背景:耐甲氧西林金黄色葡萄球菌(MRSA)是一种重要的病原体,可引起许多社区和医院获得性感染。进行这项研究是为了调查从住院患者中分离出的MRSA分离株中导致甲氧西林耐药性的SCCmec基因类型。
方法:从2021年3月至2022年1月从各个诊所送到加济安泰普大学医院微生物实验室的样本中分离的MRSA分离株被纳入研究。使用VITEK2自动化系统鉴定细菌。根据EUCAST标准,通过圆盘扩散法测定头孢西丁(FOX)抗性。青霉素结合蛋白2乳胶凝集试验证实了头孢西丁抗性。mecA的类型,mecC,coa,nuc,PantonValentinLeukocidin(PVL),ccrC2,A类mec,通过实时PCR研究了检测为MRSA的分离物中的SCCmec类型。
结果:在这项研究中,检查了116个符合研究标准的分离株。通过PCR检测所有分离物中的nuc和coa基因,金黄色葡萄球菌的表型鉴定得到证实.虽然在所有MRSA分离株中都检测到mecA基因,在任何分离株中均未检测到mecC基因。检测到的SCCmec类型如下;SCCmec类型1(2.6%),第二类(28.4%),III类(12.9%),IVa型(11.2%),IVb型(3.4%),IVc型(3.4%),IVg型(12.1%),V型(0.9%),VII类(4.3%),VIII类(18.1%),第九类(0.9%),第十二类(1.7%)。另一方面,SCCmecVI型,X,在任何分离物中都没有发现XI和XIII。确定了四个MRSA分离株(3.4%)携带PVL基因,其中两个(50%)在SCCmecVIII型中发现。
结论:监测FOX耐药性是检测MRSA分离株的有效和安全的方法。mec基因的变化会导致抗性,应该用分子方法定期监测。我们的研究是土耳其的第一项研究。
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen that can cause many community and hospital-acquired infections. This study was conducted to investigate the SCCmec gene types responsible for methicillin resistance in MRSA isolates isolated from hospitalised patients.
METHODS: MRSA isolates isolated from samples sent from various clinics to Gaziantep University Hospital Microbiology Laboratory between March 2021-January 2022 were included in the study. Bacteria were identified using by VITEK 2 automated system. Cefoxitin (FOX) resistance was determined by the disc diffusion method according to EUCAST standards. Cefoxitin resistance was confirmed by the Penicillin Binding Protein 2\' latex agglutination test. Types of mecA, mecC, coa, nuc, Panton Valentin Leukocidin (
PVL), ccrC2, class A mec, SCCmec types in isolates detected as MRSA were investigated by real-time PCR.
RESULTS: In this study, 116 isolates meeting the study criteria were examined. By detecting the nuc and coa genes in all isolates by PCR, the phenotypic identification of S.aureus was confirmed. While the mecA gene was detected in all MRSA isolates, no mecC gene was detected in any isolates. Detected SCCmec types were as follows; SCCmec Type 1 (2.6%), Type II (28.4%), Type III (12.9%), Type IVa (11.2%), Type IVb (3.4%), Type IVc (3.4%), Type IVg (12.1%), Type V (0.9%), Type VII (4.3%), Type VIII (18.1%), Type IX (0.9%), Type XII (1.7%). On the other hand, SCCmec Type VI, X, XI and XIII were not found in any isolate. It was determined that four of the MRSA isolates (3.4%) carried the
PVL gene that two (50%) of these were found in SCCmec Type VIII.
CONCLUSIONS: Monitoring of FOX resistance is an effective and safe method for determination of MRSA isolates. The change in the mec gene causes resistance, which should be monitored regularly with molecular methods. Our study is the first study in Turkey.