athogeniccocci病原性球菌.ppt

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1、1.Pathogenic cocci 2.Other bacteria,1.Pathogenic cocciConcept of pathogenic bacteria 13minStaphylococcus(Esp.,S.aureus)56minStreptococcus(Esp.,S.pyogenes)38minEnterococcus species and VRE 5minNeisseria meningitides Neisseria gonorrhoeae 13min2.Other bacteriaPseudomonas aeruginosa 10min,Highlights of

2、 content,Up to every pathogen,the following will be talked:,Biological properties Pathogenicity Immunity Microbiological detections Prevention and treatment,Pustule(脓疱)by S.aureus,Pustule(脓疱)by S.aureus,Paronychia(甲沟炎)by S.aureus,Sore throat(咽喉炎)by S.pyogenes,Untreated erysipelas(丹毒)by S.pyogenes wi

3、th skin sloughing and necrosis,Necrotizing Fasciitis(坏死性筋膜炎)by flesh-eating bacteria(S.pyogenes,anaerobic bacteria,etc.),and insects(bee,etc.)stinging,Chest x-ray Film 1just a few hours of rigors and productive cough,Chest x-ray Film 212 hours laterconsolidation in the right upper lobe,Lobar pneumon

4、ia(大叶性肺炎)by S.pneumoniae,Meningococcal septicemia(脑膜炎球菌性败血症)by N.meningitidis,widespread ecchymoses,Gonococcal conjunctivitis(淋菌性结膜炎)by N.gonorrhoeae,Causative agents of above clinical diseases?,What is Pathogenic cocci?also called Pyogenic cocci(化脓性球菌),Including-Staphylococcus(S.aureus&S.epidermidi

5、s)(金黄色葡萄球菌与表皮葡萄球菌)-Streptococcus(Group A Streptococci,S.pyogenes)(A群链球菌 or 化脓性链球菌)-Streptococcus pneumoniae(肺炎链球菌)-Neisseria gonorrhoeae(淋病奈瑟菌)-Neisseria meningitidis(脑膜炎奈瑟菌),Important cocci,Staphylococcus aureus,Important pyogenic coccusLeading pathogen of wound infections(including other staphyloc

6、occi),Shape,Stain&Culture spherical,elliptical,irregular grape-like cluster Gram+(G+)Grow well on basic medium,Biological properties,Antigenic structure Staphylococcal protein A(SPA)One kind of surface protein in cell wall Single chain peptide Actions Binds(bacterium)to hosts IgG1,IgG2&IgG4 coagglut

7、ination test Competes w/Fc receptors of phagocytes resists phagocytosis,Coagglutination test with inert particles(e.g.,heat-killed S.aureus or latex beads),SPA may resist phagocytosis by competively binding with Fc receptors of phagocytes,Capsule Teichoic acid(polysaccharide)polysaccharide A S.aureu

8、s polysaccharide B S.epidermidis,Phases of phagocytosis,Important Properties of 3 Main Species of Staphylococci,Pathogenicity&immunity,Pathogenic substances,Coagulase,Virulence Protection actions Infection localized,Bound coagulase(结合凝固酶)or clumping factor(凝聚因子)plasma to be cloted or bacteria to coa

9、gulate Slide coagulase test,classified into-,-,-,&-toxin-toxin makes pores in cell membranes,Staphylolysin(葡萄球菌溶素),kills or degranulates neutrophils¯ophages,including type A&type B causes staphylococcal scalded skin syndrome(SSSS),Exfoliatin(表皮剥夺毒素),Others,heat-stable nuclease(耐热核酸酶),Clinical di

10、seases,Invasive diseases,Toxin-mediated diseases,Pyogenic infections-local infections-systemic infections,-food poisoning-staphylococcal scalded skin syndrome(SSSS)-toxic shock syndrome(TSS),Folliculitis(毛囊炎)by S.aureus,Bullous Impetigo by S.aureus,A S.aureus infection on a 12-year-old childs cheek,

11、Pathogenesis of staphylococcal infections,Microbiological diagnosis,Identification of pathogenic staphylococci,Coagulase(+)Heat-stable nuclease(+)Golden pigment(+)Hemolyzation(+)Mannite fermentation(+),Prevention&treatment,Methicillin-resistant S.aureus,MRSA(耐甲氧西林金黄色葡萄球菌),Coagulase-negative staphylo

12、cocci(CNS)(凝固酶阴性葡萄球菌),Compare the features of common pyogenic bacteria.Discuss the pathogenic features and identification points of Staphylococcus aureus.,Questions:,Streptococci,G+,spherical,elliptical,arranged in chain Grow well on nutrient medium w/blood,Biological properties,Shape,Stain&Culture,

13、Antigenic structure,Protein antigen surface Ag,outside C antigen type-specific including M,T,R,S in Group A Polysaccharid antigen C Ag group-specific Nucleoprotein P Ag non-specific,Classification,Pathogenicity,Group A Streptococci(S.pyogenes),Pathogenic substances,Streptolysin S(SLS,链球菌溶素S)-low MW

14、glycopeptide-oxygen-stable-causes-hemolysis on Blood Agar plate-non-antigenic,Streptolysin O(SLO,链球菌溶素O)-protein w/SH group-oxygen-labile-destroys many kinds of cells-anti-SLO test(ASO test)helpful for diagnosis,Streptolysin,-coded by lysogenic bacteriophage-proteins including serotype A,B,C-causes

15、scarlet fever(猩红热)-one kind of superantigens-also causes TSS,Streptococcal pyrogenic exotoxin(SPE)(链球菌致热外毒素),Streptokinase(SK,链激酶)-also called as streptococcal fibrinolysin(链球菌溶纤维蛋白酶),Streptodornase(SD,链道酶)-hydrolyzes DNA,Hyaluronidase(透明质酸酶)-also called as spreading factor(扩散因子)-hydrolyzes hyaluron

16、ic acid in connective tissue-helpful for spreading of bacteria,Clinical diseases,Pyogenic infections,Toxin-mediated diseases,Allergic diseases(late complications),-scarlet fever(猩红热)-Streptococcal toxin-mediated TSS,-rheumatic fever(风湿热)-acute glomeruloniphritis(急性肾小球肾炎),Erysipelas(丹毒)by S.pyogenes,

17、Cellulitis(蜂窝组织炎)by S.pyogenes,Honey-crust lesion typical of S.pyogenes impetigo,Pathogenesis of S.pyogenes infections,Samples,Pus,Blood,Nasopharynx swab,Isolation w/blood agar plate,distinguishing from S.pneumoniae,Smearµscopy,G+streptococci,distinguishing from staphylococciOther streptococci,

18、-hemolysis,Assist-diagnosis for rheumatic fever,-hemolysis,ASO test,Microbiological diagnosis,S.pneumoniae Group B streptococci Group D streptococci Viridans(-hemolytic)streptococci Streptococcus suis(猪链球菌)Enterococcus species(肠球菌)&VRE,Other streptococci,Enterococcus species and VRE,Enterococcus spp

19、.(肠球菌),Previously classified as Group D streptococci In 1984,named as genus Enterococcus Gram+cocci in pairs or short chains Most are facultative anaerobes Complex nutritional requirements Group D specific teichoic acid antigen,Enterococcus spp.viewed by direct fluorescent antibody(FA)reaction,Enter

20、ococcus spp.,Commonly found in the intestines of normal healthy individuals(humans and animals).2 important human diseases-related spp.E.faecalis(粪肠球菌)and E.faecium(屎肠球菌)Cause Urinary tract infections Bacteremia&septicaemia Subacute endocarditis Wound infections Foodborne diseases Meningitis Nosocom

21、ial infections,One of important life-threatening nosocomial pathogens Vancomycin Resistant Enterococci(VRE,耐万古霉素肠球菌)Since 1986,VRE infections has become a growing problem,1.Discuss the pathogenic features of Streptococcus pyogenes.2.Discuss identification points between hemolytic streptococci and ot

22、her pyogenic bacteria.,Questions:,Neisseria gonorrhoeae(淋病奈瑟菌),Biological properties,Shape and stain-G-diplococci in or on PMNs on pus smear-No endospore&flagellum,&w/capsule&pili,Culture-Obligate aerobes,need 5%CO2 while primary isolation-High nutritional requirement“Chocolate Blood Agar Plate”,Ant

23、igenic structure and classification-Pilus protein antigens-Outer membrane protein antigens：PI,PII,&PIII-LOS(lipooligosaccharide,脂寡糖),LPS-like,N.gonorrhoeae colonies on Chocolate Blood Agar Plate,Pathogenesis,Virulent factors-Pili-Outer membrane proteins-LOS-IgA1 protease-Others,Clinical findings-Gon

24、orrhea-Gonococcal conjunctivitis,Gonorrhea symptoms,Clinical manifestations of N.gonorrhoeae infection,Immunity,Humoral immunity more effective No persistent immune responses Infection trend to-chronic&repeated occurrence,Microbiological detections,Nucleic acids detection,&so on,Samples,Pus secreta

25、from genito-urinary tracts,eyes,&others,Isolation,Oxidase testSugar fermentation testImmunofluorescence assay,Smearµscopy,G-diplococci in or on PMNs,Coloniesµscopic findings,Biochemical reactions&serologic tests,Other tests,Prevention&treatment,Take preventions as main measure Choose penic

26、illin as No.1 drug，take care of problems of drugs-resistant bacterial stains,1.What are the main differences between Neisseria meningitides and Neisseria gonorrhoeae.,Question:,Pseudomonas aeruginosa(铜绿假单胞菌),P190,Shape,Stain&Culture G bacili single terminal flagellum appears capsule in some bacteria

27、l strains grows readily and rapidly on many media produces several kinds of water-soluble pigments,Biological properties,Pseudomonas aeruginosa colonies on agar plates,Pathogenicity&immunity,adhesins pilus non-pilus adhesin polysaccharide capsule endotoxin lipopolysaccharide(LPS),Pathogenic substanc

28、es,exotoxins exotoxin A-mode of action similar to diphtheria toxin exotoxin S(exoenzyme S)-inhibits phagocytosis-acts in vitro in the same way as the toxins of Vibrio cholerae elastase(弹性蛋白酶)-Las-A(丝氨酸蛋白酶)Las-B(锌金属蛋白酶),phosphoesterase C(磷脂酶 C)pyocyanin(绿脓菌素)Cytolysin:e.g.leukocidin,Clinical diseases,Opportunistic pathogen infections following burn hospital-acquired infections,Pulmonary infections,Primary skin infections,Urinary infections,Primary skin infections of Pseudomonas aeruginosa,1.Discuss the pathogenic features of Pseudomonas aeruginosa.,Question:,