2/24/99

Microbiology II

 

GI Tract Diseases

·         Bacillaceae

·         2 genera—Clostridium and Bacillus

 

Bacillus

·         Aerobic

·         Anthrax

·         B. cereus food poisoning

·         B. subtilis—saprophyte

Clostridium

·         Gram positive, rod, spore forming member of Bacillaceae

·         2 genera—Clostridium and Bacillus

·         anaerobic

·         deadly diseases—more than any other bacteria

·         spore formation

·         exotoxin

·         4 types of diseases

1. GI associated—C. difficile (pseudomebranous entero colitis), C. perfringens (food poisoning; not as deadly as some other food poisoning)
2. Histotoxic—tissue infections; C. perfringens (anaerobic cellulitis, gas gangrene (myonecrosis)); C. novii; C. fallax; C. septicum; C. hitolyticim; C. soldellii;
3. Deadly Botulism—most deadly neurotoxin; food associated; C. botulinum—poisoning
4. Deadly spasm—tetanum, neurotoxin, C. tetani

 

C. difficile

·         Part of normal flora

·         Only when using other antibiotics to suppress part of flora is when C. difficile flourishes

·         Antibiotics like Ampicillin, Tetracycline, Clindamycin, Lincomycin

·         Flourishes in colon

·         Responsible for formation of very painful pseudomembranous colitis

·         Show extensive bleeding, diarrhae, inflammation, and dehydration---death as result

·         Opportunist

·         Not known until 1977

·         Recognized since antibiotics came into use

·         Facilitate rehydration who is suffering from this

·         Vancomycin—relatively expensive antibiotic used for C. difficile

·         Nasogastric feeding is recommended

·         Multiple enemas

 

C. perfringenes

·         Typically known to have subterminal spore (just below the tip of the organism)

·         Amost always begins w/wound of the organism system part of the body

·         Infection by wounding object is sharp like knife, nail, bullet

·         Myonecosis—gas gangrene—alpha toxin; lecithinase (breaks down tissue, same as snake venom); many more deaths during time of illegal abortions

·         Anaerobic cellulitis

	Anaerobic cellulitis	Myonecosis
	Superficial(surgical wounds)	Deep penetration
Onset	Gradual	Acute
Pain	Mild	Marked
Exudate	Thin, dark	Thick, dark
Gas production	A lot	Little
Dissipation of gas	Into air	Trapped in bubbles
System toxicity	No	Yes (puerperal fever)
Swellin	Moderate	Marked
Muscle damage	No	Plenty

·         Tx:  1)  surgical debriment

·                 2)  exposure to hyperbonicOxygen

·         antibiotic therarpy is not effective