GI Infections 8 Flashcards
_________ replicates in the phagosome
salmonella
what are the antigens that can be found with Salmonella?
O antigen (cell wall) H antigen (flagellar) Capsular Vi (virulence) antigen
________ is part of the commensal organisms of cows, cats, dogs (pets), etc
campylobacter
what are some complications of salmonella infection?
- cardiovascular
- CNS
- pulmonary
- reactive arthritis (also seen with shigella infection)
- oesteomyelitis
- hepatobiliary
GBS is a unilateral/bilateral ascending/descending paralysis and starts at the lower/upper extremities
GBS is a bilateral ascending paralysis that starts at nth slower extremities and is frequently preceded by mild respiratory or intestinal infection
salmonella invades the _______ and _____ after attaching to the SI epithelia
M cells of Peyer’s patches and enterocytes (PAI encoded)
travelers to ______, _____, or ______ are usually the only people that we see enteric fever in; what vaccines would you give them?
Asia, Mexico, or India
- oral live attenuated OR IM for Vi capsular polysaccharide antigen
what are the toxins produced by V. parahemotlyticus?
- enterotoxin (watery diarrhea)
- hemolysin (later get bloody diarrhea)
recurrent salmonella _______ (one of the three clinical manifestations of salmonella) is considered an AIDS defining
septicemia
the antibodies raised against he LPS of campylobacter strains cross react with _________ leading to GBS
the GM1 gangliosides in the myelin sheath of the nerve
Yersinia enterocolytica infection is common in kids of age _______ and adults with exposure to ________
kids < 7 years old and adults where there are outbreaks in daycares
what are three types of vibrio vulnificus infections?
- acute gastroenteritis from eating raw or uncooked shellfish
- necrotizing wound infection can occur in injured skin exposed to contaminated water
- invasive sepsis can occur after an immunocompromised person eating raw or undercooked shellfish
what are some risk factors for acquiring yersinia enterocolytica
- contaminated food: raw/undercooked pork and beef, eggs, milk, raw seafood
- contact with infected animals
sources of infection for NON cholera vibrio include ______
shellfish and seawater; (cholera vibrio source of infection include food and contaminated water)
NON cholera vibrio: virbrio parahemolyticus and vibrio vulnificus
of all the enterobacteriaceae, which 2 organisms are NON motile?
Klebsiella and Shigella
(all the rest are motile)
YES PECKSS
Yersinia
Escerichia
Serratia
Proteus Enterobacter Citrobacter Klebsiella Shigella Salmonella
salmonella is acid ______
labile; so when the pH of the stomach ↑ then the person is at risk for developing salmonella infection
shigella is acid stable
temperature can be selective for which inflammatory diarrhea causing organism?
campylobacter; no growth at 25C but can grow at 3C and 42-43C
a characteristic presentation of patients with NON cholera vibrio infection is _______
wound infection
in enteric fevers, _____ cultures are positive after the 1-2nd week and _____ cultures are positive from the 2nd week and onwards but negative before that
blood cultures is positive from 1-2nd week
stool cultures are positive from 2nd week and onwards
vibrio species are grown on _______ agar and how would you differentiate between cholera and parahemolyticus and vulnificus?
- TCBS agar and SUCROSE is the differentiating agent because cholera is it is the only one that is sucrose positive while the other two are not
what is a feature that is unique to salmonella in differentiating it from shigella?
Salmonella is H2S positive
describe the biology of campylobacter
gram NEGATIVE, comma/small spiral shaped rods
motile
microaerophilic so it requires oxygen and co2 to grow
DOES NOT FERMENT GLUCOSE
OXIDASE POSITIVE
can MacConkey’s agar be used to differentiate between Salmonella and Shigella?
NO because both are lactose NON fermenters and that is what is MacConkey’s agar differentiates with
describe the rash that is occasionally seen in typhoid fever
transient, macular rash (rose colored) on the trunk
what are some biochemical features of yersinia
- gram negative BIPOLAR staining coccobacili
- ferments glucose and sucrose
- catalase +
- oxidase -
contact with reptiles such as lizards, snakes, turtles or frogs has an increased risk for infection by _________
salmonella
_______ metabolism is used to differentiate between cholera vibrio and non cholera vibrio
SUCROSE
v. cholera is sucrose positive
is there an animal reservoir in enteric fever (typhoid/paratyphoid)
NO; (same with shigella)
ingestion of raw/poorly cooked seafood is a common risk factor for infection by vibrio ________
parahemolyticus
in diagnosing salmonellosis and the three different types, you would look at blood or stool cultures. When would you do one over the other?
stool cultures for _______ is infrequently positive so you would do a blood culture for that
stool cultures for septicemias are infrequently positive so do a blood culture for salmonella caused septicemia
of the enterobacteriaceae, which ones are lactose fermenters?
CEEK: Citrobacter enterobacter Escherichia Klebsiella
cutluring on campylobacter selective media _______ agar and is oxidase ______ and catalase ______ is dialogistic of campylobacter
Skirrow agar; oxidase + and catalase +
_________ is an associated complication of campylobacter infection due to ________
GBS due to antibodies raised against the LPS of campylobacter cross react with the GM1 gangliosides in the myelin sheet of the nerve leading to damage, loss of nerve conduction and paralysis
secondary salmonella septicemia is due to ________ (organ)
secondary exposure to S. type in the gallbladder where they can replicate there for many years (gallbladder colonization)
________ has bipolar staining when staining with ______ giving it a safety pin appearance
yersenia; wayson stain
phagosome lysis is associated with _________
shigella
what are the two types of typhoid vaccines?
- oral live attenuated
- IM for Vi capsular polysaccharide vaccine
salmonellosis has 3 clinical manifestations:
- gastroenteritis
- septicemia/bacteremia
- enteric (typhoid) fever
the most common reservoir of yersinia enterocolytica is ________
pigs
describe the biology of salmonella:
gram negative rod
motile
DOES NOT ferment lactose
Salmonella is diagnosed by plating on ________ agar which is selective due to ______
MacConkey agar which selects for lactose fermenters so wit will have pale colonies
Salmonella (and Shigella is lactose NON fermenters)
yersinia enterocolytica infection most commonly occurs in what part of the GI? What is the pathogenesis?
It mimics ________
terminal ileum (invasion of M cells and then invades further mesenteric lymph nodes) and has chromosomal ST enterotoxin which ↑ cGMP
mimics appendicitis
vibrio vulnificus is commonly found in ________
Gulf of Mexico
can you see muscle atrophy in GBS?
minimal atrophy because it progresses very quickly (hours to days) so no time for atrophy
high mortality is associated in people with __________ and have been infected by vibrio vulnificus
underlying liver conditions
________ cultures are better for diagnosis of salmonella caused enterocolitis
stool cultures; these are positive very soon after onset
