ABSTRACT
Objective: To identify unique immunogenic epitopes of Zika virus non-structural 1 (NS1) antigen and produce immunoglobulin Y (IgY) for potential use in he diagnosis of of Zika virus infection. Methods: Immunogenic epitopes were identified using in silico B-cell epitope prediction. A synthetic peptide analog of the predicted epitope was used to induce antipeptide IgY production in hens which was purified using affinity chromatography. Presence of purified IgY and its binding specificity were performed by gel electrophoresis and ELISA, respectively. Results: Out of the nine continuous epitopes identified, the sequence at position 193-208 (LKVREDYSLECDPAVI) was selected and used to produce anti-peptide IgY. The produced IgY was found to bind to the synthetic analog of the Zika virus NS1 immunogenic epitope but not to other flaviviruses and random peptides from other pathogens. Conclusions: In this study, we identified an immunogenic epitope unique to Zika virus that can be used to develop a serodiagnostic tool that specifically detect Zika virus infection.
ABSTRACT
Objective: To identify unique immunogenic epitopes of Zika virus non-structural 1 (NS1) antigen and produce immunoglobulin Y (IgY) for potential use in he diagnosis of of Zika virus infection. Methods: Immunogenic epitopes were identified using in silico B-cell epitope prediction. A synthetic peptide analog of the predicted epitope was used to induce antipeptide IgY production in hens which was purified using affinity chromatography. Presence of purified IgY and its binding specificity were performed by gel electrophoresis and ELISA, respectively. Results: Out of the nine continuous epitopes identified, the sequence at position 193-208 (LKVREDYSLECDPAVI) was selected and used to produce anti-peptide IgY. The produced IgY was found to bind to the synthetic analog of the Zika virus NS1 immunogenic epitope but not to other flaviviruses and random peptides from other pathogens. Conclusions: In this study, we identified an immunogenic epitope unique to Zika virus that can be used to develop a serodiagnostic tool that specifically detect Zika virus infection.
ABSTRACT
Background@#Human Pegivirus (HPgV), previously called Hepatitis G virus or GB virus C, is an RNA virus. It can be transmitted vertically (mother to infant), parenterally and sexually. HPgV share common routes of transmission to other viruses such as Hepatitis B virus, Hepatitis C virus and Human Immunodeficiency virus (HIV) thus co-infection is usually observed. Risk groups of HPgV include injection drug users, HIV-positive individuals, multi-transfused patients, hemodialysis patients, hemophiliacs, chronic liver disease patients and organ transplant recipients. The clinical significance of HPgV is not yet established and warrants further studies. Research on HPgV in the Philippines is scarce and has not been updated for over 10 years. There is no published data on HPgV prevalence in Filipino pediatric population specifically among risk groups like multi-transfused children with decompensated liver disease secondary to biliary cirrhosis and liver transplant pediatric patients. The lack of local data warrants conduct of this study. @*Objective@#To determine the presence of HPgV RNA, HPgV E2 antibody (anti-E2) and HBsAg among Filipino children with decompensated liver disease secondary to biliary cirrhosis (DBC) and liver transplant pediatric patients (LTP).@*Methods@#Included were 15 children with DBC and 15 LTP recruited from the Section of Pediatric Gastroenterology, Hepatology and Nutrition of the UP PGH. All patients’ sera were tested for HPgV RNA by Real Time RT-PCR, HPgV anti-E2 by Enzyme-linked Immunosorbent Assay (ELISA) and hepatitis B surface antigen (HBsAg) by immunochromatographic test. Twenty age and sex matched children with no history of liver disease and blood transfusion served as controls. @*Results@#All patient and control samples were negative for HPgV RNA. HPgV anti-E2 was detected in 6 of 15 LTP, 5 of 15 DBC and 1 of 20 controls. HBsAg was detected in 2 of 15 LTP, 5 of 15 DBC and 0 of 20 controls. Four patients (two LTP, two DBC) were positive for both HPgV anti-E2 and HBsAg. @*Conclusion@#This study showed that a proportion of liver transplant patients and those with decompensated biliary cirrhosis are positive for HPgV anti-E2, which indicates that these individuals previously had HPgV infection but is now resolved. Possible source of infection is infected blood from the blood transfusions, infected transplant organ or infected mother. Since routine HPgV screening is not yet recommended for the general population, blood donors and organ donors, the confirmation of exact source of infection may be difficult. Co-infection with HBsAg was also observed in both risk groups which suggests that at some point in time, these children were infected by both HPgV and HBV and also the possibility of simultaneous infection by the two viruses. This study provides preliminary data on the proportion of HPgV infection in Filipino children belonging to two of the HPgV risk groups. Studies with a larger and more significant sample size to determine HPgV prevalence as well as studies regarding the pathogenicity of HPgV are warranted. As this may provide basis for routine HPgV screening among risk groups and blood donations in the future.
Subject(s)
GB virus CABSTRACT
@#<p><strong>Background and Objective:</strong> Microorganisms, including bacteria, serve as major players in various processes affecting both the quality of aquatic sediment as well as the fate of pollutants released into such matrix. This study, evaluated the similarity in bacterial community structure between sediments collected from aquaculture and non aquaculture sites of a tropical lake. Describing and comparing the bacterial community present in each site may provide clues on the impact of aquaculture practices on aquatic ecosystems.<br /><strong>Methodology:</strong> Microbial DNA was extracted using PowerSoil® DNA Isolation Kit for all sediment samples. DNA isolates were used as template in the analysis of the hypervariable region of 16S rDNA through nested polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE). Excised representative 16S rDNA DGGE bands were sequenced and identified through BLAST analysis.<br /><strong>Results:</strong> Based on the generated mean Dice similarity coefficient of 57.77%, the bacterial community structure between aquaculture and non-aquaculture sediments was highly similar but certain taxa were found unique for each site. Bacteria belonging to Proteobacteria and Firmicutes dominated the aquaculture sediments while Proteobacteria, Firmicutes, and Chloroflexi dominated the non-aquaculture sediments. Certain physicochemical parameters operating in the two sites may have influenced the shift in representative microbes. Shewanella baltica and Trichococcus sp. were found only in aquaculture sediment owing to their ability to tolerate quantities of ammonia and high organic matter from their environment.<br /><strong>Conclusions:</strong> This study described the applicability of 16S rDNA PCR-DGGE as a culture-independent technique for describing and comparing the similarity between bacterial communities in sediment. Based on the generated similarity index, the bacterial community between aquaculture and non-aquaculture sediments of Taal Lake was highly similar but interestingly, harbored unique bacterial populations as seen in the DGGE profiles. The shift in dominant taxa and unique representatives per site may have been influenced by certain differences between each site's physico-chemical parameters.</p>
Subject(s)
AquacultureABSTRACT
Objective@#This study aimed to determine the antiviral activity of ten Philippine medicinal plants against Zika virus (ZIKV).@*Methods@#Lyophilized aqueous plant extracts were used for cell cytotoxicity and virus inhibition assays. The therapeutic index was computed from the 50% cytotoxic concentration (CC50) and 50% effective concentration (EC50) values. Plant metabolites were also identified using mass spectroscopy. An in-silico screening of these metabolites was done using ZIKV enzymes and the Axl protein in human microglial cells as target proteins, followed by the ranking of binding energy scores to generate a hypothesis on the possible mechanism of antiviral action.@*Results@#The plants that demonstrated the highest therapeutic index were Momordica charantia, Psidium guajava, Vitex negundo, and Blumea balsamifera. The majority of the metabolites present in the aqueous extracts were saponin, terpenes and terpenoids, and anthocyanin. Further, in-silico docking results showed a higher binding affinity for viral replication proteins compared to the viral envelope protein.@*Conclusion@#The crude aqueous extracts of M. charantia, P. guajava, V. negundo, and B. balsamifera were the most potent candidate antiviral therapies against ZIKV among the ten plants tested. Meanwhile, the in-silico results suggested that the metabolites possibly employ an intracellular mechanism for the observed antiviral activity.