《病原生物学（医学微生物学）》课程教学课件（英文）08_Spore-forming G+ bacilli_Clostridia

Learning Methods for SpecificPathogens Biological propertiesSpecial features in morphology, structure, metabolimgrowth.... Pathogenesis+ Virulent factors Pathogenic mechanisms+Clinical findings (optional)Immunological characteristics Laboratory diagnosis Treatment, control and preventiorSHIHEZI UNIVERSITY

Learning Methods for Specific Pathogens  Biological properties  Special features in morphology, structure, metabolism, growth.  Pathogenesis  Virulent factors  Pathogenic mechanisms  Clinical findings (optional)  Immunological characteristics  Laboratory diagnosis  Treatment, control and prevention SHIHEZI UNIVERSITY

Section III BacteriologySpore-Forming Gram Positive Bacill:Bacillus & Clostridium SpeciesZhao-Hua Zhong, Ph.D., ProfDepartment of MicrobiologyHarbin Medical UniversitySHIHEZI UNIVERSITY

Section III Bacteriology Spore-Forming Gram Positive Bacilli: Bacillus & Clostridium Species Zhao-Hua Zhong, Ph.D., Prof. Department of Microbiology Harbin Medical University SHIHEZI UNIVERSITY

KEY TERMS Bacillus Obligate anaerobes+ Bacillus anthracis Polymicrobic (mixed) Clostridiuminfection? C. tetani Spore former+C. botulinum+ C perfrigens Lecithinase+C. difile(phospholipase, toxin AnthraxBotulinum toxinTetanus BotulismTetanospasminSHIHEZI UNIVERSITY

KEY TERMS  Bacillus  Bacillus anthracis  Clostridium  C. tetani  C. botulinum  C. perfringens  C. difficile  Anthrax  Tetanus  Botulism  Tetanospasmin  Obligate anaerobes  Polymicrobic (mixed) infection  Spore former  Lecithinase (phospholipase, toxin)  Botulinum toxin SHIHEZI UNIVERSITY

Gram-Positive Spore-Forming Bailli Bacillus speciesAerobes- Bacillus anthracis ---- anthrax Clostridium speciesAnaerobes Clostridium tetani --- tetanus Clostridium perfringens--- gas gangrene Clostridium botulinum --- botulismClostridium dificile --- seudomembranous colitisSHIHEZI UNIVERSITY

Gram-Positive Spore-Forming Bacilli  Bacillus species Aerobes  Bacillus anthracis - anthrax  Clostridium species Anaerobes  Clostridium tetani - tetanus  Clostridium perfringens - gas gangrene  Clostridium botulinum - botulism  Clostridium difficile - pseudomembranous colitis SHIHEZI UNIVERSITY

Bacillus SpeciesThe genus bacillus includes large aerobic, grampositive rods occurring in chainsMost members of this genus are saprophyticorganisms prevalent in soil, water, and air and onvegetation, such as Bacillus cereus and Bacillussubtilis B. cereus can grow in foods and produce anenterotoxin or an emetic toxin and cause foodpoisoning B. anthracis+ causes anthrax the principal pathogenSHIHEZIUNIVERSITY

Bacillus Species  The genus bacillus includes large aerobic, gram- positive rods occurring in chains  Most members of this genus are saprophytic organisms prevalent in soil, water, and air and on vegetation, such as Bacillus cereus and Bacillus subtilis  B. cereus can grow in foods and produce an enterotoxin or an emetic toxin and cause food poisoning  B. anthracis  causes anthrax  the principal pathogen SHIHEZI UNIVERSITY

Morphology & PhysiologyGram-positive, aerobic spore-formingbailliSpores formed in culture, soil, and deadanimal tissues but not in live animalsSpores remain viable in soil for decadesSHIHEZI UNIVERSITY

Morphology & Physiology  Gram-positive, aerobic, spore-forming bacilli  Spores formed in culture, soil, and dead animal tissues but not in live animals  Spores remain viable in soil for decades SHIHEZI UNIVERSITY

MorphologyThe typical cells, measuring I× 3-4 μmhave square ends and are arranged in longchainsI Spores are located in the center ofthenonmotile bacili

Morphology  The typical cells, measuring 1 × 3–4 m have square ends and are arranged in long chains  Spores are located in the center of the nonmotile bacilli

Gram positive B. anthracis in the CSFSHIHEZI UNIVERSITY

Gram positive B. anthracis in the CSF SHIHEZI UNIVERSITY

Colony: “cut glass'SHIHEZI UNIVERSITY

Colony: “cut glass” SHIHEZI UNIVERSITY

Pathogenesis: Anthrax Major disease threat to herbivores (cattlesheep, horses, hogs, goatsHumans infected by direct contact withdiseased animal, hides, wool, brushes, orbone mealInhalation of infected dust (Wool sorter'sdisease)Basis for Koch's postulateSHIHEZI UNIVERSITY

Pathogenesis: Anthrax  Major disease threat to herbivores (cattle, sheep, horses, hogs, goats)  Humans infected by direct contact with diseased animal, hides, wool, brushes, or bone meal  Inhalation of infected dust (Wool sorter's disease)  Basis for Koch’s postulate SHIHEZI UNIVERSITY