
High rates associated with poor socioeconomic and sanitary conditions
In the US it is common among crack addicts, prostitutes, and alcoholics
Causes chancroid
Sexually transmitted disease that manefests as soft chancres (ulcerations)
Haemophilus ducreyi
(continued)
Immunity does not develop after exposure
Treatment of choice is a new drug called azithromycin
Gram-Negative
Enteric Bacilli

Chapter 15
Microbiology for Surgical Technologists
Escherichia coli
The #1 cause of nosocomial infection
Gram-negative rod that grows singly
Part of the normal flora of the GI tract in humans
Help to prevent growth of pathogenic bacteris and synthesizes vitamins
Most strains are harmless
Can be the cause of endogenous infections
An infection caused by an organism that is normal flora
Escherichia coli
(continued)
Causes urinary tract infections, sepsis, diarrheal disease, and neonatal meningitis
Immuno-compromised or debilitated pts are at higher risk for infection
Four types of pathogenic strains
Enteropathogenic
Enterotoxigenic
Enterohemorrhagic
enteroinvasive
Escherichia coli
(continued)
Diarrhea
Enteropathigenic E. coli (EPEC)
Often the cause of diarrheal disease breakouts in nurseries
The microvilli in the intestinal tract are destroyed
Usually resolves in 5 to 15 days
Infants can quickly become dehydrated requiring intravenous fluid replacement
Escherichia coli
(continued)
Enterotoxigenic E. coli (ETEC)
Referred to as “traveler’s diarrhea”
Exotoxins that are produced are responsible for the symptoms
Individuals that live in countries with ETEC often have protective antibodies
Antibiotic therapy may be needed along with IV fluid replacement
Escherichia coli
(continued)
Enterohemorrhagic E. coli (EHEC)
Causes hemorrhagic colitis
Severe form of bloody diarrhea
Referred to as E. coli 0157:H7
Found in the intestines of healthy cattle
During the slaughtering and processing the microbes contaminate the beef
EHEC is acquired from ingesting raw or undercooked beef, unpasteurized milk, and other raw contaminated foods
Escherichia coli
(continued)
Enterohemorrhagic E. coli (EHEC) (continued)
Meat contaminated with EHEC looks and smells normal
Only a small number of cells can cause infection
Other methods of becoming infected include:
Swimming in or drinking sewage-contaminated water
Person to person contact
Bacteria in stools can be passed if proper hygiene habits are not practiced
Escherichia coli
(continued)
The CDC estimates that 20,000 become ill from EHEC annually and 250 die
It is also responsible for causing hemolytic uremic syndrome (HUS)
Can be fatal
HUS involves thrombocytopenia, acute renal failure, and gemolytic anemia
Thrombocytopenia is the decrease in the number of blood platelets
Escherichia coli
(continued)
Pts with HUS most likely require hemodialysis and blook transfusions
Most HUS pts are children 5 and under
Once symptoms appear antibiotic therapy is useless, and the disease must run it’s course
Those who survive often have chronic genitourinary complications due to kidney and urinary tract damage
Escherichia coli
(continued)
EHEC Virulence factors
Produces verotoxins that destroy the inner layer of blood vessels
Shiga-like toxin which aids the ability of the bacterial cell to adhere to tissue
Both toxins are identical to the toxin produced by Shigella dysenteriae
Escherichia coli
(continued)
Enteroinvative E. coli (EIEC)
Causes a type of dysentery similar to shegellosis, but not as virulent
Children are most susceptible
Is also common among travellers
Escherichia coli

Escherichia coli
(continued)
Urinary Tract Infections
(UTI)
Common infections in infants that are still in diapers, pts with indwelling catheters, and females
Responsible for the majority of nosocomial UTIs
Can cause pyelonephritis
Severe kidney infections
Escherichia coli
(continued)
UTI
(continued)
Caused by nephropathogenic E. coli (NPEC)
Has a capsule and pilus that add to virulence
Symptoms include side pain radiating to the back, dysuria, frequent urination, and hematuria
Escherichia coli
(continued)
E. coli is a common cause of meningitis in infants
Mortality rate is high
From 40% to 80%
The majority of those that survive will display neurologic deficits and/or develop mental abnormalties
It is rarely implicated as the cause of adult meningitis
Escherichia coli
(continued)
Treatment
In all cases, accept EHEC, antibiotic therapy is successful
Pts usually do not seek treatment for diarrhea unless they become dehydrated, individuals with a sudden onset of bloody stools should seek medical treatment immediately.
Klebsiella
Klebsiella pneumoniae
Causes approx 3% of community or nosocomial bacterial pneumonias
Tends to affect those who already have a disease such as diabetes, alcoholism, or COPD
The elderly are prone to developing lobar pneumonia
A hemorrhagic necrotizing consolidation of the lungs
Klebsiella pneumoniae
(continued)
The bacteria are responsible for the necrotic destruction of the alveoli, abscess formation in the lung, and production of sputum that is thick and red
Referred to as “currant jelly” sputum because of it’s appearance
Cells have a gelatinous capsule that inhibits phagocytosis
If not treated quickly it is often fatal
Klebsiella pneumoniae
(continued)
Causes empyema
Pus surrounding the lung
Causes irritation and scar formation
Chest x-rays reveal lung abscesses in advanced cases
Can also cause nosocomial UTIs, wound infections, and burn infections
Highly resistant to antibiotic therapy
Empyema
Yersinia
Three species important to the medical community
Yersinia pestis
Yersinia pseudotuberculosis
Yersinia enterocolitica
Yersinia pestis
Bubonic Plague
Also known as the
Black death
Yersinia pestis
(continued)
Responsible for some of the greatest epidemics in history
It eliminated approx 1/3 of the population of the world between 1348 and 1530
No one knows why that epidemic stopped
No major outbreaks have occurred in over a century
Likely due to improved pest control and insecticides
Yersinia pestis
(continued)
Humans contracted the disease from the bite of an infected rat flea
Upon infection the cell loses its capsular layer and most are destroyed by phagocytosis
A few will enter tissue that provide protection and resynthesize the capsule and other virulent agents
Yersinia pestis
(continued)
The infection quickly spreads to the lymph nodes
They become tender swollen, tender and hot
They then become hemorrhagic
Giving rise to the black colored buboes
Hence the name bubonic plague
The infection invades the blood and spreads to the spleen, liver, and lungs
The result is pneumonia with a productive cough filled with the pathogen, infecting the environment
The Plague
Cutaneous infection
The Plague
Inguinal Buboes
Yersinia pestis
(continued)
Death can occur within 24 hours of the initial signs of infection
There are few drug resistant strains
Control measures have centered on the elimination of the rat flea
It is highly unlikely that it will ever be eradicated
Yersinia pseudotuberculosis
A pathogen of rodents and bird, but can infect humans
Is distinguished among other Yersinia species because it is motile
Produces large nodules in the Peyer’s patch and mesenteric lymph nodes
The Peyer’s patch is a group of lymph node located at the terminal ilial junction
May cause abscesses and require intestinal resection with anastomosis
Yersinia enterocolitica
A pathogen of cattle, pigs, deer, and birds
Excreted in the feces and can contaminate dairy products and drinking water
Humans can become infected by eating raw or undercooked pork products
The disease is called yersiniosis
Causes severe diarrhea with necrosis of the Peyer’s patch, liver and splenic abscesses, and chronic lymphadenopathy (swelling of the lymph nodes
Yersinia enterocolitica
(continued)
Often confused with appendicitis because of the right lower quadrant pain
An incidental appy may be the result
The number of reported cases in the US has increased in recent years
Rare complications include reactive arthritis and bacteremia
Salmonella
Rod shaped, Gram-negative, non spore forming
Always considered human pathogens
Most are motile
Normal flora of cattle, birds, and rodents
Cause enterocolitis (diarrhea) due to ingestion of contaminated food
The number of salmonella cases are few in the US
Salmonella
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Found in commercial meat, shell eggs, and unpasteurized milk
Cooking food at a high enough temp, for the correct period of time will kill the cells
Cutting boards and utensils used to cut uncooked meat can spread the bacteria
Hand washing and cleansing of cutting boards and utensils will prevent spreading the bacteria to other foods
Salmonella typhi
Cause the most sever infection:
Salmonella typhi
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Transmitted by the fecal-oral route
Not destroyed by macrophages and will multiply within them
Invades the Peyer’s patch and enters the lymphatic system then transported throughout the body by the circulatory system
The inflamatory response is initiated in the lungs, periosteum, and gallbladder
Salmonella typhi
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Hepatosplenomegaly occurs in many pts
Soon constipation then bloody diarrhea appears
After recovery the pt may carry and excrete S. typhi for a long period
A small percentage will become permanent carriers
Salmonella typhi
(continued)
Mary Mallon
The first documented permanent carrier of S. typhi
Caused several outbreaks and deaths before health officials caught up with her
Once caught she was isolated for life
What was her name changed to?
Salmonella typhi
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The cells persist in the gallbladder, common bile duct, hepatic duct, and cystic duct
Bile provides and excellent medium for growth
Antibiotics shorten the length of the illness
But most strains have become resistant
Anatomy of the gallbladder and ducts
Homework
Questions for further study
Page 179, # 1 and 2
Page 189, # 2