Department of Poultry Science, Auburn University, Auburn, Alabama 36849, USA.
Foodborne Pathog Dis. 2010 Jun;7(6):737-40. doi: 10.1089/fpd.2009.0464.
Listeria monocytogenes has been repeatedly isolated from foods and food-processing facilities including food contact surfaces such as conveyor belts (CB). CBs are often difficult to clean and require rigorous sanitation programs for decontamination. Ultraviolet (UV) light has exhibited microbicidal properties on food contact surfaces and this study was conducted to determine the efficacy of UV against L. monocytogenes on CB made of different materials. A four-strain cocktail of L. monocytogenes (serotypes 3A, 4A, 4B, and 4C) was made to give a suspension of approximately 10(7) CFU/mL. CBs made from four different types of materials, (1) Ropanyl DM 8/2 A2 + 04 (belt 1), (2) Volta FRMW-3.0 (belt 2), (3) Volta FRMB-3.0 (belt 3), and (4) Ropanyl DM (belt 4), were inoculated with 1 mL of the four-strain cocktail (approximately 10(7) CFU/mL) of the bacterial suspension. CBs were treated with UV light (254 nm) for 1 and 3 sec at 5.53 and 5.95 mW/cm(2). Three replications of the experiments were conducted. Two-way analysis of variance of survival populations of L. monocytogenes showed that bacterial counts were significantly reduced (p < 0.05) on all belt types irrespective of UV light intensities and times of exposure. L. monocytogenes populations were reduced (p < 0.05) to below detection limits on belts 1, 2, and 3 after exposure to 5.95 mW/cm(2) UV light intensity for 3 sec. L. monocytogenes-inoculated CBs that were exposed to 5.53 mW/cm(2) showed higher (p < 0.05) survival populations of L. monocytogenes compared with 5.95 mW/cm(2) on all the four CBs. Belt 4 showed survival populations of L. monocytogenes ranging from 1.42 to 1.73 log(10) CFU/cm(2) after UV light treatment for 1 and 3 sec. UV light can be effectively used to reduce L. monocytogenes contamination on CBs.
单增李斯特菌已从食品和食品加工设施中反复分离出来，包括食品接触面，如输送带（CB）。CB 通常难以清洁，需要严格的卫生程序进行消毒。紫外线（UV）光在食品接触表面显示出杀菌特性，本研究旨在确定 UV 对 CB 上不同材料的单增李斯特菌的效果。制备了单增李斯特菌（血清型 3A、4A、4B 和 4C）的四株混合菌，制成约 10（7）CFU/mL 的悬浮液。从四种不同类型的材料（1）Ropanyl DM 8/2 A2 + 04（带 1）、（2）Volta FRMW-3.0（带 2）、（3）Volta FRMB-3.0（带 3）和（4）Ropanyl DM（带 4）制造 CB，用 1 毫升四株混合菌（约 10（7）CFU/mL）的细菌悬浮液接种。CB 用紫外线（254nm）处理 1 和 3 秒，强度为 5.53 和 5.95mW/cm（2）。进行了三次实验重复。单增李斯特菌存活种群的双向方差分析表明，无论紫外线强度和暴露时间如何，所有带类型的细菌计数均显著降低（p <0.05）。暴露于 5.95mW/cm（2）紫外线强度 3 秒后，带 1、2 和 3 上的单增李斯特菌数量减少（p <0.05）至低于检测限。暴露于 5.53mW/cm（2）的单增李斯特菌接种 CB 显示出更高（p <0.05）的单增李斯特菌存活种群，与所有四个 CB 上的 5.95mW/cm（2）相比。紫外线处理 1 和 3 秒后，带 4 上的单增李斯特菌存活种群范围为 1.42 至 1.73log（10）CFU/cm（2）。紫外线光可有效用于减少 CB 上的单增李斯特菌污染。
