Data_Sheet_3_Biodiversity of New Lytic Bacteriophages Infecting Shigella spp. in Freshwater Environment.pdf

Bacteriophages, viruses that infect and replicate within prokaryotic cells are the most abundant life forms in the environment, yet the vast majority of them have not been properly reported or even discovered. Almost all reported bacteriophages infecting the Enterobacteriaceae family, with Escherichia coli being the major subject of studies, have been isolated from wastewater, sewage, and effluent resources. In the present study, we focused on the distribution and biodiversity of Shigella phages in an aquatic ecosystem. While no Shigella bacteria was recovered from the Yangtze River, three lytic phages were isolated from this ecosystem and were subjected to biological, morphological, and genomic characteristics. Comparative genomics and phylogenetic analyses demonstrated that vB _SflM_004 isolate belongs to Myoviridae family, Felixounavirus genus of Ounavirinae subfamily, vB_SdyM_006 was classified under the same family, however, it is suggested to be in a new genus under Tevenvirinae subfamily with some other related bacteriophages. vB_SsoS_008 phage belongs to the Siphoviridae family, Tunavirus genus, Tunavirinae subfamily. The phages did not harbor any genes involved in the lysogenic cycles and showed a high temperature and pH stability. The biodiversity of the isolated phages highly suggests that continued isolation on non-model members of Enterobacteriaceae family is necessary to fully understand bacteriophage diversity in aquatic environments.

噬菌体（Bacteriophages）是一类可在原核细胞内侵染并增殖的病毒，亦是环境中丰度最高的生命形式，但其中绝大多数尚未被正式报道甚至发现。目前已报道的侵染肠杆菌科（Enterobacteriaceae）的噬菌体，绝大多数以大肠杆菌（Escherichia coli）为主要研究对象，且均分离自废水、污水及排放液资源。本研究聚焦于水生生态系统中志贺氏菌噬菌体的分布与生物多样性。尽管未从长江中分离得到志贺氏菌，但本研究从该生态系统中分离得到3株裂解性噬菌体，并对其生物学、形态学及基因组特征进行了表征。比较基因组学与系统发育分析结果显示：vB_SflM_004分离株隶属于肌尾噬菌体科（Myoviridae）、Ounavirinae亚科下的Felixounavirus属；vB_SdyM_006同样隶属于该科，但结合其他相关噬菌体来看，其应被归入Tevenvirinae亚科下的一个新属；vB_SsoS_008噬菌体则隶属于长尾噬菌体科（Siphoviridae）、Tunavirus属及Tunavirinae亚科。上述噬菌体均未携带任何与溶原性循环相关的基因，且表现出优异的温度与pH稳定性。本次分离得到的噬菌体所展现出的生物多样性强烈表明，若要全面解析水生环境中的噬菌体多样性，需持续对肠杆菌科中非模式菌株开展分离研究。