凝固酶阴性葡萄球菌mecA基因检测及耐药性分析

目的]探讨不同方法检测凝固酶阴性葡萄球菌（Coagulase Negative Staphylococcus，CNS）的药物敏感性，并对其耐药性进行分析。方法]对收集的26株CNS进行头孢西丁纸片法耐药表型筛选以及PCRmecA基因检测，并用WHONET4软件进行耐药性分析。结果]在26株CNS中，共分离出6种葡萄球菌。表皮葡萄球菌、溶血葡萄球菌检出率最高，分别为42．3％、38．5％。科室分布依次为ICU、神经内科、外科。耐药分析显示：表皮葡萄球菌对氨苄青霉素、青霉素、红霉素明显耐药（〉90％）。对环丙沙星、克林霉素头孢唑林、阿莫西林、耐药率在50％-80％之间。溶血葡萄球菌对β-内酰胺酶类、喹诺酮类、大环内脂类等耐药，耐药率在60％-100％之间。本次实验未发现万古霉素耐药菌株。结论]CNS对各种抗菌素均产生高耐药，给医院感染造成很大压力，临床医生应了解抗菌素的应用指征以防止对其滥用，根据药敏结果选择对病原菌敏感的药物，重视药敏试验对临床的指导意义。

Detection of mecA gene in coagulase negative staphylococcus and analysis of their drug resistance

Objective ] To explore different methods in detection of drug susceptibility of CNS, and to analyze the resistance of CNS. Methods] Resistance phenotype screening with cefoxitin disk diffusion test and PCR mecA gene detection were conducted in 26 collected CNS strains, and the resistance was analyzed with WHONET 4. Results ] Six kinds of staphylococcus were isolated from the 26 strains, and high detection rates were found in staphylococcus epidermidis of 42.2% and staphylococcus haemolyticus of 38.5%, with the distribution in ICU, department of internal neurology and Surgical ward in turn. The resistance rates of staphylococcus epidermidis to AMP, penicillin and ERY were all above 90%, to CIP, CLI, EC and AMC were 50% - 80%. While the resistance rates of staphylococcus haemolyticus to beta -lactamase, quinolones and microlides were 60% - 100%. No vancomycin resistant strains were found in this test. Conclusion] CNS had a serious resistance in many kinds of antibiotics, which took great pressure on hospital infection. Clinicians should understand the application of antibiotics to prevent the abuse, and pay more attention to the clinical significance of drug susceptibility test as well as select proper drugs according to antimicrobial susceptibility test results of pathogenic bacteria.