Primary study on the survival ability of 3 species of gram-negative bacteria in larva culture water and in midguts of adult Anopheles sinensis

Abstract

Objective To investigate the survival ability of 3 species of gram-negative bacteria, Aero-monas sp. , A4 and Enterobacter sp. in water where larva anopheline mosquitoes developed from larva to adults and in midguts of adult Anopheles sinensis. Methods The 3 species of bacteria were cultivated in laboratory and added to the mosquito-rear-cups. During the period of the mosquitoes developing, water samples in mosquito-rear-cups and pupae boxes were collected when the mosquitoes finished their development in them. Midguts of adult An. sinensis samples were also collected and grinded in 0.9% NaCl solutions. Bacteria floras of cultivable bacteria and dominant bacteria were determined in all samples based on 16S rDNA sequences of cultivable bacteria and 16S rDNA cloning libraries of all samples. Bacteria floras were compared between treatments which treated with different bacteria and between different samples of same treatment. Results No target bacteria were detected in the test samples. Dominant cultivable bacteria of all treatments in water of mosquito-rear-cups and pupae boxes were A. hydrophila and Comamonas testosterone, respectively. Cultivable bacteria in midguts of female mosquitoes were also not target bacteria. Based on 16S rDNA cloning libraries, P. aeruginosa were the only dominant bacteria detected in all samples. Conclusion All 3 target bacteria cultivated in laboratory could not establish populations in mosquito-rear-cups that led to no target bacteria could be detected in the midguts of female adult mosquitoes. Key words: Bacteria flora; Dominant bacteria; Midgut bacteria; Application; Transstadial transmission