An effective live attenuated vaccine against Aeromonas veronii infection in the loach (Misgurnus anguillicaudatus). Issue 104 (September 2020)

• Record Type: Journal Article
• Authors: Zhang, Hai-peng; Chen, Meng-yao; Xu, Yu-xuan; Xu, Guan-yi; Chen, Jing-rui; Wang, Yi-ming; Kang, Yuan-huan; Shan, Xiao-feng; Kong, Ling-cong; Ma, Hong-xia
• Is Part Of: Fish & shellfish immunology. Issue 104(2020)
• Page Start: 269
• Page End: 278
• Publication Date: 2020-09
• Subjects: Loach -- Aeromonas veronii -- Live attenuated vaccine -- Enzyme activities -- Cytokines -- Disease resistance; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2020.05.027
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Aeromonas veronii is a major pathogenic bacterium in humans and animals. When it causes outbreaks, there are enormous economic losses to the aquaculture industry. An effective live attenuated vaccine strain, Δ hisJ, was obtained in our previous studies by gene knockout in Aeromonas veronii TH0426 using the suicide vector pRE112. Here, we evaluated whether the live attenuated vaccine Δ hisJ was suitable for prevention of Aeromonas veronii infection by injection and immersion in loaches. Compared with that of the TH0426 wild-type strain, the virulence of the live vaccine was significantly weakened. Vaccine safety assessment results also indicated that 1 × 10 7 CFU/mL live vaccine was safe and did not induce clinical symptoms or obvious pathological changes. Additionally, after challenging loaches with Aeromonas veronii TH0426, the relative percent survival of the IN3 injection group was 65.66%, and that of the IM group was 50.78%. Our data show that the live attenuated vaccine Δ hisJ can improve the immune protection rate of loaches. Furthermore, increased enzyme activity parameters (SOD, LZM, ACP, and AKP) in the skin mucus, increased enzyme activity parameters (SOD, LZM, ACP, AKP, and GPx) in the serum, increased specific IgM antibodies and cytokine IL-1β contents in the serum, and increased cytokine (IL-15, pIgR, IL-1β, and TNF-α) expression in the liver and spleen were observed. These data are the first to indicate that the live attenuated vaccine Δ hisJ is suitable for the development of a safe and effective vaccine against Aeromonas veronii infection in loach aquaculture. Highlights: The live attenuated vaccine △ hisJ is very safe for vaccination of loach. The live attenuated vaccine △ hisJ induced enzyme activity increase in serum and skin mucus. The expression level of immune-related genes, including IL-1β, TNF-α, IL-10 and pIgR were up-regulated after vaccination. . The Δ hisJ vaccine provided strong protection against Aeromonas veronii TH0426 infection.