Sepahvand Shahriar, Davarpanah Mohammad Ali, Roudgari Amir, Bahador Abbas, Karbasizade Vajihe, Kargar Jahromi Zahra
Department of Microbiology, Falavarjan Branch, Islamic Azad University, Isfahan, Iran.
Shiraz HIV/AIDS Research Center, Institute of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
Infect Drug Resist. 2017 Nov 27;10:455-462. doi: 10.2147/IDR.S141196. eCollection 2017.
is an important human pathogen which has recently gained increased attention due to the occurrence of drug-resistant nosocomial infections in patients suffering from immune system disorders, and those in hospital intensive care units. The aim of this research was to identify and isolate strains resistant to colistin, determine antibiotic resistance pattern of this bacteria, investigate the presence of colistin-resistant genes, and finally assess the effect of expression changes in pmrA and pmrB genes resistant to against colistin via real-time polymerase chain reaction.
The samples were initially purified and isolated using biochemical tests and Micro-gen kit. Later, the resistance pattern evaluation of validated samples to different antibiotics and colistin was carried out using two methods viz., disc diffusion and E-test. This was followed by the assessment of genes resistant to colistin via polymerase chain reaction besides gene expression changes via real-time polymerase chain reaction.
The results of this study indicated that eleven strains of isolated from Shahid Rajaee Trauma Hospital were resistant to colistin. However, in the resistance pattern evaluation of isolated from Ali Asghar Hospital, all the strains were sensitive to colistin. In the evaluation of genes resistant to pmrA and pmrB, most of the strains resistant to colistin were carriers of these genes. Besides, in the expression assessment of these genes, it was demonstrated that expression of pmrA in the strains resistant to colistin significantly increased in relation to sensitive strains, but the expression of pmrB increased at a lower rate in the strains resistant to colistin as compared to the sensitive strains.
Thus, it can be safely mentioned that increased expression of pmrA was due to the resistance of to colistin.
[病原体名称]是一种重要的人类病原体，由于免疫系统紊乱患者及医院重症监护病房患者中出现耐多药医院感染，其最近受到了更多关注。本研究的目的是鉴定和分离对黏菌素耐药的[病原体名称]菌株，确定该细菌的抗生素耐药模式，调查黏菌素耐药基因的存在情况，最后通过实时聚合酶链反应评估pmrA和pmrB基因表达变化对[病原体名称]黏菌素耐药性的影响。
最初使用生化试验和Micro-gen试剂盒对样本进行纯化和分离。随后，采用纸片扩散法和E-test两种方法对经确认的样本对不同抗生素和黏菌素的耐药模式进行评估。在此之后，通过聚合酶链反应评估黏菌素耐药基因，并通过实时聚合酶链反应评估基因表达变化。
本研究结果表明，从沙希德·拉贾伊创伤医院分离出的11株[病原体名称]对黏菌素耐药。然而，在对从阿里·阿斯加尔医院分离出的[病原体名称]进行耐药模式评估时，所有菌株对黏菌素敏感。在对pmrA和pmrB耐药基因的评估中，大多数对黏菌素耐药的菌株是这些基因的携带者。此外，在这些基因的表达评估中，结果表明，与敏感菌株相比，对黏菌素耐药的菌株中pmrA的表达显著增加，但与敏感菌株相比，对黏菌素耐药的菌株中pmrB的表达增加速率较低。
因此，可以有把握地说，pmrA表达增加是由于[病原体名称]对黏菌素耐药所致。
