Digestive tract infections III Flashcards
Clostridium spp. of intrest in gi tract
- Clostridium perfringens
- clostridium piliforme
- CLOSTRIDIODES difficile is NOT a clostridium any longer it is reclassified BUT shares the characteristics of a clostridium spp.
clostridium spp. and clostridiodes difficile characteristics
- gram pos
- spore forming
- anaerobic
- bacilli
clostridium spp. and clostridiodes difficile found where
- natural inhabitant digestive tract
- found in soil
clostridium spp. and clostridiodes difficile transmission (gi)
ingestion
clostridium spp. and clostridioudes difficile (GI) -> dx how
- produce toxins that cause dx while they are inside host in GI the dx they cause really isn’t GI based but they are in GI making the toxin
clostridium difficile infection how
- triggering event -> disturbance normal microbiome
- piglets can get infection when newborn before establish own microbiota to prevent infection or dx
clostridium piliforme infection how
usually stress to animal triggers infection
clostridium per fringes infection how
- newly ingested spores germinate and -> dx
clostridiodes difficile effects who
- horse
- pig
- dog
- RARELY cats
- maybe zoonotic?
clostridiodes difficile horse and pig (piglets0
- hemorrhagic necrotizing enterocolitis ie bldy d+
clostridiodes difficile dogs and cats
- chronic d+ may or may not contain blood
- RARELY EFFECTS CATS
clostridium perfringens types
- a-e
- based on toxins they make
clostridium perfringens -> what in who
- endotoxemia, usually acute and highly fatal
- cattle, sheep, goat, pig, horse, dog
- ZOONOTIC (some types not all)
clostridium perfringens dx spreads how
- toxins made in intestine enter blood stream -> spread -> death (usually)
clostridium perfringenes diagnosis how
necropsy
clostridium perfringens necropsy what seen
congestive hemorrhagic ulceration on intestinal mucosa
clostridium perfringenes most comon in what types animals
- v young
- overfed
clostridium perfringenes very young animals
- young: digestive enzymes not made yet or are inhibited by colostrum bacteria making toxins and toxins not degraded -> toxins have effect
- older animal: have trypsin and other enzymes so bacteria can mult and make toxins but toxins get degraded in intestinal tract
clostridium perfringenes overfed animals
- food left undigested in li microbes can grow on also intestinal motility slowed so more time for toxins to get absorbed and cause dx
clostridium piliforme affects who
- lab rodents
- lagomorphs
- occasionally foals, cats, dogs
clostridium piliforme general characteristics
- gram variable (they are gram pos but sometimes appear gram neg on staining)
- spore forming
- obligate intracell (most clostridium = extra cell this is different)
- anaerobic
- bacillus
clostridium piliforme -> what
- tyzzer’s dx
tyzzer’s dx = what / induced by what
- hepatic necrosis -> rapid death
- induced by stress
Clostridiodes difficile pathogenicity
spores endogenous in intestines germinate after triggering event ->
- produce enterotoxins
- cytotoxic to colonic epithelial cells and macrophages
- cytotoxicity to colonic epithelial cells ->killing epithelial cells -> mucohemorragic d+
clostridium perfringes pathogenesis
- spores germinate in intestines and multiply to produce one toxin that damages intestine allowing other toxins they make to spread to bld stream then spread systemically and kill animal
- diff strains produce diff toxin combinations
diagnosis clostridium spp. gi and clostridiodes difficile
- id toxins (elisa or toxin gene pcr)
- C. perfringens- gross finding on necropsy
- C. piliforme- pcr
clostridioides difficile tx
- abs (once spores germinate can treat with abs)
clostridium spp. tx
- rapid onset so can’t really treat
- antitoxin if progress slowly
clostridiodes difficile and clostridium piliforme prevention
avoid stress
clostridium perfringens prevention
- redue w/ high fiber low protein diet
- a and b toxoid vac for preg animals
escherichia coli general charcteristics
- gram neg
- bacillus
- facultative anaerobe
eschreichai coli found where
- natural inhabitant of intestines
- widely distributed in environment
escherichia coli transmission
fecal-oral
types E. coli gi
- enterotoxigenic -> secretory gi
- shiga toxin-producing E. coli (STEC) which includes subset (enterohemorrhagic E.coli EHEC)
STEC causes what in who
- edema dx in pigs
- mostly outbreaks in recently weaned pigs
- some of these are important foodborn pathogens
edema dx signs
- case fatality risk 90%
- found dead or clinical signs = neuro, sq edema, rarely d+
EHEC causes what in who
- carried by cows where -> nothing BUT is ZOONOTIC
- in humans ->
- watery d+
- more severe bldy d+
- most severe hemolytic uremic syndrome
pathogenesis shiga-toxin producing e. coli STEC
- ingested bacteria adhere to intestinal mucosa via pilli in SI -> adherent bacteria produce shiga toxin -> inhibit protein synth -> toxin kills epithelial cells and endothelial cells -> spreads to blood stream -> bind GB4 receptor on endothelial cells of small artier and articles -> damage endothelium -> edema -> death
GB4 receptor
- receptor for porcine STEC toxin
pathogenesis shiga-toxin producing e.coli EHEC
- ingested bacteria adhere to intestinal mucosa via attaching/ effacing factors in colon ->adherent bacteria produce shiga toxin -> inhibit protein synth -> toxin kills epithelial cells and endothelial cells -> hemorrhagic d+ in humans
pilli STEC binds
- in si
- same pilli enterotoxigenic E. coli bind
- found in post weaning pigs = time these receptors available
EHEC binding
their attachment via attaching/ effacing factors -> attaching/ effacing lesions in colon when adhere to colon adherence results in effacement of microvilli
diagnosis shigatoxin producing E. coli
- elisa for toxin (intestinal samples)
- pcr toxin gene (intestinal samples)
- clinical signs
shigatoxin producing E. coli tx
- antibiotics but once see neurosigns = too late for piglets treat other animals in herd to prevent issue
prevention shigatoxin producing e. coli
- stx2e vac not in us yet
yersinia spp. general characteristics
- fam= enterobacteriacea
- rod shapped
- fan an
- gram neg
yersinia spp. found where
- intesitnes and environment
yersinia spp. of interst
- yersinia enterocoliti
- yersenia pseudotuberculosis ZOONOTIC
yersinia spp. -> what in who
- rarely dx in animals usually food born pathogen of ppl
- ->
- enteritis
- mesenteric lymphadenitis
diagnosis yersinia spp.
- grow at low temp so cold enrichment
how do ppl get yersinia spp. ingested
- contaminated pork
