Lecture 17 Flashcards
What is the appearance of Salmonella on an agar plate?
Grey colonies
Classic Enterobacteriaeae morphology - smooth, round margins
Gram negative
Where is Salmonella found?
Intestinal microbiota
Many of the spp vary in Canada by province, so you need to be familiar with the spp that you are working with in your province
What are the virulence factors for Salmonella?
Salmonella Pathogenicity Islands (SPI) - gene clusters with antimicrobial resistance
Fimbriae - adherence & colonization
3 Secretion sys - when they attach to enterocytes they inj effector molecules in the cells allowing macrophages to engulf them & enabling the bacteria to colonize other tissues. Once in the tissues they perform the phagolysosome complex & resist dying
What probs does Salmonella Dublin cause in cattle? (5)
Septicemia in < 1 wk old calves
Acute enteritis in older calves & adults
Abortion
Chornic enteritis in older cows
Terminal dry gangrene - leads to DIC –> ischema & necrosis
How do you manage Salmonella Dublin to prevent its effects? (3)
Clean calving areas
Rodent control
Vaccination
What spp does Salmonella cholerasuis effect?
Pigs - host adapted
What probs does Salmonella cholerasuis cause in pigs?
Sepsis
Enterocolitis
Secondary infections following bacteria (pneumonia & hepatitis)
How do you prevent Salmonella cholerasuis in pigs? (2)
Reduce stress to reduce shedding by carriers
Autogenous bacterins (vaccine)
What spp does Salmonella pullout effect? & what happens if you see it?
Birds - host adapted
Contact CFIA ASAP
What spp does Salmonella Type effect? & how do they get it?
People - host adapted
Contaminated food & water
In the west, assoc with travel
How do you dx Yersinia in the lab?
CIN agar - highly selective for yersinia specifically
What is the metabolism of Yersinia?
Lactose non-fermenting
Motile
What disease does Yersinia pestis cause in people?
Plague/Black death
How do people get Yersinia pestis? (3)
- Direct contact with rodents
- Direct contact with infective flea
- Airborne from people (pneumonic plague) - becomes aerosolized
What is the sylvatic plague? What spp is highly susceptible?
Lifecycle b/w wild rodents & fleas
Prairie dogs are highly susceptible
Can serve as a source for our domestic animals