Reviewer Acknowledgements: Bridging Science, Care, and Community – GHMJ (Global Health Management Journal), Volume 8, Number 2, 2025

Background and Aim:The coronavirus disease-19 (COVID-19) pandemic caused global economic and health problems. The pandemic increased the number of infectious diseases categorized as neglected diseases, such as staphylococcosis, which is caused by methicillin-resistant Staphylococcus aureus (MRSA). Celery is an herb that consist of antioxidants that can potentially act as antimicrobial agents. This study aimed to analyze the efficacy of celery alcoholic extract against systemic MRSA infections in rat models.Materials and Methods:In this study, 36 male, 6-month-old Sprague-Dawley rats (average weight: 300 g) were used as models. The rats were divided into six groups: Group K− (negative control), Group K+ (infected with MRSA without therapy), Group V (infected with MRSA+100 mg vancomycin per kg body weight [BW]), Group P1 (infected with MRSA+1 mg celery extract per kg BW), Group P2 (infected with MRSA+2 mg celery extract per kg BW), and Group P4 (infected with MRSA+4 mg celery extract per kg BW). The therapy was given once daily for 7 days. Blood and organs were taken on day 7 for hematology, serology, immunohistochemistry, and histopathology.Results:Results showed that 4 mg celery extract per kg BW promotes the healing of MRSA systemic infections in rat models (p≤0.05). The better prognosis was indicated by the normalization of red blood cell indices, white blood cell, neutrophil and lymphocyte counts, Cluster of differentiation 4+, Cluster of differentiation 8+, and Cyclooxygenase-2 expression and absence of severe tissue damage. Celery extracts inhibited MRSA growth in the blood samples.Conclusion:It can be concluded that celery alcoholic extract can potentially be used as an antimicrobial agent against systemic MRSA infections. A clinical study regarding the efficacy of celery extract must be conducted to ensure its potency against MRSA infections in humans.

The worldwide expansion of four serotypes of dengue virus (DENV) poses great risk to global public health. Several vaccine candidates are under development. However, none is yet available for humans. In the present study, a novel strategy to produce tetravalent DENV vaccine based on envelope protein domain III (EDIII) was proposed. Tandem EDIIIs of two serotypes (type 1–2 and type 3–4) of DENV connected by a Gly-Ser linker ((Gly4Ser)3) were expressed in E. coli, respectively. Then, the two bivalent recombinant EDIIIs were equally mixed to form the tetravalent vaccine candidate MixBiEDIII, and used to immunize BALB/c mice. The results showed that specific IgG and neutralizing antibodies against all four serotypes of DENV were successfully induced in the MixBiEDIII employing Freund adjuvant immunized mice. Furthermore, in the suckling mouse model, sera from mice immunized with MixBiEDIII provided significant protection against four serotypes of DENV challenge. Our data demonstrated that MixBiEDIII, as a novel form of subunit vaccine candidates, might have the potential to be further developed as a tetravalent dengue vaccine in the near future.

Hyperendemic circulation of all four Dengue virus (DENV) serotypes is a severe global public health problem, so any vaccine or therapeutics should be able to target all four of them. Cells of hemopoietic origin are believed to be primary sites of DENV replication. This study aimed to identify potential host miRNAs that target 3' UTR of all four DENV serotypes, thereby directly regulating viral gene expression or indirectly modulating the host system at different virus infection steps. We used four prediction algorithms viz. miRanda, RNA22, RNAhybrid and StarMir for predicting miRNA, targeting 3'UTR of all four DENV serotypes. Statistically, the most significant miRNA targets were screened based on their Log10 P-value (> 0.0001) of Gene Ontology (GO) term and Kyoto Encyclopaedia of Gene and Genome (KEGG) pathway enrichment analysis. The intersection test of at least three prediction tools identified a total of 30 miRNAs, which could bind to 3'UTR of all four DENV serotypes. Of the 30, eight miRNAs were of hematopoietic cell origin. GO term enrichment and KEGG analysis showed four hemopoietic origin miRNAs target genes of the biological processes mainly involved in the innate immune response, mRNA 3'-end processing, antigen processing and presentation and nuclear-transcribed mRNA catabolic process.

Competitive suppression of dengue viruses – Survival of the fittest

Dengue serotypes 1–4 exhibit unique host specificity in vitro Kelli L Barr, Benjamin D Anderson, Gary L Heil, John A Friary, Gregory C Gray, Dana A FocksDepartment of Environmental and Global Health, College of Public Health and Health Professions and the Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USABackground: Over 3000 cell lines from over 150 species are commercially available today from the American Type Culture Collection. These cell lines offer alternative approaches to investigating the interactions between arboviruses and other vertebrates at the cellular level. The various cell origins, types, and morphologies can be valuable resources for studying viral ecology and examining hypotheses regarding viral reservoirs. Dengue viruses (DENV) are major re-emerging pathogens that have been studied classically in only a few cell lines.Methods: We evaluated the susceptibility of 19 distinct mammalian, avian, and reptilian cell lines to DENV infection. Cell lines were infected with DENV serotypes 1–4 and evaluated for susceptibility via focus-forming unit assays and quantitative reverse-transcription polymerase chain reaction.Results: Both methods demonstrated the ability of DENV to replicate in 14 cell lines derived from various vertebrates with viral titers ranging from 1 × 103 to 1 × 107 infectious units per milliliter. Cell line susceptibility to DENV infection was serotype specific, with DENV-1 and DENV-4 infecting more cell lines than either DENV-2 or DENV-3. Cellular type also seemed to affect the infectivity of DENV. Human endothelial cells were only susceptible to DENV-4. Of six fibroblast lines, 100% were susceptible to at least one DENV serotype whereas only 62% of 13 epithelial lines were susceptible to DENV serotypes 1–4.Conclusion: These data indicate that a variety of cell lines from human and animal species can be used to culture DENV. The serotype-specific susceptibility for certain cell lines may provide a tool to help characterize specific DENV serotypes as well as an in vitro platform for the study of host–pathogen interactions and the co-circulation of DENV serotypes in a specific region or individual.Keywords: dengue virus, cell culture, host

Says who? Northern ventriloquism, or epistemic disobedience in global health scholarship

Dengue virus (DENV) has a serious and growing impact on global health and the exact role of DENV-specific CD8(+) T-cells in DENV infection is still uncertain. In the present study, SYFPEITHI algorithm was used to screen the amino acid sequence of Dengue virus serotype 1 (DENV-1) for potential epitopes, and seven putative HLA-A*1101-restricted and five putative HLA-A*2402-restricted epitopes conserved in hundreds of DENV-1 strains were synthesized. The binding affinity of these epitope candidates to corresponding HLA molecules was evaluated using competitive peptide-binding assay. The immunogenicity and specificity of peptides were further tested in HLA-A*1101 transgenic mice, HLA-A*2402 transgenic mice and peripheral blood mononuclear cells (PBMCs) of patients infected with DENV-1. Percentage inhibition (PI) values calculated in competitive peptide-binding assay showed that six peptides (E39-47 PTLDIELLK, NS5(505-513) GVEGEGLHK, NS2b(15-23) SILLSSLLK, NS5(561-569) ALLATSIFK, NS3(99-107) AVEPGKNPK, and NS4b(159-167) VVYDAKFEK) could bind to HLA-A*1101 molecule with high affinity and five peptides (NS3472-480 QYIYMGQPL, NS4a40-48 AYRHAMEEL, NS5(880-888) DYMTSMKRF, NS3(548-556) SYKVASEGF, and NS3(22-30) IYRILQRGL) have a high affinity for HLA-A*2402 molecule. Enzyme-linked immunospot (ELISPOT) results indicated that these high-affinity peptides were recognized by splenocytes of DENV-1-infected transgenic mice and high-affinity peptide-immunized transgenic mice displayed high levels of peptide-specific IFN-γ-secreting cells. In addition, both peptide-pulsed splenocytes and DENV-1-infected splenic monocytes were efficiently killed by these peptide-specific cytotoxic T lymphocytes. Finally, except NS2b(15-23), 10 high-affinity peptides were recognized by PBMCs of patients infected with DENV-1. These identified epitopes would contribute to the understanding of the function of DENV-specific CD8(+) T-cells.

Over the past few decades, dengue fever has emerged as a significant global health threat, affecting tropical and moderate climate regions. Current vaccines have practical limitations, there is a strong need for safer, more effective options. This study introduces novel vaccine candidates covering all four dengue virus (DENV) serotypes using virus-like particles (VLPs), a proven vaccine platform. The dengue virus envelope protein domain III (EDIII), the primary target of DENV-neutralizing antibodies, was either genetically fused or chemically coupled to bacteriophage-derived AP205-VLPs. To facilitate the incorporation of the large EDIII domain, AP205 monomers were dimerized, resulting in sterically optimized VLPs with 90 N- and C-termini. These vaccines induced high-affinity/avidity antibody titers in mice, and confirmed their protective potential by neutralizing different DENV serotypes in vitro. Administration of a tetravalent vaccine induced high neutralizing titers against all four serotypes without producing enhancing antibodies, at least not against DENV2. In conclusion, the vaccine candidates, especially when administered in a combined fashion, exhibit intriguing properties for potential use in the field, and exploring the possibility of conducting a preclinical challenge model to verify protection would be a logical next step.

Designing of a multiepitope-based chimeric vaccine against dengue virus serotype 3 (DENV-3) through next generation reverse vaccinology approaches

The spread of dengue disease has become a global public health concern. Dengue is caused by dengue virus, which is a mosquito-borne arbovirus of the genus Flavivirus, family Flaviviridae. There are four dengue virus serotypes (1-4), each of which is known to trigger mild to severe disease. Dengue virus serotype 4 (DENV-4) has four genotypes and is increasingly being reported to be re-emerging in various parts of the world. Therefore, the population structure and factors shaping the evolution of DENV-4 strains across the world were studied using genome-based population genetic, phylogenetic and selection pressure analysis methods. The population genomics study helped to reveal the spatiotemporal structure of the DENV-4 population and its primary division into two spatially distinct clusters: American and Asian. These spatial clusters show further time-dependent subdivisions within genotypes I and II. Thus, the DENV-4 population is observed to be stratified into eight genetically distinct lineages, two of which are formed by American strains and six of which are formed by Asian strains. Episodic positive selection was observed in the structural (E) and non-structural (NS2A and NS3) genes, which appears to be responsible for diversification of Asian lineages in general and that of modern lineages of genotype I and II in particular. In summary, the global DENV-4 population is stratified into eight genetically distinct lineages, in a spatiotemporal manner with limited recombination. The significant role of adaptive evolution in causing diversification of DENV-4 lineages is discussed. The evolution of DENV-4 appears to be governed by interplay between spatiotemporal distribution, episodic positive selection and intra/inter-genotype recombination.

Dengue has been well recognized as a global public health threat, but only sporadic epidemics and imported cases were reported in recent decades in China. Since July 2014, an unexpected large dengue outbreak has occurred in Guangdong province, China, resulting in more than 40000 patients including six deaths. To clarify and characterize the causative agent of this outbreak, the acute phase serum from a patient diagnosed with severe dengue was subjected to virus isolation and high-throughput sequencing (HTS). Traditional real-time RT-PCR and HTS with Ion Torrent PGM detected the presence of dengue virus serotype 2 (DENV-2). A clinical DENV-2 isolate GZ05/2014 was obtained by culturing the patient serum in mosquito C6/36 cells. The complete genome of GZ05/2014 was determined and deposited in GenBank under the access number KP012546. Phylogenetic analysis based on the complete envelope gene showed that the newly DENV-2 isolate belonged to Cosmopolitan genotype and clustered closely with other Guangdong strains isolated in the past decade. No amino acid mutations that are obviously known to increase virulence or replication were identified throughout the genome of GZ05/2014. The high homology of Guangdong DENV-2 strains indicated the possibility of establishment of local DENV-2 circulation in Guangdong, China. These results help clarify the origin of this epidemic and predict the future status of dengue in China.Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s11427-014-4782-3 and is accessible for authorized users.

Decision letter: A pH-dependent cluster of charges in a conserved cryptic pocket on flaviviral envelopes

Purposes: Dengue fever, a mosquito-borne viral disease, is a global public health burden affecting millions of people each year and over 40% of world populations are at risk of dengue. Therefore, prompt and accurate dengue diagnosis is inevitable for disease surveillance and for aiding disease management. In this study we report dengue virus (DENV) seroprevalence in Chittagong, Bangladesh along with clinical manifestation of dengue infections. Methods: All samples included in this study were selected based on dengue NS1-based diagnosis, clinical sign and symptoms were judged by expert clinical physicians and infecting DENV serotyping was done by RT-PCR. The blood cells (Platelet, Haematocrit, WBC etc) were analyzed using Haematology cell counter. Results: First, among the 112 DENV infected serum samples tested by RT-PCR, 42 were DENV positive where 76% samples had single DENV serotype infection and 24% were concurrently infected with two or more DENV serotypes, indicating that all four DENVs were present in a single dengue session in Chittagong, Bangladesh. Then, DENV4 was the most prevailed serotype, followed by DENV2, DENV1 and DENV3 in single DENV serotype infections. However, in almost 90% cases of concurrent multiple DENV infections DENV1 serotype was present. A detail analysis of clinical data clearly indicated that DENV1 and DENV2 resulted very similar patterns of clinical symptoms which were quite different from those caused by DENV3 and DENV4. For example, ache and pain were absent in DENV3 infection and diarrhea was absent in DENV4 infections. Furthermore, DENV3, both in single and concurrent multiple DENV infections, might increase dengue disease severity as observed highly reduced platelet counts along with increased WBC in patients infected with DENV3 serotype. Conclusion: All four DENV serotypes, both as single and concurrent multiple DENV infections, were present in single dengue session in Bangladesh. Despite having very similar sequences and structures all four DENVs might produce different disease spectra, ranging from classical dengue fever to dengue hemorrhagic fever. Concurrent multiple DENV infections could contribute increased dengue disease severity in dengue outbreaks in Bangladesh. Bioresearch Commu. 8(1): 1042-1048, 2022 (January)

The four serotypes of dengue virus (DENV 1-4) have a significant and growing impact on global health. Dengue disease encompasses a wide range of clinical symptoms, usually presenting as an uncomplicated febrile illness lasting 5-7 days; however, a small percentage of infections are associated with plasma leakage and bleeding tendency (called dengue hemorrhagic fever, DHF), which can result in shock. Epidemiological studies indicate that severe dengue disease most often occurs during secondary heterotypic DENV infection. Additionally, plasma leakage (the hallmark of DHF) coincides with defervescence and viral clearance, suggesting that severe disease arises from the immune response to infection rather than a direct effect of the virus. A number of studies have found increased levels of markers of immune cell activation in patients with DHF compared to patients with the less severe form of disease (DF). These markers include IFNγ, TNFα, soluble CD8, soluble IL-2 receptor, soluble TNF receptor, and CD69, which support a role for T cells in mediating immunopathology. Because of the high homology of DENV 1-4, some degree of serotype-cross-reactivity is seen for most T cell epitopes. A high percentage of DENVspecific T cells recognize multiple DENV serotypes, as demonstrated by peptide-MHC (pMHC) tetramer binding and in vitro functional assays performed on PBMC from subjects vaccinated with an experimental DENV vaccine or naturally-infected subjects with secondary (>1) DENV infection.

Spectrum of activity testing for therapeutics against all four dengue virus serotypes in AG129 mouse models: Proof-of-concept studies with the adenosine nucleoside inhibitor NITD-008