Bacterial community structure of Anopheles hyrcanus group, Anopheles nivipes, Anopheles philippinensis, and Anopheles vagus from a malaria-endemic area in Ubon Ratchathani Province, Thailand

The microbiota of Anopheles mosquitoes can influence malaria transmission directly or indirectly. This study characterized the bacterial microbiota associated with field-collected female adults of Anopheles hyrcanus group, Anopheles nivipes, Anopheles philippinensis, and Anopheles vagus from a malaria-endemic area in northeastern Thailand, near the Lao PDR-Cambodia-Thailand border. The microbiota of the four Anopheles species differed between pools of the same species and between species. Abundant genera were gram-negative bacteria, including Pseudomonas, Serratia, Rosenbergiella, Ralstonia, Acinetobacter, and Pantoea, while gram-positive bacteria were not abundant, represented by the genera Staphylococcus and Carnobacterium. Pseudomonas sp. was highly abundant in all mosquito species except for An. nivipes. This is the first report of bacterial diversity in four Anopheles species that can act as secondary vectors of malaria. The present study provides new knowledge on the microbiota of four potential malaria vectors as a first step towards understanding the role of the microbiota on mosquito biology and ultimately the development of potential tools for mosquito-borne disease control. However, more work is needed before using these bacteria in any field applications aimed at limiting the transmission of mosquito-borne diseases.

按蚊属（Anopheles）昆虫的微生物群可直接或间接影响疟疾传播。本研究对采自泰国东北部老挝-柬埔寨-泰国边境附近疟疾流行区的赫坎按蚊种团（Anopheles hyrcanus group）、尼氏按蚊（Anopheles nivipes）、菲律宾按蚊（Anopheles philippinensis）及迷走按蚊（Anopheles vagus）的野外采集雌性成蚊进行了细菌微生物群特征分析。四种按蚊的微生物群在同种混合蚊样本间及不同蚊种间均存在显著差异。优势菌属以革兰氏阴性菌为主，包括假单胞菌属（Pseudomonas）、沙雷氏菌属（Serratia）、罗森伯格菌属（Rosenbergiella）、罗尔斯通氏菌属（Ralstonia）、不动杆菌属（Acinetobacter）及泛菌属（Pantoea）；革兰氏阳性菌占比相对较低，代表性菌属为葡萄球菌属（Staphylococcus）与肉杆菌属（Carnobacterium）。除尼氏按蚊外，假单胞菌属物种在其余三种按蚊中均为优势类群。本研究首次报道了四种可作为疟疾次要传播媒介的按蚊的细菌多样性。本研究为四种潜在疟疾传播媒介的微生物群研究提供了新认知，是解析微生物群在按蚊生物学中作用的第一步，最终可为蚊媒疾病防控潜在工具的开发奠定基础。然而，在将这些细菌应用于限制蚊媒疾病传播的野外实际应用前，仍需开展更多研究工作。