GI Flashcards
lab results of Salmonella enteritidis
macconkey lacotse plates - white/uncolored colonies
heketoen plates - produce H2S gas, forms dark centers
oxidase negative
API Strips
C. jejuni enterocolitis lab results?
gram negative helically curved rods in pairs "gull wings" single flagellum microaerophilic CampyBAP medium oxidase positive
why is antibiotic therapy not recommended for Enterohemorrhagic E. coli?
because it up regulates the production of shiga toxins which would garuntee paralysis or death before the antibiotic kills the bacteria
shigellae lab results?
most are Lac -
Macconkey lactose plates - white/uncolored colonies
Hektoen plate - green colonies
Do NOT produce H2S gas - colonies do not have dark centers
oxidase negative
E. coli lab results?
Macconkey agar - Lactose +
oxidase negative
serology - O and H antigens
API strips
Vibrio cholerae lab results?
gram negative curved rods thiocitrate bile salts sucrose (TCBS) medium oxidase + serological tests- O and Ag PCR
Enteric bacteria lab results?
all gram negative carbohydrate fermentation tests grows in low O2 Serology - O, K, H antigens; agglutination of oantigens in stool presence or absence of specific enzymes pcr
list family members of enterobacteriaceae
E.coli,
Salmonella enterididtis
Shigella
Salmonella typhi
list family members of vibrionaceae
V. cholerae
campylobacter jejuni
helicobacter pylori
agents of watery diarhea?
EPEC
EAEC
DAEC
all of these are diff types of E.coli
virulence factors of watery diarhea?
pili
cholera toxins to decrease Na+ absorption and increase Cl- secretion
diarrhea features
non inflammatory
small intestine
flu8id and electolyte loss
host forcibly expells the pathogen
dysentery
inflammatory disorder large intestine invasion of colonic wall blood and pus in feces enterotoxin commonly pain fever cramps
enterobacteriaceae vs vibrionacaeia
enterobacteriaceae: gram negative capsule/slime layer can be motile or non motile pili speciation by fermentation of carbohydrates, O and H Ags vibrionaceae: gram negative no capsules highly motile curved rods pili Speciation by serology - O and Ag
ETEC (travelors diarhea) toxin
Heat liable
heat stable
what are the types of GI Diseases?
watery diarrhea
dysentery (bloody diarrhea)
peptic ulcers
colonization and growth vs intoxication
colonization and growth requires presence of living bacteria
Examples: salmonella gastroenteritis, bacillary dysentery, cholera
Intoxication does not require presence of living bacteria
examples: staphyloccocal and clostidial botulism food poisonings
dysentry vs bloody diarrhea
Dysentry - frequent passage of low volume stools with blood, MUCUS, and pus
bloody diarrhea - lots of liquid, bloody, pus, stools
hemorrhagic colitis
lots of liquid blood stools with NO LEUKOCYTES
bacillary dysentery
transmission is the 4 f's fingers, flies, food, feces affects colon; GI tract common in day care and institutions symptoms: fever, damage to colonic cells, bloody and mucus stool (dysentery) Treatment is rehydration and antibiotics prevention is handwashing
why is shigellae non motile
because it only has O antigen and not H antigen
what is the shigellae toxin?
shiga toxin is enterotoxin which inactivates rRNA and causes no protein synthesis and cell death
E.coli
"hamburger syndrome" EHEC h for hamburger produces shiga like toxins which kills glomerular cells of kidney and CNS endothelial cells which cause paralysis hemolytic uremic syndrome serotype O157:H7
enterohemorrhagic e. coli (EHEC) lab results
Sorbitol macconkey plates - EHEC is sorbital neg. (white)
serology for O157
shiga toxin in stool
antibiotic therapy not recommended b/c it will speed production of shiga toxins before antibiotic kills bacteria which garuntees paralysis or death
what systemic diseases can salmonella enterica cuase?
gastroenteritis
typhoid fever
septicemia
salmonella gastroenteritis
from chickens and eggs
coloniztion
diarrhea, nausea, vomiting, fever, abdominal pain
no treatment
Salmonella. enteritidis
pili and long flagella
macconkey lactose plates : white colonies
hektoen plates: make H2S gas, colonies with dark center
oxidase negative
typhoid fever
slow onset
caused by salmonella enterica typhi
starts with organism penetrating intestinal wall
then organism invades bloodstream and biliary tree
diarrhea, fever
exhaustion
typhoid fever diagnosis and treatment
serology: IgM Abs
IgG Abs
Vi antigen
Treatment - antibiotics
viruelnce and prevention of typhoid
virulence; capsule flagella (H antigen) LPS endotoxin cell invasion machinery survive and multiplies in macrophages Prevention: Vaccines
example of enterobacteriacae?
examples of vibrionaceae
enterobacteriaceae: escherichia coli (diarrhea, hemorrhagic colitis, dysentery) shigella dysenteriae (dysentery) salmonella typhi (typhoid fever) vibrionaceae : vibrio cholerae (cholera) helicobacter pylori (peptic ulcer) gastroenteritis (Vibrio parahemolyticus) campylobacter jejuni (diarrhea)
