印度非典型肠道致病性大肠杆菌与典型肠道致病性大肠杆菌的毒力决定因素、抗生素敏感性模式及血清分型的比较分析

Comparative analysis of virulence determinants, antibiotic susceptibility patterns and serogrouping of atypical enteropathogenic Escherichia coli versus typical enteropathogenic E. coli in India.

作者信息

Malvi Supriya, Appannanavar Suma, Mohan Balvinder, Kaur Harsimran, Gautam Neha, Bharti Bhavneet, Kumar Yashwant, Taneja Neelam

机构信息

Enteric Laboratory, Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.

Advanced Pediatric Centre, Postgraduate Institute of Medical Education and Research, Chandigarh 160012, India.

出版信息

J Med Microbiol. 2015 Oct;64(10):1208-1215. doi: 10.1099/jmm.0.000131. Epub 2015 Jul 30.

DOI:10.1099/jmm.0.000131

PMID:26233663

Abstract

The epidemiology of enteropathogenic Escherichia coli (EPEC) and the significance of isolation of atypical EPEC (aEPEC) in childhood diarrhoea have not been well studied in an Indian context. A comparative study was undertaken to investigate virulence determinants, antibiotic susceptibility patterns and serogrouping of typical EPEC (tEPEC) versus aEPEC causing diarrhoea in children. A total of 400 prospective and 500 retrospective E. coli isolates were included. PCR was performed for eae, bfpA, efa, nleB, nleE, cdt, ehxA and paa genes. The Clinical and Laboratory Standards Institute's disc diffusion test was used to determine the antimicrobial susceptibility. Phenotypic screening of extended spectrum β-lactamases (ESBLs), AmpC and Klebsiella pneumoniae carbapenemase (KPC) production, and molecular detection of bla(NDM-1), bla(VIM), bla(CTX-M-15), bla(IMP) and bla(KPC) were performed. aEPEC (57.6 %) were more common as compared with tEPEC (42.3 %). The occurrence of virulence genes was observed to be three times higher in aEPEC as compared with tEPEC, efa1 (14.7 % of aEPEC, 4 % of tEPEC) being the most common. Most of the isolates did not belong to the classical EPEC O-serogroups. The highest resistance was observed against amoxicillin (93.22 %) followed by quinolones (83 %), cephalosporins (37.28 %), cotrimoxazole (35.59 %) and carbapenems (30.5 %). Overall equal numbers of aEPEC (41.17 %) and tEPEC (40 %) were observed to be multidrug-resistant. Fifteen EPEC strains demonstrated presence of ESBLs, five produced AmpC and four each produced metallo-β-lactamases and KPC-type carbapenemases; eight, seven and one isolate(s) each were positive for bla(VIM), bla(CTX-M-15) and bla(NDM-1), respectively. Here, to the best of our knowledge, we report for the first time on carbapenem resistance and the presence of bla(NDM-1) and bla(CTX-M-15) in EPEC isolates from India.

摘要

在印度背景下，肠致病性大肠杆菌（EPEC）的流行病学以及非典型EPEC（aEPEC）在儿童腹泻中分离的意义尚未得到充分研究。开展了一项比较研究，以调查引起儿童腹泻的典型EPEC（tEPEC）与aEPEC的毒力决定因素、抗生素敏感性模式和血清分型。总共纳入了400株前瞻性和500株回顾性大肠杆菌分离株。对eae、bfpA、efa、nleB、nleE、cdt、ehxA和paa基因进行了聚合酶链反应（PCR）。采用美国临床和实验室标准协会的纸片扩散法测定抗菌药物敏感性。对超广谱β-内酰胺酶（ESBLs）、AmpC和肺炎克雷伯菌碳青霉烯酶（KPC）的产生进行表型筛选，并对bla(NDM-1)、bla(VIM)、bla(CTX-M-15)、bla(IMP)和bla(KPC)进行分子检测。与tEPEC（42.3%）相比，aEPEC（57.6%）更为常见。观察到aEPEC中毒力基因的发生率比tEPEC高3倍，efa1（占aEPEC的14.7%，占tEPEC的4%）是最常见的。大多数分离株不属于经典的EPEC O血清群。观察到对阿莫西林的耐药率最高（93.22%），其次是喹诺酮类（83%）、头孢菌素类（37.28%）、复方新诺明（35.59%）和碳青霉烯类（30.5%）。总体而言，观察到aEPEC（41.17%）和tEPEC（40%）的多重耐药菌株数量相等。15株EPEC菌株显示存在ESBLs，5株产生AmpC，4株分别产生金属β-内酰胺酶和KPC型碳青霉烯酶；bla(VIM)、bla(CTX-M-15)和bla(NDM-1)分别有8株、7株和1株分离株呈阳性。在此，据我们所知，我们首次报告了印度EPEC分离株中的碳青霉烯耐药性以及bla(NDM-1)和bla(CTX-M-15)的存在情况。