The impact of Achyranthes aspera seeds and leaves supplemented feeds on the survival, growth, immune system and specific genes involved in immunostimulation in Clarias batrachus fry challenged with Aeromonas hydrophila in pond conditions.

The present study was conducted to evaluate the effect of dietary inclusion of Achyranthes aspera seeds and leaves on the immune system of magur Clarias batrachus challenged with Aeromonas hydrophila in pond conditions. Magur fry (0.51 ± 0.032 g) were cultured in hapas set inside a pond and were fed with three feeds. Two experimental feeds FS1 and FS2 were supplemented with 0.5% seeds and leaves of A. aspera, respectively and FC3 was the control one. After 90 days of feeding, fish were challenged with A. hydrophila. In FC3, 70% fish died within 48 h of challenge, while 25 and 30% mortality were recorded in FS1 and FL2, respectively. The cumulative mortality rates were 70, 45 and 35% in FC3, FL2 and FS1, respectively. The average weight and specific growth rate of magur were significantly higher in FS1 compared to others. Serum lysozyme, myeloperoxidase, nitric oxide synthase and superoxide dismutase levels were significantly higher in FS1 compared to others. Thiobarbituric acid reactive substances and carbonyl protein levels were significantly lower in FS1 compared to others. In liver and head kidney of FS1 and FS2 fed magur, the iNOS, SOD-C, TNF-α, Cytochrome c, Caspase 9 were up-regulated. Caspase 3 was also significantly up-regulated in FS1 and it was followed by FL2 treatment. A. aspera incorporated feeds improved the immune system of fish and gave protection against bacteria even in the pond conditions.

Identification of genotypic variants and its proteomic mutations of Brazilian SARS-CoV-2 isolates.

The second wave of COVID-19 caused by severe acute respiratory syndrome virus (SARS-CoV-2) is rapidly spreading over the world. Mechanisms behind the flee from current antivirals are still unclear due to the continuous occurrence of SARS-CoV-2 genetic variants. Brazil is the world's second-most COVID-19 affected country. In the present study, we identified the genomic and proteomic variants of Brazilian SARS-CoV-2 isolates. We identified 16 different genotypic variants were found among the 27 isolates. The genotypes of three isolates such as Bra/1236/2021 (G15), Bra/MASP2C844R2/2020 (G11), and Bra/RJ-DCVN5/2020 (G9) have a unique mutant in NSP4 (S184N), 2'O-Mutase (R216N), membrane protein (A2V) and Envelope protein (V5A). A mutation in RdRp of SARS-CoV-2, particularly the change of Pro-to Leu-at 323 resulted in the stabilization of the structure in BRA/CD1739-P4/2020. NSP4, NSP5 protein mutants are more virulent in genotype 15 and 16. A fast protein folding rate changes the structural stability and leads to escape for current antivirals. Thus, our findings help researchers to develop the best potent antivirals based on the new mutant of Brazilian isolates.