Shokouhi Shervin, Darazam Ilad A, Javadi Alireza, Rouhani Matin, Ghasemnejad Mahdiyeh
Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Velenjak Koodakyar Ave., P.O. Box: 1985717443, Tehran, Iran.
Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Infect Disord Drug Targets. 2017;17(2):90-94. doi: 10.2174/1871526517666170210164649.
Enterococci infection rate, mortality and morbidity have been increased in recent decades accompanied by progressive emerging antimicrobial resistance. Vancomycin-resistant enterococci (VRE), important pathogen in hospitalized patients, has distinct antibiotic susceptibility to glycopeptides that varied genetically and can influence in choosing therapeutic agents. In this study, we aimed to determine the patterns of antimicrobial resistance according to the genotypic variations in VREs.
Enterococci samples were isolated from different clinical specimens followed by antimicrobial susceptibility that was determined by the disk diffusion method during one year 2015-2016. Subsequently, VREs were selected and extraction of total DNA was performed using the QIAmp DNA mini kit. The eight oligonucleotide primer pairs were used to amplify the genes vanA, vanB, vanC1, vanC2, vanC2/3, esp, and hyl. Multiplex polymerase chain reaction (PCR) was performed to identify Van A, Van B, Van C, Van D and clonal complex 17 (CC17).
A total of 235 enterococci were isolated, including 121 and 114 Enterococcus faecalis and Enterococcus faecium, respectively. Most of VREs (42% of all enterococci) were E. faecium (91.1% vs. 8.9% E. faecalis). All VREs had Van A; and Van B, Van C and Van D genes were not found in any isolates. The frequency rate of CC17, genetic subset of E. faecium, was 68.3%.
In conclusion, we can assume that the most frequent genotype of VRE in our country is VAN A and literally, the other genotypes.
近几十年来，肠球菌感染率、死亡率和发病率不断上升，同时抗菌药物耐药性也在逐渐出现。耐万古霉素肠球菌（VRE）是住院患者中的重要病原体，对糖肽类抗生素具有独特的药敏性，其药敏性存在基因差异，会影响治疗药物的选择。在本研究中，我们旨在根据VRE的基因型变异确定抗菌药物耐药模式。
从不同临床标本中分离出肠球菌样本，随后在2015 - 2016年的一年时间里，采用纸片扩散法测定其药敏性。随后，选择VRE并使用QIAmp DNA迷你试剂盒进行总DNA提取。使用八对寡核苷酸引物对来扩增vanA、vanB、vanC1、vanC2、vanC2/3、esp和hyl基因。进行多重聚合酶链反应（PCR）以鉴定Van A、Van B、Van C、Van D和克隆复合体17（CC17）。
共分离出235株肠球菌，其中粪肠球菌121株，屎肠球菌114株。大多数VRE（占所有肠球菌的42%）为屎肠球菌（91.1%对粪肠球菌的8.9%）。所有VRE均具有Van A基因；未在任何分离株中发现Van B、Van C和Van D基因。屎肠球菌的遗传亚群CC17的频率为68.3%。
总之，我们可以假设我国VRE最常见的基因型是VAN A，实际上还有其他基因型。
