[Typing of Streptococcus faecalis and Streptococcus faecium strains with bacteriophages].

Abstract

With a set of 17 bacteriophages specific for Streptococcus faecalis and a set of 7 bacteriophages specific for Streptococcus faecium 441 strains of S. faecalis and 53 strains of S. faecium were typed. The species identification was done by means of the API 20 STREP system. For S. faecalis 22 and for S. faecium 12 lysotypes were found. Among S. faecalis strains lysotype V6b was most common (27%), followed by the lysotypes XV (9,5%), XIII1 (7%), II1 (5,7%), and I1 (4,3%). These 5 lysotypes comprised 54% of all 441 strains. 21% of the strains of S. faecalis and 6 from 53 strains of S. faecium were untypable. Strains of S. faecium were most frequently isolated from faeces and in rare cases from urine. To the contrary 50% of the S. faecalis strains were isolated from urine. There was no correlation between special lysotypes and age of the patients or the source of specimen. The results of phage typing of several strains from one patient, and especially of strains from mothers and their newborns suggest the usefulness of the typing system to clarify epidemiological questions.