Infectivity Criteria for use of ɸSEP2 and ɸSEP3 as Bio-control Agents

Abstract

The emergence of multi-drug resistant Salmonella, one of the major pathogens causing food poisoning is challenging. Salmonella Enteritidis infections in poultry are widespread and the quest for safe alternatives to antibiotics led to phages. The purpose of this study was to isolate and characterize a novel pathogenic/lytic phages that targets Salmonella and to investigate its efficacy at lysing the bacterium. Poultry isolated Salmonella BT55CW showed considerable antibiotic resistance with MAR index of 0.4. Two lytic phages ɸSEP2 and ɸSEP3 were isolated using BT55CW Salmonella strain to control Salmonella infections. Morphology, host range and growth kinetics were studied. Influence of various physical and chemical factors such as pH, temperature, NaCl concentration and survival under different nutrient deprived conditions on the infectivity and persistence of phage forms the crux of the study. By TEM analysis ɸSEP2 and ɸSEP3 showed typical features of Podoviridae and Myoviridae respectively. Both lysed 60% all the Salmonella strains tested, survived at nutrition depleted conditions and substantially reduced Salmonella growth. Both phages showed considerable stability in the range of pH and temperature studied, but ɸSEP3 was less susceptible and hence a better candidate of the two as bio-control agent.Keywords: Salmonella-Phage-Bio control-Gastroenteritis-antibiotic-resistance; ɸSEP3; BT55CW Salmonella strain Citation: Sritha KS, Shemymol KA, Bhat SG (2017) Infectivity Criteria for use of ɸSEP2 and ɸSEP3 as Bio-control Agents. J Bacteriol Mycol Open Access 5(4): 00140.