广东地区禽源致病性大肠杆菌对5种β-内酰胺类抗生素的耐药情况与ESBLs基因的携带情况

Resistance of avian pathogenic Escherichia coli to fiveβ-lactam antibiotics and its carrying status of ESBLs genes in Guangdong Province

为了解广东地区禽源致病性大肠杆菌(APEC)对5种β-内酰胺类抗生素的耐药情况和超广谱β-内酰胺酶(extended-spectrumβ-lactamases,ESBLs)基因(blaCTX-M、blaTEM、blaOXA)的携带情况,以更好地指导临床治疗,试验对2014-2019年从广东多地病死禽中分离鉴定得到的102株APEC采用PCR方法作系统进化分群与ESBLs基因检测,采用K-B纸片扩散法检测APEC对5种β-内酰胺类抗生素的敏感性,并分析不同禽源APEC对不同药物的耐药情况、102株APEC对5种抗生素的多重耐药性分布情况和耐药谱型,以及菌株耐药基因与耐药表型相关性。结果表明:A、B1、B2和D群比例分别为65.69%、9.80%、2.94%、21.57%。blaCTX-M、blaTEM、blaOXA基因的检出率分别是43.14%、35.29%、8.82%,组合blaCTX-M+blaTEM的阳性率为13.73%。APEC对2种青霉素类抗生素(阿莫西林、氨苄西林)和头孢拉定的耐药率均在85.71%以上,对头孢唑啉和头孢噻呋的耐药率分别为62.75%、47.06%。blaCTX-M基因与头孢唑啉和头孢噻呋的耐药率呈极显著相关(P<0.01),验证了blaCTX-M基因主要介导对头孢类抗生素的水解作用。说明广东地区APEC对5种β-内酰胺类抗生素的耐药情况较严重,耐药基因blaCTX-M、blaTEM的检出率要高于blaOXA基因。

In order to investigate the resistance of avian pathogenic Escherichia coli(APEC)to fiveβ-lactam antibiotics and its carrying status of extended-spectrumβ-lactamases(ESBLs)genes,containing blaCTX-M,blaTEM,blaOXA genes in Guangdong Province for a better guide to clinical treatment,a total of 102 APEC strains were isolated and identified from diseased poultry in several areas of Guangdong Province from 2014 to 2019.PCR was used for phylogenetic clustering of the strains and ESBLs genes detection;K-B paper diffusion method was used to detect the sensitivity of APEC to fiveβ-lactam antibiotics.The drug resistance of different avain APEC strains to different drugs,the multiple drug resistance distribution and drug resistance spectrum of 102 APEC strains to five antibiotics,and the correlation between resistance genes and resistant phenotypes of the strains were analyzed.The results showed that the proportions of clusters A,B1,B2 and D are 65.69%,9.80%,2.94%,21.57%,respectively.blaCTX-M,blaTEM,blaOXA were 43.14%,35.29%,8.82%,respectively;the positive detection rate of blaCTX-M and blaTEM combination was 13.73%.The resistance rates of APEC to two penicillin antibiotics(amoxicillin,ampicillin)and cefradine were above 85.71%;the resistance rates to cefazolin and ceftiofur were 62.75%and 47.06%,respectively.The blaCTX-M gene was extremely significantly correlated with the resistance rates of ceftazolin and ceftiofur(P<0.01),which verified that blaCTX-M gene mainly mediated the hydrolysis of cephalosporin antibiotics.The results suggested that the resistance of APEC to fiveβ-lactam antibiotics was serious in Guangdong Province;the detection rates of drug resistance genes blaCTX-M and blaTEM were higher than that of blaOXA gene.