Vancomycin MIC creep in methicillin-resistant Staphylococcus aureus (MRSA) isolates from 2006 to 2010 in a hospital in China
Vancomycin MIC creep in methicillin-resistant Staphylococcus aureus (MRSA) isolates from 2006 to 2010 in a hospital in China
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DOI：
10.4103/0255-0857.148837
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发表时间：
2015-04-01
影响因子：
1.6
通讯作者：
Chen, F.
中科院分区：
文献类型：
--
作者：
Chang, W.;Ma, Xiaoling;Chen, F.
目的：了解中国地区医院临床分离的耐甲氧西林金黄色葡萄球菌中万古霉素最低抑菌浓度(MIC)的变化情况。分析MRSA感染患者发生万古霉素MIC爬行的原因及与预后的关系。材料和方法：检索2006-2010年所有临床分离的耐甲氧西林金黄色葡萄球菌，采用微量肉汤稀释法测定其对万古霉素的最低抑菌浓度。同时对相关病历进行分析。结果：虽然所有菌株对万古霉素都敏感，但从2006年(37.0%)到2010年(75.7%)，万古霉素MIC=1 mg/L的菌株比例显著增加。同时，从2006年到2010年，万古霉素的使用密度(DDDS/1000床日)显著增加。平均线性相关分析显示，万古霉素用量与万古霉素MIC=1 mg/L的耐甲氧西林金黄色葡萄球菌的比例呈显著正相关(r=0.905，P<0.05)。临床记录显示，高万古霉素MIC与耐甲氧西林金黄色葡萄球菌血流感染的微生物失败率有关。结论：本院临床分离株中存在万古霉素MIC蠕变现象，MIC蠕变可能与万古霉素使用量增加有关。此外，分析强烈表明，万古霉素MIC在易感范围内的这种变化可能与治疗失败的可能性增加有关。
Purpose: To assess whether vancomycin minimum inhibitory concentration (MIC) creeps among clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) in a regional hospital in China. Furthermore, to analyze the causes of vancomycin MIC creeps and the relationship between vancomycin MICs and the outcome among patients with MRSA infection. Materials and Methods: All clinical isolates of MRSA from 2006-2010 were retrieved and tested by the broth microdilution procedure to determine their vancomycin MIC. Meanwhile, related patient records were analyzed. Results: While all isolates were susceptive to vancomycin, the percentage of isolates with a vancomycin MIC = 1 mg/L increased significantly from 2006 (37.0%) to 2010 (75.7%). Meanwhile, vancomycin usage density (DDDs/1000 bed-days) had increased significantly from 2006-2010. Mean linear correlation analysis showed a statistically significant positive correlation (r = 0.905, P < 0.05) between the consumption of vancomycin and the percentage of MRSA isolates with a vancomycin MIC = 1 mg/L. Clinical records revealed high vancomycin MIC was associated with a higher microbiologic failure rate in MRSA bloodstream infections. Conclusions: The data demonstrated vancomycin MIC creep among clinical isolates in our hospital, and the MIC creep may be caused by the increasing usage of vancomycin. Furthermore, the analysis strongly suggested this shift of vancomycin MIC within the susceptible range may be associated with an increasing probability of treatment failure.