Yersinia Flashcards
Identify the bacteria
● pleomorphic (coccoid to bacilli)
● 5um long or more
● single; occasionally in chains
● sometimes bipolar stained
Yersinia
Yersinia
● gram positive or gram negative?
● acid fast or non-acid fast?
● capsulated or non-capsulated?
● gram negative
● non-acid fast
● non-capsulated
French bacteriologist who isolated Y. pestis
Yersin
Yersinia has what type of flagella when cultured at 18-30ºC?
Peritrichous flagella
Yersinia has what type of flagella when cultured at 37ºC?
None
flagella is detached and antigens are absent at 37º
Yersinia colonies on culture are hemolytic or non-hemolytic?
non-hemolytic
Colony size of Yersinia on culture?
0.1-1.0mm
Colony appearance of Yersinia on culture? (3)
● translucent and granular
● centers of old colonies are more opaque
● periphery colonies have radial striations
Colony elevation of Yersinia on culture?
centers of old colonies are raised
Optimum growth temperature of Yersinia?
28ºC
Yersinia can ferment what?
glucose and other carbohydrates
Gas production of Yersinia?
Negative
little to no gas
Does Yersinia produce urease?
No
can’t break down urea
cause of plague in 1894
Yersinia pestis
Cause of plague-like disease in guinea pigs, sometimes in rats, occasionally in other rodents, rare in other animals
Yersinia pseudotuberculosis
Envelope antigen, composed of protein and carbohydrates, important virulence factor, found in Y. pestis
F1 antigen
Plasmid-encoded antigens that contribute to virulence and immune modulation, found in Y. pestis and Y. pseudotuberculosis
V and W antigens
Yersinia species are divided into 6 serogroups (I-VI), based on what?
● thermostable O antigens (O antigens l-VI)
● H antigens (a to e)
Used to categorize bacteria into serogroups I-VI based on outer membrane polysaccharides
thermostable O antigens
Flagellar antigens involved in motility and used in serotyping, identified by types a to e
H antigens
Epizootiology and Pathogenesis of Yersinia in rodents, birds, and soil
infected by ingestion mostly during cold weather
Yersinia infections in cattle are associated
with _________ and ________.
pneumonia and abortion
Yersinia infections in cats are associated with…?
abdominal and urinary disturbances
Yersinia infections in captive birds are associated with…?
Pseudotuberculosis
These clinical signs of Yersinia infection can be observed in what animal?
● weight loss, develop diarrhea, and die in 3-4 weeks
● mesenteric lymph nodes greatly swollen and caseous, nodular abscesses in Peyer’s patches, liver, and spleen
Guinea pigs
Antigens necessary for virulence of Yersinia
F1, V, and W
Incubation of Yersinia at __ºC results in loss plasmid encoded V and W antigens and loss of invasive ability
37ºC
Immunity against Yersinia
intranasal (IN) administration of live, avirulent culture in guinea pigs against virulent strains
Yersinia is a facultative intracellular parasite, meaning it can live inside host cells or outside them. Its ability to survive within cells contributes to its virulence and makes it challenging for immune system to clear infection. True or False?
True
Immunity response crucial for controlling Yersinia infection, it involves T cells and macrophages that target and kill infected cells, especially in the case of an intracellular pathogen like Yersinia
Cell-mediated immunity
How to diagnose Yersinia or differentiate Y. pestis?
● urease test
● ability to grow well in deoxycholate-citrate agar
Yersinia is susceptible to which antibiotics?
1.) Chloramphenicol
2.) Nalidixic acid
3.) Streptomycin
4.) Sulfonamides
5.) Tetracycline
Characteristics of Yersinia infection in humans
rare but severe fatal infection, mesenteric adenitis or septicemia
Yersinia sp. present in alimentary tract of animals (as carrier) and can serve as source of infection for humans; ubiquitous but isolated from humans & chinchillas with alimentary tract disturbances
Yersinia enterocolitica
Yersinia enterocolitica has also been isolated from…? (5)
1.) healthy cattle
2.) healthy swine
3.) meat
4.) shellfish
5.) ice cream
Y. enterocolitica resembles which Yersinia sp. in colonial and microscopic morphology?
Y. pseudotuberculosis
Y. enterocolitica is a heat-stable enterotoxin produced at 30ºC. True or False?
True
Y. enterocolitica diseases in humans (4)
ST MD
1.) symptoms that simulate appendicitis
2.) terminal ileitis
3.) mesenteric adenitis
4.) diarrhea
Sources of Y. enterocolitica infections in humans (2)
animal sources
contaminated food by human carriers
Cause of bubonic plague or black death in humans, primarily disease of rats, but dogs and cats maybe naturally infected
Yersinia pestis
In what climate does disease from Y. pestis infection assumes bubonic form?
Warm climate
What are the swollen lymph nodes in bubonic form of disease from Y. pestis infection called?
Buboes
In what climate does disease from Y. pestis infection is in pneumonic form?
Cold climate
In which aspects does Y. pestis resembles Y. pseudotuberculosis? (3)
CAM
● colonial morphology
● antigenic make-up
● microscopic morphology
Bubonic plague is a disease of domestic animals. True or False?
False
Rats can get infected by Y. pestis through what?
through bite of infected Rat Fleas (Xenopsylla cheopis)
Where does Y. pestis multiplies?
in flea
How fast does Y. pestis infection spread once introduced into population?
spreads rapidly
In what form does the plague take in when it spreads in areas sparsely inhabited by humans?
Sylvatic form
