STREPTOCOCCI

(staphylococci are catalase positive) Streptococci facultative anaerobe Gram-positive chains or pairs catalase negative (staphylococci are catalase positive)

Streptococcus in chains

Streptococcus pneumoniae (diplococcus). Fluorescent stain

Streptococci Lancefield groups Satu atau lebih spesies per group antigen permukaan

groupable streptococci A, B and D most important C, G, F rare

Non-groupable S. pneumoniae viridans streptococci pneumonia e.g. S. mutans dental caries

hemolysis reaction - sheep blood agar α (alpha) partial hemolysis green color β (beta) complete clearing A and B γ (gamma) no lysis

Hemolysis Groups A an B β Group D α or γ S. pneumoniae and viridans γ

hemolysis reaction + one characteristic presumptive identification

Group A streptococcus (S. pyogenes)

Group A streptococcal menginfeksi semua umur Insiden tertinggi pd usia 5-15 thn

S. pyogenes -suppurative non-invasive pharyngitis Infeksi kulit, impetigo invasive bacteremia toxic shock-like syndrome "flesh eating" bacteria pyrogenic toxin

Pyrogenic toxin superantigen T cell mitogen Mengaktifkan sistem imun

Scarlet fever rash erythrogenic toxin

non-suppurative rheumatic fever inflammatory disease life threatening Sekuel kronik demam jantung sendi rheumatic tidak sama dengan rheumatoid arthritis

Rheumatic fever -etiology M protein cross-reacts heart myosin autoimun Antigen dinding sel sedikit dicerna in vivo bertahan lama

Rheumatic fever penicillin menyembuhkan pharyngitis Menurunkan resiko carditis

Acute glomerulonephritis immune complex disease of kidney

Major pathogenesis factors lipoteichoic acid/F protein fimbriae binds to epithelial cells M protein anti-phagocytic

M protein major target strain variation re-infection Imunitas alami antigenicity re-infection Terjadi dengan strain yg berbeda

Capsules Anti-phagocytic mucoid strains

Isolation and identification β hemolytic colonies bacitracin menghambat pertumbuhan β hemolytic colonies group A antigen

β hemolysis hemolysin O hemolysin S Sensitif oksigen Non sensitive oksigen

Post-infectious diagnosis (serology) Antibodi thd streptolysin O Penting! Bila menetap sekuel kronik terjadi

Serotyping M T R

Group B streptococcus neonatal meningitis septicemia transmission vaginal flora

Group B streptococcus - identification β hemolysis hippurate hydrolysis CAMP reaction meningkatkan β hemolisis S. aureus

Group D streptococcus Tumbuh pada bile esculin agar precipitasi hitam 6.5% salin Tumbuh enterococci Tidak tumbuh non-enterococci

Enterococci Hubungannya agak jauh dr streptococci lain genus Enterococcus Flora usus urinary tract infection Kontaminasi dr anus opportunistic infections khususnya endocarditis Paling sering E. (S.) faecalis

Enterococci resisten thd banyak antibiotik termasuk vancomycin ujung D-ala diganti dengan D-lactat

Minute colony streptococci Various groups (e.g. group A) berbeda scr genetik koloni yg besar (e.g. S. pyogenes) tdk ada demam rheuma Koloni besar Koloni kecil

Viridans streptococci diverse species oral Karies gigi α hemolytic dan negatif thd tes lain non-groupable. termasuk S. mutans endocarditis cabut gigi