Fig. 2: Gut symbiotic bacteria are involved in ZIKV infection in lab-adapted mosquitoes.

a Identifying the role of symbiotic bacteria in lab-adapted Ae. aegypti (UGAL/Rockefeller strain) infected with ZIKV (1.0 × 10⁶ FFU/mL) for 7 d (n = 20 for Con.; n = 21 for both Eh_B17 and Ec_68; n = 22 for E_B7, Kg_B9, Es_B36, Pag_B37, Pan_B40, Ss_B43, Ba_B44, P_B47, C_B50, E_B54, Eh_B56, and Et_B61; Kruskal–Wallis test followed by Dunn’s post hoc tests). Each dot represents one mosquito. b Virus titers in saliva were measured using focus-forming assay at 10 d post infection (n = 15 for Con.; n = 16 for Eh_B17; two-sided Mann–Whitney test). Each dot represents one saliva sample. Con.: LB treatment. c Identifying the role of Eh_B17 in ZIKV (1.0 × 10⁵ FFU/mL) infection of field-derived Ae. aegypti (Haikou strain). Virus RNA levels in midguts (n = 17 for Ae. aegypti; n = 18 for Ae. albopictus) and carcasses (n = 16 for Ae. aegypti; n = 17 for Ae. albopictus) were measured using qPCR at 7 d post infection. Carcasses: mosquito body without the midgut. Virus titers in saliva (n = 15 for Ae. aegypti; n = 16 for Ae. albopictus) were detected using focus-forming assay at 10 d post infection. Each point represents one midgut, carcass, or saliva sample. Statistical significance was determined using a two-sided Mann–Whitney test. d Phylogenetic analysis of the serine palmitoyltransferase (SPT) gene from Enterobacter strains. Each black dot represents a bacteria species. Colors represent different species of Enterobacter. e Bacteria colonization assay. After feeding antibiotic-treated females with bacteria for 3 d, colony forming units (CFU) were counted for each midgut (n = 3 biologically independent midguts). Con.: LB treatment. f The growth of Eh_B17-GFP and Eh_B17 in LB medium (n = 3 biologically independent cultures; two-sided unpaired t-test). g Bacterial counts in the midgut of female Ae. aegypti after a blood meal on the indicated days (n = 3 biologically independent midguts). The top of each column shows the number of infected mosquitoes relative to the total number of mosquitoes in a–c. Percentages represent the rate of mosquito infection in a–c. Data are shown as mean ± SEM. The experiments were repeated twice with similar results. *P < 0.05, **P < 0.01, ***P < 0.001. ns: not significant. Source data are provided as a Source Data file.