Streptococcus Tao Chuanmin

Widespread in nature Some strains as virulent pathogens Other strains live harmoniously Transient colonizers of skin Resident colonizer of mucous membranes Normal flora of alimentary, respiratory and genital tracts

Classification 40 species and subspecies Traditional rules Hemolytic reactions α hemolytic β hemolytic γ hemolytic Lancefield serological tests A、B、C、D、E…

Clinical significant Impressive human pathogen Group A streptococci(S. pyogenes) Impressive human pathogen Acute pharyngitis,respiratory infection Skin (impetigo and erysipelas) and soft tissue infection

Numerous virulence factors Endoarditis, meningitis, scarlet fever and more serious toxic shock-like symptoms Acute glomerulonephritis, rheumatic fever Numerous virulence factors M protein, Pyrogenic exotoxins, Hyaluronic acid capsule, Hemolysins etc.

Viridans Streptococci Group B streptococci(S. agalactiae) Neonatal infection sepsis and meningitis Group C and G streptococci Similar to S. pyogenes Viridans Streptococci Normal flora Subacte bacterial endocaditis(SBE)

Streptococcus pneumoniae Community-acquired pneumonia, bacteremia Otitis media, sinusitis, meningitis, and endocarditis

Microbial Characters GPC Arranged：single,pairs,chains S. pneumoniae：

Facultatively anaerobe Chemical reaction: active metabolism Catalase：negative

Microbial diagnostics procedure 　　　　　　 specimen Smear and stain culture　direct examination 　　　　　　　 colony Smear and stain biochemical serology　 antibiotic identification　 identification susceptibility 返回

Microbial diagnostics Specimen collection Throat swab, sputum, pus and blood, et al Specimen direct diagnostics Smear and Gram stain Direct antigen detection

Culture and identification β hemolytic PYR test：Group A Bacitracin-susceptible：Group A VP(Voges-Proskauer) test CAMP test：Group B The PYR test determines activity of pyrrolidonyl arylamindase, also called pyrrolidonyl aminopeptidase, an enzyme produced by S. pyogenes but not by other beta-hemolytic streptococci except for the rarely encountered animal-associated species S. porcinus and S, iniae. CAMP factor(a diffusable extrceelular protien) acts synergistically with staphylococcal beta-lysin to cause lysis of red blood cells.

Non β hemolytic Optochin test Bile solubility test Bile esculin test

Serologic tests：Streptolysin O Antibiotic susceptibilities：A、B、C group Evaluation, interpretation and reporting of results Beta-hemolytic streptococci and pneumococci are virulent pathogens, all reporting PRSP(penicillin resistant Streptococcus pneumonia)

Enterococcus Common description Classification Widespread in nature Gastrointestinal and genitourinary tract flora Hospital-acquired infection pathogen Classification E. feacalis and E. faecium

Clinical significant Urinary tract infections(UTIs)：underlying structural abnormalities and undergone urologic manipulations Abdominal and pelvic infections sepsis

Microbial Characters GPC(single, pairs, short chains) Facultative anaerobes PYR test positive Higher resistance to chemical and physical agents Bile-esculin positive Resistance to several antibiotics

Microbial diagnostics procedure Specimen collection Direct detection Culture and identification Catalase negative Grow in 6.5% NaCl broth Bile-esculin positive

Antibiotic susceptibilities A group Penicillin or ampicillin B group Vancomycin C group　Tetracycline, erythromycin, chlormphenicol, Rifampin D group Ciprofloxacin, Norfloxin high-level resistance(HLR) to aminoglycosides Enterococcus 500ug/ml gentamicin 　　2000ug/ml streptomycin vancomycin resistant Enterococcus (VRE) 6ug/ml vancomycin

Neisseria and Branhamella Neisseriaceae Neisseria, Branhamella, Moraxella, Kingella and Acinetobacter Mainly pathogens N. gonorrhoeae N. meningitidis B. catarrhalis

Clinical significant N. gonorrhoeae Common sexual transmitted diseases(STD) Transmitted by direct, close, usually sexual Transmission to neonates usually occurs during birth

virulence factor :pili

N. meningitidis B. catarrhalis Meningitis, meningococcemia Usually transmitted by direct contact with contaminated respiratory secretions or air-borne droplets School-age children, adolescents, and young adults B. catarrhalis Acute localized infections: otitis media, sinusitis, and bronchopneumonia Life-threatening systemic diseases: endocarditis and meningitis

Microbial Characters Gram-negative diplococci Adjacent sides flattened to give a characteristic kidney or coffee bean appearance Nonmotile，no endospores，some species are encapsulated Cell may autolyze in culture

Complex growth requirements aerobe The growth is enhanced by humidity and CO2 Oxidase positive catalase positive

Microbial diagnostics Procedure Collection Direct detection Direct microscopy Antigen and nucleate detection

Culture and identification Selective media：MTM，ML，NYC（N. gonorrhoeae ） Nonselective media：Chocolate agar or blood agar 5%CO2

Colonial appearance N. G：small,smooth N. M：small,smooth,flat,mucoid B. C：small, friable

Presumptive identification Confirmatory identification GNC，OX+ Confirmatory identification G.M：acid production from glucose and maltose G.N：acid production from glucose B.C：DNase +，nitrate reduction + (-) (+) 氧化酶 DNA酶试验 硝酸盐还原试验阳性

Antibiotic Susceptibilities Penicillin, cephalosporin、tetracycline、ciprofloxacin Resistant strains G.N：3rd cephalosporins、new fluoroquinolone B.C：extended-spectrum penicillin＋penicillinase inhibitory

Evaluation, interpretation and reporting results confirm：depend on culture and identification Early and rapidly diagnosis

Summary Staphylococcus Streptococcus Enterococcus Neisseria and Branhamella Classification、Clinical Significance、Microbial Characters、Microbial diagnostics