Sutcliffe Steven G, Reyes Alejandro, Maurice Corinne F
McGill Centre for Microbiome Research, McGill University, Montreal, QC, Canada.
Department of Microbiology & Immunology, McGill University, Montreal, QC, Canada.
iScience. 2023 Jan 18;26(2):106007. doi: 10.1016/j.isci.2023.106007. eCollection 2023 Feb 17.
Bacteriophages, viruses specific to bacteria, coexist with their bacterial hosts with limited diversity fluctuations in the guts of healthy individuals where they replicate mostly via lysogenic replication. This favors 'piggy-back-the-winner' over 'kill-the-winner' dynamics which are driven by lytic bacteriophage replication. Revisiting the deep-viral sequencing data of a healthy individual sampled over 2.4 years, we explore how these dynamics occur. Prophages found in assembled bacterial metagenomes were also found extra-cellularly, as induced phage particles (iPPs), likely derived from prophage activation. These iPPs were diverse and continually present in low abundance, relative to the highly abundant but less diverse lytic phage population. The continuous detection of low levels of iPPs suggests that spontaneous induction regularly occurs in this healthy individual, possibly allowing prophages to maintain their ability to replicate and avoiding degradation and loss from the gut microbiota.
噬菌体，即细菌特异性病毒，在健康个体的肠道中与它们的细菌宿主共存，其多样性波动有限，在这些肠道中它们大多通过溶原性复制进行繁殖。这有利于“搭乘胜者便车”而非由裂解性噬菌体复制驱动的“杀死胜者”动态。通过重新审视一名健康个体在2.4年期间采样的深度病毒测序数据，我们探究了这些动态是如何发生的。在组装的细菌宏基因组中发现的前噬菌体也在细胞外被发现，作为诱导噬菌体颗粒（iPPs），可能源自前噬菌体激活。相对于高度丰富但多样性较低的裂解性噬菌体群体，这些iPPs种类多样且持续以低丰度存在。对低水平iPPs的持续检测表明，在这个健康个体中自发诱导经常发生，这可能使前噬菌体能够维持其复制能力，并避免从肠道微生物群中降解和丢失。
