Kiani Masoumeh, Astani Akram, Eslami Gilda, Khaledi Mansoor, Afkhami Hamed, Rostami Soodabeh, Zarei Mohadeseh, Rezaei Khozani Nahid, Zandi Hengameh
Department of Microbiology, Faculty of Medicine, Shahid-Sadoughi University of Medical Sciences, Yazd, Iran.
Department of Parasitology and Mycology, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
AMB Express. 2021 Jun 5;11(1):82. doi: 10.1186/s13568-021-01243-3.
The current study was aimed at investigating the prevalence of the mutations upstream of the oprD coding region and its promoters among imipenem-resistant and sensitive Pseudomonas aeruginosa isolated from educational hospitals in Yazd City, Iran. All isolates were identified by the conventional biochemical tests. Then, the antibiotic resistance of these isolates was determined using the disk diffusion method according to the CLSI guidelines. Also, the E.test was performed to determine the minimum inhibitory concentrations (MIC) of imipenem. The mutations of this gene were recognized by the amplification of this region and subsequently sequenced. Sequencing of the genomic region upstream of oprD these regions were done in the 29 clinical strains. Statistical analysis was done by the statistical software SPSS-18. Seventy (77.7%) of isolates had MIC ≥ 16 and were resistant to imipenem. Mutations of the upstream of the oprD gene and its promoters were seen in 25 (86.2%) isolates and 4 isolates had no mutation. One isolate had a base substitution A→Cat nt 25 in the coding region and this isolate had a point mutation leading to an amino acid change at positions 9 (I→L). Our study results indicated that none of the strains had mutation in Shine-Dalgarno and the point mutations were the most common mutations upstream of the oprD coding region among P. aeruginosa isolates. Mutations were observed in imipenem-resistant isolates and it seems this mechanism is effective in resistance of isolates to imipenem and this confirmed that the indiscriminate use of antibiotic should be controlled.
本研究旨在调查从伊朗亚兹德市教学医院分离出的耐亚胺培南和敏感的铜绿假单胞菌中oprD编码区上游及其启动子的突变发生率。所有分离株均通过传统生化试验进行鉴定。然后，根据CLSI指南，采用纸片扩散法测定这些分离株的抗生素耐药性。此外，还进行了E试验以确定亚胺培南的最低抑菌浓度（MIC）。通过扩增该区域并随后进行测序来识别该基因的突变。对29株临床菌株的oprD上游基因组区域进行了测序。使用统计软件SPSS-18进行统计分析。70株（77.7%）分离株的MIC≥16，对亚胺培南耐药。25株（86.2%）分离株出现oprD基因上游及其启动子的突变，4株未发生突变。1株分离株在编码区第25位核苷酸处发生A→C碱基替换，该分离株存在点突变，导致第9位氨基酸发生变化（I→L）。我们的研究结果表明，所有菌株在Shine-Dalgarno区域均未发生突变，点突变是铜绿假单胞菌分离株中oprD编码区上游最常见的突变类型。在耐亚胺培南的分离株中观察到了突变，似乎这种机制在分离株对亚胺培南的耐药中起作用，这证实了应控制抗生素的滥用。
