医学微生物学课件：13 人畜共患菌

1、Animal Source Bacteria(动物源性细菌)Zoonosis (动物源性疾病) are human diseases caused by organisms that are acquired from animals. There are bacterial, viral, fungal, and parasitic zoonosis. Some zoonotic organisms are acquired directly from the animal reservoir（宿主）, whereas others are transmitted by vectors, s

2、uch as mosquitoes, fleas, or ticks.Zoonosis (动物源性疾病)from animalsdirectly from the animal reservoirIndirectly by vectors, such as mosquitoes, fleas, or ticks There are bacterial, viral, fungal, and parasitic zoonosisZoonosisBacillus anthracis (炭疽芽胞杆菌) Yersinia pestis (鼠疫耶尔森菌) Brucella abortus ( 牛布鲁菌)

3、Brucella (布鲁菌属) Brucella (布鲁菌属)G-, small rodsfacultative intracellular pathogens (兼性胞内寄生杆菌)Pathogenic strains for human beingB. melitenisis(羊布鲁菌)B. abortus(牛布鲁菌)B. suis(猪布鲁菌)Infectious routesMucous membranes-(ingestion/inhalation routes, or through the conjunctiva. ), such as, ingestion of milk or m

4、ilk products. Skin-contact with infected tissues of animalsPathogenesisPathogenic factorsCapsuleHyaluroniase (透明质酸酶)Anti-phagocytosis, intracellular pathogens , repeat bacteremia, lesions of many organsenterotoxinFever, hypersensitivity reactionDiseaseAnimals: abortionBrucellosis is primarily a dise

5、ase of animals and it affects organs rich in the sugar erythritol(赤藻糖醇) (breast, uterus, epididymis副睾, etc.). The organism localizes in these animal organs and cause infertility(不孕 ), sterility(不育), mastitis(乳腺炎), abortion or resides as carriage. Human being: Brucellosis (undulant fever)Humans in cl

6、osed contact with infected animals are at risk of developing undulant fever.The symptoms in brucellosis are due to the presence of the organism and appear 2 - 4 weeks (sometimes up to 2 months) after exposure. B. melitensis(羊布鲁菌 ) is the cause of most severe prolonged recurring disease. The intracel

7、lular persistence of bacteria results in granuloma(肉芽肿) formation in the reticuloendothelial system organs and tissue damage due to hypersensitivity reactions, mostly type-IV.The bacteria are engulfed by neutrophils and monocytes and localize in the regional lymph nodes, where they proliferate intra

8、cellularly. The organisms migrate to other lympho-reticular organs (spleen, bone marrow, liver, testes) producing granulomas and/or micro abscesses.Symptoms include fever, chills, sweats, fatigue(疲劳), myalgia(肌痛), profound muscle weakness, and anorexia(厌食). Prevention and TreatmentThe control measur

9、es include animal vaccination and avoidance of infected material.Prolonged treatment with rifampin, which penetrates cells with streptomycin or tetracyclin is used to treat human Brucella infections. Bacillus 芽胞杆菌属aerobic, G+ spore-forming large bacillusPathogenic bacilliB. anthracis (炭疽芽胞杆菌)zoonosi

10、s-Anthrax (炭疽)B. cereus (蜡样芽胞杆菌) food borne infectionenterotoxinVomitive form caused by heat stable enterotoxin Diarrheal formcaused by heat labile enterotoxin B. Anthracis (炭疽芽胞杆菌)The first bacterium(1877), first attenuated live vaccineSpores are in nature (soil, animal coat)Infections by wound or

11、inhalation(一)Biological characteristicsMorphology Pure culture, gram stain, stained blood smearcultureaerobicColonies:R type curled edge(under CM)Ground glass(毛玻璃) appearance(二)Pathogenesis and immunityPathogenic factorscapsuleexotoxins (A-B type toxin)protective antigen, PA (保护性抗原)- antitoxinedema

12、factor, EF (水肿因子)lethal factor, LF (致死因子)Diseases- anthraxCutaneous anthrax (95%)Gastrointestinal anthrax (5%) Pulmonary anthrax (very rare)4d5d6d8d11d13d皮肤炭疽(三) Diagnosis and prevention & treatmentdiagnosisSmear, microscopic examinationCulture串珠试验(+)Prevention and treatmentvaccinepenicillin二.Yersin

13、ia 耶尔森菌属G- small bacillusPathogenic Yersinia for human beingYersinia pestis 鼠疫耶尔森菌Y. enterocolitica 小肠结肠炎耶尔森菌Y. pseudotuberculosis 假结核耶尔森菌Yersinia pestis 鼠疫耶尔森菌G-, short and wide rodsYersinia pestis 鼠疫耶尔森菌characteristicsenterobacteriaceaefacultatively aerobicfacultative intracellular pathogens (兼性细胞

14、内寄生), bipolar staining (两端浓染)Yersinia pestis grows well on most standard laboratory media, after 48-72 hours, grey-white to slightly yellow opaque raised, irregular “fried egg” morphology; alternatively colonies may have a “hammered copper” shiny surface Yersinia pestis 鼠疫耶尔森菌Ag and pathogenic facto

15、rsF1 Ag (fraction 1 Ag) : Capsule Ag, protective AgV/W Ag: coded by a plasmid, be associated rapid proliferation and septicemia.Yersinia outer membrane proteins(Yop):A group of 11 proteins, which are coded by plasmids, are essential for rodent pathogenesis and are responsible for cytotoxicity, inhib

16、ition of phagocyte migration and engulfment and platelet aggregation.endotoxin murine toxin(MT) : blood vessel, toxoid, one is lethal for mice in amount of 1mg.Infectious source and routesCarrier: rodent(啮齿动物) fleasBy bite (mice-flea-human being)by contact with infected animalsby respiratory tractDi

17、seasePlaque (鼠疫)- black deathbubonic plague (腺鼠疫)Septicemia plague (败血症型鼠疫)pneumonic plague (肺鼠疫): 100%mortalitySeveral bacteria can cause diseasePlague patient displaying a swollen axillary lymph nodePrevention and treatmentDestroy mice and fleaHospitalization and strict isolation are the ruleVacci

18、ne- murine toxoidAntibiotics - 庆大霉素、链霉素或强力霉素 Other bacteriaNonfermentative gram-negative bacilli Pseudomonas aeruginosa (铜绿假单胞菌) Pseudomonas (假单胞菌属)G- bacillus, polar flagellastrictly aerobicwater-solubility (水溶性) pigment strong resistance, resistance to various antibiotics pathogenesisVirulent fact

19、orsinvasivenesspili, micro-capsuleproteinasestoxinsendotoxinexotoxin A (similar to Diphtheria toxin)pathogenesisOpportunistics pathogen-Nosocomial infections (院内感染) fatal pneumonia-especially in Cystic fibrosis (囊状纤维化)patients Cutaneous infections-in burn, wound septicemia (败血症)urinary tract infecti

20、on-as a result of catheter use or surgery Helicobacter pylori, HP (幽门螺杆菌)2005年10月3日，巴里马歇尔（右）与罗宾沃伦得知自己获得2005年诺贝尔生理学或医学奖后，举杯互相庆贺。 1997年9月2日，沃伦（右）和马歇尔在澳大利亚珀斯市 Helicobacter pylori, HP (幽门螺杆菌)G-, curved or spiral shaped , S, or gull-wing shaped, multiple flagella at a polar and is actively motileHelicoba

21、cter pylori, HP(幽门螺杆菌)G-Gastric biopsy (Giemsa stain)p226G-, spiral shaped , S, or gull-wing shaped , polar flagellaHelicobacter pylori, HP (幽门螺杆菌)Urease(+), oxidase and catalase (+)Diagnosis vivo tests for urease activity urea（C14-labeled urea）urease（脲酶） NH3+ CO2* Helicobacter pylori, HP (幽门螺杆菌)Chr

22、onic gastritis, ulcers, gastric carcinomaBacteria infected through respiratory tractBacteria infected through respiratory tractLegionella (军团菌属)L. pneumophila (嗜肺军团菌)Haemophilus (嗜血杆菌属)H. influenzae (流感嗜血杆菌)Bordetella (鲍特菌属)B. pertussis (百日咳鲍特菌)Legionella pneumophila (嗜肺军团菌)facultative intracellular

23、 pathogens (兼性细胞内寄生), G- bacilus, stain poorly by Gramp 229Legionella pneumophila (嗜肺军团菌)Be ubiquitous in warm moist environments, aerosol inhalation (气溶胶吸入) Virulent factorspili, flagellum, micro-capsule, enzymesenterotoxin, cytotoxindisease-legionellosis (军团病)diagnosisSmear, staining and microscop

24、yfluorescence Ab testSilver staindiagnosiscultureBCYE agar（活性炭-酵母浸出液琼脂, buffered charcoal-yeast extract agar）Antibody testsBCYE(3-5d)二. Haemophilus influenzae (流感嗜血杆菌)Biological characteristicsG- small bacillus, pleomorphic (多形性)can be grown on chocolate agar (heated blood) and requires factor and f

25、actor (hemin ) satellite phenomenon (卫星现象)二. H. influenzae (流感嗜血杆菌)Virulent factorspili, capsule, IgA proteinase, LOS(脂寡糖)Disease-depend on bacterial capsulePrimary infection-suppurate infection (化脓性感染, caused by bacteria with capsule) Secondary infection- Endogenous infection (内源性感染, without capsule )三. Bordetella pertussis (百日咳鲍特菌) Biological characteristicsG- small bacillus, strictly aerobic, B-G media (bordet-Gengou media, 鲍-金培养基)Virulent factors-capsule, pili, endotoxin etcPertussis toxin (pertussigen, PT,百日咳毒素)Adenylcyclase toxin (腺苷酸环化酶毒素)Tracheal cytotoxin (气管细胞毒素)Dermon