Liu Hui, Billington Craig, Ji Xing, Sun Haichang, Hou Xiang, Soleimani-Delfan Abbas, Wang Ran, Wang Heye, Zhang Lili
Key Laboratory of Food Quality and Safety of Jiangsu Province-State Key Laboratory Breeding Base, Institute of Food Safety and Nutrition, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, P.R. China.
College of Animal Science and Technology, Guangxi University, Nanning, 530004, Guangxi, P.R. China.
BMC Microbiol. 2025 Mar 31;25(1):184. doi: 10.1186/s12866-025-03900-0.
Livestock-associated Staphylococcus aureus ST398 is a highly pathogenic species that causes infections in a wide variety of animals, including humans. The bacteriophage (phage) vB_SauS_S1 was isolated originally using a ST398 strain as its "isolating host", then the spot tests showed it was able to infect 73.33% (22/30) ST398 isolates. Phage S1 was assigned as a temperate phage based on genome analysis and phenotypic validation. Phylogenetic analysis showed that S1 was closely related to temperate phages tp310-2 and SA137ruMSSAST121PVL. Following infection of ST398 by phage S1, the lysogenic strain showed enhanced biofilm forming ability compared to the wildtype strain, and the invasion rate of MAC-T cells increased by 10.39%. The minimum inhibitory concentration showed that phage S1 did not change the antibiotic sensitivity of the lysogen strain, and the virulence of the lysogen strain did not change significantly in the injection models of Galleria mellonella (G. mellonella) and mice. The lysogen demonstrated superinfection immunity and reduced sensitivity to virulent phage infection. Thus, this study contributes to understanding the co-evolutionary relationships between temperate phages and the multi-host zoonotic pathogen S. aureus ST398.
与家畜相关的金黄色葡萄球菌ST398是一种高致病性菌种，可在包括人类在内的多种动物中引起感染。噬菌体vB_SauS_S1最初使用ST398菌株作为其“分离宿主”进行分离，随后的点滴试验表明它能够感染73.33%（22/30）的ST398分离株。基于基因组分析和表型验证，噬菌体S1被归类为温和噬菌体。系统发育分析表明，S1与温和噬菌体tp310-2和SA137ruMSSAST121PVL密切相关。噬菌体S1感染ST398后，溶原性菌株与野生型菌株相比，生物膜形成能力增强，MAC-T细胞的侵袭率提高了10.39%。最低抑菌浓度表明，噬菌体S1没有改变溶原性菌株的抗生素敏感性，并且在大蜡螟（G. mellonella）和小鼠注射模型中，溶原性菌株的毒力没有显著变化。溶原性菌株表现出超感染免疫性，对毒性噬菌体感染的敏感性降低。因此，本研究有助于理解温和噬菌体与多宿主人畜共患病原体金黄色葡萄球菌ST398之间的共同进化关系。
