万古霉素最低抑菌浓度漂移对甲氧西林耐药金黄色葡萄球菌感染治疗效果的影响

Effect of vancomycin minimum inhibitory concentration creeping on the treatment outcome of MRSA infections

目的了解万古霉素最低抑菌浓度(MIC)的变化与治疗甲氧西林耐药金葡菌(MRSA)感染之间的关系。方法分析2007—2009年安徽省立医院微生物实验室MRSA的分离率及MRSA万古霉素的MIC值变化,并结合临床资料评价万古霉素MIC漂移对疗效的影响。结果 3年中我院MRSA在金葡菌中的比率逐渐增加。未发现万古霉素耐药株,但MIC≤0.5mg/L的菌株所占比率逐年下降,而MIC≥2.0 mg/L的比率逐年上升。MIC≤1 mg/L时,治愈率、临床有效率、细菌清除率分别为56.5%、87.0%和78.3%,MIC≥2 mg/L时,分别为44.0%、68.0%和64.0%,抗菌药物平均使用时间后者明显延长。结论 3年中我院MRSA在金葡菌中分离率增加,万古霉素MIC显著增高,但治愈率、临床有效率、细菌清除率仍无差异。

Objective The aim of this study was to investigate the clinical relevance of vanconaycin minimum inhibitory concentration （MIC） creeping for treatment outcome of methicillinresistant Staphylococcus aureus （MRSA） infections. Methods Nonduplicate MRSA strains were isolated from clinical samples of patients in Anhui Provincial Hospital from January 2007 to January 2009. The prevalence of MRSA and the trend of vanconaycin MIC for S. aureus isolates were analyzed over 3 years. The clinical relevance of vancomycin minimum inhibitory concentration values creeping for treatment outcome of MRSA infec tions was discussed consdiering the clinical data. Results In the past 3 years, the prevalence of MRSA had kept increasing. In crease of vancomycin MIC was observed even though no vanconayeinresistant S. aureus was identified. In the 3 years, the pro portion of MRSA strains with MIC ≤ 0.5 nag/L decreased, while the percentage of MRSA strains with MIC ≤2.0 nag/L in creased. When vaneomycin MIC 1 nag/L, the cure rate, clinical effecacy rate and bacterial clearance rate were 56. 5%, 87.0% and 78.3%, respectively. When MIC ≥2 mg/L, the corresponding rates were 44.0%, 68.0% and 64.0%, respec tively. The average hospital stay and duration of antibiotic treatment were significantly longer. Conclusions In the 3year period, the prevalence of MRSA was increasing gradually. The MIC value of vanconaycin showed an creeping trend. However, the cure rate, clinical effeeacy rate and bacterial clearance rate in vancomycintreated MRSA infections did not show significant difference.