Characterization of a novel T7-like Salmonella Typhimurium (ATCC13311) bacteriophage LPST144 and its endolysin

Abstract Salmonella Typhimurium, one of the most common Salmonella spp. serovars, is recognized as a globally important foodborne pathogen. In this study, bacteriophage LPST144 against S. Typhimurium (ATCC13311) was isolated from sewage and selected owing to its excellent lytic capacity. After genome sequence analysis, the endolysin from LPST144 was cloned and expressed, and its lytic activity was verified. Morphological analysis showed that bacteriophage LPST144 belongs to Podoviridae family and Caudovirales order, and could completely inhibit host bacterial growth within 7 h at multiplicity of infection of 0.01–1000. Genome analysis indicated LPST144 genome comprised a 39,050 bp DNA with 43 putative open reading frames, of which 27 were annotated to known functions. No genes associated with lysogeny, antibiotic resistance and virulence factor were found. Putative endolysin LysT144 could significant decrease OD600nm from 0.80 to 0.14 against chloroform-treated S. Typhimurium within 30 min. Endolysin LysT144 remained highly active at pH ranging from 6.0 to 12.0, temperature below 50 °C, and NaCl concentration below 300 mM. Besides, LysT144 also exhibited extensive and broad spectrum of host bacteria strains, including multiple antibiotic-resistant Salmonella. Therefore, the bacteriophage LPST144 and its endolysin could be used as potential antibacterial agents for Salmonella control in food industry.