1.Large-scale salmonella outbreak associated with banh mi, Viet Nam, 2024
Tinh Huu Ho ; Phuong Hoai Hoang ; Lam Vo Thi Ngoc ; Minh Nguyen Dinh ; Dong Do Thanh ; Viet Nguyen Dinh ; O Phan Van ; Phuong Nguyen Thi Lan ; Thanh Nguyen Quoc ; Nhan Ho The ; Nhan Le Dinh Trong ; Chinh Van Dang
Western Pacific Surveillance and Response 2024;15(3):36-42
Objective: To investigate the cause of a foodborne outbreak that occurred in Dong Nai province, Viet Nam, in 2024, and implement control measures.
Methods: An initial investigation was conducted to confirm the outbreak, which was followed by epidemiological and environmental investigations to find the plausible causative food item. Clinical specimens and food samples were tested to identify the pathogen.
Results: A total of 547 symptomatic cases were recorded, of whom two were in severe condition requiring extracorporeal membrane oxygenation and ventilation, one of whom died. Among 99 interviewed cases, the mean incubation time was 9 hours (range 2–24 hours), with the main symptoms being fever, abdominal pain, diarrhoea and vomiting. All patients had eaten banh mi from a local bakery. Salmonella spp. were identified in food samples and clinical specimens. The bakery halted production, and the outbreak ended after 1 week.
Discussion: All the patients were exposed to only one food in common, which facilitated the investigation process. This outbreak is a reminder to small retailers and take-away shops of the importance of food safety management in preventing similar future outbreaks. All food handlers must comply with food hygiene principles, especially in hot temperatures, which boosts bacterial growth.
2.Identification of Phenolic Compounds from Vietnamese Artichoke (Cynara scolymus L.) Leaf and Their Antioxidant Activities
Anh Nguyet Thi NGUYEN ; Thanh Tuyen Thi VU ; Hong Tuoi Thi DO ; Thien Hai NGUYEN ; Huan Van LE ; Hong Khuyen Thi PHAM ; Phu Chi Hieu TRUONG ; Dong Phuong PHAM ; Manh Hung TRAN
Natural Product Sciences 2024;30(1):39-51
Artichoke (Cynara scolymus L.) is a perennial plant belonging to the Asteraceae family originating from the Mediterranean region. In Vietnam, there are some varieties of artichoke which are extensively cultivated and propagated in highland areas, however, there have been limited detailed scientific publications on the chemical composition and biological activity of artichoke grown in Vietnam. Therefore, this study provides a detailed description of the extraction, isolation, and structural determination of 20 natural secondary metabolites present in harvested artichoke. The antioxidant activity of the extract and the 9 isolated compounds are tested in 1,1-diphenyl-2-picrylhydrazyl radical scavenging and ex vivo malondialdehyde model. Among the selected compounds, 1-caffeoylquinic acid, 3-caffeoylquinic acid, chlorogenic acid, 4-caffeoylquinic acid, cynarin, 1,5-dicaffeoylquinic acid, 4,5-di-caffeoylquinic acid, cynaroside, and scolymoside exhibited strong radical scavenging activity with IC50 values ranging from 5.7 to 61.6 µM. In the malondialdehyde assay, 1,3-dicaffeoylquinic acid (or cynarin) showed the strongest activity with an IC50 value of 24.7 µM, followed by 1,5-di-caffeoylquinic acid (66.8 µM), and 4,5-di-caffeoylquinic acid (127.3 µM). This outcome contributes to establishing a database on the phytochemical and antioxidant activity of the Vietnamese artichoke.
3.Systematic sequencing of imported cases leads to detection of SARS-CoV-2 B.1.1.529 (Omicron) variant in central Viet Nam
Do Thai Hung ; Nguyen Bao Trieu ; Do Thi Thu Thuy ; Allison Olmsted ; Trinh Hoang Long ; Nguyen Duc Duy ; Huynh Kim Mai ; Bui Thi Thu Hien ; Nguyen Van Van ; Tran Van Kiem ; Vo Thi Thuy Trang ; Nguyen Truong Duy ; Ton That Thanh ; Huynh Van Dong ; Philip L Gould ; Matthew R Moore
Western Pacific Surveillance and Response 2022;13(4):82-85
As authorities braced for the arrival of the Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), infrastructure investments and government directives prompted action in central Viet Nam to establish capacity for genomic surveillance sequencing. From 17 November 2021 to 7 January 2022, the Pasteur Institute in Nha Trang sequenced 162 specimens from 98 150 confirmed SARS-CoV-2 cases in the region collected from 8 November to 31 December 2021. Of these, all 127 domestic cases were identified as the B.1.617.2 (Delta) variant, whereas 92% (32/35) of imported cases were identified as the B.1.1.529 (Omicron) variant, all among international flight passengers. Patients were successfully isolated, enabling health-care workers to prepare for additional cases. Most (78%) of the 32 Omicron cases were fully vaccinated, suggesting continued importance of public health and social measures to control the spread of new variants.
4.Potentiation of the glycine response by serotonin on the substantia gelatinosa neurons of the trigeminal subnucleus caudalis in mice
Hoang Thi Thanh NGUYEN ; Dong Hyu CHO ; Seon Hui JANG ; Seong Kyu HAN ; Soo Joung PARK
The Korean Journal of Physiology and Pharmacology 2019;23(4):271-279
The lamina II, also called the substantia gelatinosa (SG), of the trigeminal subnucleus caudalis (Vc), is thought to play an essential role in the control of orofacial nociception. Glycine and serotonin (5-hydroxytryptamine, 5-HT) are the important neurotransmitters that have the individual parts on the modulation of nociceptive transmission. However, the electrophysiological effects of 5-HT on the glycine receptors on SG neurons of the Vc have not been well studied yet. For this reason, we applied the whole-cell patch clamp technique to explore the interaction of intracellular signal transduction between 5-HT and the glycine receptors on SG neurons of the Vc in mice. In nine of 13 neurons tested (69.2%), pretreatment with 5-HT potentiated glycine-induced current (I(Gly)). Firstly, we examined with a 5-HT₁ receptor agonist (8-OH-DPAT, 5-HT(1/7) agonist, co-applied with SB-269970, 5-HT₇ antagonist) and antagonist (WAY-100635), but 5-HT₁ receptor agonist did not increase IGly and in the presence of 5-HT₁ antagonist, the potentiation of 5-HT on I(Gly) still happened. However, an agonist (α-methyl-5-HT) and antagonist (ketanserin) of the 5-HT₂ receptor mimicked and inhibited the enhancing effect of 5-HT on I(Gly) in the SG neurons, respectively. We also verified the role of the 5-HT₇ receptor by using a 5-HT₇ antagonist (SB-269970) but it also did not block the enhancement of 5-HT on I(Gly). Our study demonstrated that 5-HT facilitated I(Gly) in the SG neurons of the Vc through the 5-HT₂ receptor. The interaction between 5-HT and glycine appears to have a significant role in modulating the transmission of the nociceptive pathway.
Animals
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Glycine
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Mice
;
Neurons
;
Neurotransmitter Agents
;
Nociception
;
Patch-Clamp Techniques
;
Receptors, Glycine
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Serotonin
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Signal Transduction
;
Substantia Gelatinosa
5.L1 Recombinant Proteins of HPV Tested for Antibody Forming Using Sera of HPV Quadrivalent Vaccine.
Begum AKUZUM ; Sinae KIM ; Tam Thanh NGUYEN ; Jeawoo HONG ; Siyoung LEE ; Eunhye KIM ; Joohee KIM ; Yeook CHOI ; Hyunjhung JHUN ; Youngmin LEE ; Hyunwoo KIM ; Dong Hyun SOHN ; Soohyun KIM
Immune Network 2018;18(3):e19-
Virus-like particles (VLPs) derived from human papillomavirus (HPV) L1 capsid proteins were used for HPV quadrivalent recombinant vaccine. The HPV quadrivalent vaccine is administrated in a 3-dose regimen of initial injection followed by subsequent doses at 2 and 6 months to prevent cervical cancer, vulvar, and vaginal cancers. The type 6, 11, 16, or 18 of HPV infection is associated with precancerous lesions and genital warts in adolescents and young women. The HPV vaccine is composed of viral L1 capsid proteins are produced in eukaryotic expression systems and purified in the form of VLPs. Four different the L1 protein of 3 different subtypes of HPV: HPV11, HPV16, and HPV18 were expressed in Escherichia coli divided into 2 fragments as N- and C-terminal of each protein in order to examine the efficacy of HPV vaccine. Vaccinated sera failed to recognize N-terminal L1 HPV type 16 and type 18 by western blot while they detected N-terminal L1 protein of HPV type 11. Moreover, the recombinant C-terminal L1 proteins of type 16 was non-specifically recognized by the secondary antibody conjugated with horseradish peroxidase. This expression and purification system may provide simple method to obtain robust recombinant L1 protein of HPV subtypes to improve biochemical analysis of antigens with immunized sera.
Adolescent
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Blotting, Western
;
Capsid Proteins
;
Condylomata Acuminata
;
Enzyme-Linked Immunosorbent Assay
;
Escherichia coli
;
Female
;
Horseradish Peroxidase
;
Humans
;
Methods
;
Papillomaviridae
;
Recombinant Proteins*
;
Uterine Cervical Neoplasms
;
Vaginal Neoplasms
6.IL-32-induced Inflammatory Cytokines Are Selectively Suppressed by α1-antitrypsin in Mouse Bone Marrow Cells.
Siyoung LEE ; Dong Ki CHOI ; Areum KWAK ; Sinae KIM ; Tam Thanh NGUYEN ; Gaae GIL ; Eunhye KIM ; Kwang Ha YOO ; In Ae KIM ; Youngmin LEE ; Hyunjhung JHUN ; Edward D CHAN ; Xiyuan BAI ; Hyunwoo KIM ; Yong Sung KIM ; Soohyun KIM
Immune Network 2017;17(2):116-120
The induction of interleukin (IL)-32 in bone marrow (BM) inflammation is crucial in graft versus host disease (GvHD) that is a common side effect of allogeneic BM transplantation. Clinical trials on α-1 antitrypsin (AAT) in patients with GvHD are based on the preliminary human and mouse studies on AAT reducing the severity of GvHD. Proteinase 3 (PR3) is an IL-32-binding protein that was isolated from human urine. IL-32 primarily induces inflammatory cytokines in myeloid cells, probably due to PR3 expression on the membrane of the myeloid lineage cells. The inhibitory activity of AAT on serine proteinases may explain the anti-inflammatory effect of AAT on GvHD. However, the anti-inflammatory activity of AAT on BM cells remains unclear. Mouse BM cells were treated with IL-32γ and different inflammatory stimuli to investigate the anti-inflammatory activity of AAT. Recombinant AAT-Fc fusion protein inhibited IL-32γ-induced IL-6 expression in BM cells, but failed to suppress that induced by other stimuli. In addition, the binding of IL-32γ to PR3 was abrogated by AAT-Fc. The data suggest that the specific anti-inflammatory effect of AAT in mouse BM cells is due to the blocking of IL-32 binding to membrane PR3.
Animals
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Bone Marrow Cells*
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Bone Marrow*
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Cytokines*
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Graft vs Host Disease
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Humans
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Inflammation
;
Interleukin-6
;
Interleukins
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Membranes
;
Mice*
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Myeloblastin
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Myeloid Cells
;
Serine Proteases
7.The Protective Effect of Eupatilin against Hydrogen Peroxide-Induced Injury Involving 5-Lipoxygenase in Feline Esophageal Epithelial Cells.
Jae Chun LIM ; Sun Young PARK ; Yoonjin NAM ; Thanh Thao NGUYEN ; Uy Dong SOHN
The Korean Journal of Physiology and Pharmacology 2012;16(5):313-320
In this study, we focused to identify whether eupatilin (5,7-dihydroxy-3',4',6-trimethoxyflavone), an extract from Artemisia argyi folium, prevents H2O2-induced injury of cultured feline esophageal epithelial cells. Cell viability was measured by the conventional MTT reduction assay. Western blot analysis was performed to investigate the expression of 5-lipoxygenase by H2O2 treatment in the absence and presence of inhibitors. When cells were exposed to 600 microM H2O2 for 24 hours, cell viability was decreased to 40%. However, when cells were pretreated with 25~150 microM eupatilin for 12 hours, viability was significantly restored in a concentration-dependent manner. H2O2-treated cells were shown to express 5-lipoxygenase, whereas the cells pretreated with eupatilin exhibited reduction in the expression of 5-lipoxygenase. The H2O2-induced increase of 5-lipoxygenase expression was prevented by SB202190, SP600125, or NAC. We further demonstrated that the level of leukotriene B4 (LTB4) was also reduced by eupatilin, SB202190, SP600125, NAC, or nordihydroguaiaretic acid (a lipoxygenase inhibitor) pretreatment. H2O2 induced the activation of p38MAPK and JNK, this activation was inhibited by eupatilin. These results indicate that eupatilin may reduce H2O2-induced cytotoxicity, and 5-lipoxygenase expression and LTB4 production by controlling the p38 MAPK and JNK signaling pathways through antioxidative action in feline esophageal epithelial cells.
Anthracenes
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Arachidonate 5-Lipoxygenase
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Artemisia
;
Blotting, Western
;
Cell Survival
;
Epithelial Cells
;
Flavonoids
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Hydrogen
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Hydrogen Peroxide
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Imidazoles
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Leukotriene B4
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Lipoxygenase
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MAP Kinase Signaling System
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Nordihydroguaiaretic Acid
;
p38 Mitogen-Activated Protein Kinases
;
Pyridines
8.Virulence factors in Escherichia coli isolated from calves with diarrhea in Vietnam.
Tan Duc NGUYEN ; Thin Thanh VO ; Hung VU-KHAC
Journal of Veterinary Science 2011;12(2):159-164
This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.
Animals
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Cattle
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Cattle Diseases/epidemiology/*microbiology
;
DNA, Bacterial/chemistry/genetics
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Diarrhea/epidemiology/microbiology/*veterinary
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Escherichia coli/genetics/*isolation & purification/pathogenicity
;
Escherichia coli Infections/epidemiology/microbiology/*veterinary
;
Feces/microbiology
;
Fimbriae, Bacterial/genetics
;
Polymerase Chain Reaction/veterinary
;
Polymorphism, Restriction Fragment Length
;
Vietnam/epidemiology
;
Virulence Factors/*genetics
9.Evaluation of microbial contamination in shrimp paste
Cuong Tuan Ngo ; Minh Binh Nguyen ; Tu Dong Nguyen ; Huong Thanh Le ; Thu Hoai Nguyen
Journal of Preventive Medicine 2008;18(1):50-53
Background: Food-born bacteria can be present in raw materials or contaminated foods during process and storage. Shrimp paste is a popular food in Viet Nam, but there are no studies on the hygiene and safety of this food. Objectives: To identify the microbial contamination of commercial shrimp paste available in Ha Noi City. Materials and method: A total of 50 shrimp paste samples were collected randomly from markets around Ha Noi City. Enumeration and isolation methods were used to determine the microbial contamination in these samples. Results: 100% of the samples were contaminated with Clostridium perfringens and Candida albicans. 10% of samples were contaminated with Coliform. Other pathogenic bacteria, including Escherichia coli, Salmonella, Staphylococcus aureus, Vibrio parahaemolyticus and Vibrio cholerae were not found in shrimp paste samples. Conclusion: Evaluation of microbial contamination in popular foods such as shrimp paste should be done regularly to prevent food-born diseases in the community.
Microbial contamination
;
Food safety.
10.Major enteropathogenic bacteria isolated in Hai Phong pediatric hospital from diarrhea patients
Huong Thanh Le ; Tu Dong Nguyen ; Cuong Tuan Ngo ; Thu Hoai Nguyen ; Minh Binh Nguyen
Journal of Preventive Medicine 2008;0(3):33-37
Background: Diarrhea is a leading cause of death in children under 5 years old, especially in developing countries. About 12.600 children die because of diarrhea everyday in Asia, Africa and Latin-America. Objective: To identify the main organism that causes diarrhea in children under 5 years old. Subject and Method: The etiology agents of diarrheal children under 5 years old admitted to the Pediatric Hospital in Hai Phong city were studied in the period from September 2006 to August 2007. A total of 968 children were examined for diarrheagenic Escherichia coli (DEC), Salmonella, Shigella, Vibrio, Aeromonas, Campylobacter, these pathogens as being significant bacteria associated with diarrhea. A total of 212 out of 968 cases were positive for bacteria. Result: The main pathogens were diarrheagenic Eschierichiacoli 153 (15.7%), Salmonella 12 (1.24%), Shigella 32 (3.3%). Vibirio paraheamolyticus 1(0.1%), Aeromonas 8 (0.8%), Campylobacter 6(0.6%) from rectal swabs and no Vibrio cholerae was found. The multiplex PCR assays for the identification of DEC was developed. DEC was classified into 6 categories with frequencies of EPEC 3.9%, ETEC 4.4%, EIEC 0.6%, EAggEC 6.7%, DAEC 0.1%, no EHEC was identified. Conclusion: An analysis of incidence of enteropathogens with respect to seasonal variant demonstrated that the frequencies of isolation of etiology agents mainly in July, August and September. This study also showed that diarrheagenic- Escherichia coli is the main organism causing diarrhea in children under 5 years old.
Diarrhea
;
enteropathogenic bacteri
;
diarrheagenic Eschierichiacoli


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