Carbapenem heteroresistance in Acinetobacter baumannii and Pseudomonas aeruginosa blood isolates from a Turkish tertiary hospital: a comprehensive study.

IF 3.2 3区生物学 Q2 BIOTECHNOLOGY & APPLIED MICROBIOLOGY

Journal of Applied Microbiology Pub Date : 2025-09-01 DOI:10.1093/jambio/lxaf204

Ekin Kırbaş, Banu Sancak

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引用次数: 0

Abstract

Aims: To investigate the prevalence of carbapenem resistance and carbapenem heteroresistance (CAHR) in Acinetobacter baumannii and Pseudomonas aeruginosa blood isolates.

Methods: The susceptibility of 408 bloodstream isolates (256 A. baumannii and 152 P. aeruginosa) to imipenem (IMI) and meropenem (MER) was determined using the broth microdilution method. CAHR was investigated by population analysis profiling (PAP) and diffusion-based tests, including disk diffusion and antibiotic gradient tests. Carbapenemase genes in carbapenem-resistant and carbapenem-heteroresistant isolates were identified by polymerase chain reaction.

Results: Based on the Clinical Laboratory Standards Institute suceptibility breakpoints, the resistance rates for A. baumannii were 88.3% for IMI and 87.5% for MER, while P. aeruginosa showed resistance rates of 43.4% for IMI and 46.7% for MER. Among carbapenem-resistant A. baumannii strains, blaOXA-51 (100%) and blaOXA-23 (86.3%) were the most prevalent. Among carbapenem-resistant P. aeruginosa strains, blaOXA-10 (26.8%) was the most frequent. The PAP method revealed that the IMI- and MER-HR rates were 24.1% and 30%, respectively, in A. baumannii isolates, while in P. aeruginosa isolates, the rates were 57.9% and 13.8%, respectively. blaOXA-51 was detected in all carbapenem-resistant A. baumannii subpopulations, whereas blaOXA-23 was detected in 75% (n= 12) of isolates. No carbapenemase genes were identified in any of the carbapenem-resistant P. aeruginosa subpopulations.

Conclusions: Upon comparison of the results obtained with diffusion-based tests and PAP, diffusion-based tests were found to be unreliable for detecting CAHR.

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土耳其某三级医院鲍曼不动杆菌和铜绿假单胞菌血液分离株碳青霉烯类耐药的综合研究

目的：了解鲍曼不动杆菌和铜绿假单胞菌对碳青霉烯耐药和碳青霉烯异源耐药（CAHR）的情况。方法：采用微量肉汤稀释法（BMD）检测408株血液分离株（鲍曼不动杆菌256株、铜绿假单胞菌152株）对亚胺培南（IMI）和美罗培南（MER）的敏感性。采用群体分析谱（PAP）和基于扩散的试验（包括Kirby-Bauer盘扩散试验和梯度试验）对CAHR进行了调查。采用聚合酶链反应对耐药株和异耐药株碳青霉烯酶基因进行鉴定。结果：根据美国临床实验室标准协会的断点，鲍曼假单胞菌对IMI和MER的耐药率分别为88.3%和87.5%，铜绿假单胞菌对IMI和MER的耐药率分别为43.4%和46.7%。耐碳青霉烯鲍曼不动杆菌中以blaOXA-51（100%）和blaOXA-23（86.3%）最为常见。耐碳青霉烯P. aeruginosa菌株中以blaOXA-10（26.8%）最为常见。PAP法检测鲍曼假单胞菌的IMI-和MER-HR分别为24.1%和30%，铜绿假单胞菌的IMI-和MER-HR分别为57.9%和13.8%。在所有耐碳青霉烯鲍曼不动杆菌亚群中检测到blaOXA-51，而在75% （n=12）的分离株中检测到blaOXA-23。在耐碳青霉烯的铜绿假单胞菌亚群中未发现碳青霉烯酶基因。结论：通过对弥散试验和PAP试验结果的比较，发现弥散试验对CAHR的检测不可靠。

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来源期刊

Journal of Applied Microbiology 生物-生物工程与应用微生物

CiteScore

7.30

自引率

2.50%

发文量

427

审稿时长

2.7 months

期刊介绍： Journal of & Letters in Applied Microbiology are two of the flagship research journals of the Society for Applied Microbiology (SfAM). For more than 75 years they have been publishing top quality research and reviews in the broad field of applied microbiology. The journals are provided to all SfAM members as well as having a global online readership totalling more than 500,000 downloads per year in more than 200 countries. Submitting authors can expect fast decision and publication times, averaging 33 days to first decision and 34 days from acceptance to online publication. There are no page charges.