Department of Biotechnology, Guru Jambheshwar University of Science & Technology, Hisar, India.
Department of Microbiology, College of Basic Science & Humanities, Chaudhary Charan Singh Haryana Agricultural University (CCS HAU), Hisar, India.
Int J Food Microbiol. 2025 Jan 2;426:110924. doi: 10.1016/j.ijfoodmicro.2024.110924. Epub 2024 Sep 27.
A novel Escherichia coli phage designated as EC BD was isolated from cattle dung samples. Transmission electron microscopy demonstrated that the morphology of phage EC BD belongs to the family Myoviridae. The efficiency of plating (EOP) and scanning electron microscopy revealed the strong lytic activity of phage EC BD with a large burst size and a short latent period. Whole genome data analysis suggested that phage EC BD was inclined towards being completely lytic and revealed the absence of toxins, virulence and antibiotic resistance genes. Phylogenomic analysis of phage EC BD receptor binding proteins (RBPs) showed 74-100 % similarity with sixteen Enterobacter phages, representing their broad host range. The phage genome contains 262 ORFs, of which 107 displayed a unique pattern and additionally, the presence of a tRNA gene directed their fast replication and high stability. Comparative genome analysis suggested phage EC BD as a novel member of the genus Duplodnaviria and family Myoviridae. The efficiency of phage EC BD was determined in dairy food matrices (milk, cheese and paneer) artificially contaminated with enterotoxigenic E. coli strains ETEC H10407, ETEC K 12S and ETEC PB 176 with a significant reduction of 4.8, 6.0 and 5.3 log CFU/mL in milk and a substantial 4.9, 5.8 and 4.6 log CFU/mL reduction in cheese samples after 6 days at low storage temperature (4 °C); furthermore, within the similar conditions, paneer samples showed 4, 5.1 and 3.5 log CFU/mL reduction. EC BD phage treatment represents the complete eradication of three ETEC strains in liquid and semisolid dairy food matrices. This study suggested that phage EC BD might have potential as a biocontrol approach against ETEC foodborne infections.
从牛粪样本中分离到一株新型大肠杆菌噬菌体，命名为 EC BD。透射电子显微镜显示，噬菌体 EC BD 的形态属于肌尾噬菌体科。噬菌斑效价（EOP）和扫描电子显微镜揭示了噬菌体 EC BD 的强烈裂解活性，具有较大的爆发量和较短的潜伏期。全基因组数据分析表明，噬菌体 EC BD 倾向于完全裂解，并且缺乏毒素、毒力和抗生素耐药基因。噬菌体 EC BD 受体结合蛋白（RBPs）的系统发育分析显示，与 16 株肠杆菌噬菌体具有 74-100%的相似性，表明其宿主范围广泛。噬菌体基因组包含 262 个 ORF，其中 107 个具有独特的模式，此外，存在一个 tRNA 基因，指导其快速复制和高度稳定。比较基因组分析表明，噬菌体 EC BD 是 Duplodnaviria 属和肌尾噬菌体科的一个新成员。噬菌体 EC BD 对人工污染有 enterotoxigenic E. coli 菌株 ETEC H10407、ETEC K 12S 和 ETEC PB 176 的乳制品基质（牛奶、奶酪和印度奶酪）的效率进行了测定，在低储存温度（4°C）下 6 天后，牛奶中的 4.8、6.0 和 5.3 log CFU/mL，奶酪样本中的 4.9、5.8 和 4.6 log CFU/mL 显著减少；此外，在相同条件下，印度奶酪样本减少了 4、5.1 和 3.5 log CFU/mL。噬菌体 EC BD 处理代表了在液体和半固体乳制品基质中完全消除三种 ETEC 菌株。本研究表明，噬菌体 EC BD 可能具有作为针对食源性 ETEC 感染的生物控制方法的潜力。
