Van Duy Nguyen

Introduction. Helicobacter pylori infection is a major global health concern, linked to the development of various gastrointestinal diseases, including gastric cancer. To study the pathogenesis of H. pylori and develop effective intervention strategies, appropriate animal pathogen models that closely mimic human infection are essential. Gap statement. This study focuses on the understudied hpEastAsia genotype in Southeast Asia, a region marked by a high H. pylori infection rate. No mouse-adapted model strains has been reported previously. Moreover, it recognizes the urgent requirement for vaccines in developing countries, where overuse of antimicrobials is fuelling the emergence of resistance. Aim. This study aims to establish a novel mouse-adapted H. pylori model specific to the hpEastAsia genotype prevalent in Southeast Asia, focusing on comparative genomic and histopathological analysis of pathogens coupled with vaccine preclinical studies. Methodology. We collected and sequenced the whole genome of clinical strains of H. pylori from infected patients in Vietnam and performed comparative genomic analyses of H. pylori strains in Southeast Asia. In parallel, we conducted preclinical studies to assess the pathogenicity of the mouse-adapted H. pylori strain and the protective effect of a new spore-vectored vaccine candidate on male Mlac:ICR mice and the host immune response in a female C57BL/6 mouse model. Results. Genome sequencing and comparison revealed unique and common genetic signatures, antimicrobial resistance genes and virulence factors in strains HP22 and HP34; and supported clarithromycin-resistant HP34 as a representation of the hpEastAsia genotype in Vietnam and Southeast Asia. HP34-infected mice exhibited gastric inflammation, epithelial erosion and dysplastic changes that closely resembled the pathology observed in human H. pylori infection. Furthermore, comprehensive immunological characterization demonstrated a robust host immune response, including both mucosal and systemic immune responses. Oral vaccination with candidate vaccine formulations elicited a significant reduction in bacterial colonization in the model. Conclusion. Our findings demonstrate the successful development of a novel mouse-adapted H. pylori model for the hpEastAsia genotype in Vietnam and Southeast Asia. Our research highlights the distinctive genotype and pathogenicity of clinical H. pylori strains in the region, laying the foundation for targeted interventions to address this global health burden.

This comprehensive article addresses the pressing challenges confronting the global agriculture, primarily driven by climate change and resource constraints. With a focus on promoting climate-smart and sustainable agricultural practices, the study explores the transformative potential of emerging technologies, e.g., the innovative use of digital technologies like Internet of Things, Artificial Intelligence, and Blockchain, showcasing real-world examples of their benefits, and circular technologies, e.g., waste-to-value practices. The challenges of population growth, climate change, environmental impact, and the plight of smallholder farmers are elucidated. Climate-Smart Agriculture initiatives supported by the World Bank Group demonstrate practical efforts in addressing these challenges, aligning with sustainable development goals. Here, we introduce an innovative and smart agriculture (INNSA) platform for the creation and operation of sustainable coffee value chain in Vietnam as a case of study. Thought-provoking questions for future research conclude the review, encouraging interdisciplinary collaboration. In summary, this article provides a compelling case for adopting sustainable agricultural practices through digital and circular technologies, offering a roadmap for global agriculture’s transformation and resilience in the face of climate change.

The antimicrobial activity of silver nanoparticles is widely known. However, their application to biodegradable polymeric materials is still limited. In this work, we report a strategy involving the green synthesis of nanocomposite films based on a natural biodegradable matrix. Nanometer-sized silver nanoparticles (C-AgNPs) were synthesized with the aid of ultrasound waves between the silver nitrate solution and the nanocurcumin solution. The green synthesized C-AgNPs were found to have particle sizes in the range of 5-25 nm and demonstrated good antimicrobial activity against Clostridium perfringens, Staphylococcus aureus, Bacillus subtilis, Macrophoma theicola, and Aspergillus flavus. Owing to their physical-chemical and mechanical properties and the excellent antimicrobial activities, the obtained AgNPs were used together with chitosan, cassava starch, and poly(vinyl alcohol) (PVA) to make nanocomposite films, which are suitable for the packaging requirements of various key agricultural and food products such as coffee beans, bamboo straws, and fruits. The nanocomposite films lost up to 85% of their weight after being buried in the soil for 120 days. This indicates that the films made with natural biodegradable materials are environmentally friendly.

Background: Helicobacter pylori infection remains a major public health threat leading to gastrointestinal illness and increased risk of gastric cancer. Mostly affecting populations in developing countries no vaccines are yet available and the disease is controlled by antimicrobials which, in turn, are driving the emergence of AMR.Materials and Methods: We have engineered spores of Bacillus subtilis to display putative H. pylori protective antigens, urease subunit A (UreA) and subunit B (UreB) on the spore surface. Following oral dosing of mice with these spores, we evaluated immunity and colonization in animals challenged with H. pylori.Results: Oral immunization with spores expressing either UreA or UreB showed antigen‐specific mucosal responses (fecal sIgA) including seroconversion and hyperimmunity. Following challenge, colonization by H. pylori was significantly reduced by up to 1‐log.Conclusions: This study demonstrates the utility of bacterial spores for mucosal vaccination to H. pylori infection. The heat stability and robustness of Bacillus spores coupled with their existing use as probiotics make them an attractive solution for either protection against H. pylori infection or potentially for therapy and control of active infection.

Penicillium vietnamense sp. nov. was isolated from Nha Trang Bay, Vietnam in June 2017. It is phylogenetically distinct from the sister species of Penicillium section Charlesia series Indica based on multi-locus sequence typing results using internal transcribed spacer, large subunit ribosomal RNA, β-tubulin, calmodulin, and RNA polymerase II second largest subunit regions. It showed strong growth on Czapek yeast autolysate agar at 37 °C, a strong acid production on Creatine sucrose agar, and produced short stipes, small vesicles, and subglobose to globose conidia delicately roughened with very short ridges. As the first novel marine fungi species described from Vietnam and discovered in a unique environment, the data could be significant for understanding the taxonomy and geographical distribution of marine fungi in tropical coastal systems such as Vietnam.