Genotoxic impact of emerging contaminant amoxicillin residue on zebra fish (Danio rerio) embryos

The widest-spectrum, most-consumed β-lactam antibiotic amoxicillin (AMX) is used to treat bovine mastitis that is caused primarily by many bacteria. Excessive use of antibiotics can lead to established residual contamination of the milk even after pasteurization. The amount of antibiotic residue above Maximum Residue Limit (MRL) has a negative impact on both public health and the environment. Therefore, the objective of this study is to determine the concentration of amoxicillin residue (AMXR) in raw and pasteurized milk samples of cow suffered from mastitis, by the standard methods of HPLC compared to pure AMX drug and effect of the said residue on the developmental toxicity and genotoxicity of zebra fish at 72 hpf and 48 hpf embryo, respectively. Results obtained by HPLC showed that AMXR exhibits 574.89 and 250.75 times higher concentration in the raw and pasteurized milk than MRL in compare to pure AMX drug. This current study showed that AMXR decreased the body length and yolk sac region, while the pure AMX drug-treated group showed increased height and length of the yolk sac and shorter body length relative to the other groups. The Comet Assay measured the DNA damage caused by AMXR. The group where AMXR were applied showed the highest percentage of tail DNA and tail moment relative to other groups. So, here AMXR is considered as the genotoxic contaminant that is emerging and affect on public health.