Prophage-encoded gene VpaChn25_0734 amplifies ecological persistence of Vibrio parahaemolyticus CHN25

Abstract

Vibrio parahaemolyticus is a waterborne pathogen that can cause acute gastroenteritis, wound infection, and septicemia in humans. The molecular basis of its pathogenicity is not yet fully understood. Phages are found most abundantly in aquatic environments and play a critical role in horizontal gene transfer. Nevertheless, current literature on biological roles of prophage-encoded genes remaining in V. parahaemolyticus is rare. In this study, we characterized one such gene VpaChn25_0734 (543-bp) in V. parahaemolyticus CHN25 genome. A deletion mutant ΔVpaChn25_0734 (543-bp) was obtained by homologous recombination, and a revertant ΔVpaChn25_0734-com (543-bp) was also constructed. The ΔVpaChn25_0734 (543-bp) mutant was defective in growth and swimming mobility particularly at lower temperatures and/or pH 7.0–8.5. Cell surface hydrophobicity and biofilm formation were significantly decreased in the ΔVpaChn25_0734 (543-bp) mutant (p < 0.05). Based on the in vitro Caco-2 cell model, the deletion of VpaChn25_0734 (543-bp) gene significantly reduced the cytotoxicity of V. parahaemolyticus CHN25 to human intestinal epithelial cells (p < 0.05). Comparative secretomic and transcriptomic analyses revealed a slightly increased extracellular proteins, and thirteen significantly changed metabolic pathways in the ΔVpaChn25_0734 (543-bp) mutant, showing down-regulated carbon source transport and utilization, biofilm formation, and type II secretion system (p < 0.05), consistent with the observed defective phenotypes. Taken, the prophage-encoded gene VpaChn25_0734 (543-bp) enhanced V. parahaemolyticus CHN25 fitness for survival in the environment and the host. The results in this study facilitate better understanding of pathogenesis and genome evolution of V. parahaemolyticus, the leading sea foodborne pathogen worldwide.

Antibacterial Activity and Components of the Methanol-Phase Extract from Rhizomes of Pharmacophagous Plant Alpinia officinarum Hance

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Inoviridae prophage and bacterial host dynamics during diversification, succession, and Atlantic invasion of Pacific-native Vibrio parahaemolyticus

“…This could reflect their fastidious nature, but the success of the two northernmost Atlantic populations harboring inoviruses contrasting with the unsuccessful lineages that lacked them signals alternatives are possible: that inoviruses may confer advantages in some as yet undefined context. For example, shed inovirus virions contribute to biofilm matrix ( 65 ) thereby promoting virulence and antimicrobial resistance but also potentially enhancing survival during long-distance movement on particles ( 53 , 55 , 66 – 68 ). Shed inoviruses can mislead human immune responses and decrease host ability to clear bacterial infections, thereby enhancing virulence ( 69 ).…”

Understanding the transcriptomic response of Lactiplantibacillus pentosus LPG1 during Spanish-style green table olive fermentations

“…Genes encoding major and minor capsid proteins, tail protein, head and tail connector protein, small and large subunits of the terminase were found to be upregulated in the biofilm. Previous RNA-seq studies have revealed that Vibrio parahaemolyticus , after the removal of prophage, exhibited a reduced ability to form biofilms due to a change in the cell surface hydrophobicity ( Xu et al, 2022 ). However, few studies have been conducted on prophage induction within the biofilm context.…”