Salmonella Flashcards
what family is salmonella a part of
enterobacteriales
what are the species of salmonella
- s. enterica
- s. bongori
many subspecies based on O and H antigen
what are the antigens that cause a strong innate response to salmonella
O: saccharide repeat of LPS
H: flagellin
host restricted salmonella
causes severe systemic disease (septicemia) in a single host species
host adapted salmonella
causes systemic infections in a small number of hosts
causes some disease in other species
host generalist salmonella
causes acute gastroenteritis in diverse hosts
healthy adult susceptibility
tend to get gastroenteritis from salmonella
infant susceptibility
tend to get systemic infections (foals and calves)
immunocompromised host susceptibility
tend to get systemic infections
transmission of salmonella
fecal oral
salmonella reservoirs
livestock
birds
rodents
reptiles
reptiles as reservoirs for salmonella
major carriers of both species of salmonella
do not often get clinical disease
disease is not eliminated by antibiotics
salmonella virulence factors
pathogenicity islands (groups of genes that contribute to virulence)
molecular syringes
molecular syringes
needle complex that pokes through the host epithelial cell membrane to inject pathogenic proteins
SPI-1
pathogenicity island used for invasion
- allows bacteria to enter a cell
induced by pH change to express Prg I –> injects proteins into host cell –> alters signaling pathways, re-organizes cytoskeleton, and induces uptake of bacteria
SPI-2
pathogenicity island used for survival within macrophages
- modifies the cell to meet the bacteria’s need
what immune module does salmonella induce
Th17: during extracellular phase (in intestines)
Th1: during intra-macrophage phase
can a raw food diet be a predisposing factor for salmonella
yes - often spread in raw meat/eggs
what is the clinical presentation of a salmonella infection
highly variable
can range from subclinical shedding to intermittent diarrhea to septic shock
what does the clinical manifestation of salmonella depend on
host and pathogen factors
what host factors can increase the risk of developing salmonella
immunosuppression
administering immunosuppressive drugs can often cause acute salmonellosis signs
what is the ideal antibiotic for salmonella
enrofloxacin IV
fluoroquinolones are able to go intracellularly
should antibiotic treatment be used in clinical, subclinical, or both cases
clinical cases only
does NOT include uncomplicated diarrhea - will be self-limiting
