Recognition of Group D Streptococcal Species of Human Origin by Biochemical and Physiological Tests

Abstract

The speciation of 262 strains of group D streptococci isolated from human sources is described. One hundred forty-two isolates from blood cultures were included; 96 of these were submitted as isolates from clinical cases of subacute bacterial endocarditis. The results show that 98 Streptococcus faecalis , 29 S. faecalis var. zymogenes , 44 S. faecalis var. liquefaciens , 27 S. faecium , 13 S. durans , 44 S. bovis , and 7 unspeciated S. bovis -like group D isolates were identified. No S. faecium var. casseliflavus, S. equinus , or S. avium (group Q streptococci) were identified among the human isolates. The speciation procedures and techniques are detailed. The procedures and limitations of the tests used are discussed. Ninety-eight percent of the 262 strains were speciated by a spectrum of tests that allowed us to recognize atypical as well as typical strains within species.