Koupahi Hossein, Honarmand Jahromy Sahar, Rahbar Mohammad
Dept. of Microbiology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran.
Dept. of Microbiology, Iranian Reference Health Laboratory Research Center, Ministry of Health and Medical Education, Tehran, Iran.
Iran J Pathol. 2016 Fall;11(4):370-376.
Methicillin resistant (MRSA) has been emerged as a nosocomial and community acquired pathogen worldwide. There are many challenges for laboratory detection of MRSA. The aim of this study was to compare different phenotypic methods with PCR based method as a gold standard for detection of gene.
A total of 220 clinical isolates of which were isolated from various clinical specimens from September 2013 until the June of 2014 in Milad Hospital of Tehran, Iran was subject of our study. Methicillin resistance was determined by oxacillin and cefoxitin disks, oxacillin screen agar and CHROMagar™ MRSA medium. The results of these methods were compared with gene based PCR method as a gold standard method.
Among 220 isolates from , 105 (47.72%) isolates were positive for gene by PCR method. The results of cefoxitin disk diffusion method with 100% sensitivity and specificity was the same as PCR method .CHROMagar™ MRSA medium had 98.13% sensitivity and 100% specificity. Oxacillin disk diffusion and oxacillin screen agar had 95.42% and 97.22% sensitivity respectively.
Result of cefoxitin disk diffusion method with 100% sensitivity and specificity was the same as PCR method for detection gene. Cefoxitin disk diffusion method can be used as an alternative method of PCR for detection of MRSA.
耐甲氧西林金黄色葡萄球菌（MRSA）已成为全球医院获得性和社区获得性病原菌。MRSA的实验室检测存在诸多挑战。本研究旨在比较不同的表型检测方法与以基于PCR的方法作为基因检测金标准的差异。
我们的研究对象为2013年9月至2014年6月期间从伊朗德黑兰米拉德医院的各种临床标本中分离出的总共220株临床分离株。通过苯唑西林和头孢西丁纸片、苯唑西林筛选琼脂和CHROMagar™ MRSA培养基来测定耐甲氧西林情况。将这些方法的结果与作为金标准方法的基于基因的PCR方法进行比较。
在220株分离株中，通过PCR方法检测到105株（47.72%）基因阳性。头孢西丁纸片扩散法的结果与PCR方法相同，灵敏度和特异性均为100%。CHROMagar™ MRSA培养基的灵敏度为98.13%，特异性为100%。苯唑西林纸片扩散法和苯唑西林筛选琼脂的灵敏度分别为95.42%和97.22%。
头孢西丁纸片扩散法检测基因的灵敏度和特异性均为100%，与PCR方法相同。头孢西丁纸片扩散法可作为检测MRSA的PCR替代方法。
