Departments of Pharmacy, Boston University School of Medicine,c Boston, Massachusetts, USA.
Antimicrob Agents Chemother. 2012 Nov;56(11):5655-60. doi: 10.1128/AAC.01011-12. Epub 2012 Aug 20.
There are an increasing number of indications for trimethoprim-sulfamethoxazole use, including skin and soft tissue infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Assessing the relationship between rates of use and antibiotic resistance is important for maintaining the expected efficacy of this drug for guideline-recommended conditions. Using interrupted time series analysis, we aimed to determine whether the 2005 emergence of CA-MRSA and recommendations of trimethoprim-sulfamethoxazole as the preferred therapy were associated with changes in trimethoprim-sulfamethoxazole use and susceptibility rates. The data from all VA Boston Health Care System facilities, including 118,863 inpatient admissions, 6,272,661 outpatient clinic visits, and 10,138 isolates were collected over a 10-year period. There was a significant (P = 0.02) increase in trimethoprim-sulfamethoxazole prescriptions in the post-CA-MRSA period (1,605/year) compared to the pre-CA-MRSA period (1,538/year). Although the overall susceptibility of Escherichia coli and Proteus spp. to trimethoprim-sulfamethoxazole decreased over the study period, the rate of change in the pre- versus the post-CA-MRSA period was not significantly different. The changes in susceptibility rates of S. aureus to trimethoprim-sulfamethoxazole and to methicillin were also not significantly different. The CA-MRSA period is associated with a significant increase in use of trimethoprim-sulfamethoxazole but not with significant changes in the rates of susceptibilities among clinical isolates. There is also no evidence for selection of organisms with increased resistance to other antimicrobials in relation to increased trimethoprim-sulfamethoxazole use.
使用 trimethoprim-sulfamethoxazole 的指征越来越多，包括由社区相关耐甲氧西林金黄色葡萄球菌（CA-MRSA）引起的皮肤和软组织感染。评估使用率与抗生素耐药性之间的关系对于维持该药物在指南推荐条件下的预期疗效非常重要。使用中断时间序列分析，我们旨在确定 CA-MRSA 的出现以及将 trimethoprim-sulfamethoxazole 推荐为首选治疗药物的建议是否与 trimethoprim-sulfamethoxazole 使用和敏感性率的变化相关。在 10 年期间，从所有 VA Boston 医疗保健系统设施中收集了数据，包括 118863 例住院患者、6272661 例门诊就诊和 10138 株分离株。在 CA-MRSA 后时期（1605/年），与 CA-MRSA 前时期（1538/年）相比，trimethoprim-sulfamethoxazole 处方明显增加（P = 0.02）。尽管大肠杆菌和变形杆菌属对 trimethoprim-sulfamethoxazole 的总体敏感性在研究期间有所下降，但 CA-MRSA 前后期间的变化率并无显著差异。金黄色葡萄球菌对 trimethoprim-sulfamethoxazole 和甲氧西林的敏感性率变化也无显著差异。CA-MRSA 时期与 trimethoprim-sulfamethoxazole 使用量的显著增加相关，但与临床分离株的敏感性率变化无显著相关性。也没有证据表明与 trimethoprim-sulfamethoxazole 使用量增加相关的其他抗菌药物耐药性增加的选择。
