title: The dusky-footed woodrat (Neotoma fuscipes) is susceptible to infection by Anaplasma phagocytophilum originating from woodrats, horses, and dogs.
abstract: The dusky-footed woodrat (Neotoma fuscipes) is the putative reservoir for Anaplasma phagocytophilum in the western United States based on high prevalence of A. phagocytophilum genetic material detected by polymerase chain reaction (PCR), high antibody prevalence, and infestation with the vector tick Ixodes pacificus. Following inoculation of nine wild-caught woodrats with woodrat-, canine-, or equine-origin A. phagocytophilum, all became PCR-positive and seroconverted. However, when PCR-positive woodrat blood was delivered as inoculum to three horses, the horses never became clinically ill, PCR-positive, or antibody-positive. Each horse was subsequently infected with either the equine- or chipmunk-origin A. phagocytophilum, resulting in clinical anaplasmosis. Our data show that woodrats are permissive to several strains of A. phagocytophilum, but strains originating from woodrats did not cause clinical disease in horses.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. ncnieto@ucdavis.edu
authors.forename: Nathan C
authors.initials: NC
authors.lastname: Nieto
authors.forename: John E
authors.initials: JE
authors.lastname: Madigan
authors.forename: Janet E
authors.initials: JE
authors.lastname: Foley
mesh_terms: D041081:Anaplasma phagocytophilum / Q000472:pathogenicity*; D000818:Animals; D004197:Disease Reservoirs / Q000382:microbiology / Q000662:veterinary*; D004198:Disease Susceptibility / Q000662:veterinary; D004283:Dog Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D004285:Dogs; D016873:Ehrlichiosis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D005260:Female; D006734:Horse Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission; D006736:Horses; D018884:Ixodes / Q000382:microbiology*; D008297:Male; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015995:Prevalence; D012376:Rodent Diseases / Q000453:epidemiology / Q000382:microbiology / Q000635:transmission*; D016205:Sigmodontinae / Q000276:immunology / Q000382:microbiology; D013045:Species Specificity; D014481:United States / Q000453:epidemiology