摘要
      对霍乱弧菌菌株VC1和VC2进行基因分型，以表征对氯霉素、SXT、萘啶酸和链霉素的抗微生物耐药性基因（ARGs），通过抗体谱分析发现它们对这些抗生素具有耐药性。通过PCR检测strAB、sxt、sul2、qace∆1-sul1。用WGS对ARGs进行基因组注释和鉴定有助于检测almG、varG、strA（APH（3''）-Ib）、strB（APH）-Id）、sul2、catB9、floR、CRP、dfrA1基因的存在。在与参考蛋白30%-100%同源性的基础上，鉴定了与抗微生物耐药性有关的耐药性决定因素和蛋白结构域的特征，主要是抗生素的外排。基于与参考蛋白和核苷酸序列的100%同一性和100%覆盖率，预测这些结构域参与其他代谢功能，并预测其具有不同的分类来源，强调了微生物群对AMR获得的影响。QRDR（喹诺酮类耐药性决定区）的序列分析揭示了SNPs。Cytoscape v3.8.2用于分析MDR蛋白MdtA和EmrD-2与重要AMR途径节点的蛋白-蛋白相互作用。发现VC1和VC2中不存在参与不同类别抗生素流出的重要节点，这证明了这些菌株对大多数抗生素的敏感性。这项研究有助于检测从最近的疫情中分离出的VC的耐药性，以了解对大多数抗生素敏感的根本原因，并表征其基因组中的ARGs。研究表明，VC是耐药性决定因素的标志库，是霍乱严重AMR危机的前兆。
Abstract
Genotyping of Vibrio cholerae strains, VC1 and VC2 was undertaken to characterize antimicrobial resistance genes (ARGs) against chloramphenicol, SXT, nalidixic acid and streptomycin against which they were found to be resistant by antibiogram analysis. strAB, sxt, sul2, qace∆1-sul1 were detected by PCR. Genome annotation and identification of ARGs with WGS helped to detect the presence of almG, varG, strA (APH(3'')-Ib), strB (APH(6)-Id), sul2, catB9, floR, CRP, dfrA1 genes. Signatures of resistance determinants and protein domains involved in antimicrobial resistance, primarily, efflux of antibiotics were identified on the basis of 30%-100% homology to reference proteins. These domains were predicted to be involved in other metabolic functions on the basis of 100% identity with 100% coverage with reference protein and nucleotide sequences and were predicted to be of a diverse taxonomic origin accentuating the influence of the microbiota on AMR acquisition. Sequence analysis of QRDR (quinolone resistance-determining region) revealed SNPs. Cytoscape v3.8.2 was employed to analyse protein-protein interaction of MDR proteins, MdtA and EmrD-2, with nodes of vital AMR pathways. Vital nodes involved in efflux of different classes of antibiotics were found to be absent in VC1 and VC2 justifying the sensitivity of these strains to most antibiotics. The study helped to examine the resistome of VC isolated from recent outbreaks to understand the underlying reason of sensitivity to most antibiotics and also to characterize the ARGs in their genome. It revealed that VC is a reservoir of signatures of resistance determinants and serving as precursors for severe AMR crisis in cholera.

https://www.researchsquare.com/article/rs-2727745/v1