title: Active but nonculturable cells of Salmonella enterica serovar Typhimurium do not infect or colonize mice.
abstract: The possibility that nonculturable cells of a normally culturable bacterial pathogen may constitute a source or reservoir for infective disease was investigated. In multiple experiments and with careful attention to the statistical limitations of the assays used, Salmonella enterica serovar Typhimurium cells rendered nonculturable by carbon and nitrogen stress in the presence of chloramphenicol were administered orally and intraperitoneally to over 300 female BALB/c mice. Neither infection nor colonization was detected in these studies, even when active but nonculturable (ABNC) cells, as defined by the Kogure cell elongation assay, were present in the inoculum. Doses of ABNC cells exceeding the oral and intraperitoneal LD(50) values by 3.5 and 2 orders of magnitude, respectively, were administered. It was concluded that ABNC cells of the salmonella strains used could not be considered potentially infective and that their detection in samples from material being evaluated as a potential source or reservoir of infection by the Kogure test does not specifically represent an infective hazard.
authors.affiliation: Department of Microbiology and Immunology, Medical Sciences Building, PO Box 138, University Road, Leicester LE1 9HN, UK1.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Smith
authors.affiliation: Department of Microbiology and Immunology, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK2.
authors.forename: Angela T
authors.initials: AT
authors.lastname: Newton
authors.affiliation: Department of Microbiology and Immunology, University of Newcastle, Newcastle upon Tyne NE2 4HH, UK2.
authors.forename: Colin R
authors.initials: CR
authors.lastname: Harwood
authors.affiliation: Department of Microbiology and Immunology, Medical Sciences Building, PO Box 138, University Road, Leicester LE1 9HN, UK1.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Barer
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002701:Chloramphenicol / Q000494:pharmacology; D005260:Female; D007274:Injections, Intraperitoneal; D007928:Lethal Dose 50; D051379:Mice; D008807:Mice, Inbred BALB C; D012481:Salmonella Infections, Animal / Q000382:microbiology*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000472:pathogenicity* / Q000502:physiology; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D002701:Chloramphenicol