Khajuria Atul, Praharaj Ashok Kumar, Kumar Mahadevan, Grover Naveen
PhD Scholar, Department of Microbiology, Armed Forces Medical College , Pune, India .
Post Graduate, Department of Microbiology, Armed Forces Medical College , Pune, India .
J Clin Diagn Res. 2014 Jun;8(6):DC01-4. doi: 10.7860/JCDR/2014/7952.4413. Epub 2014 Jun 20.
To detect genes encoding carbapenem resistance in urinary isolates of Escherichia coli recovered from hospitalized patients in tertiary care centre in Pune, India.
From Jan 2012 to Dec 2012, a total of 300 consecutive non-duplicate (one isolate per patient) clinical isolates of Escherichia coli were recovered from urine cultures of hospitalized patients including hospital acquired infection cases admitted to the medical and surgical intensive care units. Polymerase chain reaction (PCR) assays and sequencing was used to determine the presence of beta-lactamase encoding genes. Conjugation experiments were performed to determine the transferability of beta-lactamase.
All the isolates were completely resistant to the second and third generation cephalosporins tested as well as carbapenems. All the isolates showed 100% susceptibility to tigecycline and colistin in vitro. Conjugation experiments demonstrated that blaNDM-1 was transferable via plasmid. All the isolates showed presence of blaNDM-1 and co-association of blaOXA-48 was 25/45(55%) of the isolates. Repetitive element based PCR (REP PCR), Enterobacterial Repetitive Intergenic Consensus (ERIC PCR) and Randomly Amplified Polymorphic DNA (RAPD) revealed a diversity of six clonal types among E.coli isolates.
Co-production of NDM-1with OXA-48 in urinary isolates of E. coli was detected for the first time in India. Transmission of plasmid carrying these resistant genes to other members of Enterobacteriaceae will increase incidence of multidrug resistance. Early detection of these genes will help in prevention and adequate infection control by limiting the spread of these organisms.
检测从印度浦那一家三级医疗中心住院患者尿液分离出的大肠埃希菌中编码碳青霉烯耐药性的基因。
2012年1月至2012年12月，从住院患者的尿液培养物中总共分离出300株连续的非重复（每位患者一株）大肠埃希菌临床分离株，包括入住内科和外科重症监护病房的医院获得性感染病例。采用聚合酶链反应（PCR）检测和测序来确定β-内酰胺酶编码基因的存在。进行接合实验以确定β-内酰胺酶的可转移性。
所有分离株对所检测的第二代和第三代头孢菌素以及碳青霉烯类均完全耐药。所有分离株在体外对替加环素和黏菌素均表现出100%的敏感性。接合实验表明blaNDM-1可通过质粒转移。所有分离株均显示存在blaNDM-1，且blaOXA-48的共检出率为25/45（55%）。基于重复元件的PCR（REP PCR）、肠杆菌重复基因间共有序列（ERIC PCR）和随机扩增多态性DNA（RAPD）分析显示大肠埃希菌分离株中有六种克隆类型。
在印度首次检测到大肠埃希菌尿液分离株中NDM-1与OXA-48的共同产生。携带这些耐药基因的质粒向肠杆菌科其他成员的传播将增加多重耐药的发生率。早期检测这些基因将有助于通过限制这些微生物的传播来预防和进行充分的感染控制。
