Campana Eloiza H, Carvalhaes Cecilia G, Nonato Bruna, Machado Antonia M de O, Gales Ana C
Laboratório Alerta, Disciplina de Infectologia, Universidade Federal de São Paulo, São Paulo - SP, Brazil.
Laboratório Central do Hospital São Paulo, Universidade Federal de São Paulo, São Paulo - SP, Brazil.
PLoS One. 2014 Apr 14;9(4):e94627. doi: 10.1371/journal.pone.0094627. eCollection 2014.
The main objective of this study was to comparatively evaluate the performance of M.I.C.E. and Etest methodologies to that of agar dilution for determining the antimicrobial susceptibility profile of oxacillin-resistant Staphylococcus spp.
A total of 100 oxacillin-resistant Staphylococcus spp. isolates were collected from hospitalized patients at a teaching hospital. Antimicrobial susceptibility testing for vancomycin, teicoplanin and linezolid was performed using the reference CLSI agar dilution method (2009), Etest and M.I.C.E. methodologies. The MIC values were interpreted according to CLSI susceptibility breakpoints and compared by regression analysis.
In general, the essential agreement (±1-log2) between M.I.C.E. and CLSI agar dilution was 93.0%, 84.0% and 77.0% for linezolid, teicoplanin and vancomycin, respectively. Essential agreement rates between M.I.C.E. and Etest were excellent (>90.0%) for all antibiotics tested. Both strips (M.I.C.E. and Etest) yielded two very major errors for linezolid. Unacceptable minor rates were observed for teicoplanin against CoNS and for vancomycin against S. aureus.
According to our results, linezolid and teicoplanin MICs against all staphylococci and S. aureus, respectively, were more accurately predicted by M.I.C.E. strips. However, the Etest showed better performance than M.I.C.E. for predicting vancomycin MICs against all staphylococci. Thus, microbiologists must be aware of the different performance of commercially available gradient strips against staphylococci.
本研究的主要目的是比较评估M.I.C.E.法和Etest法与琼脂稀释法在测定耐苯唑西林葡萄球菌属抗菌药物敏感性谱方面的性能。
从一家教学医院的住院患者中收集了总共100株耐苯唑西林葡萄球菌属分离株。使用参考的CLSI琼脂稀释法（2009年）、Etest法和M.I.C.E.法对万古霉素、替考拉宁和利奈唑胺进行抗菌药物敏感性测试。根据CLSI敏感性断点解释MIC值，并通过回归分析进行比较。
总体而言，M.I.C.E.法与CLSI琼脂稀释法之间的基本一致性（±1-log2），利奈唑胺、替考拉宁和万古霉素分别为93.0%、84.0%和77.0%。对于所有测试抗生素，M.I.C.E.法与Etest法之间的基本一致率均极佳（>90.0%）。两种试纸条（M.I.C.E.法和Etest法）对利奈唑胺均产生了两个非常大的误差。观察到替考拉宁对凝固酶阴性葡萄球菌以及万古霉素对金黄色葡萄球菌的次要误差率不可接受。
根据我们的结果，M.I.C.E.试纸条分别能更准确地预测利奈唑胺和替考拉宁对所有葡萄球菌和金黄色葡萄球菌的MIC值。然而，在预测万古霉素对所有葡萄球菌的MIC值方面，Etest法的性能优于M.I.C.E.法。因此，微生物学家必须意识到市售梯度试纸条对葡萄球菌的不同性能。
