Prevalence and Associated Factors of optrA-Positive-Enterococcus faecalis in Different Reservoirs around Farms in Vietnam.

Linezolid is an antibiotic of last resort for the treatment of infections caused by Gram-positive bacteria, including vancomycin-resistant enterococci. Enterococcus faecalis, a member of enterococci, is a significant pathogen in nosocomial infections. E. faecalis resistance to linezolid is frequently related to the presence of optrA, which is often co-carried with fex, phenicol exporter genes, and erm genes encoding macrolide resistance. Therefore, the common use of antibiotics in veterinary might promote the occurrence of optrA in livestock settings. This is a cross-sectional study aiming to investigate the prevalence of optrA positive E. faecalis (OPEfs) in 6 reservoirs in farms in Ha Nam province, Vietnam, and its associated factors and to explore genetic relationships of OPEfs isolates. Among 639 collected samples, the prevalence of OPEfs was highest in flies, 46.8% (51/109), followed by chickens 37.3% (72/193), dogs 33.3% (17/51), humans 18.7% (26/139), wastewater 16.4% (11/67) and pigs 11.3%, (14/80). The total feeding area and total livestock unit of the farm were associated with the presence of OPEfs in chickens, flies, and wastewater. Among 186 OPEfs strains, 86% were resistant to linezolid. The presence of optrA was also related to the resistant phenotype against linezolid and levofloxacin of E. faecalis isolates. Close genotypic relationships identified by Pulsed Field Gel Electrophoresis between OPEfs isolates recovered from flies and other reservoirs including chickens, pigs, dogs, and wastewater suggested the role of flies in the transmission of antibiotic-resistant pathogens. These results provided warnings of linezolid resistance although it is not used in livestock.

ZIKV Inhibitors Based on Pyrazolo[3,4-d]pyridazine-7-one Core: Rational Design, In Vitro Evaluation, and Theoretical Studies.

The Zika virus (ZIKV) is believed to cause birth defects, and no anti-ZIKV drugs have been approved by medical organizations to date. Starting from antimicrobial lead compounds with a pyrazolo[3,4-d]pyridazine-7-one scaffold, we synthesized 16 derivatives and screened their ability to interfere with ZIKV infection utilizing a cell-based phenotypic assay. Of these, five compounds showed significant inhibition of ZIKV with a selective index value greater than 4.6. In particular, compound 9b showed the best anti-ZIKV activity with a selectivity index of 22.4 (half-maximal effective concentration = 25.6 µM and 50% cytotoxic concentration = 572.4 µM). Through the brine shrimp lethality bioassay, 9b, 10b, 12, 17a, and 19a showed median lethal dose values in a range of 87.2-100.3 µg/mL. Compound 9b was also targeted to the NS2B-NS3 protease of ZIKV using molecular docking protocols, in which it acted as a noncompetitive inhibitor and strongly bound to five key amino acids (His51, Asp75, Ser135, Ala132, Tyr161). Utilizing the pharmacophore model of 9b, the top 20 hits were identified as prospective inhibitors of NS2B-NS3 protease, and six of them were confirmed for their stability with the protease via redocking and molecular dynamics simulations.

Analysis of Periodontal Conditions in the Provinces of Vietnam: Results From the National Dental Survey.

Nationwide dental health surveys are crucial for providing essential information on dental health and dental condition-related problems in the community. However, the relationship between periodontal conditions and sociodemographic data has not been well investigated in Vietnam. With data from the National Oral Health Survey in 2019, we performed several machine learning methods on this dataset to investigate the impacts of sociodemographic features on gingival bleeding, periodontal pockets, and Community Periodontal Index. From the experiments, LightGBM produced a maximum AUC (area under the curve) value of 0.744. The other models in descending order were logistic regression (0.705), logiboost (0.704), and random forest (0.684). All methods resulted in significantly high overall accuracies, all exceeding 90%. The results show that the gradient boosting model can predict well the relationship between periodontal conditions and sociodemographic data. The investigated model also reveals that the geographic region has the most significant influence on dental health, while the consumption of sweet foods/drinks is the second most crucial. These findings advocate for a region-specific approach for the dental care program and the implementation of a sugar-risk food reduction program.

An observational study of breakthrough SARS-CoV-2 Delta variant infections among vaccinated healthcare workers in Vietnam.

BACKGROUND: Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals are limited. METHODS: We studied breakthrough infections among Oxford-AstraZeneca vaccinated healthcare workers in an infectious diseases hospital in Vietnam. We collected demographic and clinical data alongside serial PCR testing, measurement of SARS-CoV-2 antibodies, and viral whole-genome sequencing. FINDINGS: Between 11th-25th June 2021 (7-8 weeks after the second dose), 69 staff tested positive for SARS-CoV-2. 62 participated in the study. Most were asymptomatic or mildly symptomatic and all recovered. Twenty-two complete-genome sequences were obtained; all were Delta variant and were phylogenetically distinct from contemporary viruses obtained from the community or from hospital patients admitted prior to the outbreak. Viral loads inferred from Ct values were 251 times higher than in cases infected with the original strain in March/April 2020. Median time from diagnosis to negative PCR was 21 days (range 8-33). Neutralizing antibodies (expressed as percentage of inhibition) measured after the second vaccine dose, or at diagnosis, were lower in cases than in uninfected, fully vaccinated controls (median (IQR): 69.4 (50.7-89.1) vs. 91.3 (79.6-94.9), p=0.005 and 59.4 (32.5-73.1) vs. 91.1 (77.3-94.2), p=0.002). There was no correlation between vaccine-induced neutralizing antibody levels and peak viral loads or the development of symptoms. INTERPRETATION: Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies. Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals. FUNDING: Wellcome and NIH/NIAID.

Metabolomics Approach for Discrimination and Quality Control of Natural and Commercial Fallopia multiflora Products in Vietnam.

A precise HPLC-DAD-based quantification together with the metabolomics statistical method was developed to distinguish and control the quality of Fallopia multiflora, a popular medicinal material in Vietnam. Multivariate statistical methods such as hierarchical clustering analysis and principal component analysis were utilized to compare and discriminate six natural and twelve commercial samples. 2,3,4',5-Tetrahydroxystilbene 2-O-ß-D-glucopyranoside (THSG) (1), emodin (4), and the new compound 6-hydroxymusizin 8-O-α-D-apiofuranosyl-(1⟶6)-ß-D-glucopyranoside (5) could be considered as important markers for classification of F. multiflora. Furthermore, seven phenolics were quantified that the variation in the contents of selected metabolites revealed the differences in the quality of natural and commercial samples. Recovery of the compounds from the analytes was more than 98%, while the limits of detection (LOD) and the limits of quantitation (LOQ) ranged from 0.5 to 6.6 µg/ml and 1.5 to 19.8 µg/ml, respectively. The linearity, LOD, LOQ, precision, and accuracy satisfied the criteria FDA guidance on bioanalytical methods. Overall, this method is a promising tool for discrimination and quality assurance of F. multiflora products.

Reducing Antimicrobial Usage in Small-Scale Chicken Farms in Vietnam: A 3-Year Intervention Study.

Indiscriminate antimicrobial use (AMU) in animal production is a driver of antimicrobial resistance globally. There is a need to define sustainable interventions to reduce AMU in small-scale production systems, which currently represent the most widespread farming systems in South East Asia and many low- and middle-income countries. We conducted a before-and-after intervention study on a random sample of small-scale chicken farms in the Mekong Delta of Vietnam from 2016 to 2019. The study included a baseline followed by an intervention phase where farmers were provided with regular veterinary advice on flock health and husbandry, as well as antimicrobial replacement products. Of 102 recruited farms (raising >100 chickens per flock cycle), thirty-five (34.2%) entered the intervention phase, whilst the rest stopped raising chickens, mainly due to suboptimal flock performance. Through the implementation of our intervention, chicken flocks reduced levels of AMU by 66% [adjusted hazard ratio (HR) = 0.34; p = 0.002) from a baseline of 343.4 Animal Daily Doses per 1,000 chicken-days and decreased weekly mortality by 40% (adjusted HR = 0.60; p = 0.005) from a baseline mortality of 1.60 per 100 birds. Chicken bodyweight increased by 100 g (p = 0.002) in intervention flocks. Our findings demonstrate that the provision of veterinary advice can achieve substantial reductions in AMU in small-scale production systems without compromising flock health and productivity.

Mifepristone and misoprostol compared with misoprostol alone for second-trimester abortion: a randomized controlled trial.

OBJECTIVE: To estimate the clinical benefit of pretreatment with mifepristone followed by misoprostol compared with misoprostol alone for second-trimester abortion. METHODS: Two hundred sixty women with live fetuses of gestational ages 14-21 weeks were enrolled in a randomized, placebo-controlled, double-blind trial in Vietnam. Eligible consenting women received either mifepristone or placebo to take on their own at home and were scheduled to return to the hospital the next day. At the hospital, women were given 400 micrograms buccal misoprostol every 3 hours, up to five doses, until both the fetus and placenta were expelled. Efficacy was evaluated 15 hours after misoprostol dosing began and the procedure was considered complete if uterine evacuation was achieved without recourse to surgical evacuation. RESULTS: Pretreatment with mifepristone resulted in more than twice the chance of complete uterine evacuation in 15 hours (79.8% compared with 36.9%, relative risk 2.16, 95% confidence interval 1.70-2.75). The mean induction-to-abortion interval for complete uterine evacuations was statistically significantly shorter among participants pretreated with mifepristone compared with those given misoprostol alone (8.1, standard deviation 2.8, range 2.5-14.8; and 10.6, standard deviation 2.5, range 6.5-15.5 hours, respectively; P<.001). The side-effect profiles for the two regimens did not differ significantly and acceptability of the treatments was high. CONCLUSION: Mifepristone-misoprostol is more efficacious and faster than misoprostol alone. Services offering home administration of mifepristone as pretreatment could optimize efficacy and acceptability of medical abortions for women with gestations 14-21 weeks since the last menstrual period. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00784186. LEVEL OF EVIDENCE: I.