This study aimed to investigate whether bacterial ghosts (BGs), empty cell envelopes of a gram-negative bacterium, delivering envelope protein domain III (EDIII) of dengue virus (DENV) serotype 2 could induce protective immune responses against dengue infection. In this study, we constructed Salmonella Typhimurium BGs expressing and delivering EDIII (BG-EDIII) and evaluated these ghosts for their immunogenicity studies in C57BL/6 mice. Our results demonstrated that the mice vaccinated once orally with BG-EDIII followed by an intramuscular boosting with a recombinant EDIII protein elicited significantly higher humoral and cell-mediated immune responses compared to the BGs alone vaccinated group (p<0.001). Upon challenge with DENV2, significantly lower viral load and liver damage was observed in BG-EDIII vaccinated group than BGs alone control group (p<0.05). The outcomes of this study revealed the ability of BG- EDIII to stimulate immune response with no observable damage to the vital organs.

Dengue is the most important arboviral disease in tropical and subtropical areas where 2.5 billion people are at risk of infection. Aedes albopictus will be a major vector transmitting dengue virus in Korea, where this virus overseas inflow is possible. We collected mosquitoes in Jeju, Busan, Gunsan, and Incheon using BG sentinel trap from April to October in 2016. Collected mosquitoes were conducted virus detection using real-time PCR method and analysis bloodmeal source of Ae. albopictus. A total of 15 species comprising 7 genera were identified and 4,854 female mosquitoes collected. The most dominant species ratio (SR) was 52.9% (Culex pippins complex) followed by 20.3% (Ae. albopictus), 10.8% (Ae. vexans nipponi) and Ochlerotatus dorsalis (3.8%). Dengue virus was not detected. Bloodmeal source of Ae. albopictus was mammals (80.9%) followed by birds (18.6) and amphibians (0.5).

Dengue is the most important arboviral human infection worldwide. Approximately 50-100 million cases occur annually and more than 2.5 billion people are at risk of infection. This virus is possibility of overseas inflow to be high in Korea. We collected mosquitoes in Jeju, Busan, Gunsan, and Incheon using BG Sentinel trap from April to August in 2016. Collected mosquitoes were conducted virus detection using real-time PCR method. A total of 15 species comprising 7 genera were identified and 3,696 female mosquitoes collected. The most dominant species ratio (SR) was 49.4% (Culex pippins complex) followed by 21.8% (Aedes albopictus), 13.6% (Ae. vexans) and Ochlerotatus dorsalis (4.8%). Dengue virus was not detected in any mosquitoes until now.