title: Comparison of the environmental survival characteristics of Salmonella Dublin and Salmonella Typhimurium.
abstract: To examine possible correlations in bovine Salmonella isolates between environmental survival and serovar-associated epidemiological patterns, bovine field isolates of Salmonella serovars Typhimurium and Dublin (two each) were inoculated into bovine faeces slurry and tested monthly by culture for survival during a six-month period of storage at a variable ambient temperature in a disused animal transporter. Low moisture conditions, where the slurry was dried onto wooden dowels, increased detectable survival of a low-level inoculum by up to five months, compared with wet slurry. A more modest increase of survival time was seen with storage of wet slurry under refrigeration at 4°C. Under both dry and wet conditions, the concentration of culturable Salmonella Typhimurium declined at a slower rate than did that of Salmonella Dublin. Salmonella that was naturally contaminating bovine faeces from farms with Salmonella Typhimurium did not show superior survival times compared with Salmonella Typhimurium that had been artificially inoculated into samples. The differing survival characteristics of the two serovars that was observed in environmental faeces may complement their different modes of infection in cattle. Salmonella Dublin, being a bovine host-adapted strain that establishes chronic infection in some animals, may have less need to survive for a prolonged period outside of its host than does Salmonella Typhimurium.
authors.affiliation: Department of Bacteriology, Animal Health and Veterinary Laboratories Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, United Kingdom.
authors.forename: Miranda J
authors.initials: MJ
authors.lastname: Kirchner
authors.forename: Ernesto
authors.initials: E
authors.lastname: Liebana
authors.forename: Ian
authors.initials: I
authors.lastname: McLaren
authors.forename: Felicity A
authors.initials: FA
authors.lastname: Clifton-Hadley
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Wales
authors.forename: Robert H
authors.initials: RH
authors.lastname: Davies
mesh_terms: D000818:Animals; D002417:Cattle; D004783:Environmental Microbiology; D005243:Feces / Q000382:microbiology; D050296:Microbial Viability; D012481:Salmonella Infections, Animal / Q000382:microbiology; D019779:Salmonella enterica / Q000145:classification / Q000302:isolation & purification / Q000502:physiology*; D012486:Salmonella typhimurium / Q000302:isolation & purification / Q000502:physiology*