摘要
目的探讨沈阳地区部分医院万古霉素治疗金黄色葡萄球菌感染患者失败的因素,为有效治疗提供依据。方法 2011年6月-2012年8月对临床分离的172株金黄色葡萄球菌中耐甲氧西林金黄色葡萄球菌（MRSA）102株、甲氧西林敏感金黄色葡萄球菌（MSSA）70株,采用E-test法检测其对万古霉素最低抑菌浓度MIC值;用含万古霉素4.0μg/ml的脑心浸液琼脂培养基筛选异质性万古霉素中介耐甲氧西林金黄色葡萄球菌（hVISA）,在无万古霉素血平皿培养基中对MRSA进行连续传代培养,检测其对万古霉素MIC值的变化。结果 172株临床分离金黄色葡萄球菌,对万古霉素MIC值在（1.0-2.0）μg/ml有146株,占84.89%;102株MRSA对万古霉素MIC值在（1.0-2.0）μg/ml有88株,占86.27%,其中有两株MIC值为（2.5-3.0）μg/ml;70株MSSA对万古霉素MIC值在（1.0-1.5）μg/ml有46株,占65.71%,其余〈1.0μg/ml;含万古霉素4.0μg/ml的脑心浸液琼脂培养基未筛选出hVISA,也未筛选出对万古霉素MIC值〉8.0μg/ml的VRSA;体外传代培养发现,MRSA对万古霉素的MIC值随传代次数呈现一定变化规律。结论沈阳地区hVISA检出率极低,大部分临床治疗失败可能与菌株MIC值漂移有关,MIC值漂移菌株脱离抗菌药物环境连续传代,其MIC值较初始分离时未见下降,提示MIC值的漂移可能也涉及到了稳定的遗传变异,其机制有待进一步研究。
OBJECTIVE To explore the causes of failed vancomycin therapy for patients with Staphylococcus aureus infections,so as to provide guidance for effective treatment.METHODS A total of 172 S.aureus clinical isolates were collected from Jun 2011 to Aug 2012,including 102 strains of methicillin-resistant S.aureus（MRSA）and 70 strains of methicillin-sensitive S.aureus（MSSA）.The minimum inhibitory concentration（MIC）value of vancomycin was determined by using E-test,the heteroresistant vancomycin-intermediate S.aureus（hVISA）strains were screened by using brain heart infusion agar medium containing 4.0μg/ml of vancomycin,the MRSA strains were subcultured on blood plates medium without vancomycin,and the change of MIC value of vancomycin was observed.RESULTS Of the 172 clinical S.aureus isolates,146（84.89%）strains had the MIC value of vancomycin ranging between 1.0μg/ml and 2.0μg/ml.There were 88 of 102（86.27%）strains of MRSA with the MIC value of vancomycin ranging between 1.0μg/ml and 2.0μg/ml and 2strains with the MIC value ranging between 2.5μg/ml and 3.0μg/ml.There were 46 of 70（65.71%）strains of MSSA with the MIC value of vancomycin ranging between 1.0μg/ml and 1.5μg/ml,the remaining strains less than 1.0μg/ml.No hVISA strain was screened from the brain heart infusion agar medium containing 4.0μg/ml of vancomycin,and no VRSA strain with the MIC value of vancomycin more than 8.0μg/ml was screened.The in vitro subculture revealed that the MIC value of vancomycin for the MRSA strains presented certain change rule with the passage number.CONCLUSION The isolation rate of hVISA is extremely low in Shenyang area,most of the failed clinical treatments may be associated with the drift of MIC value of the strains;as compared with the MIC value at the initial isolation,it is not reduced,indicating that the drift of MIC value may involve in stable genetic variation,and the mechanism needs to be further studied.
出处
《中华医院感染学杂志》
CAS
CSCD
北大核心
2015年第4期724-726,共3页
Chinese Journal of Nosocomiology
基金
辽宁省科技攻关计划基金资助项目(2011225021)
