title: Experimental salmonellosis challenge model in older calves.
abstract: Non-typhoidal Salmonella serovars (NTS) are the leading cause of foodborne illnesses worldwide and the leading cause of hospitalization and death due to foodborne illnesses in the United States. While there has been some progress in vaccine development against Salmonella spp., there are no broadly protective vaccines. A compounding factor in the development of these vaccines is the lack of a natural model. Most vaccine research is performed utilizing a mouse typhoid model. Unlike mice, calves infected with Salmonella develop gastroenteritis similar to the disease in humans. The initial step in developing a model of infection in older calves is the determination of a bacterial dose that elicits substantial clinical disease without causing death. Ten-week-old calves were orally inoculated with increasing doses of either Salmonella enterica serovar Typhimurium or Newport. Clinical illness scores were assigned based on rectal temperature, fecal consistency, attitude and hydration. Gross and microscopic pathology findings were also evaluated. These older calves exhibited clinical and pathologic signs of severe gastroenteritis without death losses with effective dose of 1 × 108 CFUs for S. Typhimurium and 1 × 107 CFUs for S. Newport.
authors: Oklahoma State University Center for Veterinary Health Sciences, Department of Veterinary Pathobiology, Stillwater, OK 74078, USA. Electronic address: tim.snider@okstate.edu.
authors: Timothy A
authors: TA
authors: Snider
authors: Oklahoma State University Center for Veterinary Health Sciences, Department of Veterinary Pathobiology, Stillwater, OK 74078, USA.
authors: Tamara
authors: T
authors: Gull
authors: Oklahoma State University Center for Veterinary Health Sciences, Department of Veterinary Pathobiology, Stillwater, OK 74078, USA.
authors: Todd A
authors: TA
authors: Jackson
authors: Oklahoma State University, Department of Microbiology and Molecular Genetics, Stillwater, OK 74078, USA.
authors: Francisco J
authors: FJ
authors: Martinez-Becerra
authors: Oklahoma State University, Department of Microbiology and Molecular Genetics, Stillwater, OK 74078, USA.
authors: Daniel R
authors: DR
authors: Picking
authors: Oklahoma State University, Department of Microbiology and Molecular Genetics, Stillwater, OK 74078, USA.
authors: William D
authors: WD
authors: Picking
authors: Oklahoma State University, Department of Microbiology and Molecular Genetics, Stillwater, OK 74078, USA.
authors: Wendy L
authors: WL
authors: Picking
mesh_terms: D000818:Animals; D001831:Body Temperature; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology* / Q000473:pathology*; D004195:Disease Models, Animal; D007422:Intestines / Q000473:pathology; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D012475:Salmonella / Q000502:physiology*; D012481:Salmonella Infections, Animal / Q000382:microbiology* / Q000473:pathology*; D012486:Salmonella typhimurium / Q000502:physiology; D014481:United States
keywords: Calf; Experimental infection; Newport; Salmonella; Typhimurium