CTX-M-27 Producing Salmonella enterica Serotypes Typhimurium and Indiana Are Prevalent among Food-Producing Animals in China.
CTX-M-27 Producing Salmonella enterica Serotypes Typhimurium and Indiana Are Prevalent among Food-Producing Animals in China.
复制标题
产CTX-M-27肠沙门氏菌血清型鼠伤寒和印第安纳在中国食品生产动物中流行
DOI：
10.3389/fmicb.2016.00436
复制
发表时间：
2016
影响因子：
5.2
通讯作者：
Jiang HX
中科院分区：
文献类型：
--
作者：
Zhang WH;Lin XY;Xu L;Gu XX;Yang L;Li W;Ren SQ;Liu YH;Zeng ZL;Jiang HX
沙门氏菌是引起人类和动物消化道和侵入性感染的最重要的食源性病原体之一。超广谱β-内酰胺酶（ESBLs）尤其是CTX-M型ESBLs在世界范围内和我国的报道日益增多。这些研究很少关注来自食用动物的沙门氏菌分离株。本研究的目的是表征中国鸡和猪沙门氏菌分离株的耐药性、血清型和ESBLs，特别是产CTX-M的沙门氏菌。采用API 20 E系统和聚合酶链反应（PCR）方法对分离菌株进行鉴定;采用玻片凝集法和超免疫血清法进行血清型鉴定;采用琼脂稀释法进行药物敏感性试验;采用PCR方法对ESBLs和PMQR基因进行筛查;采用接合沿着、遗传相关性和质粒复制子类型对产CTX-M菌株进行鉴定。共检出沙门氏菌159株，其中鼠伤寒沙门氏菌95株，沙门氏菌63株。肠杆菌印第安纳州型，1株为沙门氏菌。肠道血清型所有这些菌株均呈现多重耐药表型。45株分离株携带blaCTX-M基因，最常见的亚型是CTX-M-27（34），其次是CTX-M-65（7）和CTX-M-14（4）。大多数blaCTX-M基因通过大小为80至280 kb的不可分型或IncN/IncFIB/IncP/印加/C/IncHI 2质粒传播。特别地，所有14个不可分型质粒均携带blaCTX-M-27基因并且具有相似的大小。PFGE图谱表明，CTX-M阳性菌株在同一血清型之间存在克隆相关性，而不同血清型的菌株在遗传上存在差异。这表明耐药菌株的克隆传播和耐药质粒的水平传播都有助于blaCTX-M-9 G阳性沙门氏菌的传播。CTX-M，特别是CTX-M-27在S.食源性动物的肠道血清型鼠伤寒和印第安纳州对公共卫生构成潜在威胁。有必要采取控制战略，限制这些菌株通过食物链传播。
Salmonella spp. is one of the most important food-borne pathogens causing digestive tract and invasive infections in both humans and animals. Extended-spectrum β-lactamases (ESBLs) especially the CTX-M-type ESBLs are increasingly being reported worldwide and in China. These studies seldom focused on Salmonella isolates from food-producing animals. The aim of this study was to characterize the antimicrobial resistance profiles, serotypes and ESBLs and in particular, CTX-M producing Salmonella isolates from chickens and pigs in China. Salmonella isolates were identified by API20E system and polymerase chain reaction (PCR) assay; serotypes were determined using slide agglutination with hyperimmune sera; antimicrobial susceptibility was tested using the ager dilution method; the prevalence of ESBLs and PMQR genes were screened by PCR; CTX-M-producing isolates were further characterized by conjugation along with genetic relatedness and plasmid replicon type. In total, 159 Salmonella strains were identified, among which 95 strains were Salmonella enterica serovar Typhimurium, 63 strains were S. enterica serovar Indiana, and 1 strain was S. enterica serovar Enteritidis. All of these isolates presented multi-drug resistant phenotypes. Forty-five isolates carried blaCTX-M genes, the most common subtype was CTX-M-27(34), followed by CTX-M-65(7) and CTX-M-14(4). Most blaCTX-M genes were transmitted by non-typeable or IncN/IncFIB/IncP/IncA/C/IncHI2 plasmids with sizes ranging from 80 to 280 kb. In particular, all the 14 non-typeable plasmids were carrying blaCTX-M-27 gene and had a similar size. PFGE profiles indicated that CTX-M-positive isolates were clonally related among the same serotype, whilst the isolates of different serotypes were genetically divergent. This suggested that both clonal spread of resistant strains and horizontal transmission of the resistance plasmids contributed to the dissemination of blaCTX-M-9G-positive Salmonella isolates. The presence and spread of CTX-M, especially the CTX-M-27 in S. enterica serovars Typhimurium and Indiana from food-producing animals poses a potential threat for public health. Control strategies to limit the dissemination of these strains through the food chain are necessary.