Efficacy of bacteriophages to reduce Salmonella in mung bean sprouts

The sprouts are nutritionally rich snack foods. They are helpful in digestion and contribute various health benefits. However, many outbreaks associated with consumption of pathogen-contaminated sprouts have been reported. Minimally processed sprouts are preferred for consumption. Consequently, population of pathogens like Salmonella increases to significant level. The bacteriophages, vB_SalS_PM8 (PM8) and vB_SalM_ PM10 (PM10) were isolated from sewage and characterized for their host range, morphology, growth and genomic features. The ability of these phages to reduce Salmonella in sprout preparation was tested. Mung bean seeds were artificially infested with Salmonella serovars viz. Typhimurium, Typhi and Enteritidis. Simultaneously, phages, PM8, PM10 and PM8-PM10 mixture were added at multiplicity of infectionof 103, 103 and 2×103, respectively.In the samples devoid of phages, 48 hours post inoculation, it was found that the Salmonella population reaches to 9 ±0.2 log10 CFU g–1. Phages, PM8, PM10 and PM8-PM10 mixture, reduced Salmonellae by 96.2, 92.1 and 98.8%, respectively. Therefore, the phages, PM8 and PM10 can be used in processes of preparation of sprouts as a hurdle technology for reduction of Salmonellae.