Toxic Effects Of Florfenicol And Its Analogues To Aquatic Organisms

Florfenicol, thiamphenicol and chloramphenicol are three kinds of typical pharmaceuticals used widely as therapeutical antibiotic agent in aquaculture. However, little is known about the potential adverse effects of these pharmaceuticals mentioned above on the non-target organisms in the aquatic ecosystem while they were used in aquaculture. In this research, Chlorella pyrenoidosa, Daphnia Carinata and Xiphophorus helleri were chosen as the representative organisms of three trophic levels in aquatic ecosystem to study the toxic effects of Florfenicol and its analogues on aquatic organisms.Acute toxic effects of florfenicol, thiamphenicol and chloramphenicol to Chlorella pyrenoidosa was investigated, the results showed that the growth of Chlorella pyrenoidosa was subject to different degrees of inhibition. It was high-toxic for florfenicol to Chlorella pyrenoidosa, while mid-toxic for thiamphenicol and chloramphenicol. The 48h EC50 and 96h EC50 of florfenicol for Chlorella pyrenoidosa were 10.42 mg/L and 9.40mg/L, respectively. They were 84.35 mg/L and 64.92mg/L for thiamphenicol, respectively, and 28.66 mg/L and 25.26mg/L for chloramphenicol, respectively. The safe concentrations were 0.94mg/L,6.49mg/L and 2.53mg/L, respectively.It was low-toxic for florfenicol, thiamphenicol and chloramphenicol to Daphnia Carinata. The 48h LC50 were 491.13 mg/L,951.49 mg/L and 192.60mg/L for florfenicol,thiamphenicol and chloramphenicol, respectively. The safe concentrations were 49.1 mg/L,95.15 mg/L and 19.26mg/L, respectively.Florfenicol, thiamphenicol and chloramphenicol were all low-toxic to Xiphophorus helleri. In the range of 1.25mg/L to 80mg/L in florfenicol exposure,0.8mg/L to 100mg/L in thiamphenicol exposure,0.48mg/L to 60mg/L in chloramphenicol exposure, GSH, GST and EROD were induced or inhabited remarkably on some concentrations, but this response was not continuous. In this research, GSH, GST, EROD could not be regarded as the candidate biomarkers of florfenicol, thiamphenicol and chloramphenicol exposure to xiphophorus helleri.