IDENTIFICATION OF PIONEER VIRIDANS STREPTOCOCCI IN THE ORAL CAVITY OFHUMAN NEONATES

Three hundred and sixty-seven strains of pioneer streptococci isolated from the mouths of 40 healthy, full-term infants during the first mon th of life were examined by two taxonomic schemes that incorporated bi ochemical and physiological characteristics, IgA1 protease production and glycosidase activities. Streptococcus mitis biovar 1 and S. oralis comprised 55.0% of the pioneer streptococci isolated from neonates. S . salivarius constituted 25.3% of the isolates, while S. anginosus, S. mitis biovar 2, S. sanguis and S. gordonii accounted collectively for 11.4%. Difficulties in identifying streptococci were encountered and 8.4% of the 367 isolates could not be assigned to a recognised species .