耐甲氧西林凝固酶阴性葡萄球菌的耐药性

目的 观察凝固酶阴性葡萄球菌（CNS）对甲氧西林等的耐药性和β-内酰胺酶的产生率，指导临床用药。方法 对本院临床感染标本常规分离鉴定菌株，药敏试验应用K-B纸片扩散法，按NCCLS规定的标准进行，耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）MIC测定应用Vitex微生物自动分析系统，β-内酰胺酶检测采用碘量试管法。结果 CNS95株中MRCNS的分离率为39%，β-内酰胺酶的阳性率为63%，MRCNS的产酶率为95%，以甲氧西林敏感的葡萄球菌（MSCNS）的产酶率为43%；95%株CNS对万古霉素100%敏感，对氨苄青、青霉素、红霉素最低耐药率为85%，对头孢派酮、头孢唑林、舒普深最低敏感率为83%。结论 MRCNS和MSCNS的产酶率与对甲氧西林的耐药性呈正相关，MRCNS与产β-内酰胺酶葡萄球菌间的耐药率无显差异。目前万古霉素和舒普深是治疗MRCNS和产酶CNS的首选抗生素。

Resistance to antibiotics for methicillin-resistance to coagulase-negative staphylococci

AIM To study the methicillin resistance to coagulase negative staphylococci to methicilin and other antibiotics, and producing rats of beta lactamase for coagulasenegative staphylococci(CNS) in order to indicate clinical selecting drugs. METHODS All isolates were indentified by routine procedure, K B paper disk diffusion in accordance with the NCCLS standards was employed for drug sensitivity tests. VITEK microbe auto analysis instrument was used for measurement of MIC of MRCNS. Beta lactamase was measured by iodine volume tube method. RESULTS The isolating rate of MRCNS in 95 strains of CNS was 39%. The positive rates of beta lactamase of CNS, MRCNS and MSCNS were 63%, 95%, 43% respectively; The susceptibility for vancomycin of CNS was 100%.The lowest drug resistance rates of CNS to ampicillin,penicillin,erythromycin were 85%. The lowest susceptibility rates of CNS to cepoperazone,cefazolin,sulperazone were 83%. CONCLUSION The zymogenic rates of MRCNS and MSCNS were related with resistance to methicillin. The difference of the drug resistance rates between MRCNS and zymogenic CNS was not prominent. Now in the case of MRCNS and zymogenic CNS, vancomycin and sulperazone are the best choices. MRCNS' drug resistance should be paid attention broadly.