Selection of suitable parameter of phage titer growth reaction setup for indication of K.oxytoca bacteria
The article presents the results of studies related to the selection of appropriate conditions for reaction setup of phage titer growth with bacteriophages active against bacteria of K. oxytoca species. When using the phage titer growth reaction method, the bacteriophages Kokh-9 UGSKHA and Kokh-11 UGSKHA were used, which had strict specificity and sufficient lytic activity against bacteria of K. oxytoca species (K. oxytoca 86 - indicator culture for the bacteriophage Kokh-9 UGSKHA, K. Oxytoca 124 is indicator culture for the bacteriophage Kokh-11 UGSKHA). The conducted research consisted in specification of reaction quantitative parameter (which has diagnostic value) and specification of appropriate time parameter, which provides the best interaction of corpuscles of a phage with bacteria. The infectious concentration of cultures varied within the limits of 10<sup>1</sup>-10<sup>5</sup> m.a / ml. When selecting the time parameter of the reaction, which ensures appropriate interaction of the phage with bacteria, the method of preliminary growth of the studied material was used and the contact time of the studied material with the bacteriophage was increased. It was found that the most effective for this reaction is the regime where the infecting bacterial concentration of K. oxytoca species is equal to 10<sup>3</sup> m.c. /ml, with a 5-hour incubation of the test material with the phage. The analysis of the obtained results made it possible to conclude that there was no need in preliminary growth of the research material at 37 ° C for 5, 6,10,16 and 24 hours. The total research time was 22 hours. An increase of the growth time of the studied material to 16 hours allows to detect bacteria of K. oxytoca species in the amount of 10<sup>2</sup> m.c. / ml, provided that there is an increase of the research period to 37 hours.