Phage typing scheme for group D streptococci isolated from human urogenital tract.

Streptococci of Lancefield group D were isolated from 52.2% of pharyngeal, 55.5% of urethral, 56.6% of endocervical, and 75.4% of ano-rectal specimens. Seventeen phages isolated from sewage and urogenital specimens were selected for phage typing. Four of these lysed only the strains of Streptococcus faecalis and its variety liquefaciens. Another six phages lysed only the strains of Streptococcus faecium and its variety durans. With the help of seven bacteriophages, 346 of 384 (90.1%) strains of S. faecalis and its variety liquefaciens could be classified into 27 types. Similarly, with the help of 10 other bacteriophages, 97 of 117 (82.9%) strains of S. faecium and its variety durans could be grouped into 22 types. In 72 of 87 (82.7%) cases, similar phage types were obtained at different culture sites of the same individual.