上海交通大学：《医学微生物》课程教学资源（PPT课件讲稿）英文版 chaper 12 Anaerobic Bacteria

Anaerobic Bacteria

Anaerobic Bacteria

Category a Spore-forming rod, Gram(+)---Clostridium Nonspore-forming see next slides

Category ◼ Spore-forming: rod, Gram (+)--- Clostridium ◼ Nonspore-forming: see next slides

Category Spore-forming: rod, Gram(+)--Clostridium Nonspore-forming Rod, Gram (+) Propionibacterium丙酸菌属 Bifidobacterium Lactobacillus Eubacterium Actinomyces Rod, Gram(-) Bacteroides Fusobacterium梭菌属 Campylobacter Cocci, Gram(+) Peptococcus Peptostreptococcus Cocci, Gram(-) Vellone

Spore-forming: rod, Gram (+)--- Clostridium Nonspore-forming: Rod, Gram (+) Propionibacterium丙酸菌属 Bifidobacterium Lactobacillus Eubacterium Actinomyces Rod, Gram (-) Bacteroides Fusobacterium梭菌属 Campylobacter Cocci, Gram (+) Peptococcus Peptostreptococcus Cocci, Gram (-) Veillonella Category

Clostridium Species The clostridia are opportunistic pathogens. Nonetheless, they are responsible for some of the deadliest diseases including gas gangrene, tetanus and botulism less life threatening diseases include pseudomembranous colitis(Pc) and food poisoning。 cause disease primarily through the production of numerous exotoxins. perfringens, tetani, botulinum, difficile

Clostridium Species ◼ The clostridia are opportunistic pathogens. Nonetheless, they are responsible for some of the deadliest diseases including gas gangrene, tetanus and botulism. Less life￾threatening diseases include pseudomembranous colitis (PC) and food poisoning. ◼ cause disease primarily through the production of numerous exotoxins. ◼ perfringens, tetani, botulinum, difficile

Clostridium Tetani 3. Disease 1. Entry. wound, C tetani Rigid paralysis, e. g lockjaw (cranial and peripheral motor nerves Respiratory failure 2. Spread of toxin 4. No exit Pathogenesis of tetanus caused by c tetani

Clostridium Tetani Pathogenesis of tetanus caused by C tetani

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