pathogeniccocci病原性球菌.ppt

1. Pathogenic cocci 2. Other bacteria,1. Pathogenic cocci Concept of pathogenic bacteria 13min Staphylococcus (Esp., S. aureus) 56min Streptococcus (Esp., S. pyogenes) 38min Enterococcus species and VRE 5min Neisseria meningitides Neisseria gonorrhoeae 13min 2. Other bacteria Pseudomonas aeruginosa 10min,Highlights of 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 with 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 1 just a few hours of rigors and productive cough,Chest x-ray Film 2 12 hours later consolidation in the right upper lobe,Lobar pneumonia (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. epidermidis) (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 coccus Leading pathogen of wound infections (including other staphylococci),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 coagglutination 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. aureus 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 coagulate Slide coagulase test,classified into -, -, -, & -toxin -toxin makes pores in cell membranes,Staphylolysin(葡萄球菌溶素),kills or degranulates neutrophils & macrophages,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 diseases,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,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 staphylococci (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,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 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 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 hyaluronic 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,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,Smear & microscopy,G+ streptococci,distinguishing from staphylococci Other streptococci,-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. (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,Enterococcus 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 Nosocomial 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 other 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”,Antigenic 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 -Gonorrhea -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 from genito-urinary tracts, eyes, & others,Isolation,Oxidase test Sugar fermentation test Immunofluorescence assay,Smear & microscopy,G- diplococci in or on PMNs,Colonies & microscopic findings,Biochemical reactions & serologic tests,Other tests,Prevention & treatment,Take preventions as main measure Choose penicillin 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 capsul