医学微生物学课件：11-13病原球菌

1、athogenic coccus (pyogenic coccus) ClassificationStaphylococci(葡萄球菌属)S.aureus(金黄色葡萄球菌) Coagulase(-) (凝固酶阴性葡萄球菌)Streptococci(链球菌属)Streptococcus pyogens (A族链球菌)Strept. pneumoniae (肺炎链球菌)Other Streptococcus (其他链球菌)Neisseriae(奈瑟菌属)Neisseria gonorrhoeae (淋病奈瑟菌)Neisseria meningitidis (脑膜炎奈瑟菌)Sec. 1 Staphy

2、lococci . Biological characteristicsMorphology and stainingG+ CoccusGrape like-clusters. Biological characteristicsculturepigmented b hemolysisClassification of Staphylococci characterics S.aureus S epidermidis S saprophyticus(腐生)pigment yellow white white or lemoncoagulase + - - hemolysin + - -Heat

3、 stable nuclease + - -Protein A + - -mannitol fermentation + - -pathogenecity strong weak weakSPASurface Ag, Species specificityCombine to Fc fragment of IgG1, 2, 4 -inhibit phagocytosisCoagglutination (协同凝集试验)S aureus SPA Fc Fab AgY. pathogenicityprimary pathogenic materialscoagulase Free coagulase

4、To generate Staphylothrombin (葡萄球菌凝血酶) serum clottingBound coagulaseTo deposit fibrin on the surface of Staphylococci Coagulase is considered synonymous with invasive pathogenic potentialmakes fibrin clot limit the infectionwbc penetrate badly anti-phagocytosisprimary pathogenic materialstoxinCellul

5、ar toxinStaphylosis (溶血素): is toxic for many kinds of cells, including human red blood cellsleukocidin (杀白细胞素): kill white blood cells of humans and rabbitsexfoliatin (表皮剥脱毒素或表皮溶解毒素):super Ag dissolving the mucopolysaccharide matrix of the epidermisToxic shock syndrome toxin-I (TSST-1 ) is associate

6、d with fever, shock, and multisystem involvement, including a desquamative skin rashsuper Agprimary pathogenic materialstoxinEnterotoxin-vomiting and diarrhea, heat stableStable to heating at 100C for 30 minutesSuper AgBind to neural receptors in the gutvomiting centerDiseases caused by S aureus Pyo

7、genic infection local- skin infectionBoils (疖) carbuncle(痈)Impetigo(脓疱疮)Sycosis(须疮)Systemic-septicemia, pyemia(脓血症）, organs infectionDiseases caused by S aureus Toxic diseases (毒素性疾病)Food poisoningScalded skin syndrome (烫伤样皮肤综合征)Toxic shock syndrome (毒性休克综合征)opportunistic infections flora disequilib

8、riumpseudomembranous colitis (假膜性肠炎)Coagulase negative Staphylococcus (CNS)Difference from S aureus Primary Pathogenic materialsextracellular slime substance, ESS（细胞外粘质）Opportunistic bacterium/ nosocomial infections (医院感染)diseasesUrinary tract infectionbacteremia, septicemiapost-operation infection/

9、 heart valves/ catheters (导管, 导尿管等)IdentificationNon-hemolytic sheep blood agarDoes not ferment mannitol Non-pigmentedCoagulase-negativeSec. 2 Streptococci. Biological CharacteristicsG+ coccuschains or pairsAg: protein AgC (carbohydrate) Ag(多糖Ag)P (nucleoprotein) Ag (核蛋白Ag). Biological Characteristi

10、csBlood agar, serum-brothb hemolysis a hemolysishemolysis reaction - sheep blood agar: hemolysishemolysisno hemolysisClassification of Streptococcushemolysis reaction - sheep blood agar:a-hemolytic streptococcus(甲型溶血性链球菌）- henolysis, opportunistic pathogenb-hemolytic streptococcus(乙型溶血性链球菌)- hemolys

11、is, pathogeng streptococcus（丙型链球菌）-no hemolysis, usually no pathogenecityC Ag（多糖Ag): A-H,K-V20 groups Group A Streptococcus(A族链球菌,pyogenic streptococcus, hemolysisOxygen requirement:Aerobe(需氧)/facultative anaerobe(兼性厌氧): b-hemolytic streptococcusAnaerobe(厌氧):normal flora (变异链球菌, 消化链球菌). Pathogenesis

12、Major virulence factors of StreptococcusInvasiveness: strongCell surface structure protein F - LTA+M proteinadhere (黏附) to epithelial cellsM Protein - strain variationanti-phagocytosiscross-reacts human cardiac muscle tissue autoimmunity. PathogenesisMajor virulence factors of StreptococcusEnzymes-e

13、asily spreading infectionHyaluronidase (透明质酸酶)Streptokinase (链激酶，溶纤维蛋白酶) streptodornase (链道酶, DNase). PathogenesisMajor virulence factors of Streptococcustoxinpyrogenic exotoxin (致热外毒素)rashStreptolysin (溶血素) hemolysin O (SLO) - cardiac muscle, Wbc, blood platelet sensitive oxygen Anti-SLOhemolysin S

14、 (SLS) - Wbc, et al insensitive oxygen hemolytic. Pathogenesis Diseases caused by Streptococcus1.Local or systemic pyogenic infectionTonsillitis (扁桃体炎)/咽峡炎/鼻窦炎/中耳炎Erysipelas(丹毒)/lymphatitis (淋巴管炎)gangrene (坏疽)/蜂窝组织炎Necrotizing fascitis (坏死性筋膜炎）Puerperal fever (产褥热)septicemia2.Toxic diseasesScarlet f

15、ever(猩红热)pyrogenic exotoxin Streptococcal toxic shock syndrome (STSS)3.Allergic diseasesRheumatic fever(风湿热)fever, non-suppurative inflammation of all parts of the heart and polyarthritisAcute glomerulonephritis (急性肾小球肾炎). Pathogenesis Diseases caused by StreptococcusStrept. pneumoniae umbilicus col

16、oniesStrept. pneumoniae hemolysisStrept. Pneumoniae (肺炎链球菌)PathogenecityPathogenic factorcapsuleLower resistance in local or systemic diseaseslobar pneumonia (大叶性肺炎)Meningitis (脑膜炎), bronchitis (支气管炎), tympanitis (中耳炎)Other Streptococcus a hemolysis Streptococcus distributionoral cavitydiseasesdecay

17、ed tooth(龋齿)subacute endocarditis (亚急性细菌性心内膜炎)Other Streptococcus Group B streptococcusNormal floravagina and rectum (直肠)diseasessepticemia in a newborn, post partum infection (产后感染), Urinary tract infectionGroup D StreptococcusNormal floraskin, upper respiratory tract intestine tract , vaginaDiseas

18、es nosocomial infections , Urinary tract infection, bile duct infection (胆道感染), septicemia and . Other Streptococcus Streptococcus suis (猪链球菌)a zoonotic disease, capable of transmission to humans from pigs. Humans can be infected with S. suis when they handle infected pig carcasses or meat, especial

19、ly with exposed cuts and abrasions on their hands. Human infection can be severe, with meningitis, septicaemia, endocarditis, and deafness as possible outcomes of infection. Fatal cases of S. suis are uncommon, but not unknown.Sec. 3 Neisseriae(奈瑟菌属)Neisseria gonorrhoeae Biological characteristics m

20、orphology and staining G- , diplococci (pairs of cocci) most in PMNculture-enriched media chocolate agar-heated blood (brown) 5% CO2resistance weakNeisseria gonorrhoeae (淋病奈瑟菌)PathogenesisPili - adherenceOMP - adherence， anti-pahgocytosisIgA proteaselipooligosaccharide ( LOS, 脂寡糖)Lack of long O anti

21、gen side chainsHelps gonococci evade immune recognition Similar to LPSDiseases caused by N gonorrhoeae found only in manadultsSTDgonorrhea(淋病)Gonococcal urithritis (尿道炎), epididymitis (副睾炎)Gonococcal colpitis (阴道炎), cervicitis(子宫颈炎), salpingitis (输卵管炎)NewbornGonococcal ophthalmia neonatorum (淋球菌性结膜炎

22、, 脓漏眼)(the meningococcus)Neisseria meningitidis (脑膜炎奈瑟菌) Ag and pathogenic materialscapsule Aganti-phagocytosis pili adherence LOS endotoxin diseaseMeningococcal meninigitis(流行性脑脊髓膜炎) N. meningitidis resides in man only usually sporadic cases mostly young children outbreaks adults crowded conditions

23、Neisseria meningitidis upper respiratory tract infection pili adhere to epithelial cellsbloodstreambrainMeningococcal meninigitis second most common meningitis pneumococcus, most common fatal if untreated responds well to antibiotic therapy penicillin Sec. 4 Laboratory DiagnosisSpecimensN. meningiti

24、disSensitive to low temperature and drySmears and stainingG+ or G- coccusCulture and coloniesCommon media Laboratory DiagnosisEnriched mediablood, serum, heated blood (chocolate agar) coloniesvirulence: coagulase test, enterotoxin testAg/Ab tests: ASOrapid test for meningitidis: SPA coaggulationSusc

25、eptibility testingThe distinguish tests of a hemolytic Streptococcus and S. pneumonia a hemolytic StreptococcusS pneumoniabile solubility test胆汁溶菌试验+Optochin test奥普托欣试验+菊糖发酵试验+Not optochin sensitiveoptochin sensitiveOptochin test奥普托欣试验brief summary for pyogenic coccuskinds-G+, G-microscopy - shape, staining, array, piliPrimary pathogenic materialsCell surface structures -SPA, M protein, LTA, pili, capsuleenzyme