Murthy Nalina, Bisht Bhawana, Bhardwaj Priya, Priyadarshini Poornima
Department of Molecular Nutrition, CSIR-Central Food Technological Research Institute (CSIR-CFTRI), Mysore, Karnataka, 570020, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 202002, India.
Mol Biol Rep. 2025 Aug 9;52(1):812. doi: 10.1007/s11033-025-10927-z.
In response to rising antibiotic resistance, bacteriophage application is gaining renewed attention, marking a paradigm shift in managing bacterial infections, especially foodborne pathogens. Non-typhoidal salmonellosis remains a major global health burden. In this context, a novel lytic bacteriophage targeting Salmonella typhimurium was isolated and characterized.
A novel phage, vB_ntSalS-cftriSP11, targeting S. typhimurium, was isolated using spot and double agar overlay methods. One-step growth analysis showed a burst size of 146 ± 10 particles with a 20 min latency period. The phage exhibited a broad host range and stability across a wide pH and temperature range. Morphological and genomic analyses identified it as a member of Casjensviridae, with a 56,837 bp genome encoding 103 of 105 predicted ORFs linked to biological processes, cellular components, and molecular functions. Notably, no toxin genes, virulence factors, or antimicrobial resistance genes were detected in the genome. BLAST and phylogenetic analyses revealed high sequence similarity (97-98%) with known Salmonella phages 35, 37 and PK4. Functionally, the phage demonstrated strong anti-Salmonella activity, reducing biofilm biomass by 1.86-fold and 2.11-fold in 48- and 72-h-old biofilms, respectively, after 24 h of treatment. It also significantly decreased Salmonella counts on chicken breast samples at RT and 4 ℃ at MOI 1 compared to the culture control.
The Phage vB_ntSalS-cftriSP11 was identified as a stable, lytic bacteriophage with a broad host range and strong antibiofilm activity against S typhimurium. Its genetic safety profile and efficacy highlight its potential as a promising biocontrol agent against antibiotic-resistant Salmonella infections.
为应对日益增长的抗生素耐药性，噬菌体的应用正重新受到关注，这标志着在管理细菌感染，尤其是食源性病原体方面的范式转变。非伤寒沙门氏菌病仍然是全球主要的健康负担。在此背景下，分离并鉴定了一种新型的靶向鼠伤寒沙门氏菌的裂解性噬菌体。
采用点滴法和双层琼脂平板法分离出一种新型噬菌体vB_ntSalS - cftriSP11，其靶向鼠伤寒沙门氏菌。一步生长分析显示，其裂解量为146±10个粒子，潜伏期为20分钟。该噬菌体在较宽的pH和温度范围内表现出广泛的宿主范围和稳定性。形态学和基因组分析确定它为卡申斯病毒科的成员，其基因组大小为56,837 bp，编码105个预测开放阅读框中的103个，这些开放阅读框与生物学过程、细胞成分和分子功能相关。值得注意的是，在基因组中未检测到毒素基因、毒力因子或抗菌耐药基因。BLAST和系统发育分析显示，它与已知的沙门氏菌噬菌体35、37和PK4具有高度的序列相似性（97 - 98%）。在功能上，该噬菌体表现出强大的抗沙门氏菌活性，在处理24小时后，分别使48小时和72小时龄的生物膜生物量减少了1.86倍和2.11倍。与培养对照相比，在感染复数（MOI）为1时，它还显著降低了室温及4℃条件下鸡胸肉样本中的沙门氏菌数量。
噬菌体vB_ntSalS - cftriSP11被鉴定为一种稳定的裂解性噬菌体，具有广泛的宿主范围和对鼠伤寒沙门氏菌强大的抗生物膜活性。其遗传安全性和有效性突出了它作为一种有前景的生物防治剂来对抗耐抗生素沙门氏菌感染的潜力。
