Negative Cocci

Bacteriology GRAM - NEGATIVE COCCI I. NEISSERIA MORPHOLOGY AND CULTURE CHARACTERISTICS • Usually in pairs with flattened adjacent sides, immotile • Cell envelope present • Aerobic or facultatively anaerobic o Very sensitive to drying, chilling, pH change o Iron required for growth o Best grown in 2-8% C02 enhancement o Chocolate agar will support primary isolation from usually sterile sites. o Thayer-Martin medium (chocolate agar plus Vancomycin, colistin, and nystatin) permits isolation in otherwise contaminated specimen. • Speciation based on carbohydrate metabolism o N. meningitidis produces acid from glucose and maltose o N. gonorrhoeae produces acid from glucose only

TRANSMISSION N. meningitidis • Adult nasopharyngeal carrier provides a reservoir • Exclusively a human pathogen • Enters upper respiratory tract; then may eventually disseminate N. gonorrhoeae • Venereal transmission • Peak incidence-July through September • Increased prevalence in nonwhites, low socio-economic groups, and urban dwellers CLINICAL MANIFESTA TIONS N. meningitidis • Mild febrile illness with or without pharyngitis • Meningitis • Meningococcemia o Vasculitic purpura o Disseminated intravascular hemolysis o Waterhouse-Friderichsen syndrome (coagulopathy, Hypotension, adrenal hemorrhage, and sepsis) o Metastatic lesions to lung, pericardium, joints, eyes, etc. N. gonorrhoeae - Uses pili to attach to epithelial cells Acute anterior urethritis More common complications o Urethral stricture o Epididymitis o Prostatitis Less common complications o Septicemia o Meningitis o Peritonitis

Gonorrhea (genital) in females • 20-80% asymptomatic • Complications -Pelvic inflammatory disease -Generalized peritonitis Proctitis (especially common in male homosexuals) Disseminated disease -Arthritis-dermatitis syndrome -Subacute bacterial endocarditis Ophthalmia neonatorum Neonatal gonococcal arthritis Vulvovaginitis in prepubescent females DIAGNOSIS Identification of the organism by gram stain or in culture (Thayer-Martin chocolate agar from infectious material) N. meningitidis -Blood, petechiae, CSF, synovial fluid

-Nasopharyngeal or throat swab N. gonorrhoeae -Urethral discharge, conjunctival discharge -Skin lesion scrapings -Synovial fluid, blood -Endocervical, urethral exudate -Pharyngeal swab, rectal swab Counterimmunoelectrophoresis (N. meningitides) • (a)CSF • (b)Synovial fluid • (c) Urine Treatmant N. meningitides: Penicillin G N. gonorrhoeae: Penicillin, however there are now resistant organisms and spectinomycin or cefoxitin is recommended