Background: Malaria is one of the most lethal infectious diseases in tropical and subtropical areas of the world. Following the mosquito insecticide resistance, Plasmodium drug-resistant and lack of an effective vaccine, paratransgenesis using symbiotic bacteria is nominated as new strategy to fight malaria.HasA). A group of mosquito with no bacteria was used as control. 2-5 days old female mosquitoes were fed with the bacteria [1×109cells/mL of 5% (wt/vol) fructose and red dye(1/50ml)] soaked in cotton pads for 24h. Then the sugar fed mosquitoes starved for 8h and allowed to feed for 30 min on P.berghei–infected mouse in dark condition at 17-20°C. The mosquitoes were maintained in 19±1°C and RH 80±5 and parasite infection was measured in different groups by counting the oocyst number 10 days post infection.Results: We reported an excessive (> 3,000 times) increase of E. cloacae in the midgut of mosquitoes 24h after blood meal. The wild and engineered bacterial strains could significantly (P< 0.0001) disrupt rodent malaria parasite P.berghei development in An. stephensi in comparison with the control group. The mean malaria inhibition of E. cloacae WT, E. cloacaeHasA, E. cloacaeS-HasA, and E. cloacaeGFP-D was measured 72%, 86%, 92.5% and 92.8% respectively.Conclusion: The synchrony of the bacterial proliferation and ookinete stage of Plasmodium in Anopheles midgut at 18-24 h after blood feeding provided an excellent chance for the secreted effector molecules to kill efficiently malaria parasite ookinetes, inhibiting oocyst formation. It is notable that E. cloacae wild type could significantly decrease P.berghei oocyst by intrinsic nature. This bacterium could be introduced and established in wild mosquitoes by attractive sugar bait to create a refractory mosquito population to plasmodium parasites. These finding provide the foundation for using paratransgenic An. stephensi by wild type or genetically modified E. cloacae as a powerful tool to fight malaria.Objectives: Here we evaluated two strains of engineered
Enterobacter cloacae expressing different effector molecules to disrupt P.berghei ANKA 2.34 development in
Anopheles stephensi midgut.Materials and Methods:
Plasmodium berghei transmission-blocking assay was carried out by wild type(WT) and different engineered strains of E.cloacae dissolvens expressing GFP-defensin (GFP-D), GFP-HasA, and scorpine-HasA (S-