Path - Small Intestine and Colon - Micro Flashcards
clinical features of ETEC
severe watery diarrhea
clinical features of c. diff (pseudomembranous colitis)
watery diarrhea, fever
mode of transmission EIEC
cheese, other foods, water
which microorganisms can cause reactive arthritis in HLA-B27 patients?
- vibrio cholera
- shigella
mode of transmission C. diff
antibiotics allow emergence
clinical features of EHEC
bloody diarrhea
mode of transmission campylobacter spp
poultry, milk, other foods
clinical features enterobius cermicularis (pinworms)
rectal and perineal itching
clinical features of enteric (typhoid) fever (salmonella typhi)
bloody diarrhea, fever
clinical features of EIEC
bloody diarrhea
clinical features of yersinia
abd pain, fever, diarrhea
clinical features of shigella
bloody diarrhea
mode of transmission shigella
fecal-oral, food, water
mode of transmission salmonella
meat, poultry, eggs, milk
clinical features of salmonellosis
watery or bloody diarrhea
clinical features intestinal cestodes
- diphyllobothrium latum (fish tapeworms)
- taenia solium (pork tapeworms)
- hymenolepis nana (dwarf tapeworms)
abd pain, diarrhea, nausea
majority are asymptomatic though
clinical features norovirus
nausea, vomiting, watery diarrhea, abd pain
mode of transmission yersinia
pork, milk, water
clinical features of EAEC
nonbloody diarrhea, afebrile
4 properties of virulence for campylobacter spp
- motility
- adherence
- toxin production
- invasion
mode of transmission EPEC
fecal-oral
pathogenesis ETEC
produces heat-labile toxin (LT) and heat-stabile toxin (ST) –> induce chloride and water secretion while inhibiting intestinal fluid absorption
most common bacterial enteric pathogen in developed countries and an important cause of traveler’s diarrhea
campylobacter jejuni
pathogenesis yersinia
invade M cells and use adhesins to bind to B1 integrins –> pathogenicity island encodes iron uptake system (iron enhances virulence and dissemination)
mode of transmission vibrio cholera
fecal-oral, water, shellfish
clinical features entamoeba histolytica
abd pain, bloody diarrhea, weight loss
clinical features giardia lamblia
acute or chronic diarrhea, malabsorption, weight loss
pathogenesis of shigella
taken up by M cells in intestine –> proliferate intracellularly –> escape into lamina propria –> phagocytosed by macrophages –> induce apoptosis –> epithelial damage which allows shigella within intestinal lumen to gain access to basolateral membranes
pathogenesis EHEC
O157:H7 and non-O157:H7 produce shiga-like toxins
pathogenesis EIEC
invade epithelial cells and cause non-specific features of acute self-limiting colitis
(NO shiga toxin)
mode of transmission whipple disease (Tropheryma whippelii)
unkown
pathogenesis whipple dz (tropheryma whippelii)
organism-laden macrophages accumulate within the small intestinal lamina propria and mesenteric lymph nodes –> impaired lymphatic transport
mode of transmission enteric (typhoid) fever (salmonella typhi)
fecal-oral, water
clinical features strongyloides
eosinophilia
pathogenesis EPEC
produce attaching and effacing lesions in which bacteria attach tightly to enterocyte apical membrane and cause local loss (effacement) of microvilli
(NO shiga toxin)
clinical features of campylobacter spp.
watery or bloody diarrhea
pathogenesis rotavirus
selectively infects and destroys mature enterocytes in small intestine
pathogenesis tyhpoid fever (salmonella tyhpi)
taken up by M cells in intestine –> engulfed by mononuclear cells in underlying lymphoid tissue –> disseminate in the blood and lymph
mode of transmission ETEC
food or fecal-oral
clinical features ascaris lumbricoides
physical obstruction of intestine or biliary tree, hepatic abscesses, pneumonitis
mode of transmission EAEC
unkown
clinical features of EPEC
watery diarrhea
clinical features cryptosporidium
watery diarrhea
mode of transmission norovirus
large outbreaks: contaminated food or water
sporadic cases: person-person transmission
mode of transmission EHEC
beef, milk, produce
clinical features adenovirus
diarrhea, vomiting, abd pain
principal cause of traveler’s dairrhea and spread via contaminated food or water
ETEC
what microorganism can cause hemolytic uremic syndrome and ischemic colitis
EHEC
pathogenesis c. diff (pseudomembranous colitis)
release toxins that cause ribosylation of small GTPases and lead to disruption of epithelial cytoskeleton, tight junction barrier loss, cytokine release, and apoptosis
clinical features of whipple disease (Tropheryma whippelii)
malabsorption
pathogenesis of salmonella (nontyphoid)
type III secretion system capable of transferring bacterial proteins into M cells and enterocytes –> activate Rho GTPases –> trigger actin rearrangement and bacterial endocytosis –> allows bacterial growth within endosomes
clinical features of cholera
severe watery diarrhea
- “rice water stool”
pathogenesis EAEC
attach to enterocytes via adherence fimbriae and aided by dispersin which neutralizes the negative surface charge of LPS
(NO shiga toxin)
pathogenesis of vibrio cholera
stimulation of adenylate cyclase –> increase in intracellular cAMP –> opens CFTR –> releases CL- into lumen –> draws water into lumen –> severe watery diarrhea
