耐甲氧西林葡萄球菌4种检测方法的比较及临床应用

Comparison of four methods for detection of MRSA and their clinical practicability

关键词:  耐甲氧西林葡萄球菌（MRS）  K-B试验  琼脂筛选试验  MIC试验  mecA基因

Key words:  Methicillin-resistant staphylococci (MRS)  K-B disk diffusion method  salt agar screen  minimal inhibitory concentration (MIC)  mecA gene

摘要:

通过检测280株临床分离的葡萄球菌比较其耐甲氧西林葡萄球菌（MRS）阳性检出率，对其可靠性和临床实用性进行评估。［方法］K-B纸片扩散法、琼脂筛选法、琼脂二倍稀释法（MIC）、mecA基因检测法测试。［结果］　K-B法苯唑西林耐药葡萄球菌141株，阳性率惟50.36％；琼脂筛选法苯唑西林耐药葡萄球菌135株，阳性率为48.21％；MIC法苯唑西林耐药130株，阳性率为46.43％；mecA阳性葡萄球菌98株，阳性率为35%。3种表型检测法检测结果经χ 2检验无明显差异，而与mecA基因检测法结果稍有差异。［结论］mecA基因检测法是检测MRS的一种可靠的方法，但受设备、仪器、试剂和费用的限制，不易在广大医院临床实验室普遍开展，K-B法、琼脂筛选法、MIC法是检测MRS较为适用的方法。

Abstract:

To evaluate the reliability and clinical practicability of the four testing methods, 280 strains of clinical isolates of Staphylococcus were detected and the positive rate of MRS were compared. ［Methods］ K-B disk diffusion method, Salt agar screening method, Minimal inhibitory concentration (MIC) and PCR amplification of the mecA gene method. ［Results］ Oxacillin resistant Staphylococcus were 141 in using K-B disk diffusion method, positive rate was 50.36%; There were 135 in using Salt agar screening method, positive rate was 48.21%; There were 130 in using Agar diffusion method, positive rate was 46.43% and there were 98 in using PCR amplification of the mecA gene method, positive rate was 35%. There had no apparent difference among 3 phenotype detected methods and their positive rates were slightly higher than PCR amplification of the mecA gene method. ［Conclusion］ The PCR amplification of the mecA gene method is a reliable method for detection of MRS, but it is limited to facility、equipment、agent and cost, it is unfit for development in a common hospital Lab,While K-B disk diffusion method, Salt agar screening method, Agar diffusion method are appropriate methods for detection of MRS.