Oxygen requirements: generally anaerobic Motility: Other: capsule-formers; some strains alpha- and some nonhemolytic, able to ferment mannitol; capsule former Habitat: human mouth, upper respiratory tract and urogenital tract; part of normal flora Pathogenicity: responsible for mitral valve prolapse, subacute endocarditis and dental carries Transmission: Treatment: penicillin, erythromycin
S. pneumoniae
Oxygen requirements: facultative anaerobe Motility: non-motile Other: capsule-former; alpha-hemolytic; urease negative; only Streptococcus susceptible to small amounts of optochin. 80 different serotypes which are identified by their capsules. Habitat: Human sinus and nasal cavities Diagnosis: stained sputum smear with pus and gram-positive diplococci Pathogenicity: principal cause of community-acquired bacterial pneumonia (with cough, fever, rust-colored sputum, shortness of breath and chest pain), conjunctivitis (pink eye), sinus infections, major cause of bacterial meningitis in adults Transmission: inhalation of infected droplets and direct contact with a carrier Treatment: penicillin, erythromycin
S. pyogenes
Oxygen requirements: aerotolerant or facultatively anaerobic Motility: nonmotile Other: capsule-former; produces C5a peptidase which impedes phagocytosis and hemolysin which destroys red blood cells; beta hemolytic; ferments lactose Habitat: human nose, throat and skin Pathogenicity: pharyngitis ("strep throat"), impetigo, middle ear infections, mastoiditis, scarlet fever, acute rheumatic fever, glomerulonephritis, with virulent strains that eat flesh. Transmission: direct person-to-person contact, inhalation of infected droplets. Treatment: penicillin, erythromycin
Streptococcus spp.
