YERSINIA Flashcards
Bubonic plague happened on what year?
1894
From the 7 species of Yersinia, which has veterinary importance?
Y. pseudotuberculosis
Species of Yersinia that is present in alimentary tract of animals and can serve as source of infection for humans.
Y. enterolitica
Y. pestis, the cause of plague in humans, is primarily a disease of ____ but dogs and cats maybe naturally infected.
rodents
Other names of Y. pseudotuberculosis
- Corynebacterium rodentium
- Pasteurella pseudotuberculosis
Give the morphology and staining features of Y. pseudotuberculosis.
- Pleomorphic, varies from coccoid to bacilli 5 um or more long
- Maybe single and occasionally in chains
- Sometimes bipolar stained
- Gram negative, non-acid fast and non-capsulated
- Peritrichous flagella when cultured at 18 to 30 C but not at 37 C
Y. pseudotuberculosis is urease negative. True or False?
True
Y. pseudotuberculosis can ferment glucose and other carbohydrates. True or False?
True
Y. pseudotuberculosis produces abundant gas upon fermentation. True or False?
False, little or no gas
What is the optimum growth temperature of Y. pseudotuberculosis?
28 C
Describe the colonies of Y. pseudotuberculosis.
- Colonies non-hemolytic, 0.1 to 1.0 mm, translucent and granular
- Centers of old colonies raised and more opaque than the periphery which may have radial striations - hat-like
What are the antigens present in Y. pseudotuberculosis?
- F1 - envelope antigen; composed of protein and carbohydrates; found also in Y. pestis
- Plasmid encoded V and W antigens; found also in Y. pestis
- O antigens I-VI
- 5 H antigens (a to e)
What are the natural habitats for Y. pseudotuberculosis?
- Rodents
- Birds
- Soil
Y. pseudotuberculosis is transmitted mainly via _____ and mostly occur during _____ weather.
ingestion; cold
In cattle, Y. pseudotuberculosis infection induces what clinical signs?
- Pneumonia
- Abortion
In cats, Y. pseudotuberculosis infection induces what clinical signs?
- Abdominal disturbances
- Urinary disturbances
Describe the pathogenesis of Y. pseudotuberculosis in guinea pigs.
- Animals lose weight; develops diarrhea and die in 3 to 4 weeks
- Mesenteric lymph nodes greatly swollen and caseous; abscesses in Peyer’s patches, liver and spleen
What is the result when Y. pseudotuberculosis is incubated at 37 C?
Loss of plasmid encoded V and W antigens and loss of invasive ability
Give the immunization methods against Y. pseudotuberculosis.
1.In instillation of live, avirulent culture in guinea pigs against virulent strains
2. Cell-mediated immunity (due to it being facultative intracellular parasite)
Y. pseudotuberculosis is differentiated from Y. pestis by what tests?
- Urease test
- Ability to grow well in deoxycholate-citrate agar
Y. pseudotuberculosis is sensitive to?
- Chloramphenicol
- Nalidixic acid
- Streptomycin
- Sulfonamides
- Tetracycline
In humans, Y. pseudotuberculosis infection induces what clinical signs?
Rare but severe fatal infections, mesenteric adenitis or septicemia
Y. enterocolitica can be isolated from?
- Humans and chinchinillas with alimentary tract disturbances
- Healthy cattle
- Swine
- Meat
- Shellfish
- Icecream
How many O antigens are present in Y. enterocolitica?
34
In pigs, what type or what strain of Y. enterocolitica is usually present?
O3
In humans, what type or what strain of Y. enterocolitica is usually present?
O3, O8, O9
Y. enterocolitica produces heat-stable enterotoxin at what temperature?
30 C
In humans, Y. enterocolitica infection induces what clinical signs?
- Terminal ileitis
- Diarrhea
- Mesenteric adenitis
- Symptoms that simulate appendicitis
Species of Yersinia that caused bubonic plague or black death in humans
Y. pestis
In warm climates, Y. pestis assumes what form ?
Bubonic form - swollen lymph nodes known as buboes
In cold climates, Y. pestis assumes what form ?
Pneumonic form - highly fatal and contagious
Bubonic plague affected domestic animals. True or False?
False
What is the scientific of the rat flea behind Bubonic plague?
Xenopsylla cheopis
