HORIZONTAL SPREAD OF AN ALTERED PENICILLIN-BINDING PROTEIN 2B GENE BETWEEN STREPTOCOCCUS-PNEUMONIAE AND STREPTOCOCCUS-ORALIS

The region encoding the transpeptidase domain of the penicillin-bindin g protein 2B (PBP 2B) gene of two penicillin-resistant clinical isolat es of Streptococcus oralis was > 99.6% identical in nucleotide sequenc e to that of a penicillin-resistant serotype 6 isolate of Streptococcu s pneumoniae. The downstream 849 base pairs of these genes were identi cal. Analysis of the data indicates that the PBP gene has probably bee n transferred from S. pneumoniae into S. oralis, rather than vice vers a, and shows that one region of this resistance gene has been distribu ted horizontally both within S. pneumoniae and into two different viri dans group streptococci.