Bier S B, Toska J, Zhao W, Suthianthong P, Proespraiwong P, Robins W P, Mekalanos J
Department of Microbiology, Harvard Medical School, Boston, MA, USA.
Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Disease. The Sixth Affiliated Hospital, School of Medicine, Sun Yat-sen University, Guangzhou, China.
Commun Biol. 2024 Aug 8;7(1):958. doi: 10.1038/s42003-024-06637-0.
Vibrio species are recognized for their role in food- and water-borne diseases in humans, fish, and aquatic invertebrates. We screened bacterial strains isolated from raw food shrimp for those that are bactericidal to Vibrio strains. Here we identify and characterize Aeromonas dhakensis strain A603 which shows robust bactericidal activity specifically towards Vibrio and related taxa but less potency toward other Gram-negative species. Using the A603 genome and genetic analysis, we show that two antibacterial mechanisms account for its vibriocidal activity -- a highly potent Type Six Secretion System (T6SS) and biosynthesis of a vibriocidal phenazine-like small molecule, named here as Ad-Phen. Further analysis indicates coregulation between Ad-Phen and a pore-forming T6SS effector TseC, which potentiates V. cholerae to killing by Ad-Phen.
弧菌属因其在人类、鱼类和水生无脊椎动物的食源性和水源性疾病中所起的作用而被人们所认识。我们从生鲜食用虾中分离出细菌菌株，并筛选出对弧菌菌株具有杀菌作用的菌株。在此，我们鉴定并表征了达卡气单胞菌菌株A603，该菌株对弧菌及相关分类群表现出强大的杀菌活性，但对其他革兰氏阴性菌的效力较弱。通过对A603基因组和遗传分析，我们发现其杀弧菌活性有两种抗菌机制——一种是高效的VI型分泌系统（T6SS），另一种是一种杀弧菌的吩嗪样小分子的生物合成，在此命名为Ad-Phen。进一步分析表明，Ad-Phen与一种形成孔道的T6SS效应蛋白TseC之间存在共同调控，这增强了霍乱弧菌被Ad-Phen杀死的能力。
