Flashcards in 24-Zoonosis Deck (61):
Regarding bioterrorism select agent classification, there are 3 categories (A,B and C). Which is most dangerous and which is least dangerous?
A is most dangerous (easily disseminated) while C is least dangerous (requires engineering to become easily disseminated)
Yersinia pestis, Fransicella and Brucella are all select bioterrorism agents. What categories do they belong to?
Yersinia and Fransicella are in A while Brucella is in B.
There are 4 biohazard safety levels based on the disease causing ability and difficulty to treat various diseases (agents). What level do Yersinia pestis, Brucella and F. Tularensis belong to?
All are level 3 (Potentially lethal if inhaled, vaccine or treatment available)
What are the 3 Yersinia pathogens?
Pestis, enterocolitica and pseudotuberculosis
What yersinia subtype is characterized by bipolar staining and is a facultative intracellular parasite?
What yersinia subtype is associated with bubo formation, and bacteria in the blood stream?
Why is the bubonic plague called black death?
It causes vascular thrombi (petechia) in skin
What is the cause of death with bubonic plague?
Sepsis leading to hypotension and death
What is the vector for yersinia pestis? This vector is also the cause of epidemics
What disease arises when bubonic plague remains untreated and spreads to the lungs?
True or false: Both bubonic and pneumonic plague are spread person to person?
False, only pneumonic is
Regarding the urban vs. sylvatic plague, what are their respective reservoirs?
Urban plague - rats, while sylvative plague - prairie dogs (also domestic cat)
True or false, urban and sylvatic plague are what lead to pneumonic plague?
False, they both cause human infection and cause bubonic plague
What is the most common type of plague seen in the US? Where in the US?
Sylvatic plague, mainly in the western US
What is the vector for the sylvatic plague?
Fleas assoc. with wild rodents
What are the 4 corner states associated with plague?
New Mexico, Utah, Arizona and Colorado
What type of bubonic plague is likely to result in isolated cases? What about epidemic?
Sylvatic is likely to be isolated, urban likely to be epidemic
When was the last recorded case of bubonic plague in the US? Where?
November 2002 in NYC
What are the 3 major virulence factors unique to Yersinia pestis?
Yops, F1 antigen and Type 3 protein secretion system
What is the function of Yops?
Allows entry and survival inside macrophages (prevents engulfment)
How are Yops delivered into the host cell?
Type 3 protein secretion system (like a hypodermic needle)
What is the function of the Yersinia F1 antigen?
Antphagocytic to neutrophils
True or false, Yersinia grows slowly in the blood and has pigmentation for iron acquisition.
False, It grows fast AND has pigmentation for iron acquisition
What is the cause of Yersinia associated DIC and surface purpuric lesions?
What are the 2 components of Yersinia virulence factor regulation?
Calcium and temperature
True or false, Yersinia's virulence factors are on plasmids?
True. Check our slide 26 in the notes for details on all 6
What plasmids is associated with Yops, F1 antigen and Type 3 protein secretion system ?
How is Yersinia Pestis diagnosed? Where would you get a sample from?
DIrect fluorescent antibody, stain a sample from a bubo aspirate
How would you treat yersinia pestis? What are 2 components of this treatment?
Antibiotics (Streptomycin and tetracycline)
True or false: It is better to wait for development of symptoms before treating potentially infected patients.
False, prophylaxis Is important
What are 3 ways of preventing yersinia disease?
Kill vector, kill reservoir, vaccines (killed and live- attenuated)
Why doesn't the live attenuated yersinia pestis vaccine cause disease?
It is pigmentation negative (no siderophores)
What bacteria is likely to cause disease after eating refridgerated food?
True or false, Yersiniosis is associated with fever, headache, abdominal pain and can cause chronic inflammatory disease (ulcers)
What are the causes of inflammation in Yersiniosis?
Endotoxin and other toxic factors
True or false, yersinia enterocolitica is found in domesticated animals, meats and milk, animal wastes, unchlorinated water.
What is the special plate needed to grow (and diagnose) yersinia enterocolitica? What is the colony characteristic?
CIN plate. Colonies have deep red center with clear colorless zone surrounding it
Acute gastroenteritis and mesenteric lymphadenitis, often accompanied by fever and abdominal pain is associated with what type of Yersinia?
True or false, Francisella tularensis is a facultative aerobe that is difficult to culture, lives inside macrophages and has an antiphagocytic capsule.
False. It is a strict aerobe. The rest of the description is true
What are the 2 diseases caused by F. tularensis?
1) Ulceroglandular tularemia, 2) occuloglandular tularemia, 3) glandular adenopathy without lesions and 4) typhoidal (systemic multi organ)
What is the most deadly of the diseases caused by f. tularensis? How is it mainly caused in the US?
Pneumonic - caused by running over infected rodents with lawn mower
What is The mechanism by which f. tularensis escapes phagocytosis?
Manipulates endosome pH, prevents its maturation and fusion with the lysosome. Endosome gradually disrupted over time and bacteria escapes
What is the reservoir of F. tularensis? What is the mode of transmission?
Reservoir is wild rodent, transmission by insect bite or direct contact with wild rodent
How is F. tularensis treated? Prevented?
Treated with streptomycin, prevented using live attenuated vaccine
True or false, Pasteurella multocida is an aerobic, oxidase positove, gram negative coccobacillus.
How is pasteurella disease caused?
Animal bites or scratches
What are the disease manifestation of pasteurella mutocida?
1) cellulitis lymphadenitis, 2) respiratory disease progressing to septicemia and 3) systemic infection
What population are particularly suceptible to respiratory disease progressing to septicemia and systemic infection from pasteurella?
true or false, pasteurella can cause tendonitis and osteomyelitis?
True or false, pasteurella is part of the normal oral flora of animals (e.g. cats and dogs)
What are the 2 virulence factors of pasteurella?
antphagocytic capsule and LPS
How is pasteurella diagnosed? What specific type of agar does it grow on?
Need to grow organism of blood agar (doesn't grow on McConkey)
How is pasteurella treated?
True or false, Brucella is catalase and SOD positive and gram negative coccobacillus?
Where are abortus, melitensis, suis and canis varieties of brucella found?
abortus (cattle), melitensis (goats and sheep), suis (swine) and canis (dog)
What types of workers are at particularly high risk for brucella infection? How do they acquire the bacteria? (3)
Meat packers, vets and animal farmers. Acquire bacteria from direct contact, ingestion and respiratory)
True or false, Brucella causes a short lived disease characterized with short lived fever?
False. Brucella is chronic disease, characterized with long term undulant fever
True or false, brucella is part of the normal flora of animals
What are the 3 virulence factors of brucella?
b. Bacteria inhibit lysosomal fusion
c. SOD and catalase may aid in
Who gets vaccinated for brucella?
Animals (not people)