List_MAPS - Human listeriosis cases are due to the ingestion of contaminated foods with the pathogenic bacteria Listeria monocytogenes

Human listeriosis cases are due to the ingestion of contaminated foods with the pathogenic bacteria Listeria monocytogenes. The reduction of water availability in food workshops by decreasing the air relative humidity (RH) is one strategy to improve the control of bacterial contamination. This study aims to develop and implement an MSI approach on L. monocytogenes biofilms and proof of concept using a dehumidified stress condition. MSI allowed examining the distribution of low molecular weight proteins within the biofilms subjected to a dehumidification environment, mimicking the one present in a food workshop (10°C, 75% RH). Furthermore, a LC-MS/MS approach was made to link the dots between MSI and protein identification. Five identified proteins were assigned to registered MSI m/z, including two cold-shock proteins and a ligase involved in cell wall biogenesis.

人类李斯特菌病（Listeriosis）病例均因摄入被致病性单核细胞增生李斯特菌（Listeria monocytogenes）污染的食物而引发。通过降低空气相对湿度（Relative Humidity, RH）以降低食品加工车间内的水分活度，是强化细菌污染防控的有效策略之一。本研究旨在针对单核细胞增生李斯特菌生物被膜开发并应用质谱成像（Mass Spectrometry Imaging, MSI）技术，并通过除湿胁迫条件开展概念验证。借助该质谱成像技术，可分析处于模拟食品加工车间环境（10℃、75%相对湿度）的除湿胁迫生物被膜内低分子量蛋白质的分布特征。此外，本研究采用液相色谱-串联质谱（Liquid Chromatography-Tandem Mass Spectrometry, LC-MS/MS）技术，以厘清质谱成像结果与蛋白质鉴定结果之间的关联。最终有五种经鉴定得到的蛋白质被匹配至质谱成像检测到的m/z信号峰，其中包含两种冷休克蛋白（cold-shock proteins）以及一种参与细胞壁生物合成的连接酶（ligase）。