title: Differentiation of Salmonella enteritidis phage type 8 strains: evaluation of three additional phage typing systems, plasmid profiles, antibiotic susceptibility patterns, and biotyping.
abstract: Three additional phage typing systems for Salmonella enteritidis, plasmid analysis, biochemical tests, and antimicrobial susceptibility tests, were used in an attempt to subdivide 30 phage type 8 (phage typing system used by the WHO International Center for Enteric Phage Typing, London, England) isolates. These isolates represented 18 different egg-related outbreaks (21 strains) and 9 reference strains or strains that were not egg-associated. Only 7 of the 30 strains (28%) were subdivided by one or more of the methods used; this included 3 of the 21 strains from egg-related outbreaks. Twenty-seven strains contained a 55-kb plasmid that is associated with S. enteritidis. Of 65 additional phages tested, 2 from the phage typing system obtained from the Pasteur Institute, Paris, France, were useful in differentiating the three strains that lacked the 55-kb plasmid. Although the results obtained for the 21 strains from egg-related outbreaks showed that the strains had minor phenotypic differences, the overall results suggested that the strains may represent a single clone. Studies are planned to test additional phages and other typing methods to see whether strains of phage type 8 can be further differentiated.
authors.affiliation: Enteric Diseases Laboratory Section, Centers for Disease Control and Prevention, Atlanta, Georgia 30333.
authors.forename: A D
authors.initials: AD
authors.lastname: Stubbs
authors.forename: F W
authors.initials: FW
authors.lastname: Hickman-Brenner
authors.forename: D N
authors.initials: DN
authors.lastname: Cameron
authors.forename: J J
authors.initials: JJ
authors.lastname: Farmer
mesh_terms: D015373:Bacterial Typing Techniques; D001434:Bacteriophage Typing / Q000592:standards; D004531:Eggs / Q000382:microbiology; D005243:Feces / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics; D012015:Reference Standards; D012477:Salmonella enteritidis / Q000145:classification*; D012703:Serotyping