Hashem Y A, Yassin A S, Amin M A
Department of Microbiology and Immunology, Cairo University, Cairo, Egypt.
Indian J Med Microbiol. 2015 Feb;33 Suppl:80-6. doi: 10.4103/0255-0857.148836.
Enterococci are responsible for serious diseases such as bacteraemia, endocarditis and urinary tract infections. The ability of enterococci to cause such diseases is due to acquisition of certain virulence factors such as haemolysin, gelatinase and enterococcus surface protein. This study has been conducted to investigate the occurrence of virulence factors and resistance to various antibiotics with emphasis on vancomycin in the Enterococcus spp.
Clinical specimens were collected and isolates were identified by proper microscopic, culture and biochemical tests. Susceptibility and degree of resistance of the isolates to various antibiotics were determined. Virulence factors were examined by phenotypic tests followed by molecular methods. Bioinformatics analysis was used to detect regions in the genomes that might have originated from horizontal gene transfer.
The presence or absence of virulence genes did not affect the pattern of antimicrobial resistance in Enterococcus isolates; consequently, no relationship was found between virulence factors and resistance to different antibiotics used. Bioinformatics analysis showed that the virulence genes were mainly transferred by transposons.
Among the enterococci, environmental factors may interfere in the expression of virulence factors. Horizontal gene transfer plays an important role in the spread of resistance and virulence genes.
肠球菌可引发诸如菌血症、心内膜炎和尿路感染等严重疾病。肠球菌引发此类疾病的能力归因于获得了某些毒力因子,如溶血素、明胶酶和肠球菌表面蛋白。本研究旨在调查肠球菌属中毒力因子的出现情况以及对各种抗生素的耐药性,重点关注万古霉素。
收集临床标本,并通过适当的显微镜检查、培养和生化试验鉴定分离株。测定分离株对各种抗生素的敏感性和耐药程度。通过表型试验随后采用分子方法检测毒力因子。利用生物信息学分析来检测基因组中可能源于水平基因转移的区域。
毒力基因的存在与否并不影响肠球菌分离株的抗菌耐药模式;因此,未发现毒力因子与所用不同抗生素的耐药性之间存在关联。生物信息学分析表明,毒力基因主要通过转座子转移。
在肠球菌中,环境因素可能会干扰毒力因子的表达。水平基因转移在耐药性和毒力基因的传播中起重要作用。