title: Phenotypic and molecular characterization of antimicrobial resistance in Proteus mirabilis isolates from dogs.
abstract: Large-scale monitoring of resistance to 14 antimicrobial agents was performed using 103 Proteus mirabilis strains isolated from dogs in Japan. Resistant strains were analysed to identify their resistance mechanisms. Rates of resistance to chloramphenicol, streptomycin, enrofloxacin, trimethoprim/sulfamethoxazole, kanamycin, ampicillin, ciprofloxacin, cephalothin, gentamicin, cefoxitin and cefotaxime were 20.4, 15.5, 12.6, 10.7, 9.7, 8.7, 5.8, 2.9, 2.9, 1.9 and 1.9%, respectively. No resistance to ceftazidime, aztreonam or imipenem was found. Class 1 and 2 integrases were detected in 2.9 and 11.7% of isolates, respectively. Class 1 integrons contained aadB or aadB-catB-like-blaOXA10-aadA1, whereas those of class 2 contained sat-aadA1, dhfr1-sat-aadA1 or none of the anticipated resistance genes. Of five distinct plasmid-mediated quinolone-resistance (PMQR) genes, only qnrD gene was detected in 1.9% of isolates. Quinolone-resistance determining regions (QRDRs) of gyrA and parC from 13 enrofloxacin-intermediate and -resistant isolates were sequenced. Seven strains had double mutations and three had single mutations. Three of nine ampicillin-resistant isolates harboured AmpC-type β-lactamases (i.e. blaCMY-2, blaCMY-4 and blaDHA-1). These results suggest that canine Proteus mirabilis deserves continued surveillance as an important reservoir of antimicrobial resistance determinants. This is the first report, to our knowledge, describing integrons, PMQRs and QRDR mutations in Proteus mirabilis isolates from companion animals.
authors.affiliation: Department of Veterinary Internal Medicine, Tottori University, Minami 4-101, Koyama-Cho, Tottori-Shi, Tottori 680-8553, Japan.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Harada
authors.affiliation: Laboratory of Veterinary Microbiology, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
authors.forename: Ayaka
authors.initials: A
authors.lastname: Niina
authors.affiliation: Department of Veterinary Internal Medicine, Tottori University, Minami 4-101, Koyama-Cho, Tottori-Shi, Tottori 680-8553, Japan.
authors.forename: Takae
authors.initials: T
authors.lastname: Shimizu
authors.affiliation: Laboratory of Veterinary Microbiology, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Mukai
authors.affiliation: Laboratory of Veterinary Microbiology, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kuwajima
authors.affiliation: Miyamoto Animal Hospital, 2265-8, Kurokawa, Yamaguchi-Shi, Yamaguchi 753-0851, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Miyamoto
authors.affiliation: Laboratory of Veterinary Microbiology, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kataoka
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004283:Dog Diseases / Q000382:microbiology*; D004285:Dogs; D024881:Drug Resistance, Bacterial; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D011512:Proteus Infections / Q000382:microbiology / Q000662:veterinary*; D011513:Proteus mirabilis / Q000187:drug effects* / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents