lecture 29: salmonella

the 2 species of salmonella

enterica and bongori

salmonella species that accounts for all human pathogens

enterica

most common salmonella serotype in Florida

javiana

name the 3 antigens

Vi, H, O

Vi antigen

capsular polysaccharide

H antigen

flagella

O antigen

LPS

Explain agglutination assay

latex beads coated with antibody to react with antigen, 3 wells for 2 controls and test, go from milky to clear with clumps for positive result

emerging source for salmonella infections, and why

fresh produce, due to contaminated irrigation water and wild life

salmonella oxygen or no oxygen

facultative anaerobe

salmonella fermentative?

yes

salmonella temp

psychrotrophic (optimum 2-54 C)

What is pre-adaption

an increased amount of growth and survival in refrigerated food products

acid tolerance response

acid shock proteins pre-adapt to cells' pH changes, triggers cross-protection against thermal treatment

salmonella induced non-typhoid gastroenteritis

short incubation (hours), 7-10 day duration, low fatality , multiple serovars

salmonella induced typhoid fever

febrile disease, long incubation (days), 21 day duration, 10% fatality risk, caused by typhi or paratyphi

Salmonella mechanism of infection

crossing intestinal barrier via T3SS to spread systematically

list ways of internalization of salmonella

chicken, egg, vegetable via stoma, blossom, lower stem, stem scar