title: Multiresistant Salmonella Typhimurium DT104 infections of humans and domestic animals in the Pacific Northwest of the United States.
abstract: Salmonella Typhimurium definitive type 104 with chromosomally encoded resistance to five or more antimicrobial drugs (R-type ACSSuT+) has been reported increasingly frequently as the cause of human and animal salmonellosis since 1990. Among animal isolates from the northwestern United States (NWUS), R-type ACSSuT+ Typhimurium isolates increased through the early 1990s to comprise 73% of Typhimurium isolates by 1995, but subsequently decreased to comprise only 30% of isolates during 1998. NWUS S. Typhimurium R-type ACSSuT+ were consistently (99%) phage typed as DT104 or the closely related DTu302. S. Typhimurium isolates from cattle with primary salmonellosis, randomly selected from a national repository, from NWUS were more likely to exhibit R-type ACSSuT+ (19/24, 79%) compared to isolates from other quadrants (17/71, 24%; P < 0.01). Human patients infected with R-type ACSSuT+ resided in postal zip code polygons of above average cattle farm density (P < 0.05), while patients infected with other R-types showed no similar tendency. Furthermore, humans infected with R-type ACSSuT+ Typhimurium were more likely to report direct contact with livestock (P < 0.01) than humans infected with other R-types.
authors.affiliation: Department of Veterinary Microbiology and Pathology, Washington State University, Pullman 99164-7040, USA.
authors.forename: T E
authors.initials: TE
authors.lastname: Besser
authors.forename: M
authors.initials: M
authors.lastname: Goldoft
authors.forename: L C
authors.initials: LC
authors.lastname: Pritchett
authors.forename: R
authors.initials: R
authors.lastname: Khakhria
authors.forename: D D
authors.initials: DD
authors.lastname: Hancock
authors.forename: D H
authors.initials: DH
authors.lastname: Rice
authors.forename: J M
authors.initials: JM
authors.lastname: Gay
authors.forename: W
authors.initials: W
authors.lastname: Johnson
authors.forename: C C
authors.initials: CC
authors.lastname: Gay
mesh_terms: D000818:Animals; D000829:Animals, Domestic / Q000382:microbiology*; D016022:Case-Control Studies; D002417:Cattle; D004352:Drug Resistance, Microbial / Q000235:genetics; D005243:Feces / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D015205:Northwestern United States / Q000453:epidemiology; D016017:Odds Ratio; D012307:Risk Factors; D012480:Salmonella Infections / Q000453:epidemiology* / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000453:epidemiology* / Q000382:microbiology; D012486:Salmonella typhimurium / Q000235:genetics / Q000302:isolation & purification*