Bhattacharyya Debaraj, Banerjee Jaydeep, Habib Md, Thapa Geetanjali, Samanta Indranil, Nanda Pramod Kumar, Dutt Triveni, Sarkar Keka, Bandyopadhyay Samiran
ICAR-Indian Veterinary Research Institute, Kolkata, India.
Department of Microbiology, University of Kalyani, Kalyani, India.
Water Environ Res. 2021 Dec 14;94(1):e1678. doi: 10.1002/wer.1678.
This study details about the phenotypic and molecular characteristics of multidrug-resistant (MDR) Escherichia coli in the fresh community pond water (n = 257) collected from three districts of West Bengal, India. In total, 57 isolates were MDR of which 38 emerged as extended spectrum and 7 as AmpC-type β-lactamase producers in phenotypic assay. Among β-lactamase genes, blaCTXM-1was predominant (87.71%) followed by blaAmpC (77.2%) and blaTEM-1 (22.8%). Six MDR strains carried metallo-β-lactamase (MBL, blaNDM-1) gene. Tissue culture plate assay confirmed strong biofilm (SP) production in four MDR and one non-MDR isolates. In PCR-based replicon typing (PBRT), multiple plasmids of diverse replicon types (Frep, FIB, I1, FIA, K/B, HI1, and Y) were identified. The enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR)-based phylogenetic analysis revealed a high degree of genetic divergence among the MDR isolates. Multiplex PCR-based phylogrouping categorized 11 isolates as virulent (B2/D/F), which carried blaCTXM-1 gene and three had blaNDM-1 gene. Relative transcriptional activity of AcrAB efflux pump was significantly elevated among the SP and MBL producers. The presence of MDR E. coli isolates, particularly those resistant to carbapenem, in pond water used for daily domestic and household work, is a cause of concern as these pathogens may sneak into human food chain causing life-threatening infections. PRACTITIONER POINTS: Multidrug-resistant biofilm producing E. coli isolated from community pond water. A few of them were carbapenem-resistant and belonged to virulent (B2/D) types. Expression of AcrAB efflux pumps was found significantly elevated among biofilm producers and carbapenem-resistant population.
本研究详细阐述了从印度西孟加拉邦三个地区采集的新鲜社区池塘水（n = 257）中耐多药（MDR）大肠杆菌的表型和分子特征。总共57株分离株为耐多药菌株，其中38株在表型检测中表现为超广谱β-内酰胺酶产生菌，7株为AmpC型β-内酰胺酶产生菌。在β-内酰胺酶基因中，blaCTXM-1占主导地位（87.71%），其次是blaAmpC（77.2%）和blaTEM-1（22.8%）。6株耐多药菌株携带金属β-内酰胺酶（MBL，blaNDM-1）基因。组织培养平板试验证实4株耐多药菌株和1株非耐多药菌株产生强生物膜（SP）。在基于聚合酶链反应（PCR）的复制子分型（PBRT）中，鉴定出多种不同复制子类型（Frep、FIB、I1、FIA、K/B、HI1和Y）的多个质粒。基于肠杆菌重复基因间共有序列-聚合酶链反应（ERIC-PCR）的系统发育分析显示，耐多药分离株之间存在高度的遗传差异。基于多重PCR的系统发育分组将11株分离株归类为毒力型（B2/D/F），这些菌株携带blaCTXM-1基因，3株携带blaNDM-1基因。在产生SP的菌株和MBL产生菌中，AcrAB外排泵的相对转录活性显著升高。在用于日常家务的池塘水中存在耐多药大肠杆菌分离株，尤其是那些对碳青霉烯耐药的菌株，令人担忧，因为这些病原体可能潜入人类食物链，导致危及生命的感染。从业者要点：从社区池塘水中分离出耐多药生物膜产生型大肠杆菌。其中一些对碳青霉烯耐药，属于毒力型（B2/D）。在生物膜产生菌和碳青霉烯耐药群体中，发现AcrAB外排泵的表达显著升高。
