Floccari Valentina A, Feddersen Helge, Jakin Lazar Jaka, Grosboillot Virginie, Munk Anna, Kempen Paul, Hertel Robert, Accetto Tomaž, Kovács Ákos T, Bramkamp Marc, Dragoš Anna
Department of Microbiology, Biotechnical Faculty, University of Ljubljana, Ljubljana, 1000, Slovenia.
Institute of General Microbiology, Kiel University, Kiel, 24098, Germany.
Commun Biol. 2025 Aug 18;8(1):1238. doi: 10.1038/s42003-025-08672-x.
In lysogenic conversion, temperate phages can profoundly alter the phenotypes of their bacterial hosts. When studying the effects of SPbeta-like viruses on a Bacillus subtilis soil isolate, we observed that phage phi3T induced a stable and heritable acquisition of a spherical cell morphology, departing from the typical rod shape of its ancestor. Although time-lapse imaging revealed that the lysogen retained cell wall integrity and symmetric division, it exhibited reduced fitness and increased susceptibility to cell wall-targeting antimicrobials. Remarkably, when SPβ, a homologous SPbeta-like virus, was present, the host retained its rod-shaped morphology despite phi3T superinfection. This study uncovers a novel example of lysogenic conversion in which phage integration into the bacterial genome induces heritable changes in host biology. Additionally, we revealed intriguing phage-phage interactions during polylysogeny that may benefit the host. These findings offer insight into the persistence and absence of specific Spbetavirus variants in natural B. subtilis populations.
在溶原性转化中，温和噬菌体可深刻改变其细菌宿主的表型。在研究SPbeta样病毒对枯草芽孢杆菌土壤分离株的影响时，我们观察到噬菌体phi3T诱导了一种稳定且可遗传的球形细胞形态的获得，与其祖先典型的杆状形态不同。尽管延时成像显示溶原菌保持了细胞壁完整性和对称分裂，但它表现出适应性降低以及对靶向细胞壁的抗菌药物的敏感性增加。值得注意的是，当同源的SPbeta样病毒SPβ存在时，尽管phi3T发生了超感染，宿主仍保持其杆状形态。这项研究揭示了溶原性转化的一个新例子，即噬菌体整合到细菌基因组中会诱导宿主生物学的可遗传变化。此外，我们还揭示了多重溶原过程中有趣的噬菌体-噬菌体相互作用，这可能对宿主有益。这些发现为天然枯草芽孢杆菌群体中特定Spbetavirus变体的持久性和缺失提供了见解。
