Outer membrane proteins and vesicles as promising vaccine candidates against Vibrio spp. infections

Development of a Recombinant Outer Membrane Vesicles (OMVs)-Based Vaccine Against Helicobacter pylori Infection in Mice

The current vaccine development for Helicobacter pylori (H. pylori) still faces challenges of weak immune responses stimulated by existing antigens and a lack of safe adjuvants. The modification of the lipopolysaccharide (LPS) structure by H. pylori is an important mechanism involved in its immune escape. In this study, we developed a novel recombinant vaccine candidate against H. pylori infection by knocking down the key genes (lpxE, lpxF and futB) of LPS modification and employing the bacterial outer membrane vesicles (OMVs) as a vector for delivering UreB, VacA and CagA antigens, and then evaluated its safety and immune protective efficacy in vitro and in vivo mouse model. We measured the antibody and cytokine productions, detected the subtypes of immune cells, and examined the histopathological changes in mice from the control and various experimental groups. We revealed that this OMV-based recombinant vaccine candidate could induce specific humoral immune responses and a Th1/Th2/Th17 mixed immune response, with Th17 being predominant, and markedly protect the mice from H. pylori infection. Our findings suggest that the OMVs with the genetically engineered LPS may function as a vector for delivering recombinant antigens and safe adjuvants for the development of novel vaccine candidates against H. pylori infection.

Unravelling the genomic secrets of bacterial fish pathogens: a roadmap to aquaculture sustainability

In the field of aquaculture, bacterial pathogens pose significant challenges to fish health and production. Advancements in genomic technologies have revolutionized our understanding of bacterial fish pathogens and their interactions with their host species. This review explores the application of genomic approaches in the identification, classification, and characterization of bacterial fish pathogens. Through an extensive analysis of the literature, we have compiled valuable data on 79 bacterial fish pathogens spanning 13 different phyla, encompassing their whole genome sequences. By leveraging high-throughput sequencing techniques, researchers have gained valuable insights into the genomic makeup of these pathogens, enabling a deeper understanding of their virulence factors and mechanisms of host interaction. Furthermore, genomic approaches have facilitated the discovery of potential vaccine and drug targets, opening up new avenues for the development of effective interventions against fish pathogens. Additionally, the utilization of genomics in fish disease resistance and control in aquaculture has shown promising results, enabling the identification of genetic markers associated with disease resistance traits. This review highlights the significant contributions of genomics to the field of fish pathogen research and underscores its potential for improving disease management strategies and enhancing the sustainability of aquaculture practices.