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Introduction. The development and use of therapeutic drugs based on bacterial viruses, or bacteriophages, is a promising direction in the fight against bacterial infections. The composition of phage preparations must be constantly updated, which requires the search for new viruses through the screening of biological material and samples from the environment.Purpose. Development of a method for the search and identification of virulent enterococcal bacteriophages based on the polymerase chain reaction (PCR).Materials and methods. The known diversity of enterococcal viruses was assessed by database searches of the National Center for Biotechnology Information (NCBI) and the International Committee on Taxonomy of Viruses (ICTV). Primers were selected using the NCBI PrimerBlast and Primer3 programs. Primers were tested on seven commercial phage cocktails and 46 biomaterial samples. The specificity of PCR was confirmed by determining the nucleotide sequences of PCR products.Results. The obligately virulent enterococcal bacteriophages described in the literature belong to five ICTV approved genera: Copernicusvirus, Efquatrovirus, Kochikohdavirus, Saphexavirus, and Schiekvirus. Representatives of the sixth genus, Phifelvirus, have a temperate life cycle. The PCR scheme developed by us is intended for specific amplification of fragments of the gene of the main capsid protein of the mentioned genera of bacteriophages. It was used to identify representatives of all five genera of virulent enterococcal bacteriophages in commercial phage cocktails. In samples of biological material, we identified representatives of the genera Efquatrovirus, Kochikohdavirus, Saphexavirus and Schiekvirus.Conclusion. The PCR scheme presented in this work makes it possible to detect all currently described obligately virulent bacteriophages infecting Enterococcus spp. in phagolysates and samples of biological material, and can also be used to determine the genera of viruses.

Group B streptococci, or Streptococcus agalactiae, are the major cause of severe diseases in newborns and adults. The PAI-A and PAI-A1 pathogenicity islands containing the sspB1 and sspB1a genes, respectively, were found among group B streptococci mobile genetic elements. The presence of sspB genes correlates with urogenital tract infections. The aim of this study was to determine the frequency of group B streptococci strains with the PAI-A and PAI-A1 pathogenicity islands, circulating in Moscow, in comparison with strains from St. Petersburg. The sspB1 gene, and hence the PAI-A pathogenicity island, was not found in the genomes of strains from Moscow. The frequency of the sspB1a gene and the PAI-A1 pathogenicity island in the genomes of clinical strains was three times higher than in the genomes of colonizing strains. Thus, it can be assumed that the genes of the sspB family are more specific of group B streptococci colonizing pregnant women and newborns.