title: Mechanisms of antimicrobial resistant Salmonella enterica transmission associated with starling-livestock interactions.
abstract: Bird-livestock interactions have been implicated as potential sources for bacteria within concentrated animal feeding operations (CAFO). European starlings (Sturnus vulgaris) in particular are known to contaminate cattle feed and water with Salmonella enterica through their fecal waste. We propose that fecal waste is not the only mechanisms through which starlings introduce S. enterica to CAFO. The goal of this study was to assess if starlings can mechanically move S. enterica. We define mechanical movement as the transportation of media containing S. enterica, on the exterior of starlings within CAFO. We collected 100 starlings and obtained external wash and gastrointestinal tract (GI) samples. We also collected 100 samples from animal pens. Within each pen we collected one cattle fecal, feed, and water trough sample. Isolates from all S. enterica positive samples were subjected to antimicrobial susceptibility testing. All sample types, including 17% of external starling wash samples, contained S. enterica. All sample types had at least one antimicrobial resistant (AMR) isolate and starling GI samples harbored multidrug resistant S. enterica. The serotypes isolated from the starling external wash samples were all found in the farm environment and 11.8% (2/17) of isolates from positive starling external wash samples were resistant to at least one class of antibiotics. This study provides evidence of a potential mechanism of wildlife introduced microbial contamination in CAFO. Mechanical movement of microbiological hazards, by starlings, should be considered a potential source of bacteria that is of concern to veterinary, environmental and public health.
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA. Electronic address: James.C.Carlson@aphis.usda.gov.
authors.forename: James C
authors.initials: JC
authors.lastname: Carlson
authors.affiliation: Colorado State University, Veterinary Diagnostic Laboratories, College of Veterinary Medicine and Biomedical Science, 1644 Campus Delivery, Fort Collins, CO 80523-1644, USA.
authors.forename: Doreene R
authors.initials: DR
authors.lastname: Hyatt
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA.
authors.forename: Jeremy W
authors.initials: JW
authors.lastname: Ellis
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Texas Wildlife Services, P.O. Box 690170, San Antonio, TX 78269, USA.
authors.forename: David R
authors.initials: DR
authors.lastname: Pipkin
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Mangan
authors.affiliation: Colorado State University, Veterinary Diagnostic Laboratories, College of Veterinary Medicine and Biomedical Science, 1644 Campus Delivery, Fort Collins, CO 80523-1644, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Russell
authors.affiliation: Colorado State University, Veterinary Diagnostic Laboratories, College of Veterinary Medicine and Biomedical Science, 1644 Campus Delivery, Fort Collins, CO 80523-1644, USA.
authors.forename: Denise S
authors.initials: DS
authors.lastname: Bolte
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Engeman
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 4101 LaPorte Avenue, Fort Collins, CO 80521, USA.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: DeLiberto
authors.affiliation: U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Wildlife Services, National Wildlife Research Center, 2110 Miriam Circle, Suite B, Bismarck, ND 58501-2502, USA.
authors.forename: George M
authors.initials: GM
authors.lastname: Linz
mesh_terms: D000821:Animal Feed / Q000382:microbiology; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002417:Cattle; D002418:Cattle Diseases / Q000382:microbiology / Q000635:transmission*; D024881:Drug Resistance, Bacterial; D005243:Feces / Q000382:microbiology; D058751:Livestock; D012481:Salmonella Infections, Animal / Q000382:microbiology / Q000635:transmission*; D019779:Salmonella enterica / Q000187:drug effects / Q000502:physiology*; D046749:Starlings / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Antimicrobial resistance; Bacteria; Enterobacteriaceae; European starlings; Salmonella enterica