Biofilm formation by E. coli is a serious threat to meat processing plants. Chemical disinfectants often fail to eliminate biofilms; thus, bacteriophages are a promising alternative to solve this problem, since they are widely distributed, environmentally friendly, and nontoxic to humans. In this study, the biofilm formation of 10 E. coli strains isolated from the meat industry and E. coli ATCC BAA-1430 and ATCC 11303 were evaluated. Three strains, isolated from the meat contact surfaces, showed adhesion ability and produced extracellular polymeric substances. Biofilms of these three strains were developed onto stainless steel (SS) surfaces and enumerated at 2, 12, 24, 48, and 120 h, and were visualized by scanning electron microscopy. Subsequently, three bacteriophages showing podovirus morphology were isolated from ground beef and poultry liver samples, which showed lytic activity against the abovementioned biofilm-forming strains. SS surfaces with biofilms of 2, 14, and 48 h maturity were treated with mixed and individual bacteriophages at 8 and 9 log₁₀ PFU/mL for 1 h. The results showed reductions greater than 6 log₁₀ CFU/cm² as a result of exposing SS surfaces with biofilms of 24 h maturity to 9 log₁₀ PFU/mL of bacteriophages; however, the E. coli and bacteriophage strains, phage concentration, and biofilm development stage had significant effects on biofilm reduction (p < 0.05). In conclusion, the isolated bacteriophages showed effectiveness at reducing biofilms of isolated E. coli; however, it is necessary to increase the libraries of phages with lytic activity against the strains isolated from production environments.

中文翻译：

---

新型噬菌体对不锈钢上大肠杆菌生物膜的功效

大肠杆菌形成的生物膜对肉类加工厂构成严重威胁。化学消毒剂通常无法消除生物膜；因此，噬菌体是解决这一问题的一个有前途的替代方案，因为它们分布广泛、对环境友好且对人类无毒。在本研究中，评估了从肉类工业中分离出的10 种大肠杆菌菌株以及大肠杆菌ATCC BAA-1430 和 ATCC 11303的生物膜形成情况。从肉接触表面分离的三个菌株表现出粘附能力并产生细胞外聚合物。这三种菌株的生物膜在不锈钢 (SS) 表面上生长，并在 2、12、24、48 和 120 小时时进行计数，并通过扫描电子显微镜进行可视化。随后，从碎牛肉和家禽肝脏样品中分离出三种显示足病毒形态的噬菌体，其对上述生物膜形成菌株表现出裂解活性。将具有成熟度为 2、14 和 48 小时的生物膜的 SS 表面用混合和单独的噬菌体以 8 和 9 log ₁₀ PFU/mL 处理 1 小时。结果显示，由于将具有 24 小时成熟生物膜的 SS 表面暴露于 9 log ₁₀ PFU/mL 的噬菌体，其减少量大于 6 log ₁₀ CFU/cm ^{2 ；}然而，大肠杆菌和噬菌体菌株、噬菌体浓度和生物膜发育阶段对生物膜减少有显着影响（p < 0.05）。总之，分离的噬菌体在减少分离的大肠杆菌生物膜方面表现出有效性；然而，有必要增加对从生产环境中分离的菌株具有裂解活性的噬菌体文库。