کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5668902 1407926 2017 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Occurrence of blaNDM-7 within IncX3-type plasmid of Escherichia coli from India
موضوعات مرتبط
علوم زیستی و بیوفناوری ایمنی شناسی و میکروب شناسی میکروبیولوژی و بیوتکنولوژی کاربردی
پیش نمایش صفحه اول مقاله
Occurrence of blaNDM-7 within IncX3-type plasmid of Escherichia coli from India
چکیده انگلیسی

BackgroundNew-Delhi metallo-β-lactamase-7 with higher hydrolytic activity than its ancestor NDM-1 is emerging across the globe including India. In this study, we have investigated the genetic context of blaNDM-7 and alteration in plasmid copy number under concentration gradient carbapenem stress.Materials and methodsSix blaNDM-7 producing Escherichia coli isolates were obtained from Silchar Medical College and Hospital and the co-existence of other β-lactamases and transferability of this resistant determinant was determined by transformation and conjugation assay followed by typing of the plasmid by PBRT method. Genetic context and plasmid stability of blaNDM-7 was also determined. The change in copy number of transconjugable plasmid carrying blaNDM-7 under exposure of different carbapenem antibiotics was determined by quantitative Real Time PCR.ResultsAll the six isolates carrying blaNDM-7 were conjugatively transferable through an IncX3-type plasmid and were also found to co-harbor blaCTX-M-15. Genetic analysis of blaNDM-7 showed an association of ISAba125, IS5 and a truncated portion of ISAba125 in the upstream region and bleMBL gene in the downstream region of blaNDM-7. Complete loss of the plasmids carrying blaNDM-7 was observed between 85th to 90th serial passages when antibiotic pressure was withdrawn. After analyzing the relative copy number it was observed that the copy number of the blaNDM-7 encoding plasmid was highly affected by the concentration of ertapenem.ConclusionThe present study has first demonstrated presence of IncX3-type plasmid encoding blaNDM-7 within nosocomial isolates of E. coli. Measures must be taken to prevent or atleast slowdown the emergence of this resistance determinant in this country.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Infection and Chemotherapy - Volume 23, Issue 4, April 2017, Pages 206-210
نویسندگان
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