Carbapenem Resistance in Gram-negative Bacteria in South-western Nigeria: The Role of Extended-spectrum β-lactamase CTX-M-15

IF 0.2 4区医学 Q4 MEDICINE, GENERAL & INTERNAL

West Indian Medical Journal Pub Date : 2018-01-26 DOI:10.7727/wimj.2017.122

D. Ogbolu, M. Webber

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引用次数: 2

Abstract

Objective: To determine the role of extended-spectrum β-lactamases in carbapenem-resistant Gram-negative bacteria from south-western Nigeria. Methods: Twenty-seven carbapenem-resistant isolates that were found to be non-carbapenemase producers (15 Escherichia coli, 9 Klebsiella pneumoniae and 3 Pseudomonas aeruginosa) were further studied. These isolates were subjected to analysis including phenotypic and genotypic detection of various β-lactamases, efflux activity, outer membrane protein, plasmids replicon typing, detection of transferable genes and resistances and typing using random amplified polymorphic DNA tests. Results: No isolates demonstrated de-repression of efflux, but all showed either complete loss or reduced production of outer membrane proteins. Transconjugants from these strains contained various genes including plasmid-mediated quinolone resistance and extended-spectrum beta-lactamases. All the transconjugants carried the blaCTX-M-15 gene. The transconjugants had varying minimum inhibitory concentrations of carbapenems ranging from 0.03 μg/ml to 8 μg/ml. Varying resistances to other antimicrobial agents were also transferred with the plasmids. The donor isolates were not clonally related by molecular typing. Conclusion: Resistance to carbapenem antibiotics in this sample was not mediated only by carbapenemases but also by production of extended-spectrum β-lactamases (largely CTX-M-15), accompanied by protein loss. This was an important mechanism underpinning carbapenem resistance in these clinical isolates of various species.

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尼日利亚西南部革兰氏阴性菌对碳青霉烯类耐药:广谱β-内酰胺酶CTX-M-15的作用

目的:探讨广谱β-内酰胺酶在尼日利亚西南部产碳青霉烯耐药革兰氏阴性菌中的作用。方法:对27株非产碳青霉烯酶耐药菌株(大肠埃希菌15株、肺炎克雷伯菌9株、铜绿假单胞菌3株)进行进一步研究。对这些分离株进行表型和基因型检测，包括各种β-内酰胺酶、外排活性、外膜蛋白、质粒复制子分型、可转移基因和抗性检测，以及随机扩增多态性DNA检测分型。结果:没有分离物表现出外排抑制，但所有分离物都表现出完全丧失或减少外膜蛋白的产生。这些菌株的转偶联物含有多种基因，包括质粒介导的喹诺酮类药物抗性和广谱β -内酰胺酶。所有转偶联物均携带blaCTX-M-15基因。转偶联物对碳青霉烯类的最低抑制浓度在0.03 ~ 8 μg/ml之间。对其他抗菌剂的不同耐药性也随质粒转移。供体分离株分子分型无克隆亲缘关系。结论:该样品对碳青霉烯类抗生素的耐药不仅由碳青霉烯酶介导，还由广谱β-内酰胺酶(主要是CTX-M-15)的产生介导，并伴有蛋白质损失。这是支持这些临床分离的不同物种碳青霉烯类耐药的重要机制。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

West Indian Medical Journal 医学-医学：内科

CiteScore

0.20

自引率

0.00%

发文量

审稿时长

4-8 weeks

期刊介绍： The Journal is international in scope, with author and editorial contributions from across the globe. The focus is on clinical and epidemiological aspects of tropical and infectious diseases, new and re-emerging infections, chronic non-communicable diseases, and medical conditions prevalent in the Latin America-Caribbean region, and of significance to global health, especially in developing countries. The Journal covers all medical disciplines, as well as basic and translational research elucidating the pathophysiologic basis of diseases or focussing on new therapeutic approaches, and publishes original scientific research, reviews, case reports, brief communications, letters, commentaries and medical images. The Journal publishes four to six issues and four supplements annually. English is the language of publication but Abstracts are also duplicated in Spanish. Most of the articles are submitted at the authors’ initiative, but some are solicited by the Editor-in-Chief. Unless expressly stated, the Editorial Board does not accept responsibility for authors’ opinions. All papers on submission are reviewed by a subcommittee. Those deemed worthy for review are sent to two or three reviewers (one of the three might be a statistician if necessary). The returned papers with reviewer comments are reviewed by the Editor-in-Chief. Papers may be rejected, accepted or sent back to authors for revision. Resubmitted papers from authors are reviewed by the Editor-in-Chief and may be sent back to reviewers or a final decision made by Editor-in-Chief. The decision of the Editorial Board is final with regards to rejected articles. Rejected articles will not be returned to the authors. The editorial subcommittee has the right to return sub-standard manuscripts to the authors, rather than passing them on to the reviewers. This implies outright rejection of the manuscript.