Gastrointestinal Infections II (21) Flashcards
Salmonella is gram-[positive/negative]
negative
What are the two primary species of salmonella? Which is the one of veterinary importance?
salmonella bondori
salmonella enterica
Different serotypes of salmonella have different specificity for different hosts. What are the categories?
host-adapted
non-host adapted
What is the most common cause of food-borne salmonellosis in the USA? Is it host-adapted or non-host adapted?
s. typhimurium
s. enteritidis
T/F: Salmonella is part of normal flora of GI tract
FALSE
How do animals shed salmonella?
in feces
If there is a salmonella invasion, it can lead to ____ or become a _____
acute infection
or become a carrier
What is the most common source of salmonella infection?
fecal contamination
Salmonella can persist up to [days/months/years] in the environment
years
What is the primary route of infection for salmonella?
feco-oral
What are host factors that prevent disease of salmonella?
innate defense in GI tract
normal flora or antibodies from previous exposure
What are factors that promote successful infection of salmonella?
virulence of serotype
high challenge dose
host susceptibility
How does salmonella multiply and spread?
binding & replication extracellularly
invasion and replication intracellularly
cross epithelium
phagocytosis and inflammation
invasion of lamina propria
How does salmonella survive in the lamina propria and submucosa? This makes salmonella a _____
in macrophages
facultative intracellular pathogen
Salmonella spreads to lymphatics and the circulatory system. This type of dissemination leads to either ______ or ______
acute infection
carrier state
T/F: Carriers of salmonella shed it constantly
FALSE - only some intermittently
How does salmonella damage and thus cause diarrhea?
malabsorption - direct cell damage and inflammation
exudation and hypersecretion - inflammatory response - leakage of exudate, hypersecretion
What is the net result of salmonella causing damage?
malabsorption
exudation
hypersecretion
What is hemorrhagic enterocolitis?
inflammation in lamina propria and submucosa
enterotoxin - NOT significant
diarrhea - foul smelling, blood, vomiting, fever
What is septicemia regarding salmonella?
endotoxemia
s. Dublin: leading to ischemia and terminal dry gangrene
What does s. dublin cause?
septicemia
leads to ischemia and terminal dry gangrene
A calf has this on its legs. What caused this, and what is it characterized by?
septicemia - s. dublin
ischemia and terminal dry gangrene
What does fetal infection of salmonella lead to?
abortion
release of pGF2a causing luteolysis
What is the immune role against salmonella?
antibodies are primarily directed to the O side chain
Infection of salmonella often leads to _____. Why?
long-term carrier status
immune system fails to clear the INTRACELLULAR organism - protected from antibodies, antimicrobials, and complement
How do you diagnose acute infection of salmonella? What is the gold standard?
gold standard: isolation of salmonella - REPEATED
fecal sample
rectal biopsy
blood
dead animals
How do you treat salmonella?
FLUID THERAPY!
endoserum, polymyxin B, anti-inflammatory drugs
