Cefazolin high-inoculum effect in methicillin-susceptible Staphylococcus aureus from South American hospitals.
Cefazolin high-inoculum effect in methicillin-susceptible Staphylococcus aureus from South American hospitals.
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头孢唑林对南美医院甲氧西林敏感金黄色葡萄球菌的高接种效果。
DOI：
10.1093/jac/dkt254
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
Arias,CesarA
中科院分区：
文献类型：
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作者：
Rincón,Sandra;Reyes,Jinnethe;Carvajal,LinaPaola;Rojas,Natalia;Cortés,Fabián;Panesso,Diana;Guzmán,Manuel;Zurita,Jeannete;Adachi,JavierA;Murray,BarbaraE;Nannini,EstebanC;Arias,CesarA
目的头孢唑林在甲氧西林敏感的金黄色葡萄球菌A型β-内酰胺酶引起的高接种率感染中临床应用失败。我们调查了头孢唑林接种效应(INE)在南美医院MSSA中的流行情况，因为出于对异恶唑青霉素体内疗效的担忧，头孢唑林经常用于治疗MSSA。方法2001-02和2006-08两次不同的多中心监测研究中，MSSA分离株分别从血液感染(296例)和骨髓炎(68例)感染中恢复。测定标准接种量(105cfu/m L)和高接种量(107cfu/m L)头孢唑林的MIC。对所有显示头孢唑林碱的分离株进行了PFGE。对具有代表性的菌株进行多位点序列分型(MLST)和BLAZ部分序列测定。结果131株头孢唑林碱的总感染率为36%。从骨髓炎感染中恢复的MSSA分离株中有很高比例(50%)含有INE，而在从血液感染中恢复的MSSA中有33%观察到这种情况。有趣的是，厄瓜多尔的吸毒率最高(45%)。令人惊讶的是，在哥伦比亚骨髓炎感染中恢复的MSSA分离株中，有63%的菌株显示出INE。MLST显示，表现INE的MSSA分离株具有不同的遗传背景，包括ST5、ST8、ST30和ST45，这与南美洲流行的耐甲氧西林金黄色葡萄球菌克隆相关。A型(66%)和C型(31%)是最常见的β-内酰胺酶。结论在哥伦比亚和厄瓜多尔分离的甲氧西林金黄色葡萄球菌中，与A型β-内酰胺酶相关的头孢唑林存在较高的流行率，提示这两个国家头孢唑林对深层感染的治疗可能受到影响。
ObjectivesClinical failures with cefazolin have been described in high-inoculum infections caused by methicillin-susceptible Staphylococcus aureus (MSSA) producing type A β-lactamase. We investigated the prevalence of the cefazolin inoculum effect (InE) in MSSA from South American hospitals, since cefazolin is used routinely against MSSA due to concerns about the in vivo efficacy of isoxazolyl penicillins.MethodsMSSA isolates were recovered from bloodstream (n= 296) and osteomyelitis (n= 68) infections in two different multicentre surveillance studies performed in 2001–02 and 2006–08 in South American hospitals. We determined standard-inoculum (105cfu/mL) and high-inoculum (107 cfu/mL) cefazolin MICs. PFGE was performed on all isolates that exhibited a cefazolin InE. Multilocus sequence typing (MLST) and sequencing of part of blaZ were performed on representative isolates.ResultsThe overall prevalence of the cefazolin InE was 36%(131 isolates). A high proportion (50%) of MSSA isolates recovered from osteomyelitis infections exhibited the InE, whereas it was observed in 33% of MSSA recovered from bloodstream infections. Interestingly, Ecuador had the highest prevalence of the InE (45%). Strikingly, 63% of MSSA isolates recovered from osteomyelitis infections in Colombia exhibited the InE. MLST revealed that MSSA isolates exhibiting the InE belonged to diverse genetic backgrounds, including ST5, ST8, ST30 and ST45, which correlated with the prevalent methicillin-resistant S. aureus clones circulating in South America. Types A (66%) and C (31%) were the most prevalent β-lactamases.ConclusionsOur results show a high prevalence of the cefazolin InE associated with type A β-lactamase in MSSA isolates from Colombia and Ecuador, suggesting that treatment of deep-seated infections with cefazolin in those countries may be compromised.