Analysis Of Quinolones In Typical Aquaculture Regions Along The Coast Of Guangdong Province And Study Of Its Biomarkers

Quinolones has been widely used in human and animal diseases treatment around the world because of its broad spectrum and significant effects on anti-bacterial,high bioavailability and low toxicity etc.A great part of Quinolones and their active metabolites excreted into the environment will probably influence the microorganism structure of the natural ecology system and lead to the resistance in bacteria.In addition, quinolones may be absorbed by the organisms in aqautic environment and then be transferred through the food chains,which might pose a potential human health risks with the contamination in food animals.Hence,researches on the residues of quinolones in aquatic environment and study on their sensitive biomarkers are of great importances in environmental monitoring.Two typical marine aquaculture regions which locate in Daya Bay and Yangjiang along the coast of Guangdong Province were selected for this research.The concentrations of three types of Quinolones(NFLX,CPFX,ENFX) were determined in water,sediment and fish samples respectively.Mugilogobius abei,which is widely distributed in estuaries of China was applied to the laboratory simulation and field exposure in this study.The negative effects of these Quinolones on aquatic environment were evaluated by the chemical monitoring methods associated with the PhaseⅠ,PhaseⅡmetabolic enzyme response of Mugilogobius abel.The major contents of this research are listed as follows:In the first part,residues of Quinolones in samples of two marine aquiculture regions were analyzed by high performance liquid chromatographic with fluorescence detector(HPLC).The results showed that few quinolones were determined in water samples,in which pharmaceutical concentrations might lower than the limit determination.Also,ENFX was not determined in all sediment samples.The concentrations of NFLX and CPFX in sediment samples ranged from 1.88-11.20 ng·g(-1) and 0.76-2.42 ng·g^-1,respectively.Average levels in sediments from Daya Bay region were higher than that of Yangjiang region.NFLX was the highest residue both in liver and muscle tissues.Among the 9 marine fish species,Siganus fuscescens and Lutianus argentimaculatus from Yangjiang region showed the highest and lowest level of NFLX in liver tissues,the concentrations were 254.58 ng·g^-1 and 5.18 ng·g^-1,respectively.In the second part,with the comparison of background data and PhaseⅠ,PhaseⅡmetabolic enzyme activities of different fishes from two marine aquiculture regions, APND and ERND were selected as the sensitive biomarkers of Quinolones contamination,which the activity levels of these mentioned above were related negatively with the concentrations of NFLX.In the third part,the PhaseⅠ,PhaseⅡmetabolic enzyme activities of Mugilogobius abei were examined under the feed exposure with different levels NFLX.The results showed that an adaptive inducing phenomenon was observed on P450(PhaseⅠ)EROD of Mugilogobius abei.In contrast,the activities of APND and ERND were significantly inhibited.EROD,APND and ERND of P450 could act as the candidate biomarkers of NFLX contamination in environmental monitoring.In the fourth part,Mugilogobius abei were exposed in two typical sites with different priority contaminations.The activities of PhaseⅠ,PhaseⅡwere examined.The results indicated that APND and ERND could act as the biomarkers of antibiotic contamination,while EROD could be used as the biomarker of organic and heavy metal contaminations.