Bactericidal activity of orally available agents against methicillin-resistant Staphylococcus aureus
Bactericidal activity of orally available agents against methicillin-resistant Staphylococcus aureus
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DOI：
10.1093/jac/dkl283
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发表时间：
2006-09-01
影响因子：
5.2
通讯作者：
Musher, Daniel M.
中科院分区：
文献类型：
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作者：
Kaka, Anjum S.;Rueda, Adriana M.;Musher, Daniel M.
背景资料：最近社区获得性（CA）耐甲氧西林金黄色葡萄球菌（MRSA）的扩散导致MRSA感染的门诊治疗需求显着增加。许多抗MRSA的口服药物已经上市多年，但缺乏文献对它们进行比较，这使得医生在选择它们时几乎没有指导。本研究的目的是比较口服抗生素对MRSA的杀菌效果，并确定是否有抗微生物杀灭活性对CA-MRSA和医院获得性（HA）MRSA菌株的差异。方法：共有12个独特的患者MRSA菌株进行了研究。6株为CA，携带葡萄球菌染色体盒（SCCmec）IVa型，6株为HA，携带SCCmec II型。采用时间杀菌法研究了利奈唑胺、利福平、甲氧苄啶/磺胺甲恶唑、克林霉素、米诺环素和氟美沙星单用和联合应用的体外杀菌活性。结果：甲氧苄啶/磺胺甲恶唑在体外具有快速杀菌作用，在8 h和24 h时分别降低> 2 log（10）cfu/mL和> 3 log（10）cfu/mL。没有抗生素组合显示出比单独的甲氧苄啶/磺胺甲恶唑更好的杀灭效果。在甲氧苄啶/磺胺甲恶唑中添加利福平在体外表现出拮抗趋势。任何抗菌剂或抗菌剂组合对携带SCCmec IVa型的MRSA分离株与携带SCCmec II型的MRSA分离株的杀菌活性没有差异。结论：与大多数其他口服抗菌剂相比，甲氧苄啶/磺胺甲恶唑在体外对MRSA具有快速杀菌作用。当对CA-MRSA和HA-MRSA的活性进行比较时，未检测到杀菌活性的差异。
Background: The recent proliferation of community-acquired (CA) methicillin-resistant Staphylococcus aureus (MRSA) has led to a marked increase in the need for outpatient treatment of MRSA infections. Many oral agents active against MRSA have been available for years, and a paucity of literature compares them, leaving physicians with little guidance for choosing among them. The purpose of the present study was to compare the bactericidal effects of orally available antibiotics against MRSA and to determine whether there were differences in antimicrobial killing activity against CA-MRSA and hospital-acquired (HA) MRSA isolates.Methods: A total of 12 unique patient MRSA isolates were studied. Six strains were CA, carrying the staphylococcal chromosomal cassette (SCCmec) type IVa, while six were HA and carried SCCmec type II. Time-kill methods were used to study the bactericidal activity of the orally available antimicrobials linezolid, rifampicin, trimethoprim/sulfamethoxazole, clindamycin, minocycline, and moxifloxacin alone and in combination in vitro.Results: Trimethoprim/sulfamethoxazole was rapidly bactericidal resulting in > 2 log(10) cfu/mL decrease at 8 h and > 3 log(10) cfu/mL decrease at 24 h in vitro. No antibiotic combination exhibited better killing than trimethoprim/sulfamethoxazole alone. Adding rifampicin to trimethoprim/sulfamethoxazole showed a trend towards antagonism in vitro. There were no differences in the bactericidal activity of any antimicrobial or antimicrobial combination against MRSA isolates carrying SCCmec type IVa versus those carrying SCCmec type II.Conclusion: Trimethoprim/sulfamethoxazole is rapidly bactericidal against MRSA in vitro when compared with most other orally available antimicrobials. No differences in bactericidal activity were detected when activities against CA-MRSA and HA-MRSA were compared.