Bae Hee-Won, Choi Shin-Yae, Cho You-Hee
Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Gyeonggi-do 13488, Korea.
iScience. 2023 Dec 7;27(1):108675. doi: 10.1016/j.isci.2023.108675. eCollection 2024 Jan 19.
Host range of a phage is determined at the various life cycle stages during phage infection. We reported the limited phage-receptor interaction between the RNA phage, PP7 and its host strains: PAO1 has susceptible type IV pilus (TFP) pilin, whereas PA14 has resistant pilin. Here, we have created a PA14 derivative (PA14P) with the PAO1 pilin gene and found that other determinants than TFP pilin could limit PP7 infectivity in PA14P. Transposon mutant screens revealed that PP7 infectivity was restored in the PA14P mutants () lacking a secondary acyltransferase in lipid A biosynthesis. The lack of this enzyme increased the RNA phage entry, which is deemed attributed to the loosened lipopolysaccharide (LPS) structure. Polymyxin B treatment also selectively increased the RNA phage entry. These results demonstrated that LPS structures could limit the entry stage of RNA phages, providing another determinant for the host range in diverse strains.
噬菌体的宿主范围是在噬菌体感染的各个生命周期阶段确定的。我们报道了RNA噬菌体PP7与其宿主菌株之间有限的噬菌体-受体相互作用：PAO1具有易感的IV型菌毛（TFP）菌毛蛋白，而PA14具有抗性菌毛蛋白。在这里，我们创建了一个带有PAO1菌毛蛋白基因的PA14衍生物（PA14P），并发现除TFP菌毛蛋白外的其他决定因素可能会限制PP7在PA14P中的感染性。转座子突变体筛选显示，在脂质A生物合成中缺乏二级酰基转移酶的PA14P突变体中PP7的感染性得以恢复。这种酶的缺失增加了RNA噬菌体的进入，这被认为是由于脂多糖（LPS）结构的松弛所致。多粘菌素B处理也选择性地增加了RNA噬菌体的进入。这些结果表明，LPS结构可能会限制RNA噬菌体的进入阶段，为不同菌株的宿主范围提供了另一个决定因素。
