Emerging zoonotic diseases in Southeast Asia in the period 2011-2022: a systematic literature review.

As COVID-19 has shown, pandemics and outbreaks of emerging infections such as Zika, Nipah, monkeypox and antimicrobial-resistant pathogens, especially emerging zoonotic diseases, continue to occur and may even be increasing in Southeast Asia. In addition, these infections often result from environmental changes and human behaviour. Overall, public health surveillance to identify gaps in the literature and early warning signs are essential in this region. A systematic review investigated the prevalence of emerging zoonotic diseases over 11 years from 2011 to 2022 in Southeast Asia to understand the status of emerging zoonotic diseases, as well as to provide necessary actions for disease control and prevention in the region. During the 2011-2022 period, studies on pigs, poultry, ruminants, companion animals and wildlife in Southeast Asia were reviewed thoroughly to assess the quality of reporting items for inclusion in the systematic review. The review was performed on 26 studies of pigs, 6 studies of poultry, 21 studies of ruminants, 28 studies of companion animals and 25 studies of wildlife in Southeast Asia, which provide a snapshot of the prevalence of the emerging zoonotic disease across the country. The findings from the review showed that emerging zoonotic diseases were prevalent across the region and identified a few zoonotic diseases associated with poultry, mainly stemming from Cambodia and Vietnam, as high priority in Southeast Asia.Clinical relevance: Appropriate prevention and control measures should be taken to mitigate the emerging zoonotic diseases in Southeast Asia.

Bioactive-Guided Phytochemical Investigations, In Vitro and In Silico Alpha-Glucosidase Inhibition of Two Vietnamese Medicinal Plants Dicranopteris linearis and Psychotria adenophylla.

Little is known about the chemical and biological profiles of Dicranopteris linearis and Psychotria adenophylla. No previous studies have investigated alpha-glucosidase inhibition using extracts from D. linearis and P. adenophylla. In this paper, bioactive-guided isolation procedures were applied to the plants D. linearis and P. adenophylla based on alpha-glucosidase inhibition. From the most active fractions, 20 compounds (DL1-DL13 and PA1-PA7) were isolated. The chemical structures were elucidated using spectroscopic data and compared with those available in the literature. These compounds were evaluated for alpha-glucosidase inhibition, while a molecular docking study was performed to elucidate the mechanisms involved. Consequently, D. linearis and P. adenophylla might serve as a good potential for developing new antidiabetic preparations.

The Pivotal Role of Neuropeptide Crosstalk from Ventromedial-PACAP to Dorsomedial-Galanin in the Appetite Regulation in the Mouse Hypothalamus.

We have previously shown that pituitary adenylate cyclase-activating polypeptide (PACAP) in the ventromedial hypothalamus (VMH) enhances feeding during the dark cycle and after fasting, and inhibits feeding during the light cycle. On the other hand, galanin is highly expressed in the hypothalamus and has been reported to be involved in feeding regulation. In this study, we investigated the involvement of the VMH-PACAP to the dorsomedial hypothalamus (DMH)-galanin signaling in the regulation of feeding. Galanin expression in the hypothalamus was significantly increased with fasting, but this increment was canceled in PACAP-knockout (KO) mice. Furthermore, overexpression of PACAP in the VMH increased the expression of galanin, while knockdown (KD) of PACAP in the VMH decreased the expression of galanin, indicating that the expression of galanin in the hypothalamus might be regulated by PACAP in the VMH. Therefore, we expressed the synaptophysin-EGFP fusion protein (SypEGFP) in PACAP neurons in the VMH and visualized the neural projection to the hypothalamic region where galanin was highly expressed. A strong synaptophysin-EGFP signal was observed in the DMH, indicating that PACAP-expressing cells of the VMH projected to the DMH. Furthermore, galanin immunostaining in the DMH showed that galanin expression was weak in PACAP-KO mice. When galanin in the DMH was knocked down, food intake during the dark cycle and after fasting was decreased, and food intake during the light cycle was increased, as in PACAP-KO mice. These results indicated that galanin in the DMH may regulate the feeding downstream of PACAP in the VMH.

Allium sativum@AgNPs and Phyllanthus urinaria@AgNPs: a comparative analysis for antibacterial application.

Although medicinal herbs contain many biologically active ingredients that can act as antibiotic agents, most of them are difficult to dissolve in lipids and absorb through biofilms in the gastrointestinal tract. Besides, silver nanoparticles (AgNPs) have been widely used as a potential antibacterial agent, however, to achieve a bactericidal effect, high concentrations are required. In this work, AgNPs were combined into plant-based antibiotic nanoemulsions using biocompatible alginate/carboxyl methylcellulose scaffolds. The silver nanoparticles were prepared by a green method with an aqueous extract of Allium sativum or Phyllanthus urinaria extract. The botanical antibiotic components in the alcoholic extract of these plants were encapsulated with emulsifier poloxamer 407 to reduce the particle size, and make the active ingredients both water-soluble and lipid-soluble. Field emission scanning electron microscopy (FESEM) and energy-dispersive X-ray (EDX) analysis showed that the prepared nanosystems were spherical with a size of about 20 nm. Fourier transform infrared spectroscopy (FTIR) confirmed the interaction of the extracts and the alginate/carboxyl methylcellulose carrier. In vitro drug release kinetics of allicin and phyllanthin from the nanosystems exhibited a retarded release under different biological pH conditions. The antimicrobial activity of the synthesized nanoformulations were tested against Escherichia coli. The results showed that the nanosystem based on Allium sativum possesses a significantly higher antimicrobial activity against the tested organisms. Therefore, the combination of AgNPs with active compounds from Allium sativum extract is a good candidate for in vivo infection treatment application.

Polymerase chain reaction-based detection of coinfecting DNA viruses in Vietnamese pigs in 2017 and 2021.

Background and Aim: Many studies have reported on the phenomenon of co-infections involving two or more pathogens (bacteria or viruses) over the past few years. However, very few studies on this issue were conducted in Vietnam. Therefore, this study aimed to determine the circulation of single and multiple porcine parvovirus (PPV) (e.g., PPV1, PPV2, PPV3, and PPV4), porcine bocavirus (PBoV), and torque teno virus (TTV) (TTV1 and TTV2) infections in Vietnamese pigs. Materials and Methods: A total of 174 porcine circovirus 2-positive samples from pigs (n = 86 for 2017 and n = 88 for 2021), including from the sera and internal organs, across 11 provinces were examined by polymerase chain reaction. Results: This study demonstrated the wide distribution of DNA viruses among pig farms in Vietnam in 2021, with the detection rate for PPV ranging from 3.4% to 27.3% among PPV1-PPV4. Moreover, the detection rates of TTV genotypes were confirmed to be 14.8% (TTV1) and 63.6% (TTV2), respectively, and the positive rate of PBoV was 65.9%. The most frequent combinations were double and triple infections. Double infection was found in 16/86 (18.6%) in 2017 and 26/88 (29.5%) in 2021, while triple infection was found at 19/86 (22.1%) in 2017 and 26/88 (29.5%) in 2021. The incidence of simultaneous detection of more than three viruses was low. Conclusion: These results provide at least partial information about the occurrence of three viruses, including PPV (including PPV1 to 4), PBoV, and TTV (TTV1 and TTV2), in pigs. Determination of particular viruses in pigs will help to prevent the porcine respiratory disease complex caused by DNA viruses in Vietnamese pigs in the future.

Oreocharisphuongii (Gesneriaceae), a new species from central Vietnam.

Oreocharisphuongii, a new species of Gesneriaceae from central Vietnam, is described and illustrated here. The new species is most similar to O.longifolia by sharing peduncles up to 22 cm long, bracts 2, zygomorphic, yellow flowers with tubular corolla, stamens 4 with two pairs of coherent anthers and capsules up to 6 cm long. It mainly differs from the latter by the combination of some morphological characters of leaves (shape, base, apex and margin), size of calyx lobes, indumentum of corolla tube and inner surface of three lower corolla lobes. Detailed morphological description together with colour illustration, information on phenology, distribution, ecology, preliminarily conservation status of the new species and comparison with its similar species are also presented.

α-Glucosidase Inhibitory and Antimicrobial Benzoylphloroglucinols from Garcinia schomburgakiana Fruits: In Vitro and In Silico Studies.

α-Glucosidase plays a role in hydrolyzing complex carbohydrates into glucose, which is easily absorbed, causing postprandial hyperglycemia. Inhibition of α-glucosidase is therefore an ideal approach to preventing this condition. A novel polyprenylated benzoylphloroglucinol, which we named schomburgkianone I (1), was isolated from the fruit of Garcinia schomburgkiana, along with an already-reported compound, guttiferone K (2). The structures of the two compounds were determined using NMR and HRESIMS analysis, and comparisons were made with previous studies. Compounds 1 and 2 exhibited potent α-glucosidase inhibition (IC50s of 21.2 and 34.8 µM, respectively), outperforming the acarbose positive control. Compound 1 produced wide zones of inhibition against Staphylococcus aureus and Enterococcus faecium (of 21 and 20 mm, respectively), compared with the 19 and 20 mm zones of compound 2, at a concentration of 50 µg/mL. The MIC value of compound 1 against S. aureus was 13.32 µM. An in silico molecular docking model suggested that both compounds are potent inhibitors of enzyme α-glucosidase and are therefore leading candidates as therapies for diabetes mellitus.

A new diphenyl ether from Parmotrema indicum Hale growing in Vietnam.

Chemical investigation of the lichen Parmotrema indicum Hale led to the isolation of one new diphenyl ether, parmetherine D (1), along with eight known compounds (2-9). The structures were determined by analysis of MS and NMR data and by comparison with the literature. Compounds 1, 2, and 7 were evaluated for α-glucosidase inhibition. Only compound 1 exhibited significant inhibition.[Formula: see text].

Parmosidone K, a new meta-depsidone from the lichen Parmotrema tsavoense.

Further phytochemical investigation on P. tsavoense led to one new meta-depsidone, parmosidone K together with one known compound, barbatic acid. Their structures were determined by 1D and 2D NMR analysis, high resolution mass spectroscopy, and comparison their NMR data with those reported in literatures. Parmosidone K was evaluated for α-glucosidase inhibition and revealed the powerful activity with IC50 value of 3.12 µM.

Estimation of the herd-level basic reproduction number for African swine fever in Vietnam, 2019.

Background and Aim: African swine fever (ASF) is a notifiable viral disease of pigs and wild boars that causes severe economic losses to the swine industry. The pig industry in Vietnam was recently attacked by the ASF virus (ASFV) for the first time in history. However, we lack information regarding the transmissibility of ASF within indoor production systems communities, such as those in Vietnam. Therefore, we aimed to estimate the basic reproduction number (R0) for ASF during the early stages of transmission between farms in indoor production system communities from local and national data in Vietnam. Materials and Methods: The linear regression model approach for the susceptible infectious method was used in this study to estimate the transmission rate and, consequently, the R0 value. Results: The R0 values between-farm of ASF ranged from 1.41 to 10.8 in different scenarios of infectious period duration, from 15 to 30 days at the national and local levels. Conclusion: These results help to understand the scale and speed of ASF infection in Vietnam and to provide a scientific basis to implement control measures to restrict the spread of ASFV in other locations.

Serological and Molecular Characterization of Avian Metapneumovirus in Chickens in Northern Vietnam.

Avian Metapneumovirus (aMPV) is a causative agent of respiratory disease complex in turkeys and chickens that has recently been detected in Vietnam. Due to its novelty, this study was conducted to elucidate the distribution of aMPV in several provinces in northern Vietnam. By the application of Enzyme-Linked Immunosorbent Assay (ELISA) and nested Reverse Transcription-Polymerase Chain Reaction (RT-PCR), this study demonstrated the circulation of aMPV in 12 out of 14 cities/provinces with positive rates of 37.6% and 17.2%, respectively. All nested RT-PCR positive samples were aMPV subgroup B. By pairing the detection results with age groups, it was observed that aMPV infections occurred in chickens of all ages. Additionally, by genetic characterization, aMPV strains were demonstrated to not be attenuated vaccine viruses and to belong to at least two genetic clades. Overall, the obtained results provided insights into the prevalence of aMPV and indicated a greater complexity of respiratory diseases in chickens in Vietnam.

Sero-Prevalence of SARS-CoV-2 Antibodies in High-Risk Populations in Vietnam.

As a response to the coronavirus disease 2019 (COVID-19) pandemic, Vietnam enforced strict quarantine, contact tracing and physical distancing policies resulting in one of the lowest numbers of individuals infected with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) globally. This study aimed to determine the prevalence of SARS-CoV-2 antibody positivity among high-risk populations in Vietnam. A prevalence survey was undertaken within four communities in Vietnam, where at least two COVID-19 cases had been confirmed. Participants were classified according to the location of exposure: household contacts, close contacts, community members, and healthcare workers (HCWs) responsible for treating COVID-19 cases. Participants completed a baseline questionnaire and SARS-CoV-2 IgG antibodies were quantified using a commercial assay. A total of 3049 community members and 149 health care workers consented to the study. Among 13 individuals who were seropositive (0.4%), five household contacts (5/27, 18.5%), one close contact (1/53, 1.9%), and seven community members (7/2954, 0.2%) had detectable SARS-CoV-2 antibodies. All HCWs were negative for SARS-CoV-2 antibodies. Participants were tested a median of 15.1 (interquartile range from 14.9 to 15.2) weeks after exposure. Our study found a low prevalence of SARS-CoV-2 antibodies in high-risk communities and healthcare workers in communities in Vietnam with known COVID-19 cases.

In vitro antimycobacterial studies of flavonols from Bauhinia vahlii Wight and Arn.

Mycobacterial infections and fast-growing strains are increasing globally with 8 million new cases and 1.8 million fatalities per annum worldwide. The acid-fast bacterium, Mycobacterium tuberculosis (M.t), can spread diseases like tuberculosis (Tb) and weaken the immune system. In Ayurveda, the Bauhinia genus is most valued for the treatment of tuberculosis lymphadenitis. The objective of the present study is to identify anti-tubercular compounds from the under-investigated medicinal plant B. vahlii Wight and Arn. using bioassay guided isolation. The antimycobacterial activity was evaluated against non-virulent strains: Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis BCG (ATCC 35743). Also, antibacterial and cytotoxicity activities were tested to identify the specificity of the isolated metabolites. Bioassay-guided isolation yielded three known flavonols, namely quercetin (1), ombuin (2), and kaempferol (3), from the methanolic extract of bark of B. vahlii. The results of antimycobacterial activity tests revealed that 2 showed much better mycobactericidal activity than 1 and 3 under ex vivo condition with minimum inhibitory concentration (MIC) values ranged from 0.05 ± 0.01 to 0.26 ± 0.01 nM, and half-maximal inhibitory concentration (IC50) values ranged from 2.85 ± 0.14 to 7.21 ± 1.09 nM against dormant and active forms, respectively. Also, compound 2 showed higher resistance with MIC values > 100 µg/mL against both Gram-positive and Gram-negative bacteria and the least cytotoxicity up to 100 µg/mL concentration against the tested series of cancer cell lines. The results revealed the Ayurvedic use of extracts of the Bauhinia genus for treating tuberculosis, and the key bioactive compounds were found to be flavonols (1-3). The present work provides the first evidence for the presence of antimycobacterial compounds in B. vahlii. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02672-4.

Chronic Royal Jelly Administration Induced Antidepressant-Like Effects Through Increased Sirtuin1 and Oxidative Phosphorylation Protein Expression in the Amygdala of Mice.

BACKGROUND: Major depressive disorder (MDD) is a common psychological disorder worldwide. However, one-third of patients with MDD are resistant to the present anti-depressant medicine, which regulates monoamine contents in the brain. Thus, another drug target is strongly required. Much evidence strongly suggests that sirtuin1, which is the key factor in regulating the mitochondrial activity, may be implicated in MDD. OBJECTIVE: Since it is suggested that royal jelly (RJ) ameliorated depressive-like behavior and affected mitochondrial activity in mice, we hypothesized that RJ could be an alternative medicine against MDD, which acts via sirtuin1 signaling to improve mitochondrial activity. METHODS: In the present study, we applied a mouse model of MDD to investigate the effect of RJ on the depressive-like behavior and the sirtuin1 signaling on mitochondrial activity. RESULTS: Our results indicated that either the oral administration of RJ for 12 days or single intracerebroventricular (i.c.v.) injection decreased the duration of immobility in the tail suspension test, which suggested that RJ had an antidepressant-like effect. Moreover, sirtuin1 protein expression increased in mice following RJ treatment in the amygdala region, but not in the other brain regions. Similarly, the expressions of oxidative phosphorylation (OXPHOS) related proteins increased in the amygdala regions, but not in the hippocampal regions. CONCLUSION: The increase of sirtuin1 and OXPHOS protein expression may at least in part contribute to the antidepressant-like effect of the RJ pathway, and RJ may have the potential to be a novel anti-depressant drug.

Dilatatone, a new chlorinated compound from Parmotrema dilatatum.

Chemical investigation of the lichen Parmotrema dilatatum led to the isolation of a new chlorinated compound, named dilatatone (1), along with a known compound, sernanderin (2). Their chemical structures were determined by analysis of their 1 D and 2 D NMR spectra, HRESIMS, and ECD data. Both compounds showed weak α-glucosidase inhibitor activity.

Subnudatones A and B, new trans-decalin polyketides from the cultured lichen mycobionts of Pseudopyrenula subnudata.

Chemical investigation of the cultured polyspore-derived mycobionts of a Pseudopyrenula subnudata lichen led to the isolation of two new compounds, subnudatones A and B (1 and 2), together with four known compounds, 1-(2-hydroxy-1,2,6-trimethyl-1,2,4a,5,6,7,8,8a-octahydronaphthalen-1-yl)ethanone (3), libertalide C (4), aspermytin A (5), and 6,7-dimethoxy-4-hydroxymellin (6). Their chemical structures were elucidated by extensive 1D and 2D NMR analysis and high resolution mass spectroscopy, and comparisons were made with the literature. The absolute configuration of 1 was defined unambiguously using single crystal X-ray crystallography. Compound 1 represents the first dimeric decalin polyketide to be found in nature. The in vitro cytotoxicity of 1 against two cancer cell lines (K562 and MCF-7) was evaluated. Compound 1 showed moderate cytotoxic activity with IC50 values of 23.5 ± 1.0 and 51.9 ± 1.4 µM, respectively.

Pituitary Adenylate Cyclase-Activating Polypeptide in the Ventromedial Hypothalamus Is Responsible for Food Intake Behavior by Modulating the Expression of Agouti-Related Peptide in Mice.

Pituitary adenylate cyclase-activating polypeptide (PACAP) is abundantly expressed in the hypothalamus and contributes to hypothalamic functions, including appetite regulation. Although food intake is suggested to be decreased in PACAP (-/-) mice, the detailed mechanisms are still being discussed. We sought to investigate this link. The food consumption at 8 h after refeeding in the (-/-) mice who had fasted for 2 days was significantly lower than in the PACAP (+/+) mice. The nocturnal and daily food intake of (-/-) mice was significantly lower than those of (+/+) mice, but the diurnal food intake showed a tendency to increase. mRNA expression levels of agouti-related peptide (AgRP) were decreased, but those of proopiomelanocortin (POMC) were increased in the hypothalamus of (-/-) mice 4 h after refeeding. Furthermore, intracerebroventricular administration of a PACAP receptor antagonist, PACAP6-38 (1 nmol/4 µL/mouse), decreased food intake and body weight 1, 2, and 4 h after refeeding, as well as expression levels of AgRP at 4 h after refeeding in (+/+) mice. The selective overexpression of PACAP by the infection of an adeno-associated virus in the ventromedial hypothalamus (VMH) resulted in an increase in food intake and AgRP expression in the nocturnal period in addition to the increased food intake at 8 h after refeeding. These results suggest that food intake behavior in mice is triggered by the increase in PACAP expression in the VMH via modulation of AgRP expression in the hypothalamus, pointing to PACAP inhibition as a potential strategy for the development of anti-obesity drugs.

An optimized molecular method for detection of influenza A virus using improved generic primers and concentration of the viral genomic RNA and nucleoprotein complex.

For reported primer sets used to detect influenza A viruses (IAVs), we verified the nucleotide identities with 9,103 complete sequences of matrix (M) genes. At best, only 93.2% and 85.3% of the sequences had a 100% match with reported forward and reverse primers, respectively. Therefore, we designed new degenerate forward and reverse primers with 100% identity to 94.4% and 96.2% of compared genes, respectively, and the primer set was used with SYBR-based reverse-transcription real-time PCR (SYBR-RT-rtPCR) for lower detection limits. The sensitivity of SYBR-RT-rtPCR with the new primers was 10-fold higher than that with a conventional method in ~2.37% of all M genes in the database used in our study. We successfully increased the sensitivity of SYBR-RT-rtPCR by concentrating the viral ribonucleoprotein (RNP) using immunomagnetic beads and Triton X-100. The improved generic primer set and RNP concentration method may be useful for sensitive detection of IAVs.

Evaluating Food Safety Knowledge and Practices of Food Processors and Sellers Working in Food Facilities in Hanoi, Vietnam.

Consumption of fast food and street food is increasingly common among Vietnamese, particularly in large cities. The high daily demand for these convenient food services, together with a poor management system, has raised concerns about food hygiene and safety (FHS). This study aimed to examine the FHS knowledge and practices of food processors and sellers in food facilities in Hanoi, Vietnam, and to identify their associated factors. A cross-sectional study was conducted with 1,760 food processors and sellers in restaurants, fast food stores, food stalls, and street vendors in Hanoi in 2015. We assessed each participant's FHS knowledge using a self-report questionnaire and their FHS practices using a checklist. Tobit regression was used to determine potential factors associated with FHS knowledge and practices, including demographics, training experience, and frequency of health examination. Overall, we observed a lack of FHS knowledge among respondents across three domains, including standard requirements for food facilities (18%), food processing procedures (29%), and food poisoning prevention (11%). Only 25.9 and 38.1% of participants used caps and masks, respectively, and 12.8% of food processors reported direct hand contact with food. After adjusting for socioeconomic characteristics, these factors significantly predicted increased FHS knowledge and practice scores: (i) working at restaurants and food stalls, (ii) having FHS training, (iii) having had a physical examination, and (iv) having taken a stool test within the last year. These findings highlight the need of continuous training to improve FHS knowledge and practices among food processors and food sellers. Moreover, regular monitoring of food facilities, combined with medical examination of their staff, should be performed to ensure food safety.

Effect of the fourth nucleotide at the 3' end of neuraminidase and matrix viral genomic RNA on the pathogenicity of influenza virus A/PR/8/34.

Twelve nucleotides located at the 3' end of viral genomic RNA (vRNA) are conserved among influenza A viruses (IAV) and have a promoter function. Hoffmann's 8-plasmid reverse genetics vector system introduced mutations at position 4, C nucleotide (C4) to U nucleotide (U4), of the 3' ends of neuraminidase (NA) and matrix (M) vRNAs of wild-type A/PR/8/34 (PR8). This resulted in a constellation of C4 and U4 vRNAs coding for low (polymerases) and relatively high (all others) copy number proteins, respectively. U4 has been reported to increase promoter activity in comparison to C4, but the constellation effect on the replication efficiency and pathogenicity of reverse genetics PR8 (rgPR8) has not been fully elucidated. In the present study, we generated 3 recombinant viruses with C4 in the NA and/or M vRNAs and rgPR8 by using reverse genetics and compared their pathobiological traits. The mutant viruses showed lower replication efficiency than rgPR8 due to the low transcription levels of NA and/or M genes. Furthermore, C4 in the NA and/or M vRNAs induced lower PR8 virus pathogenicity in BALB/c mice. The results suggest that the constellation of C4 and U4 among vRNAs may be one of the multigenic determinants of IAV pathogenicity.