Department of Veterinary Internal Medicine, Tottori University, Minami 4-101, Koyama-Cho, Tottori-Shi, Tottori 680-8553, Japan.
Laboratory of Veterinary Microbiology, Nippon Veterinary and Life Science University, 1-7-1, Kyonan-cho, Musashino, Tokyo 180-8602, Japan.
J Med Microbiol. 2014 Nov;63(Pt 11):1561-1567. doi: 10.1099/jmm.0.081539-0. Epub 2014 Sep 3.
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.
对来自日本犬的 103 株奇异变形杆菌进行了 14 种抗菌药物耐药性的大规模监测。对耐药株进行了分析，以确定其耐药机制。对氯霉素、链霉素、恩诺沙星、复方磺胺甲噁唑、卡那霉素、氨苄西林、环丙沙星、头孢噻吩、庆大霉素、头孢西丁和头孢噻肟的耐药率分别为 20.4%、15.5%、12.6%、10.7%、9.7%、8.7%、5.8%、2.9%、2.9%、1.9%和 1.9%。未发现对头孢他啶、氨曲南或亚胺培南的耐药性。分别在 2.9%和 11.7%的分离株中检测到 1 类和 2 类整合酶。1 类整合子含有 aadB 或 aadB-catB-like-blaOXA10-aadA1，而 2 类整合子含有 sat-aadA1、dhfr1-sat-aadA1 或没有预期的耐药基因。在 5 种不同的质粒介导喹诺酮耐药 (PMQR) 基因中，仅在 1.9%的分离株中检测到 qnrD 基因。对 13 株恩诺沙星中介和耐药株的 gyrA 和 parC 的喹诺酮耐药决定区 (QRDR) 进行了测序。7 株有双突变，3 株有单突变。9 株氨苄西林耐药株中有 3 株携带 AmpC 型β-内酰胺酶（即 blaCMY-2、blaCMY-4 和 blaDHA-1）。这些结果表明，犬奇异变形杆菌作为抗菌药物耐药决定因素的重要储存库，值得持续监测。据我们所知，这是首次描述来自伴侣动物的奇异变形杆菌分离株中的整合子、PMQR 和 QRDR 突变。
