Introduction. Several studies have been conducted on the use of Immunoglobulin Y (IgY) technology in the fields of diagnostics and therapeutics. IgY is the avian counterpart of the mammalian immunoglobulin G (IgG) which is exclusively transferred from the hen to the yolk thus conferring passive immunization to the growing embryo. However, despite the advantages it offers over the use of mammalian immunoglobulin, IgY technology has remained underutilized. Objective. The objective of this study is to produce an IgY with activity against synthetic peptide analogs of known immunogenic epitopes of the Hepatitis B Surface Antigen (HBsAg) - a molecular marker of Hepatitis B infection. Methods. Chickens were immunized with synthetic peptide analogs of previously reported immunogenic epitopes of the S and the pre-S1 regions of the Hepatitis B surface antigen (HBsAg). IgY specific for the synthetic peptides was isolated by delipidation and salt precipitation and was further purified by affinity chromatography. Purity and molecular weights of the whole IgY molecule and its subunits were assessed and determined by SDS-PAGE. Anti-peptide activity and specificity were determined by indirect ELISA. The study was approved by the Ethical Review Board (ERB) and Technical Review Board of the Research Implementation and Development Office (RIDO), University of the Philippines Manila. Results and Conclusion. The IgY that was purified in this study had an approximate molecular weight of 165 kilodaltons. The heavy and light chains are 60 and 28 kilodaltons, respectively. The affinity purified IgY demonstrated anti-peptide antibody activity against synthetic peptide analogs of known immunogenic epitopes of the HBsAg. Specific binding against a battery of synthetic peptides also revealed that the affinity purified IgY specifically binds to the known immunogenic epitope of the HBsAg.
HEPATITIS B SURFACE ANTIGENS ; HEPATITIS B ANTIGENS ; HEPATITIS B VIRUS ; IGY

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.
GB virus C

Background and Objective: 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.
Methodology: 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.
Results: 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.
Conclusions: 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.

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.
Herbal Medicine

Background: Virgin coconut oil (VCO) has anti-viral and anti-inflammatory properties, making it a potential therapeutic candidate against COVID-19 infection. Objective: To determine the efficacy and safety of VCO as adjunctive therapy for hospitalized patients with COVID-19. Methods: We conducted a randomized, open-label controlled trial involving laboratory-confirmed COVID-19 patients admitted at the Philippine General Hospital. The study participants were randomized to the intervention group who received virgin coconut oil with local standard of care, or to the control group who received local standard of care alone. Results: We enrolled 39 participants into the VCO group and 38 participants into the control group. Significantly fewer participants in the VCO group had abnormal CRP levels at the end of treatment compared to control. (relative risk [RR] 0.75, 95% confidence interval [CI] 0.58 to 0.95; p=0.02) No significant difference was found in the duration of hospital stay (mean 9.33 days for VCO vs. 10.29 days for control; p=0.45) and time to symptom resolution (mean 6.8 days for VCO, vs. 6.74 days for control; p=0.91). Although the proportion of patients who developed the secondary outcomes of mortality, need for ICU admission, need for invasive ventilation, and negative viral conversion was lower in the VCO group, results did not reach statistical significance. The VCO group had larger reduction in the inflammatory markers ferritin, lactate dehydrogenase, TNF-alpha, IP-10 and IL-6, but results did not reach statistical significance. Adverse events were significantly higher in the VCO group (RR 4.87, 95% CI 1.14 to 20.79; p=0.03). Conclusion This clinical trial on hospitalized patients showed significant benefit in CRP levels of participants given VCO compared to control. There was no significant benefit in the use of VCO as adjunctive therapy in reducing duration of hospital stay. Larger studies are needed to conclusively demonstrate the effect of VCO on other clinical outcomes and inflammatory markers.
COVID-19 ; Clinical Trial

BACKGROUND

Allergic respiratory diseases are prevalent in the Philippines, with allergic rhinitis and asthma occurring at 20% and 8.7% of the population, respectively. The diagnosis of respiratory allergies is achieved by a combination of patient history and different screening tools, especially for the identificati on of the allergic triggers such as allergy skin prick test (SPT) and serum-specific IgE enzyme-linked immunosorbent assays (sIgE ELISA). The Philippines, being a tropical country, have a wide variety of plant species with potential to produce allergenic pollen grains. Knowledge of the sensitization profiles of Filipino allergic patients to our local pollen allergens is currently limited.

The aim of this study is to determine the sensitization profile of patients with respiratory allergies (allergic rhinitis and/or asthma) through the allergy skin prick test (SPT) using allergenic local pollen extracts. It also aimed to determine if there is a positive agreement between the SPT and sIgE ELISA positivity rate and whether the results have relationship with the pollen purity and the protein content of the extracts.

Pollen allergens were extracted from Amaranthus spinosus (pigweed), Mimosa pudica (makahiya), Tridax procumbens (wild daisy), Imperata cylindrica (cogon), Oryza sativa (rice), Pennisetum polystachion (foxtail grass), Sorghum halepense (Johnson grass), Albizia saman (acacia), Cocos nucifera (coconut), Leucaena leucocephala (ipil-ipil), and Mangifera indica (mango). SPT was performed at the Allergy Clinic of the University of the Philippines-Philippine General Hospital on patients with allergic rhinitis and/or bronchial asthma. Blood samples were collected from patients who developed wheal diameters of 3 mm or more than the negative control. Sera were tested against the same pollen extracts using ELISA.

Of the one hundred sixty-five (165) patients who submitted for skin prick test, 129 showed positive SPT results to the pollen extracts. Weeds were the most sensitizing (51.9%-58.1%). Blood samples were collected from these patients and tested for sIgE ELISA and among them, 71 were positive in the sIgE ELISA. Highest sensitization rates in sIgE ELISA were found in coconut, pigweed, Johnson grass, and rice. The highest positive agreements or the proportion of patients with positive sIgE ELISA among those with positive SPT were in coconut, followed by Johnson grass, pigweed, and rice. Most of the pollen sensitized patients on SPT are polysensitized.

SPT is a safe, simple, and rapid method for the diagnosis of IgE-mediated allergy. The lower number of positive patients in sIgE ELISA may be attributed to the low serum IgE levels and low quantities of effectual allergen components in extracts. Results of both SPT and ELISA must be correlated with a patient's clinical history, particularly the patient’s exposures, and physical examination.

COVID-19 has turned into a protracted emergency to Philippine urban populations. The pandemic can be an opportunity for the country to strengthen surveillance capacity through wastewater-based epidemiology for COVID-19 and antimicrobial resistance. This capacity can translate to detection and monitoring for other emerging infectious diseases.

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.