Anti-Malassezia globosa (MYA-4889, ATCC) activity of Thai propolis from the stingless bee Geniotrigona thoracica.

Malassezia globosa, a lipophilic pathogen, is known to be involved in various chronic skin diseases. Unfortunately, the available treatments have unwanted side effects and microbial drug resistance is evolving. As the antimicrobial activity of propolis is outstanding, this study aimed to examine the potential of propolis from the stingless bee Geniotrigona thoracica against the yeast. Anti-M. globosa growth activity was ascertained in agar well diffusion and broth microdilution assays and the inhibitory concentration value at 50 % (IC50) was determined. Since the yeast cannot synthesize its own fatty acids, extracellular lipase is important for its survival. Here, anti-M. globosa extracellular lipase activity was additionally investigated by colorimetric and agar-based methods. Compared to the crude hexane and crude dichloromethane extracts, the crude methanol partitioned extract (CMPE) exhibited the best anti-M. globosa growth activity with an IC50 of 1.22 mg/mL. After CMPE was further enriched by silica gel column chromatography, fraction CMPE1 (IC50 of 0.98 mM or 184.93 µg/mL) presented the highest activity and was later identified as methyl gallate (MG) by nuclear magnetic resonance analysis. Subsequently, MG was successfully synthesized and shown to have a similar activity, and a minimal fungicidal concentration of 43.44 mM or 8.00 mg/mL. However, lipase assay analysis suggested that extracellular lipase might not be the main target mechanism of MG. This is the first report of MG as a new anti-Malassezia compound. It could be a good candidate for further developing alternative therapeutic agents.

Nucleic Acid-Templated Synthesis of Cationic Styryl Dyes in Vitro and in Living Cells.

A novel method for synthesizing cationic styryl dyes through a nucleic acid-templated reaction has been developed. This approach overcomes issues associated with traditional synthesis methods, such as harsh conditions, low throughput, and wasteful chemicals. The presence of a nucleic acid template accelerated the styryl dye formation from quaternized heteroaromatic and cationic aldehyde substrates. These styryl dyes show remarkable optical properties change when bound to nucleic acids, hence the success of the synthesis could be readily monitored in situ by UV-Vis and fluorescence spectroscopy and the optical properties data were also observable at the same time. This method provides the desired products from a broad range of coupling partners. By employing different substrates and templates, it is possible to identify new dyes that can bind to a specific type of nucleic acid such as a G-quadruplex. The templated dye synthesis is also successfully demonstrated in live HeLa cells. This approach is a powerful tool for the rapid synthesis and screening of dyes specific for diverse types of nucleic acids or cellular organelles, facilitating new biological discoveries.

Paper-based electrochemical immunosensor for highly sensitive detection of chicken anemia virus.

Chicken anemia virus (CAV) is one of the primary causes of morbidity and mortality in young chickens. Given the importance of timely detection for maintaining livestock quality, there is a pressing need for rapid and field-deployable diagnostic tools. This study introduces a highly sensitive paper-based electrochemical immunosensor (PEI) for the detection of the 60 amino acid N-terminally truncated viral protein 1 (Δ60VP1), a derivative of the CAV capsid (VP1). A custom antibody was produced for precise immunoassay detection, with results obtainable within 30 min using Square Wave Voltammetry (SWV). The underlying mechanism involves an immunocomplex in the sample zone that hinders the electron transfer of redox species, thereby reducing the current signal in proportion to the Δ60VP1 concentration. Under optimal conditions, the detection linearity for Δ60VP1 ranged from 80 to 2500 ng/mL, with a limit of detection (LoD) of 25 ng/mL. This device was then successfully applied to detect VP1 in 29 chicken serum samples, achieving 91.6% sensitivity and 94.1% selectivity. In conclusion, the PEI device presents a promising solution for rapid, sensitive, and disposable detection of chicken pathogens, potentially revolutionizing productivity and quality assurance in chicken farming.

Development of a lateral flow assay for rapid and accurate detection of chicken anemia virus.

Significant challenges to poultry health are posed by chicken anemia virus (CAV), which induces immunosuppression and causes increased susceptibility to secondary infections. The effective management and containment of CAV within poultry stocks require precise and prompt diagnosis. However, a deficiency persists in the availability of low-cost, rapid, and portable CAV detection devices. In this study, an immunochromatographic lateral-flow test strip-based assay was developed for CAV detection using in-house generated monoclonal antibodies (MABs) against CAV viral protein 1 (VP1). The recombinant truncated VP1 protein (Δ60VP1), with amino acid residues 1 to 60 of the native protein deleted, was produced via a prokaryotic expression system and utilized for immunizing BALB/c mice. Subsequently, high-affinity MABs against Δ60VP1 were generated and screened using conventional hybridoma technology combined with serial dilution assays. Two MABs, MAB1, and MAB3, both binding to distinct epitopes of Δ60VP1, were selected for the development of a lateral-flow assay. Sensitivity analysis demonstrated that the Δ60VP1 antigen could be detected by our homemade lateral-flow assay at concentrations as low as 625 ng/mL, and this sensitivity was maintained for at least 6 mo. The assay exhibited high specificity, as evidenced by its lack of reactivity with surrogate recombinant proteins and the absence of cross-reactivity with other chicken viruses and viral antigens. Comparative analysis with quantitative PCR data demonstrated substantial agreement, with a Kappa coefficient of 0.66, utilizing a sample set comprising 305 clinical chicken serum samples. In conclusion, the first lateral-flow assay for CAV detection was developed in this study, utilizing 2 specific anti-VP1 MABs. It is characterized by simplicity, rapidity, sensitivity, and specificity.

Strain Variation Can Significantly Modulate the miRNA Response to Zika Virus Infection.

Zika virus (ZIKV) is a mosquito-transmitted virus that has emerged as a major public health concern due to its association with neurological disorders in humans, including microcephaly in fetuses. ZIKV infection has been shown to alter the miRNA profile in host cells, and these changes can contain elements that are proviral, while others can be antiviral in action. In this study, the expression of 22 miRNAs in human A549 cells infected with two different ZIKV isolates was investigated. All of the investigated miRNAs showed significant changes in expression at at least one time point examined. Markedly, 18 of the miRNAs examined showed statistically significant differences in expression between the two strains examined. Four miRNAs (miR-21, miR-34a, miR-128 and miR-155) were subsequently selected for further investigation. These four miRNAs were shown to modulate antiviral effects against ZIKV, as downregulation of their expression through anti-miRNA oligonucleotides resulted in increased virus production, whereas their overexpression through miRNA mimics reduced virus production. However, statistically significant changes were again seen when comparing the two strains investigated. Lastly, candidate targets of the miRNAs miR-34a and miR-128 were examined at the level of the mRNA and protein. HSP70 was identified as a target of miR-34a, but, again, the effects were strain type-specific. The two ZIKV strains used in this study differ by only nine amino acids, and the results highlight that consideration must be given to strain type variation when examining the roles of miRNAs in ZIKV, and probably other virus infections.

Understanding the role of galectins toward influenza A virus infection.

INTRODUCTION: Influenza A virus (IAV) is highly contagious and causes respiratory diseases in birds, mammals, and humans. Some strains of IAV, whether from human or avian sources, have developed resistance to existing antiviral drugs. Therefore, the discovery of new influenza antiviral drugs and therapeutic approaches is crucial. Recent studies have shown that galectins (Gal), a group of ß-galactose-binding lectins, play a role in regulating various viral infections, including IAVs. AREAS COVERED: This review provides an overview of the roles of different galectins in IAV infection. We discuss the characteristics of galectins, their impact on IAV infection and spread, and highlight their positive or negative regulatory functions and potential mechanisms during IAV infection. Furthermore, we explore the potential application of galectins in IAV therapy. EXPERT OPINION: Galectins were first identified in the mid-1970s, and currently, 15 mammalian galectins have been identified. While all galectin members possess the carbohydrate recognition domain (CRD) that interacts with ß-galactoside, their regulatory functions vary in different DNA or RNA virus infections. Certain galectin members have been found to regulate IAV infection through diverse mechanisms. Therefore, a comprehensive understanding of their roles in IAV infection is essential, as it may pave the way for novel therapeutic strategies.

Development of a plastic waste treatment process by combining deep eutectic solvent (DES) pretreatment and bioaugmentation with a plastic-degrading bacterial consortium.

Polyethylene terephthalate (PET), a petroleum-based plastic, and polylactic acid (PLA), a biobased plastic, have a similar visual appearance thus they usually end up in municipal waste treatment facilities. The objective of this project was to develop an effective PET and PLA waste treatment process that involves pretreatment with deep eutectic solvent (DES) followed by biodegradation with a plastic-degrading bacterial consortium in a composting system. The DES used was a mixture of choline chloride and glycerol, while the bacterial strains (Chitinophaga jiangningensis EA02, Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, Achromobacter xylosoxidans A9 and Mycolicibacterium parafortuitum J101) used to prepare the bacterial consortium were selected based on their ability to biodegrade PET, PLA, and plasticizer. The plastic samples (a PET bottle, PLA cup, and PLA film) were pretreated with DES through a dip-coating method. The DES-coated plastic samples exhibited higher surface wettability and biofilm formation, indicating that DES increases the hydrophilicity of the plastic and facilitates bacterial attachment to the plastic surface. The combined action of DES pretreatment and bioaugmentation with a plastic-degrading bacterial consortium led to improved degradation of PET and PLA samples in various environments, including aqueous media at ambient temperature, lab-scale traditional composting, and pilot-scale composting.

Dengue overview: An updated systemic review.

Dengue is caused by the dengue virus (DENVs) infection and clinical manifestations include dengue fever (DF), dengue hemorrhagic fever (DHF), or dengue shock syndrome (DSS). Due to a lack of antiviral drugs and effective vaccines, several therapeutic and control strategies have been proposed. A systemic literature review was conducted according to PRISMA guidelines to select proper references to give an overview of DENV infection. Results indicate that understanding the virus characteristics and epidemiology are essential to gain the basic and clinical knowledge as well as dengue disseminated pattern and status. Different factors and mechanisms are thought to be involved in the presentation of DHF and DSS, including antibody-dependent enhancement, immune dysregulation, viral virulence, host genetic susceptibility, and preexisting dengue antibodies. This study suggests that dissecting pathogenesis and risk factors as well as developing different types of therapeutic and control strategies against DENV infection are urgently needed.

Bioaugmentation with a defined bacterial consortium: A key to degrade high molecular weight polylactic acid during traditional composting.

Polylactic acid (PLA) is commercialized as a compostable bio-thermoplastic. PLA degrades under industrial composting conditions where elevated temperatures are maintained for a long timeframe. However, these conditions cannot be achieved in a non-industrial compost pile. Therefore, this study aims to degrade high molecular weight PLA films by adding a PLA-degrading bacterial consortium (EAc) comprised of Nocardioides zeae EA12, Stenotrophomonas pavanii EA33, Gordonia desulfuricans EA63, and Chitinophaga jiangningensis EA02 during traditional composting. With EAc-bioaugmentation, PLA films (5-30% w/w) had complete disintegration (35 d), 77-82% molecular weight reduction (16 d), and higher CO2 liberation and mineralization than non-bioaugmented composting. Bacterial community analyses showed that EAc-bioaugmentation increased the relative abundance of Schlegelella, a known polymer degrader, and interacted positively with beneficial indigenous microbes like Bacillus, Schlegelella and Thermopolyspora. The bioaugmentation also decreased compost phytotoxicity. Hence, consortium EAc shows potential in PLA-waste treatment applications, such as backyard and small-scale composting.

Simultaneous Production of a Virus-Like Particle Linked to dsRNA to Enhance dsRNA Delivery for Yellow Head Virus Inhibition.

A co-expressed Penaeus stylirostris densovirus (PstDNV) capsid and dsRNA specific to the yellow head virus (YHV) protease (CoEx cpPstDNV/dspro) has been shown to suppress YHV replication in the Pacific white-legged shrimp (Litopenaeus vannamei). However, maintaining two plasmids in a single bacterial cell is not desirable; therefore, a single plasmid harboring both the PstDNV capsid and the dsRNA-YHV-pro gene was constructed under the regulation of a single T7 promoter, designated pET28a-Linked cpPstDNV-dspro. Following induction, this novel construct expressed an approximately 37-kDa recombinant protein associated with a roughly 400-bp dsRNA (Linked cpPstDNV-dspro). Under a transmission electron microscope, the virus-like particles (VLP; Linked PstDNV VLPs-dspro) obtained were seen to be monodispersed, similar to the native PstDNV virion. A nuclease digestion assay indicated dsRNA molecules were both encapsulated and present outside the Linked PstDNV VLPs-dspro. In addition, the amount of dsRNA produced from this strategy was higher than that obtained with a co-expression strategy. In a YHV infection challenge, the Linked PstDNV VLPs-dspro was more effective in delaying and reducing mortality than other constructs tested. Lastly, the linked construct provides protection for the dsRNA cargo from nucleolytic enzymes present in the shrimp hemolymph. This is the first report of a VLP carrying virus-inhibiting dsRNA that could be produced without disassembly and reassembly to control virus infection in shrimp.

Boosting the detection performance of severe acute respiratory syndrome coronavirus 2 test through a sensitive optical biosensor with new superior antibody.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus emerged in late 2019 leading to the COVID-19 disease pandemic that triggered socioeconomic turmoil worldwide. A precise, prompt, and affordable diagnostic assay is essential for the detection of SARS-CoV-2 as well as its variants. Antibody against SARS-CoV-2 spike (S) protein was reported as a suitable strategy for therapy and diagnosis of COVID-19. We, therefore, developed a quick and precise phase-sensitive surface plasmon resonance (PS-SPR) biosensor integrated with a novel generated anti-S monoclonal antibody (S-mAb). Our results indicated that the newly generated S-mAb could detect the original SARS-CoV-2 strain along with its variants. In addition, a SARS-CoV-2 pseudovirus, which could be processed in BSL-2 facility was generated for evaluation of sensitivity and specificity of the assays including PS-SPR, homemade target-captured ELISA, spike rapid antigen test (SRAT), and quantitative reverse transcription polymerase chain reaction (qRT-PCR). Experimentally, PS-SPR exerted high sensitivity to detect SARS-CoV-2 pseudovirus at 589 copies/ml, with 7-fold and 70-fold increase in sensitivity when compared with the two conventional immunoassays, including homemade target-captured ELISA (4 × 103 copies/ml) and SRAT (4 × 104 copies/ml), using the identical antibody. Moreover, the PS-SPR was applied in the measurement of mimic clinical samples containing the SARS-CoV-2 pseudovirus mixed with nasal mucosa. The detection limit of PS-SPR is calculated to be 1725 copies/ml, which has higher accuracy than homemade target-captured ELISA (4 × 104 copies/ml) and SRAT (4 × 105 copies/ml) and is comparable with qRT-PCR (1250 copies/ml). Finally, the ability of PS-SPR to detect SARS-CoV-2 in real clinical specimens was further demonstrated, and the assay time was less than 10 min. Taken together, our results indicate that this novel S-mAb integrated into PS-SPR biosensor demonstrates high sensitivity and is time-saving in SARS-CoV-2 virus detection. This study suggests that incorporation of a high specific recognizer in SPR biosensor is an alternative strategy that could be applied in developing other emerging or re-emerging pathogenic detection platforms.

The first case of monkeypox virus infection detected in Taiwan: awareness and preparation.

OBJECTIVES: Monkeypox has recently been detected outside African countries. This study aimed to report and analyze the first case of monkeypox virus infection in Taiwan. METHODS: The global epidemiological information was collected from the World Health Organization (WHO) and US Centers for Disease Control and Prevention (CDC). The data from the first confirmed Taiwanese monkeypox case was obtained from Taiwan Centers for Disease Control. Monkeypox diagnosis and prevention strategies were obtained from WHO guidelines on monkeypox. Phylogenetic tree analysis and sequence alignment and comparison were used to identify the phylogeny and single nucleotide polymorphism (SNP) characterization. RESULTS: Epidemiological data indicated that since 2013, monkeypox has caused outbreaks outside African countries through contact with infected animals and international travels. Recently, two confirmed monkeypox cases were reported in Singapore and South Korea. On June 24, 2022, Taiwan CDC reported the first confirmed case of monkeypox virus infection in a 20-year-old man who returned from Germany, from January to June 2022. This is the third confirmed case of an imported monkeypox infection in Asia. Phylogenetic analysis demonstrated that this imported monkeypox virus belonged to the West African clade and is clustered with the 2022 European outbreak monkeypox isolates. Full-length sequence analysis indicates that this virus contains 51 SNPs, and has five variant SNPs compared with the recent outbreak strains. CONCLUSION: This study suggests that active surveillance, enhancing border control, and the development of vaccines and antiviral drugs are urgently required to prevent and control the burden of monkeypox disease.

Enhancing Peptide Nucleic Acid-Nanomaterial Interaction and Performance Improvement of Peptide Nucleic Acid-Based Nucleic Acid Detection by Using Electrostatic Effects.

Single-stranded peptide nucleic acid (PNA) probes interact strongly with several nanomaterials, and the interaction was diminished in the presence of complementary nucleic acid targets which forms the basis of many nucleic acid sensing platforms. As opposed to the negatively charged DNA probes, the charges on the PNA probes may be fine-tuned by incorporating amino acids with charged side chains. The contribution of electrostatic effects to the interaction between PNA probes and nanomaterials has been largely overlooked. This work reveals that electrostatic effects substantially enhanced the quenching of dye-labeled conformationally constrained pyrrolidinyl PNA probes by several nanomaterials including graphene oxide (GO), reduced graphene oxide, gold nanoparticles (AuNPs), and silver nanoparticles. The fluorescence quenching and the color change from red to purple in the case of AuNPs because of aggregation were inhibited in the presence of complementary nucleic acid targets. Thus, fluorescence and colorimetric assays for DNA and RNA that can distinguish even single-base-mismatched nucleic acids with improved sensitivity over conventional DNA probes were established. Both the GO- and AuNP-based sensing platforms have been successfully applied for the detection of real DNA and RNA samples in vitro and in living cells. This study emphasizes the active roles of electrostatic effects in the PNA-nanomaterial interactions, which paves the way toward improving the performance of PNA-nanomaterial based assays of nucleic acids.

Targets and strategies for vaccine development against dengue viruses.

Dengue virus (DENV) is a global health threat causing about half of the worldwide population to be at risk of infection, especially the people living in tropical and subtropical area. Although the dengue disease caused by dengue virus (DENV) is asymptomatic and self-limiting in most people with first infection, increased severe dengue symptoms may be observed in people with heterotypic secondary DENV infection. Since there is a lack of specific antiviral medication, the development of dengue vaccines is critical in the prevention and control this disease. Several targets and strategies in the development of dengue vaccine have been demonstrated. Currently, Dengvaxia, a live-attenuated chimeric yellow-fever/tetravalent dengue vaccine (CYD-TDV) developed by Sanofi Pasteur, has been licensed and approved for clinical use in some countries. However, this vaccine has demonstrated low efficacy in children and dengue-naïve individuals and also increases the risk of severe dengue in young vaccinated recipients. Accordingly, many novel strategies for the dengue vaccine are under investigation and development. Here, we conducted a systemic literature review according to PRISMA guidelines to give a concise overview of various aspects of the vaccine development process against DENVs, mainly targeting five potential strategies including live attenuated vaccine, inactivated virus vaccine, recombinant subunit vaccine, viral-vector vaccine, and DNA vaccine. This study offers the comprehensive view of updated information and current progression of immunogen selection as well as strategies of vaccine development against DENVs.

A multi-target dsRNA for simultaneous inhibition of yellow head virus and white spot syndrome virus in shrimp.

Outbreaks of diseases caused by yellow head virus (YHV) and white spot syndrome virus (WSSV) infection in shrimp have resulted in economic losses worldwide. DsRNA-mediated RNAi has been used to control these viruses, and the best target genes for efficient inhibition of YHV and WSSV are the protease and ribonuleotide reductase small subunit (rr2), respectively. However, one dsRNA can suppress only one virus, and therefore the production of multi-target dsRNA to effectively inhibit both YHV and WSSV is needed. In this study, plasmids pETpro-rr2_one stem and pETpro-rr2_two stems were constructed to produce two different forms of multi-target dsRNA in E. coli, which were designed specifically to both YHV protease and WSSV rr2 genes. The potency of each dsRNA in inhibiting YHV and WSSV and reducing shrimp death were investigated in L. vannamei. Shrimp were injected with the dsRNAs into the hemolymph before challenge with YHV or WSSV. The results showed that both dsRNAs could inhibit the viruses, however the one stem construct was more effective than the two stems construct when shrimp were infected with WSSV. This study establishes a potential strategy for dual inhibition of YHV and WSSV for further application in shrimp aquaculture.

Effective production of recombinant Δ60VP1 chicken anemia virus protein in Escherichia coli and its application to a serodiagnostic indirect ELISA.

Chicken anemia virus (CAV) causes severe anemia and immunosuppression in chickens. VP1 is the main capsid protein, and is suitable for diagnostic kit development, however, it has 24 arginine residues in the first forty N-terminal amino acids of the protein causing toxicity to bacteria leading to reduced prokaryotic expression. In this study, a 60 amino acid N-terminally truncated VP1 (Δ60VP1) which removes the toxic region was expressed in Escherichia coli and the resultant insoluble recombinant protein was purified by Ni-NTA affinity chromatography with anionic denaturing detergents. The high amounts of purified Δ60VP1 produced (150 mg/L) retained appropriate antigenicity and the antigen was used to develop an indirect enzyme-linked immunosorbent assay (ELISA) for serological diagnosis of CAV. One hundred fifty-two chicken serum samples (n = 152) were evaluated using the newly developed Δ60VP1 indirect ELISA (cutoff value = 7.58 % S/P). The sensitivity and specificity of the Δ60VP1 indirect ELISA were 87.50 % and 95.31 %, respectively, while the agreement between the Δ60VP1 indirect ELISA and the commercial IDEXX CAV ELISA was 90.79 % (kappa = 0.814). In this study, we have developed an alternative VP1 production platform in E. coli by truncating the N-terminal 60 amino acids (Δ60VP1) and using anionic denaturing detergents during the purification to successfully solubilize the insoluble Δ60VP1. The antigen was purified with high yield and good immunoreactivity, and an indirect ELISA was developed. The assay could potentially be applied to large-scale CAV serosurveillance.

Dengue hemorrhagic fever - A systemic literature review of current perspectives on pathogenesis, prevention and control.

BACKGROUND: Dengue is an arboviral disease caused by dengue virus. Symptomatic dengue infection causes a wide range of clinical manifestations, from mild dengue fever (DF) to potentially fatal disease, such as dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS). We conducted a literature review to analyze the risks of DHF and current perspectives for DHF prevention and control. METHODS: According to the PRISMA guidelines, the references were selected from PubMed, Web of Science and Google Scholar database using search strings containing a combination of terms that included dengue hemorrhagic fever, pathogenesis, prevention and control. Quality of references were evaluated by independent reviewers. RESULTS: DHF was first reported in the Philippines in 1953 and further transmitted to the countries in the region of South-East Asia and Western Pacific. Plasma leakages is the main pathophysiological hallmark that distinguishes DHF from DF. Severe plasma leakage can result in hypovolemic shock. Various factors are thought to impact disease presentation and severity. Virus virulence, preexisting dengue antibodies, immune dysregulation, lipid change and host genetic susceptibility are factors reported to be correlated with the development of DHF. However, the exact reasons and mechanisms that triggers DHF remains controversial. Currently, no specific drugs and licensed vaccines are available to treat dengue disease in any of its clinical presentations. CONCLUSION: This study concludes that antibody-dependent enhancement, cytokine dysregulation and variation of lipid profiles are correlated with DHF occurrence. Prompt diagnosis, appropriate treatment, active and continuous surveillance of cases and vectors are the essential determinants for dengue prevention and control.

An epidemiological survey of the current status of Zika and the immune interaction between dengue and Zika infection in Southern Taiwan.

OBJECTIVES: This study was performed to examine the current status of Zika and the effects of pre-existing dengue immunity on Zika virus (ZIKV) infection in Southern Taiwan. METHODS: A phylogenetic tree was used to analyze the phylogeny of detected ZIKVs. Paired sera from dengue patients were collected for the determination of dengue and Zika infection. Plaque reduction neutralization tests (PRNT) and quantitative reverse transcription PCR (qRT-PCR) were used to determine the titers of neutralizing antibodies and viruses, respectively. An antibody-dependent enhancement (ADE) assay was used to evaluate the effect of anti-dengue antibodies on ZIKV infection. RESULTS: Epidemiological data indicated the continuous importation of ZIKV infection from neighboring Zika epidemic countries into Taiwan. A total of 78 dengue patients were enrolled and 21 paired serum samples were obtained. PRNT90 results for the 21 samples identified eight cases of primary dengue infection and 13 cases of secondary dengue infection; two samples were positive for ZIKV (MR766). Results from the ADE assay indicated that convalescent sera from primary and secondary dengue infection patients displayed significant ADE of the ZIKV infection when compared to healthy controls (p < 0.05). CONCLUSIONS: This study suggests that pre-existing dengue immunity facilitates ZIKV infection and that the continuous importation of ZIKV infection may pose a threat to indigenous Zika emergence in Southern Taiwan.