1.Isolation and toxicity of Xanthomonas oryzae pv. oryzae in rice and a collection of phages against the pathogen
Ngoc Quynh Anh Pham ; Vo Thanh Phuc ; Pham Do Tra My ; Le Thi My Duyen ; To Hue Ngoc ; Nguyen Minh Thien ; Nguyen Hai Duong ; Le Thi Thuy Tien ; Le Phi Nga ; Hoang Anh Hoang
Malaysian Journal of Microbiology 2024;20(no.1):15-23
Aims:
The objective of the study was to isolate bacteriophages and conduct a comprehensive analysis of their potential against Xanthomonas oryzae pv. oryzae (Xoo) strains in the Mekong Delta, Vietnam.
Methodology and results:
Twelve Xoo strains were isolated from rice fields located in the Mekong Delta, Vietnam. Among these strains, three strains Xoo L019, L020 and L024, showed the highest disease index of bacterial blight. Four
phages specific to Xoo were isolated from soil, water and leaf samples, and their morphologies were determined. In a test against 12 Xoo strains, phage L541, MLA23 or W41 could infect 10 of the 12 Xoo strains, while phage LBH01 could infect 8 of the 12 Xoo strains. The stability of the phages to pH, organic solvents, UV-A and UV-B was also evaluated.
Conclusion, significance and impact of study
The initial characterization of the phages indicates their potential as biocontrol agents against bacterial blight in rice. The study is one of the very first studies about Xoo phages in rice in Vietnam.
2.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
3.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
4.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
5.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
6.Sesquiterpenes from Curcuma zedoaria (Christm.) Rosc. Rhizomes and Their Alpha-Glucosidase Inhibitory Effects
Ngan Thi TRAN ; Phuong Nguyen Thi THU ; Mai-Ngan Thi LE ; Quynh-Mai Thi NGO
Natural Product Sciences 2024;30(4):300-303
Curcuma zedoaria (Christm.) Rosc. is a popular traditional herb to treat digestive disorders in Asian tropical countries. Previous studies indicated the presence of sesquiterpenoids, diterpenoids, and curcuminoids with various bioactivities. To enrich the phytocomposition data of this plant, this investigation was conducted.The dried rhizomes of C. zedoaria were collected in Hai Phong City (Vietnam), extracted with methanol and fractionated with n-hexane, CH2Cl2 , and EtOAc. Compounds were isolated from n-hexane soluble fraction by open column chromatography combined with thin layer chromatography from fraction n-hexane. Their chemical structures were elucidated by 1D, and 2D NMR spectra and comparison with reported data. As a result, a phytochemical investigation was conducted to isolate six sesquiterpenes from C. zedoaria. Their chemical structures were elucidated to be curcumenol (1), procurcumenol (2), neoprocurcumenol (3), 13-hydroxygermacrone (4), zederone (5), and curcumalactone (6). Among isolated compounds, compounds 1, 2, 4, and 5 were reported from C. zedoaria. Meanwhile, neoprocurcumenol (3) and curcumalactone (6) are isolated from this species for the first time. Compound 5 exhibited a mild inhibitory effect on α-glucosidase with an IC50 of 99.45 ± 0.50 μg/mL.
7.Mental Health Among Healthcare Workers During the COVID-19 Pandemic in Vietnam
Nhan Phuc Thanh NGUYEN ; Ha Phan Ai NGUYEN ; Cao Khoa DANG ; Minh Tri PHAN ; Huynh Ho Ngoc QUYNH ; Van Tuan LE ; Chinh Van DANG ; Tinh Huu HO ; Van Trong PHAN ; Thang Van DINH ; Thang PHAN ; Thi Anh Thu DANG
Journal of Preventive Medicine and Public Health 2024;57(1):37-46
Objectives:
The objective of this study was to characterize mental health issues among Vietnamese healthcare workers (HCWs) and to identify related factors.
Methods:
A cross-sectional study was conducted with 990 HCWs in 2021. Their mental health status was measured using the Depression, Anxiety, and Stress Scale.
Results:
In total, 49.9%, 52.3%, and 29.8% of respondents were found to have depression, anxiety, and stress, respectively. The multivariable linear regression model revealed that factors associated with increased anxiety scores included depression scores (β, 0.45; 95% confidence interval [CI], 0.39 to 0.51) and stress scores (β, 0.46; 95% CI, 0.41 to 0.52). Factors associated with increased depression scores included being frontline HCWs (β, 0.57; 95% CI, 0.10 to 1.10), stress scores (β, 0.50; 95% CI, 0.45 to 0.56), and anxiety scores (β, 0.41; 95% CI, 0.36 to 0.47), while working experience was associated with reduced depression scores (β, -0.08; 95% CI, -0.16 to -0.01). Factors associated with increased stress scores included working experience (β, 0.08; 95% CI, 0.00 to 0.16), personal protective equipment interference with daily activities (β, 0.55; 95% CI, 0.07 to 1.00), depression scores (β, 0.54; 95% CI, 0.48 to 0.59), and anxiety scores (β, 0.45; 95% CI, 0.39 to 0.50), while age was associated with reduced stress scores (β, -0.12; 95% CI, -0.20 to -0.05).
Conclusions
Specific interventions are necessary to enhance and promote the mental health of HCWs so they can successfully cope with the circumstances of the pandemic.
8.The condition of cervical tooth wear and association with brushing habits among students of Hue University of Medicine and Pharmacy
Thi Quynh Thu LE ; Thi Hue Chi HUYNH ; Ngoc Tam Dan NGUYEN
Hue Journal of Medicine and Pharmacy 2023;13(6):58-
Background: Cervical tooth wear is a common oral health issue that often leads to the loss of tooth structure integrity, making the teeth sensitive, prone to plaque buildup, affecting the dental pulp, and causing aesthetic concerns. Assessing the extent of tooth erosion and its correlation with brushing habits is crucial for enhancing the effectiveness of necessary interventions and preventive measures. Objective: To determine the prevalence and severity of cervical tooth wear in young individuals aged 18-25 and examine the association between brushing habits and cervical tooth wear. Methods: A cross-sectional descriptive study was conducted on 60 undergraduate students from the Hue University of Medicine and Pharmacy, aged 18 - 25, who visited the Odonto-Stomatology Clinic, Family Medicine Center from November 2020 to April 2021. Study participants were interviewed and provided clinical examinations after obtaining their consent. Results: The study findings revealed a relatively high prevalence of cervical tooth wear (53.3%). Most cases exhibited a severity score 0 (no tooth wear), and no cases were classified as score 4. The highest prevalence of cervical tooth wear was observed in the left mandibular (65.6%). Regarding the association between cervical tooth wear and brushing habits, there was a significant correlation between horizontal brushing technique and brush hardness with cervical tooth wear (p < 0.05). However, there was no significant correlation between brushing frequency, toothbrush replacement time, brushing duration, and force applied during brushing with cervical tooth wear (p > 0.05). Conclusion: In general, the prevalence of cervical tooth wear is relatively high, and there exists a correlation between horizontal tooth brushing habits and brush hardness with the condition of cervical tooth wear. Therefore, implementing preventive measures against cervical tooth wear is crucial for enhancing oral health for everyone.
9.Circulation of human respiratory syncytial virus and new ON1 genotype in northern Viet Nam, 2017–2020
Thi Hong Trang Ung ; Vu Mai Phuong Hoang ; Huy Hoang Nguyen ; Vu Son Nguyen ; Thi Thanh Le ; Le Khanh Hang Nguyen ; Duc Cong Vuong ; Thi Thu Huong Tran ; Thi Hien Nguyen ; Phuong Anh Nguyen ; Mai Quynh Le
Western Pacific Surveillance and Response 2023;14(4):13-21
Objective: Human respiratory syncytial virus (RSV) is a primary cause of paediatric severe acute respiratory infection (SARI) worldwide, especially in developing countries. We investigated the genetic characteristics of RSV in northern Viet Nam to determine the prevalence and distribution of subtypes as well as the diversity and transmission patterns of genotypes.
Methods: In two facilities, from January 2017 to December 2020, 1563 clinical specimens were collected from paediatric patients hospitalized with SARI and tested for RSV. Selected positive samples underwent sequencing analysis targeting the second hypervariable region of the G gene using next-generation sequencing.
Results: The RSV positivity rate was 28.02% (438/1563 samples), and prevalence was highest in children aged <1 year (43.84%; 192/438). Subtype RSV-A accounted for 53.42% (234/438) of cases, RSV-B for 45.89% (201/438), and there was coinfection in 0.68% (3/438). Both subtypes cocirculated and peaked during August–September in each year of the study. Phylogenetic analysis showed that RSV-A samples belonged to the ON1 genotype, which has three subgenotypes: ON1.1, ON1.2 and ON1.3. However, we did not find the 72-nucleotide duplication in the second hypervariable region of the G gene, a characteristic of genotype ON1, in any RSV-A samples. RSV-B samples belonged to genotype BA9.
Discussion: Our results provide additional molecular characterization of RSV infections in Viet Nam. Specially, our study is the first to report the absence of the 72-nucleotide duplication in the G gene of RSV-A genotype ON1 in Viet Nam, which may help in understanding the genetic evolution of RSV and be useful for vaccine development in the future.
10.Virological characteristics of cases of COVID-19 in northern Viet Nam, January–May 2020
Hang Khanh Le Nguyen ; Son Vu Nguyen ; Phuong Mai Vu Hoang ; Thanh Thi Le ; Huong thi Thu Tran ; Long Hai Pham Nguyen ; Thai Quang Pham ; Thuy Thanh Nguyen ; Anh Duc Dang ; Anh Phuong Nguyen ; Mai thi Quynh Le
Western Pacific Surveillance and Response 2021;12(4):65-70
Background:
Viet Nam confirmed its first case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection on 23 January 2020 among travellers from Wuhan, China, and experienced several clusters of community transmission until September. Viet Nam implemented an aggressive testing, isolation, contact tracing and quarantine strategy in response to all laboratory-confirmed cases. We report the results of SARS-CoV-2 testing during the first half of 2020 in northern Viet Nam.
Methods:
Between January and May 2020, 15 650 upper respiratory tract specimens were collected from 14 470 suspected cases and contacts in northern Viet Nam. All were tested for SARS-CoV-2 by real-time RT-PCR. Individuals with positive specimens were tested every three days until two tests were negative. Positive specimens from 81 individuals were cultured.
Results:
Among 14 470 tested individuals, 158 (1.1%) cases of SARS-CoV-2 infection were confirmed; 89 were imported and 69 were associated with community transmission. Most patients (122, 77%) had negative results after two tests, while 11 and 4 still tested positive when sampled a third and fourth time, respectively. SARS-CoV-2 was isolated from 29 of 81 specimens (36%) with a cycle threshold (Ct) value <30. Seven patients who tested positive again after testing negative had Ct values >30 and negative cultures.
Conclusion
Early, widespread testing for SARS-CoV-2 in northern Viet Nam identified very few cases, which, when combined with other aggressive strategies, may have dramatically contained the epidemic. We observed rapid viral clearance and very few positive results after clearance. Large-scale molecular diagnostic testing is a critical part of early detection and containment of COVID-19 in Viet Nam and will remain necessary until vaccination is widely implemented.


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