Department of Food Science and Biotechnology, Global K-Food Research Center, Hankyong National University, Anseong-si, 17579, South Korea.
Department of Food Science and Biotechnology, Global K-Food Research Center, Hankyong National University, Anseong-si, 17579, South Korea.
Food Microbiol. 2022 Sep;106:104054. doi: 10.1016/j.fm.2022.104054. Epub 2022 May 4.
Human pathogens can develop biofilm structures on different artificial substrates common in the food industry. In this study, we investigated the inactivation efficacy of low-energy X-ray irradiation on Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes biofilms on food contact surfaces, including polyvinyl chloride (PVC), stainless steel with finish 2B (STS 2B), and Teflon. The numbers of viable cells in biofilms on all test coupons were significantly (p < 0.05) reduced as the X-ray dose increased. Interestingly, different biofilm inactivation levels were observed relative to various material surfaces. Teflon showed the lowest Dd (dose required for a 5-log reduction in cell count) values among three groups of coupons, whereas PVC exhibited higher Dd values than the other two coupons. The mechanism of the X-ray antibiofilm effect was identified through the measurement of extracellular polymeric substances (EPS) in biofilms. X-ray irradiation could remove exopolysaccharides, which are major component of EPS and the removal rate increased with increasing irradiation dose. The analyses also confirmed that the disintegration of EPS was strongly related to the trends of biofilm inactivation on different coupon surfaces. This study is the first to demonstrate that X-ray irradiation effectively inactivates major foodborne pathogen biofilms on various food contact surfaces and to evaluate its antibiofilm mechanisms to enhance safety in the food processing industries.
人类病原体可以在食品工业中常见的不同人工基质上形成生物膜结构。在这项研究中，我们研究了低能量 X 射线照射对食品接触表面上大肠杆菌 O157:H7、鼠伤寒沙门氏菌和单核细胞增生李斯特菌生物膜的灭活效果，这些表面包括聚氯乙烯（PVC）、具有 2B 光洁度的不锈钢（STS 2B）和特氟龙。随着 X 射线剂量的增加，所有测试试片上生物膜中存活细胞的数量明显（p<0.05）减少。有趣的是，相对于各种材料表面，观察到不同的生物膜灭活水平。特氟龙在三组试片中表现出最低的 Dd（减少细胞计数 5 对数所需的剂量）值，而 PVC 表现出比其他两种试片更高的 Dd 值。通过测量生物膜中的胞外聚合物物质（EPS）来确定 X 射线抗生物膜效应的机制。X 射线照射可以去除胞外多糖，这是 EPS 的主要成分，去除率随着照射剂量的增加而增加。分析还证实，EPS 的崩解与不同试片表面上生物膜灭活的趋势密切相关。这项研究首次证明，X 射线照射可有效灭活各种食品接触表面上的主要食源性病原体生物膜，并评估其抗生物膜机制，以增强食品加工业的安全性。
