Abdel Massih M, Planchon V, Polet M, Dierick K, Mahillon J
Laboratory of Food and Environmental Microbiology, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Agriculture and Natural Environment Department, Walloon Agricultural Research Centre (CRA-W), Gembloux, Belgium.
J Appl Microbiol. 2016 Feb;120(2):346-54. doi: 10.1111/jam.13009.
Based on the results of 19 food microbiology proficiency testing (PT) schemes, this study aimed to assess the laboratory performances, to highlight the main sources of unsatisfactory analytical results and to suggest areas of improvement.
The 2009-2015 results of REQUASUD and IPH PT, involving a total of 48 laboratories, were analysed. On average, the laboratories failed to detect or enumerate foodborne pathogens in 3·0% of the tests. Thanks to a close collaboration with the PT participants, the causes of outliers could be identified in 74% of the cases. The main causes of erroneous PT results were either pre-analytical (handling of the samples, timing of analysis), analytical (unsuitable methods, confusion of samples, errors in colony counting or confirmation) or postanalytical mistakes (calculation and encoding of results).
PT schemes are a privileged observation post to highlight analytical problems, which would otherwise remain unnoticed. In this perspective, this comprehensive study of PT results provides insight into the sources of systematic errors encountered during the analyses.
This study draws the attention of the laboratories to the main causes of analytical errors and suggests practical solutions to avoid them, in an educational purpose. The observations support the hypothesis that regular participation to PT, when followed by feed-back and appropriate corrective actions, can play a key role in quality improvement and provide more confidence in the laboratory testing results.
基于19项食品微生物能力验证（PT）计划的结果，本研究旨在评估实验室性能，突出分析结果不理想的主要原因，并提出改进领域。
分析了REQUASUD和IPH PT在2009 - 2015年的结果，共涉及48个实验室。平均而言，实验室在3.0%的测试中未能检测或计数食源性病原体。由于与PT参与者的密切合作，在74%的案例中能够确定异常值的原因。PT结果错误的主要原因包括分析前（样品处理、分析时间）、分析中（方法不合适、样品混淆、菌落计数或确认错误）或分析后错误（结果计算和编码）。
PT计划是突出分析问题的特权观察站，否则这些问题将不会被注意到。从这个角度来看，这项对PT结果的全面研究深入了解了分析过程中遇到的系统误差来源。
本研究以教育为目的，提请实验室注意分析误差的主要原因，并提出避免这些误差的实际解决方案。这些观察结果支持这样的假设，即定期参加PT并随后进行反馈和适当的纠正措施，可以在质量改进中发挥关键作用，并为实验室检测结果提供更多信心。
