GI/Liver Bacteriology - Hepatobilliary

What is the preferred habitat of Fusobacterium spp?

GI tract

oral cavity

genitourinary tract

What are the effects of endotoxin (LPS) on Fusobacterium spp?

necrotic effect and induces DIC, then creates an anaerobic environment

What are the effects of leukotoxins on Fusobacterium spp?

tissue necrosis

What is the mode of entry for Fusobacterium spp?

opportunistic entry into mouth, rumen, or feet

What is the pathogenesis for Fusobacterium necrophorum?

combination of grain feeding causing ruminal acidosis AND mucosal trauma -> colonization -> spread via the portal vein -> resulting in LIVER ABSCESSES

What are the clinical signs of Fusobacterium?

necrobacillosis - suppurative and necrotic tissue with foul swelling pus

What are the clinical signs of Fusobacterium necrophorum in calves?

calf diphtheria (oral necrobacillosis)

What does calf diphtheria result in?

necroulcerative lesions of the pharynx, larynx, buccal mucosa

What are the clinical signs of Fusobacterium in cattle?

liver abscesses (hepatic necrobacillosis)

What is the most common cause of liver condemnation at slaughter?

Fusobacterium in cattle

What are the diagnostics for Fusobacterium at the clinical signs level?

oral lesions

What are the diagnostics for Fusobacterium antemortem?

hematology and liver function

What are the diagnostics for Fusobacterium postmortem?

Liver abscesses at slaughter

What is the treatment of Fusobacterium?

antimicrobial therapy

What is the control of Fusobacterium?

feedlot management to minimize acidosis

What are the characteristics of Clostridium?

gram positive rods

straight or slightly curved

motile

peritrichous flagella

FORMS ENDOSPORES

anaerobes

What is the proper habitat for Clostridium?

GI tract, soil, freshwater, sediments

What is an endospore?

a resistant asexual spore that develops inside some bacteria cells

What animals are more prone to histotoxic Clostridium?

grazing animals

Is histotoxic clostridium zoonotic?

No

What is the pathogenesis of Clostridium novyi type B?

spores migrate to the liver and are activated by liver damage that creates an anaerobic environment

What animals primarily have Clostridium novyi type B?

sheep and cattle

What animals primarily have Clostridium septicum?

sheep

What are the clinical signs of Clostridium speticum?

necrotizing abomasitis

anorexia, depression, fever

acutely fatal

What does Clostridium septicum cause?

damage to the lining of the abomasum

What season is Clostridium septicum observed?

winter

How is histotoxic Clostridium diagnosed?

cytology

anaerobic culture

fluorescent antibody staining

PCR

How do you prevent C. novyi?

fluke control

What is required to produce disease in enteropathogenic/ enterotoxemic Clostridium?

exotoxins

_________ helps to protect against phagocytosis

encapsulation

Enteric bacteria can spread via what vein to the liver?

portal vein

What are the characteristics of Fusobacterium spp?

gram negative

non-motile

pleomorphic rods

anaerobe (aerotolerant)

grows well at physiologic pH (7/4)

lactate fermenter

What is found in the normal microbiota in mammals?

Fusobacterium spp.

What allows Fusobacterium spp to have a necrotic effect and induce DIC, then create an anerobic microenvironment?

Endotoxin (LPS)

What is the proper habitat for enteropathogenic/ enterotoxemic Clostridium?

soil; intestinal tract and feces of animals and humans

For Clostridium perfringens, bacteria or their toxins expand if both ___ ___ ___ and ___ ___ ___ happen

altered enteric microenvironment AND intestinal clostridia are present

Altered enteric microenvironment can be due to what?

trypsin inhibitors

What does Clostridium perfringens Type A and C cause in piglets?

hemorrhagic enteritis

What type of Clostridium perfringens do newborn piglets get?

type C

What type of Clostridium perfringens do feeder pigs get?

type A

What animals get type A and C Clostridium perfringens?

piglets and feeder pigs

What animals get type B Clostridium perfringens?

sheep, neonate calves, foals, piglets, and lambs

What does type B Clostridium perfringens cause in lambs?

lamb dysentery

What does type B Clostridium perfringens cause in neonates?

hemorrhagic enterocolitis

Why does hemorrhagic enterocolitis occur in neonates?

Neonates have low levels of trypsin and, therefore, are more susceptible to beta toxins than adults

How can you diagnose Clostridium perfringens?

sudden death in unvaccinated animals with history of Clostridial disease

post-mortem exam

prompt sample collection

anaerobic culture

toxin detection

Why is Clostridium perfringens hard to treat with antimicrobials?

often ineffective because of acute nature of disease

How do you control Clostridium perfringens?

vaccination prior to and after birth

What is a significant pathogen in human and veterinary medicine that is highly zoonotic?

Clostridium difficile

What can Clostridium difficile cause in dogs?

chronic diarrhea

What can Clostridium difficile cause in horses?

hemorrhagic enterocolitis

What is the disease associated with Tyzzer's Disease in foals?

Clostridium piliforme

What are the clinical signs of Tyzzer's disease?

acute fatal disease after brief illness

Clostridium novyi is associated with....

infectious necrotic hepatitis

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