Abstract
Vibrio alginolyticus (V. alginolyticus) is a common pathogen for humans and marine aquatic animals. Vibriosis of marine aquatic animals, caused by V. alginolyticus, has become more prevalent globally in recent years. Hence, a safe and effective vaccine is urgently needed for the control of this disease. Here, the strain 16‐3 isolated from the large yellow croaker (Larimichthys crocea) suffered from canker was identified as V. alginolyticus based on morphological, biochemical, and 16S rDNA sequencing analysis. Then, recombinant temperature‐controlled lysis plasmid pBV220‐lysisE was electroporated into the strain 16‐3 to generate V. alginolyticus bacterial ghosts (VaBGs) by inducing lysis gene E expression, and the safety and immune effects of VaBGs were further investigated in mice and large yellow croaker. The results showed that VaBGs were as safe as formalin‐killed V. alginolyticus cells (FKC) to mice and fish. Compared with FKC and PBS groups, significant elevations of the serum agglutinating antibody titer, serum bactericidal activity, lymphocyte proliferative responses, and levels of four different cytokines (Th1 type: IL‐2, TNF‐α; Th2 type: IL‐4 and IL‐6) in serum were detected in the VaBGs group, indicating that a Th1/Th2‐mediated mixed immune response was elicited by the VaBGs. More importantly, after challenged with the parent strain 16‐3, VaBGs‐vaccinated mice and fish showed higher protection than FKC‐vaccinated mice, the relative percent of survival (RPS) being 60%, 66.7% and 40%, respectively. Taken together, this is the first demonstration that the newly constructed V. alginolyticus ghosts may be developed as a safe and effective vaccine against V. alginolyticus infection in aquaculture.
Highlights
Vibrio alginolyticus is one of the most common pathogenic marine Vibrio species and has been found to cause serious vibriosis in marine aquatic animals (Damir, Irena, Damir, & Emin, 2013; Gómezleón, Villamil, Lemos, Novoa, & Figueras, 2005; Kahlanakbi, Chaieb, & Bakhrouf, 2009; Sadok, Mejdi, Nourhen, & Amina, 2013), and induce seafood-p oisoning or fatal extra-intestinal infections in humans after consumption of raw or undercooked sea products (Lin, Ou, Dong, & Chen, 2001; Qiang, Qing, & Shen, 2006)
The structural integrity and the apparent loss of cytoplasmic materials were observed in V. alginolyticus strain 16-3 bacterial ghosts (BGs) by transmission electron microscopy (Figure 5b). These results indicated that V. alginolyticus bacterial ghosts (VaBGs) possessed the normal array of cell surface antigens of live bacteria, but basically no cytoplasmic contents
The results showed that the average stimulation index (SI) in the five groups were 2.06 ± 0.09 (VaBGs group in mice), 1.39 ± 0.13 (FKC group in mice), 1.27 ± 0.09 (PBS group in mice), 1.86 ± 0.04 (VaBGs group in fish), and 1.35 ± 0.03 (PBS group in fish), respectively
Summary
Vibrio alginolyticus is one of the most common pathogenic marine Vibrio species and has been found to cause serious vibriosis in marine aquatic animals The reported V. alginolyticus vaccines for fisheries in laboratory studies mainly include formaldehyde-killed vaccine, subunit vaccine, live-attenuated vaccine, and naked DNA vaccine (Cai et al, 2010, 2013; Idris, Alhaj, Shamsudin, & Rahim, 2009; Li, Ma, & Woo, 2015). The resultant BGs retain the functional and antigenic determinants of the envelope with their living counterparts They possess good immunogenicity and adjuvant properties and can be used as a vaccine directly (Riedmann, Kyd, Cripps, & Lubitz, 2007). The main objectives of the present study were (1) to identify the strain 16-3, (2) to develop V. alginolyticus strain 16-3 BGs vaccine, and (3) to evaluate the immune effects of the vaccine in mice and large yellow croaker
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
