Xia Jing, Fang Liang-Xing, Cheng Ke, Xu Guo-Hao, Wang Xi-Ran, Liao Xiao-Ping, Liu Ya-Hong, Sun Jian
National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural UniversityGuangzhou, China.
Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural UniversityGuangzhou, China.
Front Microbiol. 2017 Mar 29;8:529. doi: 10.3389/fmicb.2017.00529. eCollection 2017.
We screened 30 isolates from dogs and cats at a single animal hospital in Guangdong Province, China. Among them, 12 strains possessed high-level resistance to amikacin and gentamicin and these were screened for 16S rRNA methyltransferase (16S-RMTase) genes. And then the genes positive isolates were detected for ESBLs (extended spectrum β-lactamases) and analyzed by pulsed-field gel electrophoresis, multilocus sequence typing, PCR-based replicon typing and plasmid analysis. The genetic profiles of were also determined by PCR mapping. The twelve 16S-RMTase gene-positive isolates were (11/30) and (2/30) with one isolate carrying both genes. Extended spectrum β-lactamases genes were represented by (9/12), (2/12) and (1/12). The twelve 16S-RMTase containing strains were grouped into five clonal patterns and ST37 was the most prevalent sequence type. Ten -bearing plasmids conjugated successfully and all belonged to IncN and IncF (F33:A-:B-) incompatibility groups. Nine of the transconjugants carried a 97 kb plasmid and the other harbored both ∼60 and ∼200 kb plasmids. and were present on the same plasmid and indicated the co-transfer of these two genes, with the gene showing highly relevant relationships with IS and Tn. Our findings suggested a high prevalence of 16S-RMTase genes in ST37 from dogs and cats. Additional studies are needed to trace the evolutionary path of this type of resistance among the isolates, and to determine whether they have been transferred to humans.
我们在中国广东省的一家动物医院对30株犬猫分离株进行了筛选。其中，12株对阿米卡星和庆大霉素具有高水平耐药性，并对这些菌株进行了16S rRNA甲基转移酶（16S-RMTase）基因筛选。然后对基因阳性分离株检测超广谱β-内酰胺酶（ESBLs），并通过脉冲场凝胶电泳、多位点序列分型、基于PCR的复制子分型和质粒分析进行分析。还通过PCR图谱确定了其基因图谱。12株16S-RMTase基因阳性分离株中，有11株为[具体菌名1]（共30株中的11株），2株为[具体菌名2]（共30株中的2株），1株同时携带这两种基因。超广谱β-内酰胺酶基因以[具体基因1]（12株中的9株）、[具体基因2]（12株中的2株）和[具体基因3]（12株中的1株）为代表。12株含有16S-RMTase的菌株被分为五种克隆模式，ST37是最常见的序列类型。10个携带[具体基因]的质粒成功接合，均属于IncN和IncF（F33:A-:B-）不相容群。9个接合子携带一个97 kb的质粒，另一个同时含有约60 kb和约200 kb的质粒。[具体基因1]和[具体基因2]存在于同一质粒上，表明这两个基因的共同转移，其中[具体基因1]与插入序列（IS）和转座子（Tn）显示出高度相关关系。我们的研究结果表明，犬猫源ST37中的16S-RMTase基因具有较高的流行率。需要进一步研究来追踪这类耐药性在分离株中的进化路径，并确定它们是否已传播给人类。
