Antimicrobial resistance and genetic characteristics of Salmonella Typhimurium isolated from horses in Hokkaido, Japan.
In this study, we examined the antimicrobial susceptibility of 16 Salmonella Typhimurium isolates obtained from horses, and applied several genetic methods, namely polymerase chain reaction (PCR) for detecting class 1 integrons, multiplex PCR for detecting multidrug resistant S. Typhimurium definitive phage type 104 (MR-DT104), and fluorescent amplified-fragment length polymorphism (FAFLP). Seven isolates with an ampicillin, chloramphenicol, streptomycin, sulfonamide, and tetracycline (ACSSuT) type resistance pattern, harbored two class 1 integrons with sizes of 1.2 and 1.0 kb, and were identified as DT104 by bacteriophage typing. These isolates also showed a typical MR-DT104 amplification pattern, which was positive for flo(st), spvC, invA and int, in multiplex PCR. In the FAFLP analysis, the equine DT104 isolates and the previously reported ACSSuT-type resistant bovine isolates, which were also isolated in Hokkaido were included in the same genetic cluster. Our results retrospectively indicate that MR-DT104 infection has existed in horses in Japan at least since 1996, and it was suggested that there is a highly epidemiological relationship between the equine MR-DT104 isolates and certain multidrug resistant bovine isolates in the same area.
Niwa
Hidekazu
H
Equine Research Institute, Japan Racing Association, Tochigi, Japan. niwa@epizoo.equinst.go.jp
Anzai
Toru
T
Izumiya
Hidemasa
H
Morita-Ishihara
Tomoko
T
Watanabe
Haruo
H
Uchida
Ikuo
I
Tozaki
Teruaki
T
Hobo
Seiji
S
D054458:Amplified Fragment Length Polymorphism Analysis; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification; D002417:Cattle; D017931:DNA Primers; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000187:drug effects / Q000235:genetics; D006734:Horse Diseases / Q000382:microbiology*; D006736:Horses; D007564:Japan; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D012481:Salmonella Infections, Animal / Q000188:drug therapy / Q000235:genetics*; D012486:Salmonella typhimurium / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D017931:DNA Primers; D004269:DNA, Bacterial