Vitamin B6-Dependent Streptococcus mitior (mitis) Isolated from Patients with Systemic Infections

Publisher Website
Google Scholar
Abstract
Strains of nutritional-variant viridans Streptococcus were isolated from two patients with bacterial endocarditis and from one patient with a pancreatic abscess. All three strains grew as satellite colonies of other bacteria but did not grow as pure cultures in media lacking sufficient thiol compounds. For one-half maximal growth these organisms required the addition of one of the active forms of the B6 vitamin, pyridoxal · HCI (0.162–1.45 µ/ml) or pyridoxamine dihydrochloride (0.67–2.0 µ/ml), or addition of l-cysteine (0.235–0.425 mg/ml) to routine bacteriological media. The active forms of vitamin B6 are essential coenzymes in the synthesis of l-cysteine and of other thiol compounds. Use of media supplemented with 0.001% pyridoxal · HCL led to identification of the strains as Streptococcus mitior (mitis). Incorporation of pyridoxal · HCI, pyridoxamine dihydrochloride, or l-cysteine into media is recommended for the isolation and identification of vitamin B6-dependent viridans strep

This publication has 0 references indexed in Scilit: