title: Isolation and characterization of bacteriophages infecting Salmonella spp.
abstract: Bacteriophages infecting Salmonella spp. were isolated from sewage using soft agar overlays containing three Salmonella serovars and assessed with regard to their potential to control food-borne salmonellae. Two distinct phages, as defined by plaque morphology, structure and host range, were obtained from a single sample of screened sewage. Phage FGCSSa1 had the broadest host range infecting six of eight Salmonella isolates and neither of two Escherichia coli isolates. Under optimal growth conditions for S. Enteritidis PT160, phage infection resulted in a burst size of 139 PFU but was apparently inactive at a temperature typical of stored foods (5 degrees C), even at multiplicity of infection values in excess of 10 000. While neither isolate had characteristics that would make them candidates for biocontrol of Salmonella spp. in foods, phage FGCSSa1 behaved unusually when grown on two Salmonella serotypes at 37 degrees C in that the addition of phages appeared to retard growth of the host, presumably by the lysis of a fraction of the host cell population.
authors.affiliation: Food Safety Programme, ESR Ltd, Ilam, Christchurch, New Zealand.
authors.forename: Gwyneth V
authors.initials: GV
authors.lastname: Carey-Smith
authors.forename: Craig
authors.initials: C
authors.lastname: Billington
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Cornelius
authors.forename: J Andrew
authors.initials: JA
authors.lastname: Hudson
authors.forename: Jack A
authors.initials: JA
authors.lastname: Heinemann
mesh_terms: D003080:Cold Temperature; D012475:Salmonella / Q000254:growth & development / Q000821:virology*; D012483:Salmonella Phages / Q000302:isolation & purification* / Q000502:physiology* / Q000648:ultrastructure; D012722:Sewage / Q000382:microbiology
chemical_list: D012722:Sewage