Exam 3 Flashcards
Lectures 12-16
How is secondary syphilis most reliably detected?
non-treponemal tests (VDRL)
What is a secondary syphilis symptom?
rash
What type of borrelia infections cause epidemic relapsing fever?
Borrelia Recurrentis
What type of borrelia infections cause endemic relapsing fever?
Borrelia Spp.
What type of borrelia infections cause lyme disease?
Borrelia Burgdorferi
What is the reservoir for Borrelia Recurrentis?
Humans
What is the reservoir for Borrelia Spp.?
- Rodents
- Soft ticks
What is the reservoir for Borrelia Burgdorferi?
- (Deer mice) Rodents
- Deer
- Pets
- Hard ticks
What is the vector for Borrelia Recurrentis?
Body louse (perdiculus humanus)
What is the vector for Borrelia Spp.?
Soft-shelled tick (Ornithodoros spp.)
What is the vector for Borrelia Burgdorferi?
Hard-shelled tick (Ixodes spp.)
What disease will have “Bullseye rash” or Erythema Chronicum migrans rash? What causes it?
- Lyme Borreliosis (Lyme Disease)
- Borrelia Burgdorferi
What is the most severe form of Leptospirosis?
Weil’s disease
What causes Leptospirosis?
Leptospira Interrogans
When and where are leptospires usually detected?
In the urine, several weeks after the first infection
(difficult to find in the blood after the first week)
What is Lymphogranuloma Venerium (LGV)?
a sexually transmitted disease caused by the invasive serovars of Chlamydia trachomatis
Where does lymphogranuloma Venerium (LGV) cause infection?
lymphatics and lymph nodes
What are the two forms of Chlamydia?
- Elementary body
- Reticulate body
Which is the “infectious particle” between the two forms of clamydia?
elementary body
What is the most reliable detection method for Chlamydia trachomatis?
Nucleic acid probes
What is transovarian transmission?
a infected parent will pass on the infection to their offspring
(infected parent –> infected baby)
What disease can be transmitted by transovarian transmission?
Rickettsia Rickettsia
What is the vector for Rocky Mountain Spotted Fever (RMSF) or Rickettsia Rickettsii?
Ticks or Dermacentor andersoni
What is the vector for Riskettsia Prowazekii (Epidemic Typhus)?
Human Body Louse
What is the vector for Riskettsia Typhi (Endemic typhus)?
Rat flea
What is the cause of epidemic typhus (fatal)?
Rickettsia Prowazekii
What is the cause of endemic typhus (milder)?
Rickettsia Typhi
What is the acronym for Anaplasma phagocytophilum?
HGA
In Anaplasma phagocytophilum patients, they will have morulae in what type of cell?
the cytoplasm of granulocytes
In Ehrilichia (HME) patients, they will have morulae in what type of cell?
MONOCYTES
What medium does Vibrio Cholera grow on/recovery?
Thiosulphate citrate bile sucrose (TCBS) agar
What is an alternate way for testing oxidase?
Can test for oxidase by dropping oxidase reagent directly onto agar growth except for MacConkey Agar
Does vibrio cholera occur in humans, animals, or both?
humans
Does stomach acidity play a part in V. cholera susceptibility?
YES, if you have a more alkaline than normal stomach acid… you are more susceptible to V. cholerae infection
(Alkaline = more likely V. Cholera infection)
Mechanism of Action (MOA) of V. Cholera toxin is similar to what bacterium?
Enterotoxigenic E. coli
Why does Vibrio Cholera come up pink on MacConkey if it isn’t lactose fermenting?
Vibrio Cholera itself is pink (omg girlie pop), so it looks pink despite not being lactose fermenting
What does V. vulnificus have that gives them the ability to evade destruction by stomach acid?
capsular polysccharide
What type of Vibrio is most likely to be isolated from blood culture?
Vibrio Vulnificus
What does Aeromonas look like on blood agar?
Grey, shiny, big (puffy), and just grows well
Why is Aeromonas overlooked in stool cultures?
b/c aeromonas is lactose positive
(which is usually not significant)
What is useful in identifying vibrio and aeromonas?
O/129 disk susceptibility testing
What characteristics are commonly found in patients diagnosed with an Aeromonas hydrophila infection?
- oxidase positive
- indole positive
- beta hemolytic
- gram negative bacteria
- No growth in 6.5% NaCl
- O/129 resistant
- found in stool of a gastroenteritis patient
What is the most common cause of bacterial gastroenteritis?
Campylobacter
What species of Campylobacter is found in stool?
Camplobacter jejuni
What species of Campylobacter is found in blood?
Camplobacter Fetus
What are the characteristics of Campylobacter bacteria?
- small comma-shaped
1a. Greek Campylo = curved - Motile
- Microaerophilic atmosphere (inc. CO2, redu. O2)
- grows best at 42C
What illness can develop after getting Campylobacter food poisoning?
Guillain-Barre Syndrome
Helicobacter is identified by it’s rapid production of _______
urease
What test is used to diagnose helicobacter?
Campylobacter-like organism (CLO) test (using an invasive mucosal biopsy specimen)
What does P. mallei produce?
glanders
What does P. pseudomallei produce?
melioidosis
Is pseudomonas aeruginosa motile?
yes
How is Pseudomonas Aeruginosa differentiated from other Non-Fermenting Gram Negative Bacteria?
pyoverdine production
What does pyoverdine do?
it’s a siderophore that functions as a toxin by removing iron from the mitochondria (damaging the organelle)
If this patient get’s localized Pseudomonas Aeruginosa infection, it’s fatal.
Cystic fibrosis
What does Pseudomonas Aeruginosa look like?
Grows slow, faintly stained, cells are similar in size/shape
If Acinetobacter Baumannii is gram-NEGATIVE why does it get mistaken as gram-positive?
it naturally retains crystal violet
(purple usually = gram positive)
Why is Acinetobacter Baumannii confused for E. coli?
Acinetobacter Baumannii oxidizes lactose
E. coli ferments lactose on MacConkey