Thames Hudson T, Pokhrel Diksha, Willis Emma, Rivers Orion, Dinh Thu T N, Zhang Li, Schilling Mark W, Ramachandran Reshma, White Shecoya, Sukumaran Anuraj T
Department of Poultry Science, Mississippi State University, Starkville, MS 39762, USA.
Institute for Imaging & Analytical Technologies, Mississippi State University, Starkville, MS 39762, USA.
Foods. 2023 May 8;12(9):1918. doi: 10.3390/foods12091918.
This study characterized biofilm formation of various strains on common processing plant surface materials (stainless steel, concrete, rubber, polyethylene) under static and fluidic shear stress conditions. Surface-coupons were immersed in well-plates containing 1 mL of (6 log CFU/mL) and incubated aerobically for 48 h at 37 °C in static or shear stress conditions. Biofilm density was determined using crystal violet assay, and biofilm cells were enumerated by plating on tryptic soy agar plates. Biofilms were visualized using scanning electron microscopy. Data were analyzed by SAS 9.4 at a significance level of 0.05. A surface-incubation condition interaction was observed for biofilm density ( < 0.001). On stainless steel, the OD was higher under shear stress than static incubation; whereas, on polyethylene, the OD was higher under static condition. Enumeration revealed surface-incubation condition ( = 0.024) and surface-strain ( < 0.001) interactions. Among all surface-incubation condition combinations, the biofilm cells were highest on polyethylene under fluidic shear stress (6.4 log/coupon; < 0.001). Biofilms of Kentucky on polyethylene had the highest number of cells (7.80 log/coupon) compared to all other strain-surface combinations ( < 0.001). Electron microscopy revealed morphological and extracellular matrix differences between surfaces. Results indicate that biofilm formation is influenced by serotype, surface, and fluidic shear stress.
本研究对多种菌株在常见加工工厂表面材料（不锈钢、混凝土、橡胶、聚乙烯）上，在静态和流体剪切应力条件下的生物膜形成情况进行了表征。将表面试片浸入含有1 mL（6 log CFU/mL）菌液的孔板中，在37℃下于静态或剪切应力条件下需氧培养48小时。使用结晶紫测定法测定生物膜密度，并通过接种在胰蛋白胨大豆琼脂平板上对生物膜细胞进行计数。使用扫描电子显微镜观察生物膜。数据采用SAS 9.4进行分析，显著性水平为0.05。观察到生物膜密度存在表面 - 培养条件相互作用（P < 0.001）。在不锈钢上，剪切应力下的光密度高于静态培养；而在聚乙烯上，静态条件下的光密度更高。计数结果显示存在表面 - 培养条件（P = 0.024）和表面 - 菌株（P < 0.001）相互作用。在所有表面 - 培养条件组合中，流体剪切应力下聚乙烯上的生物膜细胞数量最高（6.4 log/试片；P < 0.001）。与所有其他菌株 - 表面组合相比，肯塔基菌株在聚乙烯上的生物膜细胞数量最多（7.80 log/试片）（P < 0.001）。电子显微镜显示不同表面之间在形态和细胞外基质方面存在差异。结果表明，生物膜形成受血清型、表面和流体剪切应力的影响。
