Saifi Mahnaz, Pourshafie Mohammad Reza, Eshraghian Mohammad Reaz, Soltan Dallal Mohammad Mehdi
Divivision of Microbiology, Department of Pathobiology, School of Public Health, Medical Sciences Tehran University, Tehran, Iran.
Anti-Microbial Resistance of Enterococci Isolated from Urinary Tract Infections in Iran.
Iran Biomed J. 2008 Jul;12(3):185-90.
During the last decade, enterococci have become important nosocomial pathogens, representing the second leading cause of urinary tract infections. This increasing prevalence has been paralleled by the occurrence of multi-drug resistant (MDR) and high-level gentamicin resistant (HLGR) strains.
From September 2005 to 2006, a total of 638 enterococcal isolates were collected from urine samples among 9 medical centers in Tehran (Iran). Confirmation of species and detection of gentamicin resistance genes were done by PCR method. Anti-microbial susceptibility test was determined with disk diffusion and minimal inhibitory concentration of gentamicin among HLGR isolates assayed by microdilution methods.
The isolates were found to consist of Enterococcus faecalis (77.8%) and Enterococcus faecium (22.2%). The results obtained from PCR showed a high rate of agreement with phenotypic assays for both species. MDR to most prevalent anti-microbials was present in 29% and 72% of the E. faecalis and E. faecium isolates, respectively. HLGR phenotype was detected in 64% of E. faecalis and 92% of E. faecium isolates. The aac(6')-Ie-aph(2'')-Ia gene were identified in 83% of E. faecalis and 100% of E. faecium HLGR isolates. E. faecalis and E. faecium isolates differed in their susceptibilities to different antibiotics.
Emergence of multi-resistant enterococci and high level resistance to gentamicin shown by enterococcal strains is of concern because of the decrease in the therapeutic options for treatment of infections caused by enterococci.
在过去十年中，肠球菌已成为重要的医院病原体，是尿路感染的第二大主要病因。这种患病率的上升与多重耐药（MDR）和高水平庆大霉素耐药（HLGR）菌株的出现相伴。
2005年9月至2006年，从德黑兰（伊朗）的9个医疗中心的尿液样本中总共收集了638株肠球菌分离株。通过PCR方法进行菌种确认和庆大霉素耐药基因检测。采用纸片扩散法进行抗菌药敏试验，并用微量稀释法测定HLGR分离株中庆大霉素的最低抑菌浓度。
分离株包括粪肠球菌（77.8%）和屎肠球菌（22.2%）。PCR结果显示，两种菌种的表型检测结果与PCR结果高度一致。粪肠球菌和屎肠球菌分离株中，分别有29%和72%对最常用的抗菌药物呈现多重耐药。在64%的粪肠球菌和92%的屎肠球菌分离株中检测到HLGR表型。在83%的粪肠球菌HLGR分离株和100%的屎肠球菌HLGR分离株中鉴定出aac(6')-Ie-aph(2'')-Ia基因。粪肠球菌和屎肠球菌分离株对不同抗生素的敏感性不同。
肠球菌多重耐药的出现以及肠球菌菌株对庆大霉素的高水平耐药令人担忧，因为这会减少治疗肠球菌引起感染的治疗选择。
