| 摘要: |
| 【目的】了解福建省猪源mcr-1基因阳性细菌的流行性、耐药特性及分布特征。【方法】从福建省7个地市的21个猪场采集313份粪便样本，应用PCR方法筛选、分离和鉴定mcr-1基因阳性细菌；采用K-B琼脂扩散试验进行药敏检测，分析mcr-1基因阳性细菌的耐药性，并使用PCR方法分析其耐药表型；进一步采用多位点序列分型（MLST）方法鉴定mcr-1基因阳性大肠杆菌的类型，使用脉冲场凝胶电泳（PFGE）分析方法对mcr-1阳性大肠杆菌进行聚类分析，探明其分布特征和亲缘关系。【结果】从313份猪粪便中共分离获得43株mcr-1基因阳性细菌，其中大肠杆菌39株。耐药性结果显示，分离菌株对磺胺甲基异恶唑、氟苯尼考、链霉素、强力霉素、恩诺沙星、新霉素、阿莫西林、头孢噻肟、林可-壮观、亚胺培南、呋喃妥因、利奈唑胺和替加环素的耐药率分别为90.1%，83.7%，74.4%，67.4%，67.4%，58.1%，53.5%，39.5%，34.9%，11.6%，4.6%，0和0。磺胺类耐药基因中的sul1、sul2和sul3基因检出率较高，分别达到81.4%，90.7%和74.4%；喹诺酮类耐药基因中仅有qnrS和aac(6′)-Ib-cr被检出，其检出率分别为51.2%和30.2%；氯霉素类耐药基因中Cat2和cmlA基因的检出率较高，分别达到86.0%和74.4%；氟苯尼考耐药基因（floR）的检出率为83.7%；金属β-内酰胺酶耐药基因（NDM-1）的检出率为23.2%；多药耐药基因（cfr）的检出率为7.0%；而替加环素耐药基因（tet(X)）未被检出。39株mcr-1基因阳性大肠杆菌除了4株不能分型外，其他35株共分为19个ST型，具有高度多样性，其中ST10为优势型，共有9株菌株。PFGE图谱显示，39株mcr-1基因阳性大肠杆菌共获得30种PFGE谱型，具有多态性特征，分为6组克隆群。【结论】福建猪源mcr-1基因阳性细菌主要为大肠杆菌，少部分为肠杆菌科其他菌株，且分离菌株具有明显的多重耐药性；mcr-1基因阳性大肠杆菌在地域分布上具有多态性和高度多样性特点。 |
| 关键词: 多黏菌素 耐药性 耐药基因 猪源mcr-1基因阳性菌 福建省 |
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| 基金项目:国家自然科学基金项目（31872502）；福建省农业科学院科研项目（AGY2018-6）；福建省5511协同创新工程重点项目（XTCXGC2021008） |
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| Resistance characteristics and distribution of polymyxin-resistant mcr-1 gene positive bacteria from swine in Fujian |
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CHE Yongliang,CHEN Qiuyong,CHEN Rujing,et al
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| Abstract: |
| 【Objective】This study aims at understanding the resistance characteristics and distribution of mcr-1 gene positive bacteria in Fujian.【Method】A total of 313 fecal samples from 21 pig farms in 7 cities of Fujian were collected,and mcr-1 gene positive bacteria was screened,isolated and identified by PCR.The drug sensitive was tested by K-B agar diffusion test,and the resistance phenotype was analyzed by PCR method.The sequence type (ST) of mcr-1 gene positive E.coli was determined by multilocus sequence typing (MLST) method,and cluster analysis using pulsed field gel electrophoresis (PFGE) was performed to determine the distribution and phylogenetic relationships of mcr-1 gene positive E.coli.【Result】A total of 43 strains of mcr-1 gene positive bacteria were isolated from 313 pig manure,including 39 strains of E.coli.The drug sensitive test showed that the resistance rates of these isolates to sulfamethoxazole,florfenicol,streptomycin,doxycycline,enrofloxacin,neomycin,amoxicillin,cefotaxime,linco spectacular,imipenem,nitrofurantoin,linezolid and tegacyclin were 90.1%,83.7%,74.4%,67.4%,67.4%,58.1%,53.5%,39.5%,34.9%,11.6% and 4.6%,0 and 0,respectively.The detection rates of sul1,sul2 and sul3 genes were 81.4%,90.7% and 74.4%,respectively.Among quinolone resistance genes,only qnrs and aac(6′)-Ib-cr were detected with detection rates of 51.2% and 30.2%.The detection rates of Cat2 and cmlA genes in chloramphenicol resistance genes were 86.0% and 74.4%.The detection rate of florfenicol resistance gene was 83.7%.The detection rates of NDM-1 and cfr gene were 23.2% and 7.0%.The tegacyclin resistance gene (tet(X)) was not detected.Among the 39 strains,35 of mcr-1 gene positive E.coli with high diversity were divided into 19 ST types.The ST10 type was dominant with a total of 9 strains.PFGE map showed that these 39 mcr-1 gene positive E.coli obtained 30 PFGE patterns in 6 clone groups with polymorphic characteristics.【Conclusion】The mcr-1 gene positive bacteria from swine in Fujian were mainly E.coli with multiple drug resistance and a few were other strains of Enterobacteriaceae.The mcr-1 gene positive E.coli showed characteristics of polymorphism and high diversity in regional distribution. |
| Key words: polyxycin resistance characteristics resistance gene mcr-1 gene positive bacteria from swine Fujian province |
