1Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
2Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Sanandaj, Iran.
Acta Microbiol Immunol Hung. 2021 Feb 2;68(2):113-120. doi: 10.1556/030.2021.01314. Print 2021 Jun 21.
Acinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.
鲍曼不动杆菌作为一种医院获得性病原体，近年来引起了全球关注。在本研究中，评估了来自伊朗不同省份的分离株对四环素类和黏菌素的耐药性。在本研究期间，从气管吸出物、伤口、尿液和血液培养物中收集了 270 株鲍曼不动杆菌分离株。评估了四环素、多西环素、米诺环素、替加环素和黏菌素的最小抑菌浓度（MIC）。通过 PCR 评估四环素耐药基因。使用半定量实时 PCR 评估 adeB、adeJ 和 adeG 的平均表达水平。通过重复扩展基因回文 PCR（REP-PCR）、国际克隆（IC）谱系多重 PCR 和多位点序列分型（MLST）（巴斯德方案）方法评估分离株的克隆关系。微量稀释法 MIC 显示，87.5%、51.4%、28%、0.74%和 0%的分离株对四环素、多西环素、米诺环素、替加环素和黏菌素分别耐药。四环素耐药基因 adeB、adeJ、adeG、tetB、tetA(39)、tetA、tetM 和 tetH 在四环素耐药分离株中的检出率分别为 99.2%、99.2%、98%、86.7%、10%、3.33%、0.37%和 0%。此外，与替加环素敏感鲍曼不动杆菌（TSAB）相比，替加环素不敏感鲍曼不动杆菌（TNAB）菌株中 adeB、adeJ 和 adeG 基因的表达水平更高。结果表明，伊朗的四环素耐药性是由耐药-结节-分裂（RND）和 tetB 外排泵介导的。
