Pathogenicity of Different Betanodavirus RGNNV/SJNNV Reassortant Strains in European Sea Bass

Pathogens

Alessandra Buratin¹  Marica Toson¹  Anna Toffan¹  Miriam Abbadi¹  Andrea Marsella¹  Lorena Biasini¹  Francesco Pascoli¹  Paola Berto¹ 

[1] Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, 35020 Padova, Italy;

关键词: betanodavirus;    viral encephalopathy and retinopathy;    reassortant;    European sea bass;    pathogenicity;   

DOI  :  10.3390/pathogens11040458

来源: DOAJ

【 摘 要 】

European sea bass (Dicentrarchus labrax) is an important farmed marine species for Mediterranean aquaculture. Outbreaks of betanodavirus represent one of the main infectious threats for this species. The red-spotted grouper nervous necrosis virus genotype (RGNNV) is the most widely spread in Southern Europe, while the striped jack nervous necrosis virus genotype (SJNNV) has been rarely detected. The existence of natural reassortants between these genotypes has been demonstrated, the RGNNV/SJNNV strain being the most common. This study aimed to evaluate the pathogenicity of different RGNNV/SJNNV strains in European sea bass. A selection of nine European reassortants together with parental RGNNV and SJNNV strains were used to perform in vivo experimental challenges via intramuscular injection. Additional in vivo experimental challenges were performed by bath immersion in order to mimic the natural infection route of the virus. Overall, results on survival rates confirmed the susceptibility of European sea bass to reassortants and showed different levels of induced mortalities. Results obtained by RT-qPCR also highlighted high viral loads in asymptomatic survivors, suggesting a possible reservoir role of this species. Our findings on the comparison of complete genomic segments of all reassortants have shed light on different amino acid residues likely involved in the variable pathogenicity of RGNNV/SJNNV strains in European sea bass.

【 授权许可】

Unknown