Masud Bora’s research while affiliated with West Bengal University of Animal and Fishery Sciences and other places

The aquaculture industry urgently requires effective bacterial disease management strategies, necessitating better regulation of antibiotic application. This study investigated the effects of oral oxolinic acid (OA) administration on Oreochromis niloticus at the recommended dose of 12 mg (1 ×) and overdose of 36 mg (3 ×)/kg biomass/day for 7 consecutive days in terms of growth, oxidative stress, residue accretion and histopathology relative to the control. The 1 × and 3 × groups experienced dose-dependent mortalities (3.33-8.33 %). The OA residues peaked in the liver and kidney tissues with dosing and declined upon discontinuation. The residues persisted in the kidney even on day 35 post-dosing. Elevated malondialdehyde and total nitric oxide levels signified oxidative stress and correlated with the tissue level changes in various organs. Histologically, glycogen-type vacuolation and cellular hypertrophy were observed in the liver. The kidney had hydropic swelling, renal epithelium degradation, nephrocalcinosis, vacuolation, and necrosis. Splenic alterations were confined to ne-crosis and a slight increase in sinusoidal space. Intestinal tissues exhibited a depletion of absorptive vacuoles, epithelial layer degradation, mucinous degeneration, and necrosis. Gills displayed epithelial hyperplasia, thickening of secondary lamellae, and erosion. Nevertheless, the cohort administered the recommended dose exhibited recovery with OA discontinuation. However, none of the assessed parameters normalized in the overdosed group even after 35 days of dose suspension. The results indicated that O. niloticus can safely adapt to and tolerate the toxic effects of OA. As the recommended dose of OA elicited reversible bioresponses effectively in tilapia, it can be utilized in aquaculture with due caution following regulations.

Aquaculture urgently requires effective bacterial disease management, necessitating improved regulation of antibiotic application. This study investigated the effects of oral oxolinic acid (OA) administration on Oreochromis niloticus at the dose of 12 (1×) and 36 mg (3×)/kg biomass/day for 7 consecutive days, relative to a control group. The 1× and 3× groups experienced dose-dependent mortalities ranging from 3.33% to 8.33%. The concentrations of OA residues peaked in the plasma, liver, and kidney on day 7 with the muscle tissues showing the greatest amounts. In both groups, the residues persisted even on day 35 post-dosing. Elevated concentrations of malondialdehyde and total nitric oxide were noted, signifying oxidative stress responses, which correlated with the tissue level changes in various organs. Nevertheless, the cohort administered the recommended dose (1×) exhibited recovery following OA discontinuation. Histologically, the kidney had hydropic oedema, degradation of renal epithelium, nephrocalcinosis, vacuolation, and necrosis. Glycogen-type vacuolation, cellular hypertrophy, and cytoplasmic vacuolation were observed in the liver. Gills exhibited epithelial hyperplasia, thinning, curling, thickening of secondary lamellae, and erosion. Intestinal tissues exhibited a depletion of absorptive vacuoles, degradation of the epithelial layer, mucinous degeneration, and necrotic regions. Splenic alterations were confined to necrosis and a slight increase in sinusoidal space. Recovery was noted in the 1× group. However, none of the assessed parameters normalized in the 3× group even after 35 days of dose suspension. The results, thus, indicated that O. niloticus can able to adapt and tolerate OA safely. However, the recommended dose of OA (12 mg/kg biomass/day for 7 days) elicited reversible biological reactions in tilapia and can be utilized in aquaculture with due caution following regulations.