Enterobacteriaceae 2 Flashcards
What are the Yersinia spp?
Y. pestis (non motile), Y. enterocolitica (motile), Y. pseudotuberculosis (motile)
What type of bacteria is Yersinia spp?
gram (-) rods, facultative anaerobes, Grow on BA & MAC
On a giemsa stain how to Yersinia spp. appear?
bipolar staining rods
Pathogenesis of Yersinia spp. occurs how?
survival inside macrophages via their outer proteins that inhibit outer proteins inhibition of both phagocytosis and proinflammatory cytokine production.
Which Yersinia species is associated with the Human and Feline plague? (i.e. Bubonic plague and pneumatic plague)
Yersinia pestis
Why is Yersinia pestis more invasive than the other Yersinia spp?
possesses ADDITIONAL VIRULENCE factors including an antiphagocytic protein capsule and a plasminogen activator which aids systemic spread.
What are the hosts for Y. enterocolitica?
-Pigs, other domestic animals, wildlife -Ewes -Humans
Subclinical enteric infections, occasionally enteritis is a consequence of Y. enterocolitica in what species?
Pigs, other domestic animals, wildlife
Sporadic abortion due to Y. enterocolitica occurs in what species?
sheep
Gastroenterocolitis due to Y. eneterocolitica is seen in what species?
humans
Y. pseudotuberculosis is hosted in what species?
-Farmed deer, sheep, goats, cattle, buffaloes, pigs -Cattle, sheep, goats -Guinea pigs, other laboratory animals -Caged birds -Humans
Enteritis in young animals, subclinical infections common in older animals, mesenteric lymphadenitis - is seen in what species and what Y. spp.?
Farmed deer, sheep, goats, cattle, buffaloes, pigs. Y. pseudotuberculosis
In Cattle, sheep, goats, Sporadic abortion is seen as a consequence of infection with what Y. spp?
Y. pseudotuberculosis
With Y. pseudotuberculosis, Focal hepatic necrosis, septicaemia is seen in what species with infection?
Guinea pigs, other laboratory animals
With Y. pseudotuberculosis, what is seen on infection with caged birds?
Septicaemia
Humans infected with Y. pseudotuberculosis present with what?
Enterocolitis, mesenteric lymphadenitis
What Yersinia spp. presents with plague in different species?
Yersinia pestis -Humans = Bubonic and pneumonic plague -Rodents = Sylvatic plague -Cats = Feline plague
What species is most susceptible to Y. pestis?
cats
How is the plague transmitted?
Y. pestis is transmitted by fleas (Xenopsylla cheopis) → Rodents including squirrel.
How do cats transmit the plague to their humans?
Aerosol transmission: cats directly to humans when they cough infectious droplet into the air
What species are less/not susceptible to the plague?
-dogs less susceptible -Cattle, horses, pigs not involved
Are the plague endemic regions in the US?
Yes - Plague endemic in wild rodents in Arizona, California, New Mexico
What does Yersinia pestis clinically present with due to the dissemination of the infection?
Gangrene (“Black death”)
What are the three forms of the plague?
- Bubonic form: enlarged lymph nodes (buboes): Less serious, easier to treat 2. Septicemic form: acute, serious may occur without lymphadenopathy. 3. Pneumonic form: serious may result in haematogenous spread.
How is Y. Pestis diagnosed?
Symptoms, blood/aspirate Giemsa stained smear (bipolar staining rods), culture, serology, PCR
What are the treatment and control methods for Y. pestis?
Antibiotics (e.g. tetracycline). Hospitalize the infected cat. Treat for fleas, Rodent control. No vaccine for cats.
Yersinia enterocolitica is Primarily a human enteric pathogen that causes Cause diarrhea, mesenteric lymphadenitis. What is important in diagnosing this?
differential diagnosis as many things cause diarrhea
What pathogens only cause localized and sporadic disease?
Opportunistic pathogens