Chromobacterium Csp_P Reduces Malaria and Dengue Infection in Vector Mosquitoes and Has Entomopathogenic and In Vitro Anti-pathogen Activities
In (A) and (C), antibiotic-treated adults were allowed to feed for 24 h on 1.5% sucrose containing Csp_P liquid culture at a final concentration of ∼108 CFU/ml for An. gambiae (A) and ∼106 CFU/ml for Ae. aegypti (C). After introduction of Csp_P via the sugar meal, An. gambiae mosquitoes were given a blood meal that contained P. falciparum, and Ae. aegypti mosquitoes were given a blood meal that contained dengue virus. In (B), Csp_P (106 CFU/ml) was introduced concurrently with P. falciparum via blood meal through blood feeding of antibiotic-treated An. gambiae. In all experiments, PBS was used as the non-Csp_P-exposed control. At 7 days after infection, midguts were dissected. Oocysts were counted in P. falciparum-infected An. gambiae females, and dengue virus titers were assayed in dengue-infected Ae. aegypti females by conducting standard plaque assays. Experiments were initiated using similar numbers of adult females in each treatment (A, B starting numbers = 45–50/trtmt, C starting numbers = 30–40/treatment). All experiments were replicated at least three times with final samples sizes: (A)PBS = 67, (A)Csp_P = 14, (B)PBS = 43, (B)Csp_P = 8, (C)PBS = 68, (C)Csp_P = 45. Differences between treatments were assessed by Mann-Whitney test (*, p<0.05; ***, p<0.001).