美国住院患者金黄色葡萄球菌的敏感性增加

ynosmile

感控热点丨美国住院患者金黄色葡萄球菌的敏感性增加

原创 2017-06-20 陈志锦 SIFIC感染官微

翻译丨陈志锦

审核丨周超群

团队丨SIFIC热点团队

近年来，细菌的耐药性越来越引起研究人员的关注，尤其是超级细菌的报道，更会引起大众的恐慌。相应地，更多的资源投入到“超级抗生素”的研发上，以避免无药可用而带来的世界性灾难。

然而，凡事往往会有转机，研究美国住院患者金黄色葡萄球菌敏感性趋势的结果显示，用于治疗金黄色葡萄球菌的关键抗生素在研究过程中变得更加有效，这种情况非常少见。JMI实验室的研究人员通过测试美国医疗中心的临床分离株，评估了2009年至2015年金黄色葡萄球菌的敏感性趋势，该研究于6月4日在路易斯安那州新奥尔良举行的ASM微生物会议上交流。

演讲者，JMI实验室微生物监测高级总监Helio S. Sader博士称：“结果表明，金黄色葡萄球菌对某些抗生素的耐药率随时间而下降，这是不常见的。耐甲氧西林金黄色葡萄球（MRSA）耐药率从2009年的47.2％下降至2015年的43.6％，最近数据显示，2016年进一步下降至42.2％。”

在同一时期，金黄色葡萄球菌对左氧氟沙星、克林霉素和红霉素的耐药性，也显示出一定程度的下降；而头孢洛林、甲氧苄啶-磺胺甲噁唑和四环素的耐药性则保持稳定。此外，在研究期间，头孢洛林对于耐甲氧西林金黄色葡萄球菌（MRSA）的敏感性为97.2％，对于甲氧西林敏感性金黄色葡萄球菌的敏感性为100.0％，均保持非常高的有效性，没有明显的变化趋势。还有一个重要的结果是，金黄色葡萄球菌对达托霉素、利奈唑胺、万古霉素和替加环素的耐药情况仍然非常罕见，没有增加的迹象。

研究人员测试了来自42个美国医疗中心的总共19036个临床分离株，以确定金黄色葡萄球菌对抗生素的敏感程度。JMI使用微量肉汤稀释法这一金标准方法来测定易感性。参加AWARE计划的医疗中心工作人员遵循一项共同的研究方案，将收集的细菌分离株送至JMI实验室，然后检测分离株对特定抗生素的敏感程度。

在20世纪90年代末期，美国人在社区环境中开始感染MRSA，社区获得性MRSA感染（CA-MRSA）迅速蔓延。 CA-MRSA很大程度上改变了临床医生治疗一些社区获得性感染的方法，尤其是儿童皮肤软组织感染和呼吸道感染。社区获得性MRSA感染对甲氧苄啶-磺胺甲噁唑、克林霉素和四环素敏感，而MRSA对红霉素和氟喹诺酮类药物敏感差一些；然而，CA-MRSA繁殖进化而变得对其他抗生素更耐药。

Sader博士补充，在美国许多地区，导致社区获得性感染和医院感染的金黄色葡萄球菌流行似乎在某些地区正在减少，这种下降趋势可能会改变金黄色葡萄球菌的耐药性，因此要强调通过大型耐药性监测计划来监测金黄色葡萄球菌的重要性。

目前，美国住院患者金黄色葡萄球菌敏感性的增加对于金黄色葡萄球菌的治疗无疑是一个好消息，但该研究的代表性有限。正如Sader博士所说的，若能将金黄色葡萄球菌的监测范围扩大，并在监测的过程中探讨出现如此敏感性增加的原因，或许能开辟出一条对抗耐药菌的新途径！

文章来源：

https://www.asm.org/index.php/newsroom/item/6497-increasing-susceptibility-of-staphylococcus-aureus-in-the-united-states

原文：

Study findsincreasing susceptibility of Staphylococcus aureus in U.S. hospital patients

Findings from astudy that looked at susceptibility trends of Staphylococcus aureus inU.S. hospital patients showed that key antibiotics used to treat the bacteria becamemore active over the course of the study, a rare occurrence. Researchers at JMILaboratories evaluated susceptibility trends of antibiotics from 2009 to 2015by testing clinical isolates from medical centers across the U.S. The researchis presented on June 4th at the ASM Microbe conference in New Orleans,Louisiana.

"Resultsshowed that S. aureus' rates of resistance to certain antibiotics decreasedover time, which isn't often seen," said presenting author Helio S. Sader,M.D., Ph.D., Senior Director, Microbiology & Surveillance at JMILaboratories. The rates of S. aureus being resistant to oxacillin (MRSA)decreased from 47.2% in 2009 to 43.6% in 2015, and more recent data from thisprogram showed a further decrease to 42.2% in 2016.

Resistance toother antibiotics, such as levofloxacin, clindamycin, and erythromycin, alsoshowed some decrease during the same period, whereas susceptibility toceftaroline, trimethoprim-sulfanethoxazole, and tetracycline remained stable.Furthermore, ceftaroline remained very active against methicillin-resistant S.aureus (MRSA) (97.2% susceptible) and methicillin-susceptible S.aureus (100.0% susceptible) with no marked variations or trends during thestudy period. One important result is that S. aureus resistance todaptomycin, linezolid, vancomycin, and tigecycline remained extremely rare withno sign of increasing.

Researcherstested a total of 19,036 clinical isolates from 42 U.S. medical centers todetermine how susceptible S. aureus would be to antibiotic agents. JMIused broth microdilution methods, the gold-standard method, to testsusceptibility. Medical center staff participating in the AWARE programfollowed a common study protocol to send collected bacterial isolates to JMILaboratories to test how susceptible the isolates were to specific antibiotics.

During the late1990s, people in the U.S. started to become infected with MRSA outsidehospitals, in community settings, and this community-acquired MRSA (CA-MRSA)spread rapidly. CA-MRSA greatly changed how clinicians treated somecommunity-acquired infections, especially skin and soft tissue infections andrespiratory tract infections in children. Community-acquired MRSA wassusceptible to trimethoprim-sulfamethoxazole, clindamycin, and tetracycline, andthe bacteria was less susceptible to erythromycin and fluoroquinolones;however, CA-MRSA clones evolved and became more resistant to other antibioticagents.

"Theprevalence of the main S. aureus clone causing community-acquired andhealthcare-associated infections in many parts of the U.S. seems to bedecreasing in some areas," said Dr. Sader, "A prevalence decrease maychange the antimicrobial resistance profiles of S. aureus, emphasizing theimportance of monitoring this organism through large resistance surveillanceprograms."

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图文编辑：宋小船

审稿：陈文森 卢先雷

御剑迎风

2009年的47.2％下降至2015年的43.6％，最近数据显示，2016年进一步下降至42.2％
这个是否有原始数据提供，是否会受到标本来源、检测方式的限制？

guoli2008

关于抗生素的问题，今天终于有了一个好消息。

ynosmile

随着抗菌药物合理使用的管理，希望好的消息会不断。