title: Characterization of bacteriophages used in the Salmonella enterica serovar Enteritidis phage-typing scheme.
abstract: The 16 Salmonella enterica serovar Enteritidis (S. Enteritidis) typing phages (SETPs) used in the Laboratory of Enteric Pathogens (Health Protection Agency, London, UK) phage-typing scheme have not previously been characterized in detail. We have examined the adsorption properties of the phages with respect to a number of S. enterica serovars and defined phage morphology with electron microscopy. PFGE was used to estimate overall genome size and banding patterns generated by electrophoresis following restriction endonuclease digestion of the genome with HindIII were compared. PCR amplification and sequencing of selected genes was performed. The 16 phages comprise three morphotypes, Podoviridae (SETP1, 8, 10, 14, 15 and 16), Siphoviridae (SETP3, 5, 7, 11, 12 and 13) and Myoviridae (SETP2, 4, 6 and 9). All Podoviridae and Siphoviridae, but not Myoviridae, adsorbed to the O12 lipopolysaccharide antigen of Salmonella serogroups B (4,12) and D(1) (9,12). The genome sizes for the Podoviridae and Siphoviridae (PFGE-A) were approximately 42 kb. The genome size for Myoviridae SETP2, 4 and 9 was 36.5 kb, and for myovirus SETP6 was 27 kb. HindIII digestion of phage DNA produced 9 distinct patterns of 8 to 11 bands. Relationships between phages based on digest patterns were consistent with those defined by morphology. The Podoviridae had homologues of several P22 genes while the Siphoviridae had homologues of several genes present in the sequenced siphovirus SETP3 (EF177456). This study represents an initial step in characterizing the molecular basis that underlies the widely used S. Enteritidis typing scheme.
authors.affiliation: National Salmonella Reference Laboratory, Galway, Republic of Ireland.|National University of Ireland Galway, Galway, Republic of Ireland.
authors.forename: N
authors.initials: N
authors.lastname: De Lappe
authors.affiliation: National Salmonella Reference Laboratory, Galway, Republic of Ireland.
authors.forename: G
authors.initials: G
authors.lastname: Doran
authors.affiliation: National Salmonella Reference Laboratory, Galway, Republic of Ireland.
authors.forename: J
authors.initials: J
authors.lastname: O'Connor
authors.affiliation: National Salmonella Reference Laboratory, Galway, Republic of Ireland.
authors.forename: C
authors.initials: C
authors.lastname: O'Hare
authors.affiliation: National Salmonella Reference Laboratory, Galway, Republic of Ireland.|National University of Ireland Galway, Galway, Republic of Ireland.
authors.forename: M
authors.initials: M
authors.lastname: Cormican
mesh_terms: D001434:Bacteriophage Typing / Q000379:methods*; D015967:Gene Expression Regulation, Viral / Q000502:physiology; D016679:Genome, Viral; D008070:Lipopolysaccharides; D008242:Lysogeny; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D039002:Prophages; D012483:Salmonella Phages / Q000235:genetics* / Q000502:physiology; D012477:Salmonella enteritidis / Q000821:virology*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific) / Q000378:metabolism
chemical_list: D008070:Lipopolysaccharides; C090528:DNA modification methylase HindIII; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific)