Purpose: The purpose of this present study was to isolate bacteriophages specific to Salmonella and E. coli from water samples in the Metro Detroit area.
Methods: Water samples collected from rivers and waste water treatment plant (WWTP) were centrifuged, filtered, and mixed with indicator strains (S. Typhimurium ATCC 13311, S. Typhimurium ATCC BAA-712, S. Typhimurium MZ 1260, S. Typhimurium MZ 1261, S. Typhimurium MZ 1262, S. Enteritidis MZ 1263, E. coli O157:H7 ATCC 700927, E. coli ATCC 13706 and ATCC 23631) in double strength Tryptic Soy Broth (TSB). Overnight cultures were centrifuged, filtered, and treated with chloroform. Ten microliters of resultant lysate were spotted to Tryptic Soy Agar (TSA) plates which has soft agar layer containing indicator stains and examined for phages after 18-hr incubation. Lysis- positive supernatants were purified using soft agar overlay technique with indicator strains.
Results: Phages were isolated from 3 out of 35 water samples, including 1 sample from rivers and 2 from waste water treatment plant (WWTP). Two bacteriophage samples were able to infect all 6 Salmonella indicator strains and 3 E. coli indicators, suggesting a broad host range of bacteriophages.
Significance: Bacteriophages with broad host ranges are prevalent in water and able to infect pathogens of human public health significance. These bacteriophages have potential to be applied to bacterial detection in water.