Metronidazole resistance is a key factor associated with Helicobacter pylori treatment failure. Although this resistance is mainly associated with mutations in the rdxA and frxA genes, the question ...of whether metronidazole resistance is caused by the inactivation of frxA alone is still debated. Furthermore, it is unclear whether there are other mutations involved in addition to the two genes that are associated with resistance. A metronidazole-resistant strain was cultured from the metronidazole-susceptible H. pylori strain 26695-1 by exposure to low concentrations of metronidazole. The genome sequences of both susceptible and resistant H. pylori strains were determined by Illumina next-generation sequencing, from which putative candidate resistance mutations were identified. Natural transformation was used to introduce PCR products containing candidate mutations into the susceptible parent strain 26695-1, and the metronidazole MIC was determined for each strain. Mutations in frxA (hp0642), rdxA (hp0954), and rpsU (hp0562) were confirmed by the Sanger method. The mutated sequence in rdxA was successfully transformed into strain 26695-1, and the transformants showed resistance to metronidazole. The transformants containing a single mutation in rdxA showed a low MIC (16 mg/liter), while those containing mutations in both rdxA and frxA showed a higher MIC (48 mg/liter). No transformants containing a single mutation in frxA or rpsU were obtained. Next-generation sequencing was used to identify mutations related to drug resistance. We confirmed that the mutations in rdxA are mainly associated with metronidazole resistance, and mutations in frxA are able to enhance H. pylori resistance only in the presence of rdxA mutations. Moreover, mutations in rpsU may play a role in metronidazole resistance.
The 2,3,7,8-tetrachlorodibenzodioxin (TCDD), a contaminant in Agent Orange released during the US–Vietnam War, led to a severe environmental crisis. Approximately, 50 years have passed since the end ...of this war, and vegetation has gradually recovered from the pollution. Soil bacterial communities were investigated by 16S metagenomics in habitats with different vegetation physiognomies in Central Vietnam, namely, forests (S0), barren land (S1), grassland (S2), and developing woods (S3). Vegetation complexity was negatively associated with TCDD concentrations, revealing the reasoning behind the utilization of vegetation physiognomy as an indicator for ecological succession along the gradient of pollutants. Stark changes in bacterial composition were detected between S0 and S1, with an increase in Firmicutes and a decrease in Acidobacteria and Bacteroidetes. Notably, dioxin digesters
Arthrobacter
,
Rhodococcus
,
Comamonadaceae
, and
Bacialles
were detected in highly contaminated soil (S1). Along the TCDD gradients, following the dioxin decay from S1 to S2, the abundance of Firmicutes and Actinobacteria decreased, while that of Acidobacteria increased; slight changes occurred at the phylum level from S2 to S3. Although metagenomics analyses disclosed a trend toward bacterial communities before contamination with vegetation recovery, non-metric multidimensional scaling analysis unveiled a new trajectory deviating from the native state. Recovery of the bacterial community may have been hindered, as indicated by lower bacterial diversity in S3 compared to S0 due to a significant loss of bacterial taxa and recruitment of fewer colonizers. The results indicate that dioxins significantly altered the soil microbiomes into a state of disorder with a deviating trajectory in restoration.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Although the type 4 secretion system of the integrating and conjugative elements (tfs ICE) is common in Helicobacter pylori, its clinical association with the cag pathogenicity island (cagPAI) have ...not yet been well-investigated. In this study, Vietnamese patient H. pylori samples (46 duodenal ulcer (DU), 51 non-cardia gastric cancer (NCGC), 39 chronic gastritis (CG)) were fully sequenced using next-generation sequencing and assembled into contigs. tfs3, tfs4, and cagPAI genes were compared with the public database. Most (94%) H. pylori strains possessed a complete cagPAI, which was the greatest risk factor for clinical outcomes, while the prevalences of tfs3 and tfs4 were 45% and 77%, respectively. Complete tfs3 and tfs4 were found in 18.3% and 17.6% of strains, respectively. The prevalence of H. pylori strains with complete tfs3 ICE in DU patients was significantly higher than that in NCGC patients (30.4% vs 11.7%, P < 0.05). In addition, the prevalence of strains with complete tfs3 ICE and cagPAI was significantly higher in DU patients than that in NCGC (28.4% vs 9.8%, P = 0.038) and CG patients (28.2% vs 7.7%, P = 0.024). cagPAI and complete tfs3 increased the risk of DU compared to NCGC (OR = 3.56, 95%CI: 1.1-14.1, P = 0.038) and CG (OR = 4.64, 95%CI: 1.1-27.6, P = 0.024). A complete cluster of tfs3 ICE was associated with gastroduodenal diseases in Vietnam. However, there was a low prevalence of the dupA/complete dupA cluster (15.4%) in the Vietnam strains. The prevalence of cagPAI in Vietnam strains was significantly higher than in US (P = 0.01) and Indonesia (P < 0.0001); the prevalence of the dupA cluster was also higher in the Vietnam strains than in the Indonesian strains (P < 0.05). In addition, the prevalence of ctkA, an accessory gene of tfs3, was significantly different between Vietnam and US strains (28% vs 2%, P = 0.0002). In summary, the acquisition of tfs3/4 ICE was common in H. pylori strains in patients with gastroduodenal disease in Vietnam, and the complete cluster of tfs3 ICE was a reliable marker for the severity of disease in the H. pylori infected population.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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•A semi-nested, heptaplex RT-PCR assay for SARS-CoV-2 detection has been developed.•The complex melting spectrum was interpreted by an artificial intelligence algorithm.•The developed ...assay enables 96-sample pooled testing for increase of testing capacity.•About 8,000 pre-amplified samples could be screened in one realtime PCR run.
Asymptomatic transmission was found to be the Achilles’ heel of the symptom-based screening strategy, necessitating the implementation of mass testing to efficiently contain the transmission of COVID-19 pandemic. However, the global shortage of molecular reagents and the low throughput of available realtime PCR facilities were major limiting factors.
A novel semi-nested and heptaplex (7-plex) RT-PCR assay with melting analysis for detection of SARS-CoV-2 RNA has been established for either individual testing or 96-sample pooled testing. The complex melting spectrum collected from the heptaplex RT-PCR amplicons was interpreted with the support of an artificial intelligence algorithm for the detection of SARS-CoV-2 RNA. The analytical and clinical performance of the semi-nested RT-PCR assay was evaluated using RNAs synthesized in-vitro and those isolated from nasopharyngeal samples.
The LOD of the assay for individual testing was estimated to be 7.2 copies/reaction. Clinical performance evaluation indicated a sensitivity of 100% (95% CI: 97.83–100) and a specificity of 99.87% (95% CI: 99.55–99.98). More importantly, the assay supports a breakthrough sample pooling method, which makes possible parallel screening of up to 96 samples in one real-time PCR well without loss of sensitivity. As a result, up to 8,820 individual pre-amplified samples could be screened for SARS-CoV-2 within each 96-well plate of realtime PCR using the pooled testing procedure.
The novel semi-nested RT-PCR assay provides a solution for highly multiplex (7-plex) detection of SARS-CoV-2 and enables 96-sample pooled detection for increase of testing capacity.
.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Helicobacter pylori vacuolating cytotoxin (VacA) is a secreted pore-forming toxin and a major virulence factor in the pathogenesis of H. pylori infection. While VacA is present in almost all ...strains, only some forms are toxigenic and pathogenic. While vacA and its genotypes are considered as markers of H. pylori-related diseases or disorders, the pathophysiological mechanisms of VacA and its genotypes remain controversial. This review outlines key findings of publications regarding vacA with emphasis on the relationship between vacA genotypes and the development of human disease.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The
-induced burden of gastric cancer varies based on geographical regions and ethnic grouping. Vietnam is a multiethnic country with the highest incidence of gastric cancer in Southeast Asia, but ...previous studies focused only on the Kinh ethnic group. A population-based cross-sectional study was conducted using 494 volunteers (18-78 years old), from 13 ethnic groups in Daklak and Lao Cai provinces, Vietnam.
status was determined by multiple tests (rapid urease test, culture, histology, and serology).
and
genotypes were determined by PCR-based sequencing. The overall
infection rate was 38.1%. Multivariate analysis showed that variations in geographical region, age, and ethnicity were independent factors associated with the risk of
acquisition. Therefore, multicenter, multiethnic, population based study is essential to assess the
prevalence and its burden in the general population. Only the E De ethnicity carried strains with Western-type CagA (82%) and exhibited significantly lower gastric mucosal inflammation compared to other ethnic groups. However, the histological scores of Western-type CagA and East-Asian-type CagA within the E De group showed no significant differences. Thus, in addition to bacterial virulence factors, host factors are likely to be important determinants for gastric mucosal inflammation and contribute to the Asian enigma.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Building on new institutional theory, this paper develops an analytical framework for analyzing constraints to the institutionalization of strategic environmental assessment (SEA) at four different ...institutional levels. The framework is tested in an empirical analysis of the environmental assessment system in Vietnam, which is a frontrunner among developing countries regarding the introduction and use of SEA. Building on interviews with Vietnamese and international experts, as well as an extensive literature review, we identify institutional constraints which challenge the effective use of SEA in Vietnam. We conclude that commonly identified constraints, such as inadequate training, technical guidelines, baseline data and financial resources, are strongly linked to constraints at higher institutional levels, such as incentives to not share information between ministries and severe restrictions on access to information and public participation. Without a thorough understanding of these institutional constraints, there is a risk that attempts to improve the use of SEA are misdirected. Thus, a careful institutional analysis should guide efforts to introduce and improve the use of SEA in Vietnam and other developing countries. The analytical framework for analyzing constraints to institutionalization of SEA presented in this paper represents a systematic effort in this direction.
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•A framework for analyzing constraints to institutionalizing SEA is developed•Empirical analysis of the strategic environmental assessment system in Vietnam•Constraints in the action arena linked to deeper institutional constraints•Institutional analysis needed prior to introducing SEA in developing countries
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Breadfruit's substantial carbohydrate content makes it a viable starch source, specifically resistant starch (RS) that helps prevent chronic diseases. This study investigated the effects of enzyme ...hydrolysis and microwave treatment (MT) on enriching type III RS in breadfruit. It also determined its structural and functional properties, including swelling power, solubility index, water absorption capacity, oil binding capacity, and syneresis. MT at 30 W.g-1 for 3 min resulted in the highest RS content of 74.8%, significantly surpassing pullulanase hydrolysis (1.0 U.g-1 dry basis for 12 h) at 17.3% RS. The breadfruit starch granules exhibited a regular shape, approximately 7.9 µm in length, whereas modified granules were less than 11 µm, along with observable deformation in their structural shape. In conclusion, the study demonstrates the efficacy of MT for enhancing RS content in breadfruit, highlighting its potential as a healthy functional ingredient and starch substitute.
Background Under the pressure of Human Adenovirus (HAdV)-associated acute respiratory infection (ARI) outbreak in children in Northern Vietnam in the end of 2022, this study was initiated to identify ...the HAdV subtype(s) and examine the associated clinical features and risk factors of more severe cases. Methods This study evaluated pediatric patients with ARI which had tested positive for HAdV between October and November 2022 using a multiplex real-time PCR panel. Nasopharyngeal aspirates or nasal swab samples were used for sequencing to identify HAdV subtypes. Clinical data were collected retrospectively. Results Among 97 successfully sequenced samples, the predominant subtypes were HAdV-B3 (83%), HAdV-B7 (16%) and HAdV-C2 (1%). Lower respiratory manifestations were found in 25% of the patients of which 5% were diagnosed with severe pneumonia. There was no significant association between HAdV subtype and clinical features except higher white blood cell and neutrophil counts in those detected with HAdV-B3 (p<0.001). Co-detection of HAdV with greater than or equal to1 other respiratory viruses was found in 13/24(54%) of those with lower respiratory manifestations and 4/5(80%) of those with severe pneumonia (odds ratio (95% confidence interval) vs. those without = 10.74 (2.83, 48.17) and 19.44 (2.12, 492.73) respectively after adjusting for age, sex, birth delivery method, day of disease). Conclusion HAdV-B3 and HAdV-B7 were predominant in the outbreak. Co-detection of HAdV together with other respiratory viruses was a strong risk factor for lower respiratory tract illnesses and severe pneumonia. The findings advocate the advantages of multi-factor microbial panels for the diagnosis and prognosis of ARI in children.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Adolescence is a sensitive transition time that affects rights, roles, and responsibilities in food choice, yet limited evidence exists on dietary intakes during this critical period. This study ...assessed the food consumption pattern and the adequacy of energy, macronutrient, and micronutrient intakes among female youth belonging to three occupational groups in Vietnam. Dietary intakes were measured for 1001 participants aged 16-22 years using INDDEX24's 24-h recall method. Multivariate regression analyses were conducted to examine differences in diet outcomes among the three occupational groups. Dietary diversity was similar across groups but workers, compared to high school and college students, consumed less baked/grain-based sweets and fast foods, and more soft drinks, other sweets, and processed meat. Two-thirds of the sample showed energy intake lower than the estimated energy requirement, while a substantial percentage had insufficient or excessive intake of carbohydrate and fat. The mean probability of adequacy of nutrient intakes was low (0.33) and not different across all three occupational groups except for folate, which favored workers. Our study provides novel evidence supporting the development and implementation of interventions to achieve national targets, with emphasis on female youths who undergo special transitions in education, occupation, and lifestyle.
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BFBNIB, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK
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