Biological properties and genetic characteristics of experimental diagnostic Vibrio cholerae bacteriophages

Abstract

Background. Currently, the researches focused on the design of new diagnostic and preventive preparations based on bacteriophages are underway, so it is importatnt to study the biological properties of cholera phages along with their genetic structure. This information is necessary to predict the phage life cycle and assess the prospects of its practical use in experiments, phagodiagnostics and phagoprophylaxis.Materials and methods. The presence or absence of genes characteristic of temperate bacteriophages was tested using a database created by the authors and developed software "PhageAnalyzer", which allows for rapid analysis of bacteriophage genome-wide sequencing data and prediction of their life cycle.Results and discussion. The morphological structure of experimental diagnostic cholera phages is represented by head bacteriophages of various morphogroups. Negative colonies phage differed in diameter, shape and degree of transparency. No genetic determinants of resistance factors and toxins have been found in the genomes of bacteriophages Rostov-1, Rostov-6, Rostov 7, and Rostov M3. Results of phylogenetic analysis demonstrated that the studied experimental cholera bacteriophages resemble headphages from the genus Vibrio, but are unique, since they lie outside “cluster groups”. Vibrio phages Rostov-1 and Rostov M3 are appeared to be lytic. Genes characteristic of moderate bacteriophages were found in cholera phages Rostov-6 and Rostov 7.Conclusion. The experimental cholera bacteriophage Rostov-1 can be used to differentiate cholera vibrion O1 the serogroup of the El Tor biovar, and Vibrio phage Rostov M3 can be used to differentiate the Classical biovar. Both bacteriophages are lytic and promising components for creating prophylactic drugs against cholera. Vibrio phages Rostov-6 and Rostov 7 can be successfully used only in experimental activities, as well as for monitoring cholera vibrions in the environment. Complete genomic sequences are deposited and available in the international database Genbank (NCBI).