General introduction C tetani is found worldwide Ubiquitous in soil, it is occasionally found in intestinal flora of humans and animals C, tetani is the cause of tetanus, or lockjaW. When spores are introduced into wounds by contaminated soil or foreign objects such as nails or glass splinters
General introduction ◼ C tetani is found worldwide. Ubiquitous in soil, it is occasionally found in intestinal flora of humans and animals ◼ C.tetani is the cause of tetanus,or lockjaw. When spores are introduced into wounds by contaminated soil or foreign objects such as nails or glass splinters
BIOCHEMICAL CHARACTERISTICS Morphology: long and slender peritrichous flagella, no capsule, terminal located round spore(drum-stick apperance ts diameter greater than vegetative cell Culture: obligate anaerobic; Gram (+)i swarming occures on blood agar, faint hemolysis Biochemical activitiesidoes not ferment any carbohydrate and proteins a Resistance: tolerate boiling for 60 min alive several ten years in 2-5x 0.3-0.Sum soil Classification and antigenic Types: C tetani is the on species. There are no serotypes
BIOCHEMICAL CHARACTERISTICS ◼ Morphology: long and slender; peritrichous flagella,no capsule, terminal located round spore(drum-stick apperance), its diameter greater than vegetative cell. ◼ Culture:obligate anaerobic; Gram(+); swarming occures on blood agar, faint hemolysis. ◼ Biochemical activities:does not ferment any carbohydrate and proteins. ◼ Resistance: tolerate boiling for 60 min.alive several ten years in soil. ◼ Classification and Antigenic Types: C tetani is the only species. There are no serotypes 2-5 x 0.3-0.5um
Pathogenicity No invasiveness, toxemia s, retrograde transport exogenous Inrection to(CNS) produces two exotoxins tetanolysin, and delitescence: a few tetanospasmin(a kind of days to several neurotoxin, toxicity strong) weeks The actions of 8 The two animal tetanospasmin are species most complex and involve three susceptible to this components of the nervous system: central toxemia are horses motor control, autonomic and humans ■ function and the neuromuscular junction
Pathogenicity ◼ No invasiveness; toxemia (exogenous infection） ◼ produces two exotoxins: tetanolysin, and tetanospasmin(a kind of neurotoxin, toxicity strong) ◼ The actions of tetanospasmin are complex and involve three components of the nervous system: central motor control, autonomic function, and the neuromuscular junction. ❖ retrograde transport to (CNS) ❖ delitescence：a few days to several weeks ❖ The two animal species most susceptible to this toxemia are horses and humans
Clostridium tetani-Tetanospasmin disseminates systemically binds to ganglioside receptors inhibitory neurones in CNS glycIne o neurotransmitter stops nerve impulse to muscles spastic paralysis痉挛性麻痹 severe muscle contractions and Spasms can be fatal
Clostridium tetani -Tetanospasmin ◼ disseminates systemically ◼ binds to ganglioside receptors • inhibitory neurones in CNS ◼ glycine • neurotransmitter ◼ stops nerve impulse to muscles ◼ spastic paralysis痉挛性麻痹 ◼ severe muscle contractions and spasms ◼ can be fatal
Tetanospasmin C taboni Continuous simulaton Excitator by excitatory transmiter transmItter Tetanospasmin Inhibi y transmitter Inhibitory release transmitter blocked
Tetanospasmin