聚合酶链反应检测耐甲氧西林凝固酶阴性葡萄球菌的研究

收集１３６株ＣＮＳ，用ＰＣＲ法检测ＭＲＣＮＳ，并与普通药敏试验比较，结果不相符的菌株进行诱导和抑制试验。结果表明ｍｅｃＡ基因阳性率为７８．７％，且ＰＣＲ产物经序列分析证明其为ｍｅｃＡ基因特异性产物。对１４株ｍｅｃＡ基因阳性而苯唑西林ＭＩＣ≤２μｇ／ｍｌ的细菌进行诱导试验后，其中８株苯唑西林ＭＩＣ值 提高，对４株ｍｅｃＡ基因阴性而苯唑西林（ＭＩＣ≥４μｇ／ｍｌ的细菌进行抑制试验后，其氨苄西林ＭＩＣ值

STUDY ON THE DETECTION OF METHICILLIN RESISTANT COAGULASE NEGATIVE STAPHYLOCOCCI(MRCNS) BY USING POLYMERASE CHAIN REACTION

strains of coagulase negative staphylococci(CNS)were isolated from clinical species.MecA gene was detected by PCR technique to identify MRCNS.Results of PCR were compared with that of bacterial susceptibility testing.Strains with disparity in results between the two methods were identified further by induction or inhibition test.Results show that the mecA gene positive rate is 787% among 136 strains.The PCR result was proved to be specific by sequence analysis.Eight of 14 strains sensitive to oxacillin but positive in mecA gene detection have oxacillin MIC value elevated after induction test;while 4 induction test;while 4 strains resistant to oxacillin but negative in mecA gene detection have ampicillin MIC value decreased and oxacillin MIC value in 2 strains also decreased markedly after inhibition test.Compared with routine drug sensitive test,PCR is a sensitive,specific and rapid method for the detection of MRCNS strains.