exam 5 Flashcards
What are common characteristics of Staphlococcus?
gram positive
coccus (round)
catalase positive
Where can you typically find staphylococcus organisms?
normal flora on skin and nasal passages
What protein is in the cell wall of staphylococcus aureus?
Protein A
What does staphylococcus aureus look like in a colony?
golden-yellow
smooth
What type of hemolytic reaction will staphylococcus aureus look like on a blood agar plate?
beta
A positive reaction for catalase will look like what?
bubbles
What is being used to perform a catalase reaction?
hydrogen peroxide
How will staphylococcus aureus test for a coagulase test?
positive
What does a beta hemolytic reaction on a blood agar plate indicate?
complete breakdown of red blood cells
What organism should come to mind first with any inflammatory skin case history?
Staphylococcus aureus
What test should you run first if you suspect staphylococcus aureus?
gram stain if it positive- it can indicate this organism
What major disease is staphylococcus aureus associated with?
skin infections (boils, abscess, impetigo)
How many causes can generic disease have?
multiple
How many causes can a named disease have?
usually related to ONE organism
What organism is involved in Scalded Skin Syndrome?
Staphylococcus aureus
What organism is involved in Toxic Shock Syndrome?
Staphylococcus aureus
What organism is involved in Necrotizing fasciitis?
Streptococcus pyogenes
What toxin is associated with Toxic Shock Syndrome 1?
Exotoxin c
What effect does Exotoxin c have?
pyrogenic accompanied with fever, sore throat, rash, muscle pain
What toxin is associated with enteric symptoms of Toxic Shock Syndrome?
Enterotoxin F
What are the symptoms related to Enterotoxin F?
enteric symptoms
What do systemic symptoms imply?
organism has gained access into the blood, either the product or the organism
What toxin is associated with Scalded Skin Syndrome?
Exfoliatin toxin
What organism can cause a syndrome that resembles a sever sunburn?
Staphylococcus aureus
Is staphylococcal food poisoning a food infection of intoxication?
food intoxication
What enterotoxin is present in Staphylococcal food poisoning?
Enterotoxin A or D
A presence of enterotoxin A or D indicates what?
Staphylococcal food poisoning
Food intoxication indicates what has been ingested?
toxin
Food infection indicates what has been ingested?
organism
You are on a date and eat a yummy creamy potato salad, on the drive home your stomach does not feel good. You pull over and have explosive diarrhea and projectile vomiting. What organism is responsible for your condition?
staphylococcal aureus food poisoning
Will a food infection or food intoxication have a longer incubation time?
food infection because the organism has to get established to then produce the toxin
You have a gram positive cocci, what test do you run next to gain more information? What organism do you suspect?
catalase test
Staphylococcus aureus
Staphylococcus epidermis
You have a gram positive cocci that has a positive catalase test, what test do you run next? What organisms do you suspect?
coagulase test
Staphylococcus aureus- will be positive
Staphylococcus epidermis - will be negative
What are virulence factors of Staphylococcus aureus?
coagulase
antibiotic resistance to penicillinase
Different strains have different toxins:
Exfoliatin toxin
Endotoxin c
Enterotoxins A, D or F
What does penicillinase do?
a beta lactamase that targets penicillin
What does MRSA mean?
methicillin-resistant staphylococcus aureus
You have a gram positive, catalase positive cocci. You run a coagulase test, and it is negative. What organism do you suspect?
Staphylococcus epidermidis
How will staphylococcus epidermidis test for coagulase?
NEGATIVE
Where do you normally find staphylococcus epidermidis?
normal flora
skin
respiratory tract
What organism sticks to things and is a problem with sticking to metal or plastic medical devices?
staphylococcus epidermidis
can stick to heart valves, catheters, prosthetics
What organism is life threating if it enters the blood stream?
staphylococcus epidermidis
You’ve had a heart valve replacement and 2 weeks later you have a gram positive cocci in your blood. Can you state the it is Staphylococcus epidermidis?
NO, the situation says maybe. Further testing needs to be done
What does alpha hemolysis look like?
incomplete, green hemolysis
What does gamma hemolysis look like?
no hemolysis occurred
What organism would requires a hemolysis test in order to differentiate strains?
Streptococcus
The organism is a gram positive coccus, catalase negative. What organism genus do you suspect and what test will you run next?
Streptococcus
hemolysis test
Where is streptococcus normally found?
normal flora, respiratory tract
What does Lancefield test for?
cell wall carbohyrdrates
When would you use a Lancefield test?
If you have a beta or gamma positive hemolytic test
What organism does not have any unique carbohydrates in their cell walls?
alpha streptococci
How does Streptococcus pyogenes most commonly present?
pharyngitis (sore throat)
You have an organism that gram positive, beta hemolytic and Group A for the Lancefield test. What organism is it?
Streptococcus pyogenes
What antibiotic is streptococcus pyogenes sensitive to?
bacitracin
How does streptococcus pyogenes present in a catalase test?
negative
If you have a patient that has inflamed skin lesions or impetigo, what microbiology test would you run to discern what organism could be causing this presentation?
catalase test to discern between staphylococcus aureus (catalase positive) and streptococcus pyogenes (catalase negative)
What organism is responsible for scarlet fever?
Streptococcus pyogenes
What names diseases is streptococcus pyogenes responsible for?
scarlet fever
rheumatic fever- autoimmune condition
glomerulonephritis- auto immune conditions
What is the virulence factor of scarlet fever?
streptococcus pyogenes using erythrogenic toxin
What highly invasive species cause massive tissue damage in a relatively short time?
necrotizing fasciitis
can be caused by:
streptococcus pyogenes
staphylococcus aureus
those individuals that have recurrent streptococcal infections as children will develop what later in life?
autoimmune related conditions later in life
rheumatic fever
glomerulonephritis
You have an organism that gram positive, beta hemolytic and Group B for the Lancefield test. What organism is it?
streptococcus agalactia
Where is streptococcus agalactia found?
normal vaginal flora
What disease is streptococcus agalactia associated with?
neonatal meningitis
How would you tell the top two beta hemolytic streptococci apart?
Lancefield test
Streptococcus agalactia- group B
Streptococcus pyogenes- group A
You see a baby with neonatal meningitis. What organism do you suspect?
streptococcus agalactia
You have an organism that gram positive, alpha hemolytic test with a large polysaccharide capsule. What organism is it?
Streptococcus pneumoniae
What organism has cells that appear in pairs, flattened or almond shaped?
Streptococcus pneumonia
What organism is sensitive to optochin?
streptococcus pneumonia
What organism is soluble in bile?
streptococcus pneumonia
You see a gummy appearance to your culture on a blood agar plate, and notice the cratering effect. What test would you run next to determine what this organism is?
either bile solubility test or optochin sensitivity to provide results that it is streptococcus pneumonia
You have an organism that gram positive, alpha hemolytic. What test do you run next to determine what organism is it?
bile solubility or optochin sensitivity to provide results that it is streptococcus pneumonia
What are the following diseases associated with:
pneumonia (elderly and compromised)
meningitis (adults)
otitis media (children)
streptococcus pneumonia
What organism is responsible for meningitis in adults?
streptococcus pneumonia
What organism is associated with subacute endocarditis?
streptococcus viridans
What are all other opportunistic alpha hemolytic streptococci collectively called?
streptococcus viridans
Where is streptococcus viridans normally found?
normal flora of upper respiratory tract
You have a gram positive, coccus shaped, catalase negative, gamma hemolytic, Lancefield group D organism. What is the organism?
enterococcus faecalis
Where do you normally find enterococcus faecalis
normal fecal flora
What organism that is a gram positive cocci is the most common cause of UTIs?
enterococcus faecalis
if you are dealing with the genus Streptococcus/ Enterococcus, what is the order of tests you would run to ID organisms in this genus?
Gram Stain: Positive Shape: coccus Catalase: negative Hemolytic Pattern ( A, B, G) Lancefield grouping (Beta or Gamma) Bile solubility for alpha
If you are dealing with staphylococcus aureus, what is the order of test you would run to ID the organism as this?
Gram Stain: Positive
Shape: coccus
Catalase: positive
Coagulase: positive
If you are dealing with staphylococcus epidermidis, what is the order of test you would run to ID the organism as this?
Gram Stain: Positive
Shape: coccus
Catalase: positive
Coagulase: negative
What special test is ran for genus Neisseria?
carbohydrate fermentation tests
Where do you find Neisseria normally?
normal flora of upper respiratory tract
lower genital tract
You have an organism that is gram negative, cocci shape, and oxidase positive. what is the organism you suspect and what test should you run next?
Neisseria
carbohydrate fermentation tests
What population does meningococcal meningitis effect? What is the name of the organism?
young adults
Neisseria meningitis
What are virulence factors of Neisseria meningitidis?
polysaccharide capsule
endotoxin (gram - means this is the lipid A portion which means it is not easy to treat)
siderophore
IgAse
What does the endotoxin produce for Neisseria meningitidis?
rash and DIC
You see the results for a carbohydrate fermentation test that result in the following: \+GLU \+MAL -LAC -SUC
What organism do you suspect?
Neisseria meningitidis
What would you carbohydrate fermentation test look like for Neisseria meningitis?
+GLU
+MAL
-LAC
-SUC
What does DIC mean?
disseminated intravascular coagulation
What type of gram stain that access the blood have the potential to cause what?
DIC (Disseminated intravascular coagulation)
What are the effects of the endotoxin released by Neisseria meningitis?
D: systemic damage
I: access to the bloodstream
C: Clotting of capillaries causing tissue death
What virulence factor protects Neisseria meningitis in the bloodstream?
capsule
Where is the carrier state of Neisseria meningitidis?
upper respiratory tract
Where is the staphylococcus aureus carrier state?
upper respiratory tract
Where is the streptococcus pneumoniae carrier state?
upper respiratory tract
How is Nisseria meningitis transmitted?
respiratory
What are the virulence factors of Neisseria gonorrheae?
pili
endotoxin
IgAse
What are complication of Neisseria gonnorrheae?
sterility
arthritis
Pelvic inflammatory disease
How is Neisseria gonnorrheae transmitted?
sexually transmitted
What type of environment does Neisseria gonorrheae prefer?
capnophilic ( high carbon dioxide concentration) strict mesophile (moderate temperatures)
What type of environment does Neisseria meningitis prefer?
capnophilic ( high carbon dioxide concentration) strict mesophile (moderate temperatures)
What is ophthalmia? What other organism is spread this way?
non STD of babies who pass through an infected birth canal of Neisseria gonorrheae
Streptococcus agalactia
What does Neisseria gonnorrheae primarily effect?
genital tract
How would male with Neisseria gonnorrheae present?
intense urinary pain
milky white penile discharge
gram stain is useful
What makes diagnosis Neisseria gonorrheae difficult in females?
There are too many normal non pathogenic neisseriae present in the vaginal tract so the gram stain is not useful
What will the carbohydrate fermentation results look like for Neisseria gonorrheae?
+GLU
- MAL
- LAC
- SUC
Is the organism is not matching N. gonorrheae or N. meningitidis, what is this referred to?
Non pathogenic Neisseriae
When is the genus Neisseria, what is the protocol for ID?
gram stain: negative
Shape: coccus
oxidase: positive
This group is differentiated by the Carbohydrate fermentation reactions
What is a gram positive that is an aerobic spore former?
bacillus
What is gram positive that is a anaerobic spore farmer?
clostridium
You are enjoying the cheap Sunday Chinese Buffet at China King and get yourself a big scoop of fried rice. Shortly after stuffing yourself you are driving home and experience diarrhea and vomiting. What organism is responsible for this? Is this food intoxication or food infection?
Bacillus cereus- short incubation food poisoning
food intoxication
What organism is responsible for emitic food poisoning?
Bacillus cereus- short incubation food poisoning
What is the differences and similarities of Bacillus cereus and staphylococcus aureus food poisoning?
Bacillus cereus:
fried rice
regular diarrhea and vomiting
Staphylococcus aureus:
creamy
violent diarrhea and vomiting
Same:
rapid incubation
food intoxications
duration is self limiting
What is organism is sometimes called diarrheal food poisoning?
Bacillus cereus- long incubation food poisoning
You have some old dried milk mix in your pantry, you decide you need to use it in pinch. What organism might be implicated in this product?
Bacillus cereus long incubation food poisoning
What are symptoms of Bacillus cereus long incubation food poisoning? What is another organism that this could be confused with?
abdominal pain and diarrhea
Clostridium perfringens BUT THIS IS A FOOD INFECTION FROM SLOW COOKED MEAT DISHES
You are using your new crock pot to slow cook your meat stew. What organism might be lurking to cause you abdominal pain and diarrhea in a day or so?
Clostridium perfringens- FOOD INFECTION
What is the major pathogen in genus Bacillus?
Bacillus anthracis
What is the organism that uses the zoonosis of large food animals (cows, sheep, goats)?
Bacillus anthracis
What zoonosis does Bacillus anthracis use?
large food animals
- cows
- sheep
- goats
How is Bacillus anthracis transmitted?
through spores
What are the 2 forms of Bacillus anthracis?
cutaneous- open wound
pulmonary- fatal
What is the lesion of cutaneous anthrax called?
eschar
Is the cutaneous form of anthrax fatal?
rarely- it remains localized to the skin
spores contaminate the open would
What the pulmonary anthrax disease also known as?
woolsorter’s disease
Where does bacillus anthracis- pulmonary replicate?
rapid replication in the lungs
What is the virulence factor of pulmonary bacillus anthracis?
spores
capsule: poly D glutamic acid
exotoxin that causes edema, protective antigen and is the lethal factor
Is a natural pulmonary bacillus anthracis likely to occur?
NO THAT IS RARE
SPORES HAVE TO BE THE RIGHT SIZE AND SHAPE
What can help clear bacillus anthracis?
penicillin but this is TIME sensitive
What organism has an amino acid based capsule?
Bacillus anthracis
Who should get a vaccine for Bacillus anthracis?
military
large animal vets
What organism has a poly D glutamic acid capsule
Bacillus
anthracis
What can the strains of Clostridium perfringens produce?
gas gangrene
food poisoning
How would you come into contact with clostridium perfringens that causes gas gangrene?
spores in the soil contaminate deep wounds
How does tissue damage occur if you come into contact with clostridium perfringens that causes gas gangrene?
organism spreads and releases enzymes
enzymes kill more tissues, spread continues
circulation shuts down
Where do spores germinate for clostridium perfringens?
in damaged tissues
How would you have to treat clostridium perfringens gas gangrene?
antibodies and antibiotics can’t reach, amputation is used to stop the spread
What are the major enzymes associated with gas gangrene?
proteases
lipases
What are the major toxins associated with gas gangrene?
Alpha toxin
lethicinase (phospholipase C)
What does lethicinase attack?
phospholipids
What organism is associated with gas gangrene?
a strain of Clostridium perfringens
Is gas gangrene considered flesh eating?
NO- due to the longer time of onset and progression
What is consumed with Clostridium perfringens food poisonings?
spore
This is a food infection
What toxins are produced with clostridium perfringens food poisonings?
enterotoxins
What are the symptoms you will experience with Clostridium perfringens food poisonings?
abdominal cramps
diarrhea
Where would you normally find clostridium difficile?
normal enteric flora
What is pseudomembranous colitis associated with?
Clostridium difficile
How does clostridium difficile become overgrown in the normal enteric flora?
There is a decrease of gram negative flora, allowing for this gram positive flora to overtake- causing for a superinfection
What toxins are associated with Clostridium difficile?
Endotoxin A: enterotoxin
Exotoxin B: cytotoxin
What do the lesions of Clostridium difficile consist of?
bacterial cells
damaged tissues
neutrophils (because of the inflammatory response)
Examining Clostridium difficile, would there be intestinal damage or rupture?
NO- LONG TERM ANTIBIOTIC USE IS MORE INDICATIVE THAT THIS ORGANISM IS THE PROBLEM
Who is at risk of Clostridium difficile?
nursing home patients
hospice patients
long time antibiotic users
cancer patients
The Exotoxin A of Clostridium difficile is what?
an enterotoxin
The exotoxin B of clostridium difficile is what?
a cytotoxin
What does the exotoxin of Clostridium tetani cause?
the neurotoxin blacks inhibitor of neurotransmitter (most often acetyl choline)
You see someone you has suffered a deep puncture wound while helping with hurricane demolition. They begin to have muscle contract that will not stop. what organism might be suspect for this?
clostridium tetani
How does clostridium tetani enter the body?
spores enter through a deep puncture wound
What is limited in deep wounds?
oxygen
Can clostridium tetani go systemic?
yes
What is causing the problem in tetanus, the organism or organism toxin?
toxin of Clostridium tetani
What vaccine is used to stop Clostridium tetani?
DPT
- toxoid is the modified toxin
How would you treat Clostridium tetani?
supportive thorough cleansing of wound
let wound bleed- flushing wound out
introduce oxygen with hydrogen peroxide
What is the cause of death is Clostridium tetani is not treated?
respiratory failure
What does clostridium botulism cause?
botulism
Describe Spirochetes.
spiral shaped organisms
long and slender
differ in tightness of coils
highly motile: endoflagella (axial filaments)
Would you run a gram stain if you suspect a spirochaete.
NO
Why is a gram strain problematic for spirochaete?
too thin- will stain gram negative
What stain would you run is you suspect a spirochaete?
impregnation stains, darkfield and phase contrast microscopy
Can spirochaete grow easily on artificial media?
NO
What organisms represent jags of lightening with darkfield/ silver impregnation stains?
spirochaetes
What is the spirochaete that is the causative agent of syphilis?
Treponema pallidum
How is Treponema pallidum transmitted and what does it cause?
sexually transmitted
syphilis
Listeria monocytogenes and what spirochaete have what in common?
they cross the placenta
Treponema pallidum
Treponema: What organism penetrates skin/ mucus membranes?
Treponema pallidum
What is the lesion for primary syphilis called?
chancre
this will cause the individual to contaminate other parts of the body
What level of syphilis have lesions on the palms?
secondary
What levels of syphilis resolve spontaneously?
primary and secondary
What levels of syphilis will respond to antibiotics?
primary
secondary
What lesions are associated with tertiary syphilis?
gumma lesions
What type of hypersensitivity reaction is tertiary syphilis?
Type 4
What organ can tertiary syphilis harm?
heart- causing cardiovascular syphilis
CNS- neurosyphilis
What is a gumma lesion?
infiltrative tumor of skin, bones associated with tertiary syphilis
What organism is associated with Saber shins?
congenital syphilis- Treponema pallidum
What organism is associated with Hutchinson’s Teeth?
congenital syphilis- Treponema pallidum
When seeing the the organism is a spirocheate and STD, what comes to mind?
Treponema Pallidum
What is the causative agent of Lyme disease?
Borrelia burgdorferi
What is the reservoir of Borrelia burgdorferi?
large number of animals- animals in the environment have the disease
What is the vector of Borrelia burgodoferi?
tick borne (lxodes species)
Where is a high incidence of Lyme disease?
New England
AKA Where AJ is from lol
What organism is associated with Deer Disease?
Borrelia burgdorferi
What do the effects of Borrelia burgdorferi present with in phase 1?
bulls eye rash (erythema migrans)
What do the effects of Borrelia burgdorferi present with in phase 2?
muscle pain
neurological involvement
cardiac symptoms (indicative of something in the bloodstream)
What do the effects of Borrelia burgdorferi present with in phase 3?
debilitating arthritis
What is the treatment for Lyme disease?
Jarisch-Herxheimer RX
This is causing the release of the spirochetes release toxins into the bloodstream. This is sometimes worse than the disease
What are side effects of Jarisch-Herxheimer RX?
inflammation fever headache muscle pain hyperventilation vasodilation decreased blood pressure
What organism is spread through Leptospira interrogans?
ingestion with animal urine, most often dogs
What organism has a zoonosis of dogs or small wild animals?
Leptospira interrogans
What is the causative agent of leptosporosis?
leptospira interrogans
What is the transmission of Leptospira interrogans considered?
enteric
Is Leptospira interrogans cause for enteric disease?
NO
You have a patient that presents with neurological problems including weakness, dizziness, double vision, muscle paralysis. What organism is responsible?
Clostridium botulinum
What is the most powerful toxin?
Botulinum toxin
What bacteria has a role in SIDS?
clostridium botulinum
What organism survives cold temperatures, high pH levels, high salt concentrations?
Listeria monocytogenes
You have an immunocompromised system and are eating a tub of bluebell ice cream that recently got recalled. What is most likely the organism infecting the ice cream? What are you risk to develop?
Listeria monocytogenes
Meningitis
What populations are at risk for Listeria monocytogenes?
fetuses
pregnant women
immunocompromised individuals
How is Listeria monocytogenes transmitted?
foodborne
unpasteurized milk, milk products, cheese, ice cream
processed meats
raw vegetables and fruits
Does listeria monocytogenes cause major enteric disease?
NO- most often mild enteric symptoms
Does listeria monocytogenes cross the placenta?
yes- can result in abortion of the fetus
Describe Corynebacterium
gram positive
club shaped ends to cells
Chinese lettering (X and V forms)
Metachromatic granules (shiney)
What strain of Corynebacterium causes serious problems?
Corynebacterium diphtheriae
How does Corynebacterium diphtheriae start?
respiratory then goes systemically
Where does the organism Corynebacterium diphtheriae remain?
localized in the respiratory tract
Where does the toxin of Corynebacterium diphtheriae go?
toxin goes systemically
You have a patient that is suffering chronic damage to the heart and central nervous system. what organism is responsible for this?
Corynebacterium diphtheriae
What disease causes a pseudo membrane in the back of throat?
Corynebacterium diphtheriae
Club sandwiches go to the back of the throat
What is the disease process of Corynebacterium diphtheriae?
organism inhaled, local colonization
inflammation of the pharynx (sore throat)
pseudo membrane in back of throat (tissue, dead cells, bacteria- can block air)
exotoxin produced (affects any cell it enters)
What process does the exotoxin of Corynebacterium diphtheriae affect?
protein synthesis
What are the parts of the exotoxin of Corynebacterium diphtheriae?
Part A: biological activity
Part B: allows part of A to gain access to cell
What is the virulence factor of Corynebacterium diphtheriae?
ADP ribosylating toxin (elongation factor affected and protein synthesis off)
Describe the ADP ribosylating toxin affect of Corynebacterium diphtheriae?
take NAD
splits off ADP ribose
attaches ADP ribose onto EF 2
What does EF stand for?
elongation factor
How many bacterial toxins have ADP Ribosylation?
5- the proteins being effected are not the same
How can Corynebacterium be prevented?
DPT vaccine
What population was highly effected by diphtheria?
infants and children
What will kill Corynebacterium diphtheriae?
antibiotics will kill bacteria
antitoxins inactivate the toxin (toxin is the problem)