The application of bacterophages in laboratory diagnostic of cholera.

Abstract

The capacity of cholera agent to develop, during the seventh pandemic, the forms differing by attribute of resistance to bacteriophage determines overall complexity of solving problem of their phage-diagnostics. The search of new races of diagnostic cholera phages is actual and in the first instance relates to necessity of confirmation of specific characteristics of cholera agent by efficient, simple and reliable mode. Thereupon, the target was established to search new race of cholera phages being active in relation to phage-resistant to commercial medication of diagnostic phage of strains of cholera comma bacilli of biovar El-Tor. The study used 131 museum resistant to diagnostic cholera phages strain Vibrio cholerae El Tor separated from various sources in 2001-2014. The activity of 25 cholera phages in relation to sampled strains was verified. The most promising for constructing phage medication are three bacteriophages with spectrum of lytic activity as 44%, 53% and 56% correspondingly. Out of number of selected strains only 20 cultures (15%) maintained resistance to all phages. The estimated bacteriophages have different spectrum of lytic activity in relation to cholera comma bacilli El Tor. The new avirulent test-strain was to be found for reproduction and control of cholera diagnostic bacteriophage. So, non-toxigenic culture Vibrio cholerae El Tor 19546 was used. The analysis of received results demonstrated that analyzed cholera phages with high lytic activity can be used in diagnostics of phage-resistant strains of cholera comma bacilli. The actuality of application of phage-diagnostic technique lies in the fact that it requires no expensive equipment and large material expenses.