METHODS: Two pneumococcal Brunei clinical strains were serotyped by multiplex PCR method using oligonucleotide sequences derived from Centers for Disease Control and Prevention. A validated immortalised mouse brain endothelial cell line (bEnd.3) was used as a brain endothelium model for the study of the pneumococcal breach of the blood-brain barrier using an adherence and invasion assay.
RESULTS: Both of the pneumococcal clinical strains were found to be serotype 19F, a common circulating serotype in Southeast Asia and globally and possess the ability to adhere and invade the brain endothelial cells.
CONCLUSION: In addition, this is the first report on the serotype identification of pneumococci in Brunei Darussalam and their application on a brain endothelium model. Further studies are required to understand the virulence capabilities of the clinical strains.
METHODS: This retrospective study involved consecutive hospitalized patients with non-structural protein 1 (NS1) antigen positivity during an outbreak (Jan to April 2014). Multiplex RT-PCR was performed directly on NS1 positive serum samples to detect and determine the DENV serotypes. All PCR-positive serum samples were inoculated onto C6/36 cells. Multiplex PCR was repeated on the supernatant of the first blind passage of the serum-infected cells. Random samples of supernatant from the first passage of C6/36 infected cells were subjected to whole genome sequencing. Clinical and laboratory variables were compared between patients with and without DENV co-infections.
RESULTS: Of the 290 NS1 positive serum samples, 280 were PCR positive for DENV. Medical notes of 262 patients were available for analysis. All 4 DENV serotypes were identified. Of the 262 patients, forty patients (15.3 %) had DENV co-infections: DENV-1/DENV-2(85 %), DENV-1/DENV-3 (12.5 %) and DENV-2/DENV-3 (2.5 %). Another 222 patients (84.7 %) were infected with single DENV serotype (mono-infection), with DENV- 1 (76.6 %) and DENV- 2 (19.8 %) predominating. Secondary dengue infections occurred in 31.3 % patients. Whole genome sequences of random samples representing DENV-1 and DENV-2 showed heterogeneity amongst the DENVs. Multivariate analysis revealed that pleural effusion and the presence of warning signs were significantly higher in the co-infected group, both in the overall and subgroup analysis. Diarrhoea was negatively associated with co-infection. Additionally, DENV-2 co-infected patients had higher frequency of patients with severe thrombocytopenia (platelet count < 50,000/mm(3)), whereas DENV-2 mono-infections presented more commonly with myalgia. Elevated creatinine levels were more frequent amongst the co-infected patients in univariate analysis. Haemoconcentration and haemorrhagic manifestations were not higher amongst the co-infected patients. Serotypes associated with severe dengue were: DENV-1 (n = 9), DENV-2 (n = 1), DENV-3 (n = 1) in mono-infected patients and DENV-1/DENV-2 (n = 5) and DENV-1/DENV-3 (n = 1) amongst the co-infected patients.
CONCLUSION: DENV co-infections are not uncommon in a hyperendemic region and co-infected patients are skewed towards more severe clinical manifestations compared to mono-infected patients.
METHODS: A retrospective study identifying all children aged
Methods: Each 24-well plate of Vero cells infected with all four DENV serotypes, singly, was subjected to treatments with various doses of AR-12. Following 48 h of incubation, inhibitory efficacies of AR-12 against the different DENV serotypes were evaluated by conducting a virus yield reduction assay whereby DENV RNA copy numbers present in the collected supernatant were quantified using qRT-PCR. The underlying mechanism(s) possibly involved in the compound's inhibitory activities were then investigated by performing molecular docking on several potential target human and DENV protein domains.
Results: The qRT-PCR data demonstrated that DENV-3 was most potently inhibited by AR-12, followed by DENV-1, DENV-2 and DENV-4. Our molecular docking findings suggested that AR-12 possibly exerted its inhibitory effects by interfering with the chaperone activities of heat shock proteins.
Conclusions: These results serve as vital information for the design of future studies involving in vitro mechanistic studies and animal models, aiming to decipher the potential of AR-12 as a potential therapeutic option for DENV infection.
METHODS: Active case detection and contact tracing were done at respective localities by house to house survey. Passive case detection was done among acute gastroenteritis patients attended at various health facilities. To determine the source, samples from food, water and environment were taken. A case control study was also done to determine the risk factors.
RESULTS: A total of 44 symptomatic and 34 asymptomatic cases from 19 localities were investigated. 39 cases were detected through passive case detection. Median age of cases was 23 years. All cases belonged to serogroup O1 and Ogawa serotype. The epidemiological investigation of time, place, and person identified that V. cholerae cross-transmission might have occurred in two fish markets and the fish-loading port. Circumstantial evidences indicated that cholera was possibly transmitted through contaminated sea foods.
CONCLUSIONS: We concluded that the life-style of Sea Gypsies is a challenge in cholera control; therefore vaccination might be an effective way to mitigate cholera in an outbreak prone area like Kudat.