合肥地区动物源致病性大肠杆菌ESBLs和PMQR基因流行分布

从安徽省合肥地区多个养殖厂分离鉴定了65株致病性大肠杆菌,用PCR方法检测ESBLs和PMQR基因的流行分布情况,用微量肉汤稀释法测定30株ESBLs和/或PMQR阳性菌对16种抗菌药物的最小抑菌浓度.PCR结果显示:ESBLs阳性率为24.6％(16/65),分别为blaOXA(16株)、blaTEM(15株)和blaCTX-M(14株),未检出blaSHV; PMQR的阳性率为46.2％(30/65),分别为qnrA(9株)、qnrS(18株)、aac(6')-Ib～cr(28株),未检出qnrB、qnrC、qnrD和qepA;且携带ESBLs基因的阳性菌株均携带PMQR基因.首次检测出有7株大肠杆菌同时携带ES-BLs基因型(blaOXA、blaTEM、blaCTX-M)和PMQR基因型(qnrA、qnrS、aac(6')-Ib-cr).药物敏感性测定结果显示:30株携带ESBLs和/或PMQR基因的阳性大肠杆菌对16种抗菌药物的耐药率为16.7％～100％,耐药谱较广,耐药性较严重.16株同时携带ESBLs和PMQR基因的阳性菌株对11种及11种以上药物耐药的菌株占87.5％,14株仅携带PMQR基因的阳性菌株对11种及11种以上药物耐药的菌株占28.5％,表明携带PMQR基因的同时携带ESBLs基因大大增强了菌株的耐药性,携带耐药基因的数量和种类与菌株的多重耐药性相关.     

食品动物源沙门菌aac(6')-Ib-cr基因检测

为检测质粒介导的喹诺酮类耐药性aac(6')-Ib-cr基因在食品动物源沙门菌的分布状况.采用PCR结合BstC1酶切法,以及DNA测序法检测316株食品动物源沙门菌中aac(6')-Ib-cr基因;微量肉汤稀释法检测aac(6’)-Ib-cr阳性和阴性菌株对10种抗菌药物的耐药性;采用PFGE分析阳性菌株的亲缘关系.结果是aac(6')-Ib-cr基因检出率15.82％(50/316);aac(6')-Ib-cr阳性株对氨基糖苷类耐药率高于阴性株,但对环丙沙星、恩诺沙星和氧氟沙星的耐药率低于阴性株;aac(6’)-Ib-cr阳性菌株具有不同的PFGE谱型.结论:aac(6’)-Ib-cr基因在本次检测的食品动物源沙门菌中普遍存在,以水平和垂直传播方式在菌群间传播.     

猪源大肠杆菌质粒和染色体介导的喹诺酮类药的耐药机制

采用微量肉汤稀释法对31株猪源大肠杆菌进行6种喹诺酮类药物的敏感性测定,聚合酶链式反应检测质粒介导的喹诺酮类耐药（PMQR）基因qnr、qepA和aac（6′）-Ib-cr,并分析PMQR基因阳性菌株染色体gyrA、gyrB、parC、parE基因的喹诺酮耐药决定突变区（QRDRs）突变。结果显示,31株猪源大肠杆菌对兽医临床常用的氟喹诺酮类药物均呈现耐药。在31株猪源肠杆菌中共检测到2株携带qnrB10和4株携带qnrS1基因的大肠杆菌,未检测到qnrA、qepA和aac（6′）-Ib-cr。在PMQR阳性菌株gyrA基因的QRDRs中,低耐药菌株的gyrA基因出现83位S→W突变,高耐药菌株的gyrA基因同时出现83位S→L和87位D→N突变。而在parC基因的QRDRs中,大部分耐药菌株出现80位S→I突变,1株耐药菌株出现45位V→L突变。gyrB和parE基因的QRDRs未检测到突变。结果表明,本地区猪源大肠杆菌对兽医临床常用的氟喹诺酮类药物耐药严重,PMQR的出现和QRDRs的点突变可同时协同贡献对喹诺酮类耐药,而PMQR的出现加速了喹诺酮类耐药基因的快速传播。     

动物源肠杆菌分离株质粒介导的喹诺酮类耐药基因的检测

为了解近年广东地区肠杆菌科质粒介导喹诺酮类耐药基因(PMQR)的流行情况,对广东地区猪、禽养殖场2007～2009年分离的407株肠杆菌进行PMQR基因的检测,采用琼脂平皿二倍稀释法对所有菌株进行15种抗菌药物的敏感性试验。结果显示,qnrA、qnrB、qnrS、qnrD、qepA及aac(6′)-Ib-cr的检出率分别为0.98%、4.91%、16.22%、1.72%、0.25%、5.41%,qnrC没有检测出,有27(6.63%)株同时携带两种或两种以上PMQR基因。近年广东地区动物源肠杆菌的PMQR基因流行存在上升趋势,耐药性存在严重,且存在多重耐药现象。     

食品动物源沙门菌ESBLs和PMQR耐药基因流行特征分析

本研究对从猪、鸭和鹅分离的31株沙门菌进行耐药性分析,调查ESBLs基因和PMQR基因在沙门菌的流行分布特征.结果显示,31株沙门菌中只检测到CTX-M型ESBLs,3株携带blaCTX-M-14,3株携blaCTX-M-27基因;有13株携带blaOXA型均为窄谱blaOXA-1,6株携带blaTEM型也为窄谱blaTEM-1b.blaSHV、blaPER、blaVEB、blaGES等各型β-内酰胺酶基因均未检出.PMQR基因oqxAB和aac(6′)-Ib-cr检出率最高分别为39%和26%.4株鸭源和1株猪源沙门菌中都检测到qnrA基因,而qnrD基因仅在一种猪源沙门菌中检出.qnrB、qnrC、qnrS、qepA等基因均未检出.研究发现有19株沙门菌同时携带β-内酰胺酶和PMQR,其中一株鸭源沙门菌同时携带CTX-M-14 ESBLs和CMY-2 AmpC酶;有7株同时携带4-5种β-内酰胺酶和PMQR基因.     

兔源大肠杆菌对喹诺酮药物耐药性及质粒介导的耐药基因检测

为了解四川省兔源大肠杆菌(E.coli)对喹诺酮药物耐药性及质粒介导的喹诺酮耐药(PMQR)基因的携带情况,本研究从四川地区规模化家兔养殖场共分离鉴定出97株E.coli,采用Kirby-Bauer(K-B)纸片法对分离株进行喹诺酮药物耐药性测定,同时采用PCR方法对qnrA、qnrB、qnrC、qnrD、qnrS、qnrVC、aac(6')-Ib-cr、qep A、oqx A、oqx B等PMQR基因进行检测。结果显示:分离株对左氧氟沙星耐药率最高为49.48%,对依诺沙星、诺氟沙星、恩诺沙星、氧氟沙星和环丙沙星的耐药率依次为48.45%、46.39%、39.17%、35.05%和34.02%;PMQR检测发现:aac(6')-Ib-cr检出率最高为80.4%,qnrD、qnrS、oqxA和oqxB,检出率分别为59.8%、59.8%、63.9%和51.5%,未检出qnrA、qnrB、qnrC、qnrVC和qepA。本研究通过对97株兔源E.coli对喹诺酮药物的耐药性及相关PMQR基因检测,初步明确四川地区兔源大肠杆菌对喹诺酮药物的耐药情况及PMQR的流行情况,为该地区家兔大肠杆菌病的防治中有效使用喹诺酮类药物提供参考。     

牛源大肠杆菌质粒介导喹诺酮类耐药基因的检测分析

为研究近年来新疆地区牛源大肠杆菌中质粒介导喹诺酮类药物耐药基因的分布及其对喹诺酮类抗生素的耐药情况,本研究于2016-2018年从新疆石河子、沙湾、奎屯、玛纳斯和伊犁5个地区12个规模化奶牛场分离出116株牛源大肠杆菌,药敏试验检测其耐药性,同时利用PCR扩增PMQR耐药基因。药敏试验结果显示,62.93%的菌株对氨苄西林耐药,耐药率最高。对链霉素、四环素、卡那霉素和恩诺沙星的耐药率依次为56.90%、54.31%、43.10%和42.24%。对头孢他啶和头孢噻肟的耐药率较低,分别为7.76%和11.21%。分离菌主要携带qnrA、qnrS和aac（6'）-Ⅰb-cr 3种耐药基因;116株大肠杆菌中有31株携带PMQR的耐药基因,检出阳性率为26.72%,其中26株仅携带1种PMQR耐药基因,占所有菌株的22.41%,4株携带2种PMQR耐药基因,占所有菌株的3.45%,1株携带3种PMQR耐药基因,占所有菌株的0.86%。综上所述,新疆地区牛源大肠杆菌质粒介导喹诺酮类药物基因主要为qnrA、qnrS和aac（6'）-Ⅰb-cr 3种,且对恩诺沙星、诺氟沙星、环丙沙星、左氧氟沙星均产生不同程度的耐药性。     

牛源大肠杆菌质粒介导喹诺酮类耐药基因的检测分析

为研究近年来新疆地区牛源大肠杆菌中质粒介导喹诺酮类药物耐药基因的分布及其对喹诺酮类抗生素的耐药情况,本研究于2016-2018年从新疆石河子、沙湾、奎屯、玛纳斯和伊犁5个地区12个规模化奶牛场分离出116株牛源大肠杆菌,药敏试验检测其耐药性,同时利用PCR扩增PMQR耐药基因。药敏试验结果显示,62.93%的菌株对氨苄西林耐药,耐药率最高。对链霉素、四环素、卡那霉素和恩诺沙星的耐药率依次为56.90%、54.31%、43.10%和42.24%。对头孢他啶和头孢噻肟的耐药率较低,分别为7.76%和11.21%。分离菌主要携带qnrA、qnrS和aac(6′)-Ⅰb-cr 3种耐药基因;116株大肠杆菌中有31株携带PMQR的耐药基因,检出阳性率为26.72%,其中26株仅携带1种PMQR耐药基因,占所有菌株的22.41%,4株携带2种PMQR耐药基因,占所有菌株的3.45%,1株携带3种PMQR耐药基因,占所有菌株的0.86%。综上所述,新疆地区牛源大肠杆菌质粒介导喹诺酮类药物基因主要为qnrA、qnrS和aac(6′)-Ⅰb-cr 3种,且对恩诺沙星、诺氟沙星、环丙沙星、左氧氟沙星均产生不同程度的耐药性。     

质粒介导的喹诺酮耐药基因在动物源金黄色葡萄球菌的流行分布

为了解广东省动物源金黄色葡萄球菌耐药现状、分析耐喹诺酮类金黄色葡萄球菌耐药分子特征,本研究从2010—2011年广东33个养殖场的不同动物来源的样本中分离鉴定出46株金黄色葡萄球菌,采用二倍琼脂稀释法测定对14种抗菌药物的敏感性;采用聚合酶链式反应(PCR)检测耐喹诺酮金黄色葡萄球菌grlA、grlB、gyrA、gyrB基因在喹诺酮耐药决定区(QRDR)的突变特征、质粒介导喹诺酮类耐药(PMQR)基因(qnr、aac6′-Ib-cr、oqxA和qepA)的流行分布特征,同时还检测了β-内酰胺酶编码基因(blaCTX-M、blaCMY和blaSHV)、质粒介导金黄色葡萄球菌耐氟苯尼考的基因(cfr和fexA)和万古霉素耐药基因(vanA、vanB和vanC)。结果表明,46株金黄色葡萄球菌对克林霉素耐药率最高为67%,对环丙沙星和氟苯尼考耐药率为52%,对青霉素、氨苄西林、庆大霉素、红霉素、四环素和复方新诺明的耐药率在40%⁵0%之间,对苯唑西林和氯霉素耐药率为28%,对妥布霉素耐药率为13%,对头孢噻肟的耐药率在10%左右,有2株耐万古霉素。20株耐环丙沙星金黄色葡萄球菌的grlA和gyrA基因的QRDR发生了碱基突变并导致编码的氨基酸发生改变,GrlA氨基酸只有1种突变模式,Ser80→Phe,而GyrA氨基酸存在3种突变模式:Ser84→Leu,Ala或Phe。PMQR基因中,oqxA检出率最高(80%),其次是aac6′-Ib-cr占13%,qnrS1检出3株、qnrD检出2株。检测到2株菌株携带超广谱β-内酰胺酶编码基因blaSHV-12;23株氟苯尼考耐药菌株全部携带fexA基因,其中3株同时携带cfr基因;2株耐万古霉素菌株未检测到相关耐药基因。广东省动物源金黄色葡萄球菌多重耐药现象较为普遍,本研究首次在动物源金黄色葡萄球菌中检测到超广谱质粒编码的喹诺酮耐药基因流行分布广泛,大多数菌株同时携带2种以上质粒编码的耐药基因,提示养殖过程或治疗过程中使用任何一种药物(尤其是动物促生长剂)都可以筛选出耐药菌株。     

新疆猪源沙门氏菌耐药性及耐药基因检测

为了解新疆某规模化养殖场猪源沙门氏菌对临床上常用抗菌药物的耐药情况,以及β-内酰胺酶、16S rRNA甲基化酶和质粒介导的喹诺酮耐药（plasmid mediated quinolone resistance,PMQR）基因的流行情况,本试验通过琼脂稀释法对分离的菌株进行最小抑菌浓度测定,PCR方法进行β-内酰胺酶bla_TEM、bla_CMY-2、bla_CTX-M、bla_LAP-1、bla_KPC、bla_OXA和bla_SHV基因,16S rRNA甲基化酶基因armA和rmtB及PMQR类基因qnrA、qnrB、qnrC、qnrD、qnrS、qepA、oqxA、oqxB和aac（6'）-Ib-cr的检测,确定阳性菌株,分析其携带的基因型与耐药表型之间的关系。分离的猪源沙门氏菌对环丙沙星和安普霉素耐药率最高,均为77.9%（102/131）,耐药菌主要以8耐为主（29.0%,38/131）。从被检基因中检测出11种耐药基因,不同基因共存有24种类型,主要以bla_TEM+bla_OXA+qnrS+aac（6'）-Ib-cr+oqxA+oqxB（27.6%,32/116）;bla_TEM+bla_OXA+qnrS+oqxA+oqxB（24.1%,28/116）;bla_TEM+qnrS（18.0%,21/116）形式共存。该养殖场分离的沙门氏菌耐药现象严重,分离耐药菌株存在β-内酰胺酶、16S rRNA甲基化酶和PMQR类基因共存现象,提示应加强对β-内酰胺酶、16S rRNA甲基化酶和PMQR类因子的监控。     

鸡源印第安纳沙门菌多重耐药性分析

采集山东不同地区鸡源沙门菌,根据Kauffmann-White方法测定分离株血清型,采用肉汤微量稀释法测试分离株对16种抗菌药物的敏感性,PCR方法检测10种耐药基因,分析耐药表型和耐药基因之间的关系。结果显示：共鉴定出沙门菌80株,其中印第安纳沙门菌60株。药敏试验证实：60株印第安纳沙门菌对阿莫西林-克拉维酸、头孢唑啉、多黏菌素、氨苄西林、多西环素和甲氧苄啶等16种抗菌药物普遍耐药。88.33%菌株多重耐药分布在12~15耐,未发现3耐以下的菌株。PCR扩增出int1,blaTEM,aac（6’）-Ib-cr,floR,catA1,tetA,strA,cmlA 8种耐药基因。超过90%的菌株携带int1,blaTEM,floR和aac（6’）-Ib-cr耐药基因。上述结果表明,耐药表型及耐药基因的符合呈现相关性。     

Detection of Resistance and Resistance Genes of Salmonella from Swine in Xinjiang

The objective of this study was to investigate the resistance of Salmonella and prevalence of resistance genes isolated from a pig farm in Xinjiang, and their coexistence with the major β-lactamases, 16S rRNA methylation enzyme genes and PMQR. The minimum inhibitory concentrations of Salmonella isolated from the pig farms were determined by agar dilution method, PCR was used to detect bla_TEM, bla_CMY-2, bla_CTX-M, bla_LAP-1, bla_KPC, bla_OXA and bla_SHV genes, 16S rRNA methylation enzyme genes armA and rmtB, and PMQR including qnrA, qnrB, qnrC, qnrD, qnrS, qepA, oqxA, oqxB and aac(6')-Ib genes. The positive strains were performed by using DNA sequencing to determine the purpose of the belt. The result showed that resistant rate of Salmonella isolates from swine were highest to ciprofloxacin and apramycin sulfate (77.9%, 102/131). Resistant mainly based on 8 kinds of drug resistance (29.0%, 38/131), 11 kinds of resistance genes were detection, the coexistence of different genotypes had 24 types. The main types were bla_TEM+bla_OXA+qnrS+aac(6')-Ib-cr+oqxA+oqxB (27.6%, 32/116), bla_TEM+bla_OXA+qnrS+oqxA+oqxB (24.1%, 28/116) and bla_TEM+qnrS (18.0%, 21/116). The Salmonella isolated from the farm had phenomenon seriously resistance, it coexisted with the main β-lactamase, 16S rRNA methylation enzyme genes and PMQR factors. The result suggested that it should strengthen monitoring to the β-lactamase enzymes, 16S rRNA methylation enzyme genes and PMQR factors.     

Prevalence of ESBLs and PMQR genes in fecal Escherichia coli isolated from the non-human primates in six zoos in China

The aim of this study is to characterize the prevalence of extended-spectrum β-lactamases (ESBLs) and plasmid-mediated quinolone resistance (PMQR) genes in Escherichia coli from captive non-human primates. A total of 206 E. coli isolates were collected from primates in six zoos in China in 2009 and their susceptibility to 10 antimicrobials were tested by broth microdilution. The susceptibility patterns of E. coli strains varied greatly among different zoos reflecting different backgrounds of antimicrobial usage. Both the ESBL-encoding genes and the PMQR genes were detected by PCR. Of the 206 strains, 65 (32%) were confirmed as phenotypic ESBL producers with bla(CTX-M) (27%, bla(CTX-M-15), n=31, bla(CTX-M-3), n=23 and bla(CTX-M-14), n=2) mainly mediating the ESBL phenotype. qnrS1 (18%, n=36) and oqxAB (15%, n=31) were the predominant PMQR genes and the prevalence of PMQR genes was much higher among phenotypic ESBL producers than that among phenotypic non-ESBL producers from any zoo. Notably, the PMQR genes qnrS1 and oqxAB and β-lactamase genes bla(TEM-1) and bla(CTX-M-3) were found together in 23 E. coli isolates in two zoos in Shanghai. PFGE analysis of these 23 isolates demonstrated nearly identical PFGE profiles (similarity matrix >97%) indicating this specific E. coli genotype was prevalent in these two zoos. To the best of our knowledge, this is the first report of these four genes coexisting in an E. coli genotype and the first report of antimicrobial resistance profiles in E. coli isolated from primates in China.     

2012~2013年山东省禽源大肠杆菌中质粒介导喹诺酮类药物耐药基因的检测

为研究近年来山东省禽源致病性大肠杆菌中质粒介导喹诺酮类药物耐药(plasmid-mediated quinolone resistance,PMQR)基因的基因型分布,及其对喹诺酮类抗生素的耐药性的影响,分别采用针对qnrA、qnrB、qnrC、qnrD、qnrS、oqxA、oqxB与qepA 8个耐药基因的通用引物,对93株2012~2013年分离自山东省的禽源大肠杆菌进行PCR检测,并对其进行了5种喹诺酮类药物的药敏试验。结果表明山东省禽源大肠杆菌对5种喹诺酮类抗生素均产生了较高耐药性(50.54%~86.30%);PMQR基因携带率达到60.21%(56/93),其中26.88%(25/93)的菌株携带2种PMQR基因,1.07%(1/93)的菌株携带3种PMQR基因;qnrA、qnrB、qnrC、qnrD与qepA基因未被检测到,qnrS、oqxA和oqxB基因在山东省禽源致病性大肠杆菌中分布较为广泛,其检出率依次为22.58%(21/93)、40.86%(38/93)和24.73%(23/93)。     

喹诺酮类药物耐药机制研究进展

喹诺酮类属于合成的广谱抗菌药,用于治疗与肠杆菌科相关的各种感染性疾病.近几十年来,喹诺酮类药物的广泛使用和过度使用导致了喹诺酮耐药菌株的出现.喹诺酮类药物耐药的产生是一个复杂的多因素过程,主要的耐药机制包括染色体介导的一个或多个靶点基因突变改变靶点酶的药物结合力;Ac-rAB-tolC多耐药外排泵的过表达和孔蛋白的改变...     

Prevalence of plasmid-mediated quinolone resistance qnr genes in poultry and swine clinical isolates of Escherichia coli

The prevalence of qnr genes was investigated in veterinary clinical isolates of Escherichia coli in Guangdong province, China, and the aac (6')-Ib gene and the mutations in QRDRs of gyrase and topoisomerase IV were examined in qnr-positive strains. A total of 232 E. coli strains isolated from pig and poultry were screened for the presence of the qnrA, qnrB and qnrS genes by PCR and sequencing. The aac (6')-Ib gene was detected in qnr-bearing strains by PCR and sequencing. For all strains carrying qnr, MICs for six quinolones were determined. Mutations within the gyrase and topoisomerase were analyzed by PCR and sequencing for all the QRDRs of gyrA, gyrB, parC and parE. Among 232 E. coli isolates, 14 (6%) isolates were positive for the qnr gene, including one for qnrB, 13 for qnrS, but no qnrA was identified in this population. Detection of the aac (6')-Ib gene showed that one qnrS-positive isolate from pig and one qnrB-positive isolate from duck carried aac (6')-Ib gene, and both were the cr variant allele of aac (6')-Ib. All of the 14 isolates had MICs of ciprofloxacin more than 0.25 mg/L. Mutations in the QRDR of gyrA mutations were observed in 5 (35.7%) of the 14 strains. Three fluoroquinolone-resisting strains showed one mutation S83L of gyrA, while one S83I. One high-level resistance strains harboured gyrA S83L and A87N of gyrA. A singe mutation in site 58 of parC was detected in 3 (21.4%) strains. None mutations were found in QRDRs of gyrB and parE. The emergence of qnr genes in veterinary clinical E. coli isolates is described for the first time. This is also the first report of aac (6')-Ib-cr gene in E. coli isolates from food-producing animals.     

广州市农贸市场猪肉源伦敦沙门菌的流行情况及耐药性分析

本研究旨在探究广州市2016年5—10月农贸市场猪肉源伦敦沙门菌的流行和耐药情况。从广州市农贸市场采集样品198份,分离得到28株猪肉源伦敦沙门菌,用K-B法测定其对18种抗菌药物的耐药性,用PCR方法鉴定其所携带的耐药基因。结果表明,市场猪肉样品中沙门菌的阳性率为74.2%（147/198）,伦敦沙门菌的分离率为19%（28/147）,其对磺胺异唑、四环素的耐药率分别为78.6%和75.0%;其次为链霉素、复方新诺明、氨苄西林、庆大霉素、氯霉素和氟苯尼考,耐药率依次为71.4%、67.9%、67.9%、67.9%、46.4%和42.8%;对萘啶酸（3.6%）和多黏菌素B （3.6%）耐药水平较低。有71.4%（20/28）的菌株对3种及3种以上抗菌药物耐药。氨基糖苷类耐药基因检出率为100%,aadA2（7.1%）、strA（37.9%）、aadB（100%）;酰胺醇类耐药基因检出率为42.6%,cat1b（39.3%）、floR（39.3%）;磺胺类耐药基因检出率为67.9%,sul1（60.7%）、sul2（60.7%）;四环素类耐药基因的检出率为78.6%,均同时携带tetA和tetB;β内酰胺类耐药基因bla_TEM检出率为10.7%;喹诺酮耐药基因qnrA、oqxAB和aac（6’）-lb-cr检出率为3.6%、10.7%和7.1%;黏菌素耐药基因mcr-1检出率为3.6%。伦敦沙门菌在广州农贸市场猪肉中是主要流行血清型之一,其对传统抗菌药物磺胺异唑、四环素、链霉素、复方新诺明、氨苄西林等耐药性严重,携带多种耐药基因,且具有多种多重耐药表型。这提示人们需要对市场沙门菌进行常态化检测与监测,加强对抗生素使用的监管,确保公共卫生和食品安全。     

Analysis of antibiotic resistance phenotypes and genes of Escherichia coli from healthy swine in Guizhou,China

This study was carried out to investigate the resistance phenotypes and resistance genes of Escherichia coli from swine in Guizhou, China. A total of 47 E. coli strains isolated between 2013 and 2018 were tested using the Kirby–Bauer (K–B) method to verify their resistance to 19 common clinical antimicrobials. Five classes consisting of 29 resistance genes were detected using polymerase chain reaction. The status regarding extended-spectrum β-lactamase (ESBL) and the relationship between ESBL CTX-M-type β-lactamase genes and plasmid-mediated quinolone resistance (PMQR) genes were analysed. A total of 46 strains (97.9%) were found to be multidrug resistant. Amongst them, 27 strains (57.4%) were resistant to more than eight antimicrobials, and the maximum number of resistant antimicrobial agents was 16. Twenty antibiotic resistance genes were detected, including six β-lactamase genes blaTEM (74.5%), blaCTX-M-9G (29.8%), blaDHA (17.0%), blaCTX-M-1G (10.6%), blaSHV (8.5%), blaOXA (2.1%), five aminoglycoside-modifying enzyme genes aac(3′)-IV (93.6%), aadA1 (78.7%), aadA2 (76.6%), aac(3′)-II c (55.3%), aac(6′)-Ib (2.1%) and five amphenicol resistance genes floR (70.2%), cmlA (53.2%), cat2 (10.6%), cat1 (6.4%), cmlB (2.1%), three PMQR genes qnrS (55.3%), oqxA (53.2%), qepA (27.7%) and polypeptide resistance gene mcr-1 (40.4%). The detection rate of ESBL-positive strains was 80.9% (38/47) and ESBL TEM-type was the most abundant ESBLs. The percentage of the PMQR gene in blaCTX-M-positive strains was high, and the detection rate of blaCTX-M-9G was the highest in CTX-M type. It is clear that multiple drug resistant E. coli is common in healthy swine in this study. Extended-spectrum β-lactamase is very abundant in the E. coli strains isolated from swine and most of them are multiple compound genotypes.     

乌鲁木齐地区不同健康状态和饲养环境中宠物源沙门菌耐药特征分析

为探究不同健康状态和不同饲养环境下沙门菌对临床常用抗菌药物的耐药情况及耐药基因携带情况,采用琼脂稀释法对健康与患病、家养与流浪宠物粪样中分离出的99株沙门菌进行临床常用12种抗菌药物的耐药性检测;用PCR方法对获得的耐药菌株进行相关耐药基因的检测。结果:分离出的宠物源沙门菌对所有被检的抗菌药物耐药率均未超过10.0%,对头孢噻呋、安普霉素、阿米卡星、卡那霉素和硫酸庆大霉素100%敏感;患病动物源沙门菌对被检抗菌药物的耐药率高于健康动物源沙门菌,家养动物源沙门菌对被检抗菌药物的耐药率高于流浪动物源沙门菌(P<0.05)。耐药基因检测结果显示:floR的检出率为3.0%;ant(3″)-Ia、tetA、tetB检出率均为2.0%;blaTEM、oqxA、aac(6′)-Ib-cr基因检出率均为1.0%,未检出其他被检基因。结果表明,新疆乌鲁木齐市不同健康状态和不同饲养环境下宠物源沙门菌对被检抗菌药物的耐药率及耐药基因携带率低,仅有2株沙门菌存在ant(3″)-Ia+tetA+tetB 3种耐药基因共存情况。根据试验结果发现检出的耐药表型与耐药基因之间存在相关性,可根据药敏试验结果合理选用抗菌药物进行临床细菌病的治疗。