Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran; Department of Microbiology, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran.
Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
J Glob Antimicrob Resist. 2019 Sep;18:95-99. doi: 10.1016/j.jgar.2018.12.011. Epub 2019 Feb 11.
Carbapenem-resistant Acinetobacter baumannii (CRAB) have emerged as a serious threat to public-health worldwide. This study aimed to determine the antimicrobial susceptibility of A. baumannii isolates in Iran and to investigate oxacillinase-encoding determinants and their association with insertion sequence ISAba1 in CRAB isolates.
This study was performed on A. baumannii isolates recovered from patients with burn wound infections during 2013. All isolates were evaluated for antimicrobial susceptibility by the disk diffusion method. Minimum inhibitory concentrations (MICs) of five antibiotics (imipenem, meropenem, polymyxin B, colistin and tigecycline) were determined for all CRAB isolates. PCR was performed to determine the distribution of bla determinants and ISAba1 insertion upstream of each corresponding gene in the CRAB isolates.
A total of 65 A. baumannii isolates were recovered during the 1-year period, with CRAB accounting for 63 (96.9%) of isolates. Polymyxin B, colistin and tigecycline were the most effective agents against CRAB isolates, with susceptibility rates of 100%, 87.3% and 65.1%, respectively. The proportion of CRAB isolates carrying oxacillinase determinants was as follow: bla, 100%; bla, 74.6%; bla, 47.6%; and bla, 12.7%. ISAba1, ISAba1-bla and ISAba1-bla were detected in 100%, 41.3% and 1.6% of CRAB isolates, respectively. Co-occurrence of bla determinants or inserted ISAba1 upstream of the corresponding genes was associated with increased carbapenem MICs (≥128μg/mL).
The emergence of high-level CRAB with bla and ISAba1-bla family in burn patients is a matter of increasing clinical concern, emphasising the need for infection control efforts to limit such problematic bacteria.
耐碳青霉烯鲍曼不动杆菌（CRAB）已成为全球公共卫生的严重威胁。本研究旨在确定伊朗分离的鲍曼不动杆菌对各种抗菌药物的敏感性，并研究 CRAB 分离株中产 oxacillinase 基因的决定簇及其与插入序列 ISAba1 的关系。
本研究于 2013 年对烧伤创面感染患者分离的鲍曼不动杆菌进行。所有分离株均采用纸片扩散法进行药敏试验。对所有 CRAB 分离株测定 5 种抗生素（亚胺培南、美罗培南、多黏菌素 B、多黏菌素 E 和替加环素）的最小抑菌浓度（MIC）。PCR 用于确定 CRAB 分离株中 bla 决定簇和 ISAba1 在相应基因上游的分布。
在 1 年期间共分离到 65 株鲍曼不动杆菌，其中 63 株（96.9%）为 CRAB。多黏菌素 B、多黏菌素 E 和替加环素对 CRAB 分离株最有效，敏感性分别为 100%、87.3%和 65.1%。携带 oxacillinase 决定簇的 CRAB 分离株的比例如下：bla，100%；bla，74.6%；bla，47.6%；bla，12.7%。ISAba1、ISAba1-bla 和 ISAba1-bla 在 CRAB 分离株中的检出率分别为 100%、41.3%和 1.6%。CRAB 分离株中 bla 决定簇或插入的 ISAba1 与相应基因上游的存在与碳青霉烯 MIC 值升高（≥128μg/mL）有关。
在烧伤患者中出现高水平耐碳青霉烯鲍曼不动杆菌（bla 和 ISAba1-bla 家族）引起了越来越多的临床关注，强调需要采取感染控制措施来限制此类问题细菌的传播。
