Data from: Quorum-sensing signaling by chironomid egg masses’ microbiota affects haemagglutinin/protease (HAP) production by Vibrio cholerae

Vibrio cholerae, the causative agent of cholera, is commonly isolated, along with other bacterial species, from chironomid insects (Diptera: Chironomide). Nevertheless, its prevalence in the chironomid egg masses’ microbiota is less than 0.5%. V. cholerae secretes haemagglutinin/protease (HAP) that degrades the gelatinous matrix of chironomid egg masses and prevents hatching. Quorum sensing (QS) activates HAP production in response to accumulation of bacterial autoinducers (AIs). Our aim was to define the impact of chironomid microbiota on HAP production by V. cholerae. To study QS signaling, we used V. cholerae bioluminescence reporter strains (QS-proficient O1 El-Tor wild type and QS-deficient mutants) and different bacterial species that we isolated from chironomid egg masses. These egg mass isolates, as well as a synthetic AI-2, caused an enhancement in lux expression by a V. cholerae QS-deficient mutant. The addition of the egg mass bacterial isolate supernatant to the QS-deficient mutant also enhanced HAP production and egg mass degradation activities. Moreover, the V. cholerae wild type strain was able to proliferate using egg masses as their sole carbon source while the QS-deficient was not. The results demonstrate that members of the chironomid bacterial consortium produce external chemical cues that, like AI-2, induce expression of the hapA gene in V. cholerae. Understanding the interactions between V. cholerae and the insects’ microbiota may help uncover the interactions between this pathogen and the human gut microbiota.

霍乱弧菌（Vibrio cholerae）是霍乱的致病菌，通常可与其他细菌物种一同从摇蚊（双翅目：摇蚊科）昆虫中分离得到。然而，其在摇蚊卵块微生物群中的占比不足0.5%。霍乱弧菌可分泌血凝素/蛋白酶（HAP），该酶能够降解摇蚊卵块的胶状基质并阻止卵块孵化。群体感应（QS）可响应细菌自体诱导物（AIs）的积累，从而激活HAP的产生。本研究旨在明确摇蚊微生物群对霍乱弧菌HAP产生的影响。为研究QS信号通路，我们使用了霍乱弧菌生物发光报告菌株（具备QS功能的O1 El-Tor野生型菌株与QS缺陷型突变株），以及从摇蚊卵块中分离得到的多种细菌物种。这些卵块分离菌与合成AI-2均可增强霍乱弧菌QS缺陷型突变株的lux基因表达。将卵块细菌分离菌的上清液添加至QS缺陷型突变株中，同样可增强HAP产生与卵块降解活性。此外，野生型霍乱弧菌能够以摇蚊卵块作为唯一碳源进行增殖，而QS缺陷型菌株则无法完成该过程。研究结果表明，摇蚊细菌群落的成员可产生外源性化学信号分子，该类分子与AI-2类似，可诱导霍乱弧菌hapA基因的表达。阐明霍乱弧菌与昆虫微生物群之间的相互作用，或有助于揭示该病原体与人体肠道菌群之间的互作关系。