肠杆菌中的碳青霉烯类耐药已成为全球健康关注的问题。已从费萨拉巴德的两家医院分离出产生金属β-内酰胺酶NDM的临床大肠杆菌分离株,巴基斯坦。这些大肠杆菌菌株的特征是MALDI-TOF,PCR,抗菌药物敏感性试验,XbaI和S1核酸酶脉冲场凝胶电泳(PFGE),缀合测定,DNA杂交,全基因组测序,生物信息学分析,和梅洛内拉实验。在52种非重复耐碳青霉烯菌株中鉴定出34种产生blaNDM的大肠杆菌菌株。通过抗菌药物敏感性测试,发现90%以上的分离株具有多重耐药性。S1PFGE证实在40kbps至250kbps的质粒上存在blaNDM基因,和缀合测定表明,携带blaNDM的质粒的转移频率范围为每个供体1.59×10-1至6.46×10-8。全基因组测序分析显示blaNDM-5是突出的NDM亚型,blaOXA-1,blaCTX-M-15,aadA2,aac(6')-Ib-cr,和tet(A)相关的抗性决定因素。大肠杆菌序列类型:ST405、ST361和ST167突出,和质粒公司类型:FII,国际汽联,FIB,FIC,X3,R,Y,在所有分离株中观察到。IncF质粒上blaNDM区的遗传环境包括部分ISAba125,博来霉素ble基因,和我整合的一类。毒力基因terC,traT,gad,fyuA,irp2capu,和sitA经常被观察到,和G.mellonella实验表明,毒力与毒力决定子的数量相关。医院有必要进行强有力的感染控制管理,以检查革兰氏阴性菌中碳青霉烯耐药性的出现。重要信息我们描述了来自巴基斯坦两个三级护理中心的高耐药临床大肠杆菌分离株的详细分析,包括碳青霉烯耐药以及常见的共耐药机制。南亚有一个巨大的问题,高度耐药的大肠杆菌。然而,我们发现,尽管这些分离株很难治疗,但它们的毒力很低。因此,西方世界对毒性大肠杆菌的问题日益严重,这些大肠杆菌大多具有低抗生素耐药性,然而,南亚的高抗性大肠杆菌具有低毒力潜力的问题日益严重。这些观察使我们能够开始设计方法来限制毒力和抵抗力,并解决发展中国家以及西方世界的问题。
Carbapenem resistance among Enterobacterales has become a global health concern. Clinical Escherichia coli isolates producing the metallo β-lactamase NDM have been isolated from two hospitals in Faisalabad, Pakistan. These E. coli strains were characterized by MALDI-TOF, PCR, antimicrobial susceptibility testing, XbaI and S1 nuclease pulsed-field gel electrophoresis (PFGE), conjugation assay, DNA hybridization, whole genome sequencing, bioinformatic analysis, and Galleria mellonella experiments. Thirty-four
blaNDM producing E. coli strains were identified among 52 nonduplicate carbapenem-resistant strains. More than 90% of the isolates were found to be multidrug resistant by antimicrobial susceptibility testing. S1 PFGE confirmed the presence of
blaNDM gene on plasmids ranging from 40 kbps to 250 kbps, and conjugation assays demonstrated transfer frequencies of
blaNDM harboring plasmids ranging from 1.59 × 10-1 to 6.46 × 10-8 per donor. Whole genome sequencing analysis revealed
blaNDM-5 as the prominent NDM subtype with the highest prevalence of blaOXA-1, blaCTX-M-15, aadA2, aac(6\')-Ib-cr, and tet(A) associated resistant determinants. E. coli sequence types: ST405, ST361, and ST167 were prominent, and plasmid Inc types: FII, FIA, FIB, FIC, X3, R, and Y, were observed among all isolates. The genetic environment of
blaNDM region on IncF plasmids included partial ISAba125, the bleomycin ble gene, and a class I integron. The virulence genes terC, traT, gad, fyuA, irp2, capU, and sitA were frequently observed, and G. mellonella experiments showed that virulence correlated with the number of virulence determinants. A strong infection control management in the hospital is necessary to check the emergence of carbapenem resistance in Gram-negative bacteria.IMPORTANCEWe describe a detailed analysis of highly resistant clinical E. coli isolates from two tertiary care centers in Pakistan including carbapenem resistance as well as common co-resistance mechanisms. South Asia has a huge problem with highly resistant E. coli. However, we find that though these isolates are very difficult to treat they are of low virulence. Thus the Western world has an increasing problem with virulent E. coli that are mostly of low antibiotic resistance, whereas, South Asia has an increasing problem with highly resistant E. coli that are of low virulence potential. These observations allow us to start to devise methodologies to limit both virulence and resistance and combat problems in developing nations as well as the Western world.