clostridium perferingens&clostridium botliunm&clostridium difficle

Lecture 16
• Clostridium perferingens
• Clostridium botuliunm
• Clostridium difficile
• Dr.Baha,H,AL-Amiedi
• Ph.D.Microbiology
Clostridium spp
• Anaerobic Gram-positive,Spore-Forming
• Bacilli,Four broad types of disease:
• 1- gas gangrene
• 2-tetanus
• 3-botulism
• 4-psedomembranous colitis
Clostridium perfringens
• Everyone has heard of gas gangrene,prior to antibiotics clostridium perfringens devastated solider wounded in battle,this bacteria whose spores can be found in soil mature in anaerobic condition and produce gas,the spore can contaminate wound from battle or trauma,Deep wounds with lots of dead tissue create an environment that offers an excellent home for clostridium perfringens&the exotoxine ,enzymes
• Causing further tissue distruction
• When anaerobiosis occurs in tissue surround area,this bcteria ferments the
• Carbohydrates present in tissue &produce
• Gas gangrene.other species case gas gangrene *Cl. septicum
• *CI. histolyticum
• *CI.novji
Pathogenesis:
• Clostridium perfringens produce exotoxine
• alpha-toxin,spores contaminating a wound germinate &produce alpha-toxin.
• Alpha-toxin is a lecithinase that causes damage to cell membranes, tissue destruction,bleeding, vascular permeability
• Systemic spread of toxin.
Laboratory diagnosis:
• 1-gram stained smear shows gram positive long &thick bacilli with central spore location .
• 2-Cultur on blood agar &cooked meat media incubated anaerobic for 48 &72 hr produce double zone of hemolysis when grow on blood agar
• 3-Biochemical reaction:glucose,maltose ,lactose sucrose ferment with produce acid& gase,indol negative
• 4-Neglar Reaction
Neglar Reaction
• Cl. Perfringens cultured on plate containing 20% of human serum or egg yolk. The opalescence around the colony in media due to lecitheinase of alpha-toxin, the reaction is specific and is inhibited by alpha –toxin antitoxin sera. it test for rapid detection of cl.perfringens in clinical specimen


Clostridium botulism
• It is strictly aerobic gram positive bacillus with terminal or sub terminal endospore . (6) toxignated produce types differentiated
• Antigenically are designated by capital letters A…to..F All six type produce toxin, in human caused botulism which is intoxication rather than infection.
• Disease result from ingestion of food in which bacilli spores has been germinated
• And producing toxins. The toxin type A,B,E responsible for most case of human botulism. The toxin attached to the individual motor nerve
• Terminal to prevent release of Acetylcholine & consequently results in muscle paralysis that would would lead to death.
• Transmission:
• Spores play a critical role in survival &spread by contaminated vegetables, honey, canned food.
Clostridium difficile
psedomembranous enterocolitisd
• Clostridium difficile colonization is associated with the use of antibiotics, other chemotherapies
• That kill other host flora and allow cl. difficile to growth advantage.
• Pathogenesis /virulence factors:the major virulence are exotoxine A and B in the
• A—once cl,difficle colonize,it produce exotoxins A and B in the intestine,.
• B-Exotoxine B is more cytotoxic
• C-The result of toxin production is fluid secretion cell death and an inflammatory
• Rersponse that can lead to psedomembrane formation in colon.
• Laboratory diagnosis:suspected infections can be confirmed by assaying for toxin in stool either by cytotoxicity cell culture assay &enzyme-linked immunosorbent assay