Lecture 5 - Clostridia

What is the Eh in normal healthy tissue? What happens if the Eh falls below this number?

-+150mV

-Anaerobiosis if it falls below

What are some conditions where lowered Eh values can induce anaerobiosis?

-Loss of vascular supply to tissues

-Trauma, foreign bodies, pressure from casts

-Acid production by aerobes or facultative anaerobes

-Tissue necrosis

What diseases do C. perfringens cause? What usually allows it to grow?

-Purple gut, lamb dysentery, pulpy kidney disease

-Linked to overeating

What disease does C. difficile cause?

Pseudomembranous enterocolitis

What disease does C. piliforme cause?

Hemorrhagic enteritis

What disease does C. spiroforme cause?

Enterotoxemia

Where is type A clostridium perfringens found? What disease does it cause?

-Very widespread

-Air, soil, dust, manure, lakes, streams, and rivers

-Present in intestinal contents of humans and animals

-Causes yellow lamb disease in nursing lambs and horses

What disease does Type B clostridium perfringens cause? What clinical signs would you see?

-Lamb dysentery

-Fetid, blood tinged diarrhea from hemorrhagic ulceration of small intestine

What disease does Type C clostridium perfringens cause? What are the clinical signs?

-Overeating disease

-Hemorrhagic and necrotic enteritis = purple gut

What disease does Type D clostridium perfringens cause? What species does it cause disease in? What are the clinical signs?

-Pulpy kidney disease (overeating disease) in sheep

-colic, muscle tremors, convulsions, frothing, teeth grinding, and nystagmus

What is the treatment for C. perfringens?

-Antitoxins (antibiotics ineffective → disease progresses too quickly)

-Reduce or eliminate concentrate feeding and increase amount of roughage

How is C. perfringens prevented?

-Vaccination of dam with C and D toxins

-Passive immunity

-Gradual transition from roughage to highly concentrated died

-Steady source of clean water

What disease does clostridium spiroforme cause? In what species? What toxin causes disease?

-Enterotoxemia of rabbits and lab rodents

-Iota toxin

How does Iota toxin, found with Clostridium spiroforme, cause disease?

ADP ribosylates and inhibits actin polymerization

What disease does Clostridium piliforme cause? What species?

Tyzzer’s disease in domesticated, lab, and wild animals

How can clostridium piliforme be gram stained?

Extremely oxygen sensitive and can only be gram + if fixation and staining are done under anaerobic conditions

What are the clinical signs of a clostridium piliforme infection?

Acute onset, profuse diarrhea, melanin, anal bleeding, depression, anorexia, rough hair coat