A naturally isolated symbiotic bacterium suppresses flavivirus transmission by Aedes mosquitoes.

The commensal microbiota of the mosquito gut plays a complex role in determining the vector competence for arboviruses. In this study, we identified a bacterium from the gut of field Aedes albopictus mosquitoes named Rosenbergiella sp. YN46 (Rosenbergiella_YN46) that rendered mosquitoes refractory to infection with dengue and Zika viruses. Inoculation of 1.6 × 103 colony forming units (CFUs) of Rosenbergiella_YN46 into A. albopictus mosquitoes effectively prevents viral infection. Mechanistically, this bacterium secretes glucose dehydrogenase (RyGDH), which acidifies the gut lumen of fed mosquitoes, causing irreversible conformational changes in the flavivirus envelope protein that prevent viral entry into cells. In semifield conditions, Rosenbergiella_YN46 exhibits effective transstadial transmission in field mosquitoes, which blocks transmission of dengue virus by newly emerged adult mosquitoes. The prevalence of Rosenbergiella_YN46 is greater in mosquitoes from low-dengue areas (52.9 to ~91.7%) than in those from dengue-endemic regions (0 to ~6.7%). Rosenbergiella_YN46 may offer an effective and safe lead for flavivirus biocontrol.

Study on the Effects of Orthodontics on Anterior Tooth Displacement in Patients.

Objective: The purpose of this study was to investigate the therapeutic effect of orthodontic treatment on anterior tooth displacement caused by periodontal disease. Methods: A prospective study was performed in 86 patients with anterior tooth displacement caused by periodontal disease. These patients were divided into the experimental group and the control group according to the intervention methods. For the control group, patients were treated with conventional therapy. The experimental group used straight wire orthodontic technique for orthodontic treatment on the basis of conventional treatment. Comparisons were performed between two groups in term of bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, tooth root length, inflammatory cytokines levels, and orthodontic satisfaction. Results: Comparison of bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, tooth root length, and inflammatory cytokines levels between two groups before treatment indicated that there were no statistical differences (all P > 0.05). After treatment, bleeding index, alveolar bone height, anterior tooth coverage, periodontal pocket depth, probing depth, clinical crown length, and serum levels of IL-6 and TNF-α in the experimental group were lower than those in the control group (all P < 0.05), while the serum level of IL-2 in the experimental group was more than that in the control group (P < 0.05). Also, there was no difference for tooth root length between two groups. Moreover, compared with the control group, orthodontic satisfaction in the experimental group was significantly increased. Conclusion: The efficacy of orthodontic treatment in patients with anterior tooth displacement caused by periodontal disease is higher than that of only using conventional therapy, as it helps improve their periodontal health, alveolar bone height, clinical crown length, inflammatory factor levels, and orthodontic satisfaction of patients.

[Clinical evaluation of wedge-shaped defect restored by gingival retraction technique].

OBJECTIVE: To evaluate the periodontal conditions after the wedge-shaped defect was restored by gingival retraction technique. METHODS: A total of 138 mandibular premolars with wedge-shaped defect were selected and divided into A, B groups. Group A was restored with Dyract after using retraction cord. Group B was directly restored with Dyract. Clinical parameters including plaque index (PLI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD), volumes of gingival crevicular fluid (GCF) and levels of aspartate aminotransferases (AST) of gingival crevicular fluid were measured at baseline, 1 week, 1 month, 3 months and 6 months after operation. RESULTS: There was no difference in PLI, GI, SBI, PD between group A and B during 6 months after operation, while the difference of GCF and AST was significant between group A and B at 3 months and 6 months after operation (P < 0.05, P < 0.01). CONCLUSIONS: Gingival retraction technique applied in wedge-shaped defect restoration can reduce the damage to the periodontal tissue.