Rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is essential for proper initial antibiotic therapy and timely set up of hygienic measures. Recently, detection of MRSA using MALDI-TOF mass spectrometer mediated by the peptide—phenol-soluble modulin (PSM-mec)—linked to the class A mec gene complex present in SCCmec cassettes types II, III, and VIII of MRSA strains, has been commercially available. We present here a multicentre study on MALDI-TOF MS detection of MRSA evincing a poor repeatability and reproducibility of the assay. The sensitivity of the assay varies between 50 and 90% in strains carrying psm_MEC and psm_δ genes encoding for PSM-mec and δ-toxin (a member of the PSM peptide family), respectively. No false positive results were found. The very major error calculation was 30% and the major error achieved 0%. Interlaboratory repeatability varies between 0 and 100%. No significant difference was observed with the use of different cultivation media. Our data showed a poor sensitivity of the method excluding it from the use in routine laboratory testing.

快速鉴定耐甲氧西林的金黄色葡萄球菌（MRSA）对于正确的初始抗生素治疗和及时制定卫生措施至关重要。最近，使用由MALDI-TOF质谱仪检测MRSA的方法，该质谱仪由与MRSA菌株II，III和VIII型SCC mec盒中存在的A类mec基因复合体连接的肽-酚溶性调节蛋白（PSM-mec）介导，已在市场上出售。我们在此提出了关于对MRSA进行MALDI-TOF MS检测的多中心研究，证明该方法的可重复性和可重复性很差。该测定的灵敏度在携带菌株50和90％之间变化PSM _MEC和PSM _δ分别编码PSM-mec和δ-毒素（PSM肽家族成员）的基因。没有发现假阳性结果。重大误差的计算为30％，重大误差达到0％。实验室间的重复性在0到100％之间变化。使用不同的培养基没有观察到显着差异。我们的数据表明，该方法灵敏度不佳，无法用于常规实验室测试。