METHOD DEVELOPMENT OF A OF OF INDICATOR BACTERIOPHAGES USE FOR IDENTIFICATION OF SALMONELLA SPP
The article shows the identification of Salmonella spp. by indicator bacteriophages. The purpose of the scientific research was the development of a phage identification scheme for Salmonella spp. The work was carried out in the Bacteriological Department of the Perm Veterinary Diagnostic Center in the period from 2014 to 2017. We used strains of Salmonella spp., Escherichia coli, Shigella flexneri, Proteus spp., Staphylococcus aureus and Listeria monocytogenes (total 131 strains). For the preparation of bacteriophages, white laboratory mice weighing 16-18 g (n = 22) were used. For purposes of investigation, an initial bacterial suspension containing 10<sup>8</sup> cells/cm<sup>3</sup> was prepared by the Densi-La-Meter (Erba Lachema, Czech Republic) from the daily agar cultures of the microorganisms studied. Next, a series of successive dilutions was made to obtain a slurry containing 10<sup>1</sup> cells/cm<sup>3</sup>. As a result, an inoculum containing 10 cells of Salmonella was added to 9.0 cm<sup>3</sup> of selenite broth and a similar volume of RVS- broth, an indicator phage in an amount of 0.1 to 3.0 cm<sup>3</sup> was added. As a result, it was established that the combined incubation of Salmonella and the eponymous phage in selenite broth and RVS-broth promotes the lysis of Salmonella spp., which can serve as a diagnostic sign for the identification of Salmonella. Having conducted a similar experiment with microbial associates, visualized varying degrees of turbidity and / or the presence of sediment, which led to the conclusion that the proposed method for identifying the desired bacteria is highly sensitive. The developed method for identification of Salmonella with the use of isolated bacteriophages surpassed the classical analogue for a number of indicators: sensitivity, efficiency, material and labor costs, and allowed saving 24 hours of time.