Service of Hospital Preventive Medicine, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
Institute of Microbiology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
Clin Microbiol Infect. 2019 Nov;25(11):1430.e1-1430.e4. doi: 10.1016/j.cmi.2019.03.029. Epub 2019 Apr 10.
Screening for methicillin-resistant Staphylococcus aureus (MRSA) is part of many recommendations to control MRSA. Several rapid PCR tests are available commercially and updated versions are constantly released. We aimed to evaluate the performance of three consecutive versions (G3, Gen3 and NxG) of the XpertMRSA test.
Routine samples for MRSA screening were simultaneously tested by culture and rapid PCR. The three versions of XpertMRSA were used successively and compared with culture.
A total of 3512, 2794 and 3288 samples were analysed by culture and by the G3, Gen3 and NxG XpertMRSA versions, respectively. The rates of positive-by-culture in the three groups were 5.0%, 4.7% and 4.3%, respectively. The sensitivity improved over time (71.4, 95% CI 64.0-77.9; 82.3, 95% CI 74.4-88.2; and 84.3%, 95% CI 77.0-89.7, respectively), but not significantly. The specificity (98.4, 95% CI 97.9-98.8; 96.8, 95% CI 96.0-97.4; and 99.1, 95% CI 98.7-99.4, respectively) and the positive likelihood ratios (45.7, 95% CI 34.4-60.8; 25.6, 95% CI 20.5-32.0; and 97.1, 95% CI 66.3-142.4) were significantly lower in the Gen3 version (p < 0.00001).
These significant differences in performance show the importance of evaluating each new version of a commercial test.
筛查耐甲氧西林金黄色葡萄球菌（MRSA）是控制 MRSA 的许多建议的一部分。目前有几种快速 PCR 检测方法可在商业上使用，并且不断更新版本。我们旨在评估三种连续版本（G3、Gen3 和 NxG）的 XpertMRSA 检测的性能。
同时对用于 MRSA 筛查的常规样本进行培养和快速 PCR 检测。连续使用三种版本的 XpertMRSA 并与培养进行比较。
分别用培养和 G3、Gen3 和 NxG XpertMRSA 版本分析了 3512、2794 和 3288 个样本。三组培养阳性率分别为 5.0%、4.7%和 4.3%。随着时间的推移，灵敏度有所提高（71.4%，95%CI 64.0-77.9%；82.3%，95%CI 74.4-88.2%；和 84.3%，95%CI 77.0-89.7%，分别），但无显著差异。特异性（98.4%，95%CI 97.9-98.8%；96.8%，95%CI 96.0-97.4%；和 99.1%，95%CI 98.7-99.4%，分别）和阳性似然比（45.7，95%CI 34.4-60.8%；25.6，95%CI 20.5-32.0%；和 97.1，95%CI 66.3-142.4%）在 Gen3 版本中显著降低（p<0.00001）。
这些性能的显著差异表明，评估商业检测的每个新版本都很重要。
