9+10 Enteric Bacteria Flashcards
T or F: Enterobacteriaceae are G- rods.
True
What are two major enteric and systemic pathogens from family enterobacteriaceae?
E. coli
Salmonella spp.
_______ are important opportunistic pathogens from family enterobacteriaceae.
Klebsiella spp.
E. coli (is/is not) lactose fermenting and will appear _____ on MacConkey agar.
Is; pink
Salmonella spp. (are/are not) lactose fermenting and will appear ______ on MacConkey agar.
Are not; colorless to grey
E. coli is gram (+/-) and is a _______ anaerobe.
G-; facultative anaerobe.
What is the difference between an endogenous and an exogenous E. coli infection?
Endogenous infections are from the animal’s normal flora; exogenous infections are from the ingestion of contaminated food/water.
What is the function of an enterotoxin?
To deregulate water and electrolyte secretion from affected host cells.
What are the names of the three clinical presentations of coliobacillosis?
- Enterotoxigenic (ETEC)
- Enteropathogenic (EPEC)
- Enteroinvasive/extraintestinal (EIEC)
What is the causitive agent of edema disease in postweaning pigs?
E. coli (ETEC)
What species are the greatest concern for ETEC infection?
Neonatal pigs, lambs, calves
What type of diarrhea does ETEC cause?
Secretory
Histologically, what will an intestinal ETEC infection look like?
Morphologically normal epithelial cells.
What is the method of virulence in ETEC?
Colonization and toxin secretion
What are the species likely to present with EPEC infection?
Pigs, dogs, rabbits, cats, calves
What type E. coli produces shiga toxin?
EPEC
What is the method of virulence in EPEC?
Attachment and effacement
What type of diarrhea does EPEC cause?
Malabsorption (epithelial cells so damaged they cannot absorb)
What will an EPEC infection look like histologically?
Degenerating enterocytes
What species are affected by EIEC?
All of them
What is the method of virulence in EIEC?
Endotoxin (LPS)
What type of diarrhea does EIEC cause?
None, because it is systemic or extraintestinal
What strains are responsible for ETEC?
K99 and F5
What demographics of poultry are colibacillocis most commonly observed in?
- Embryos/neonates
- Older birds
T or F: you can vaccinate animals against virulent E. coli during pregnancy.
T
Salmonella are gram (+/-) and are (rods/cocci).
G-, rods.
What are the two major species of salmonella?
S. bongori and S. enterica
T or F: Salmonella infection is always symptomatic.
F; it is commonly asymptomatic
Which causes more severe disease, adapted or non-adapted serotypes of Salmonella?
Adapted
What kind of cells do Salmonella adhere to in the intestine?
M cells and epithelial cells
After adhering, how do Salmonella get inside of intestinal cells?
Injection of secretion system effectors and internalization
Where within an intestinal cell does Salmonella replicate?
Lysosome
Does Salmonella kill the cells that it infects?
Yes, it eventually causes apoptosis or necrosis
What are the two main clinical forms of salmonellosis?
Enteric salmonellosis
Systemic salmonellosis
What species and ages are most commonly affected by enteric salmonellosis?
Farm animals of all ages
What are the clinical signs associated with acute enteric salmonellosis?
Fever, depression, anorexia, diarrhea (+/- blood, mucus, fibrin casts)
What are the clinical signs associated with chronic enteric salmonellosis?
Intermittent fever, soft stool, gradual weight loss
On necropsy, what will you see with an enteric Salmonella infection?
Evidence of diarrhea
Fibrinonecrotic enteritis/colitis
Enlarged mesenteric LNs
Enlarged liver
Intestinal button ulcers
What species and ages are most commonly affected by systemic salmonellosis?
Farm animals, usually neonates <4 weeks
T or F: Salmonella does not cause abortion.
F, some strains of Salmonella and systemic salmonellosis can cause abortion
On necropsy, what will you see with a systemic Salmonella infection?
Enlarged liver
Enlarged spleen
Serosal or adrenal hemorrhage
Cholecystitis
Icterus
What are the types of salmonellosis in poultry?
Paratyphoid
Pullorum disease
Typhoid
What serovars(s) of Salmonella cause paratyphoid salmonellosis in poultry?
Enteritidis and Typhimurium
What age of chickens tend to be affected by paratyphoid salmonellosis?
Young chicks <2 weeks
What is the primary clinical consequence of paratyphoid salmonellosis?
Septicemia
What serovar(s) of Salmonella cause Pullorum disease?
Salmonella Pullorum
T or F: Pullorum disease is common in North America
False
What type of poultry are most likely to be affected by Pullorum disease or Typhoid salmonellosis?
Backyard poultry
What is the primary clinical consequence of Pullorum disease?
Septicemia
How is Pullorum disease spread?
Ova of turkey and chicken are infected and the infection spreads when affected eggs hatch
What serovar(s) of Salmonella cause typhoid salmonellosis?
Gallinarum
Typhoid salmonellosis is a _______ (chronic/acute) disease process.
Chronic
What is the primary clinical consequence of typhoid salmonellosis?
Septicemia
What do Klebsiella colonies look like?
Mucoid (like snot!)
Does Klebsiella have a capsule?
Yes
What types of toxins do Klebsiella produce?
Endotoxin and enterotoxin
Klebsiella causes what kind of disease(s) in cows?
Bovine mastitis
Klebsiella causes what kind of disease(s) in horses?
Septicemia, reproductive tract disease, and navel ill
Klebsiella causes what kind of disease(s) in reptiles and some wildlife?
Septicemia, hypopion, and pneumonia
According to the Kauffman-White serotyping scheme, what antigens are present on Salmonella spp?
O antigen (LPS)
H antigen (flagella)
K antigen (capsule)
