Reversible phenotypic resistance to phage infection via capsule downregulation in <i>Klebsiella pneumoniae</i>.

ABSTRACT: Capsule loss is a major mechanism by which bacteria evade phage infection. This has traditionally been attributed to mutations in capsule biosynthesis genes. Here, we investigated phage resistance in Klebsiella pneumoniae, a medically relevant encapsulated bacterium. Phage infection rapidly selected for resistant acapsular cells. As expected, transcriptomic analysis revealed a marked downregulation of capsule biosynthesis genes. However, full genome sequencing showed that capsule loss occurred without evidence of mutations, and acapsular phage-resistant cells were able to rapidly restore their capsule once phage pressure was removed. These findings highlight that phage-driven selective pressure can act on non-heritable variation in gene expression, providing a faster and more flexib

SUBMITTER: Mora-Quilis L 

PROVIDER: S-EPMC12719783 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature