Distribution Of Enrofloxacin In Simulated Aquaculture System Of Chinese Mitten Crab(Eriocheir Sinensis) And Study It Resistance At The Transcription Level

This paper used reversed-phase high performance liquid chromatographic method(RP-HPLC)to research the residues of enrofloxacin(ENR)in water?sediments?Chinese mitten crab(Eriocheir sinensis)and snails of simulated aquaculture system of Chinese mitten crab.We compared the fate of enrofloxacin in three different pH systems that weak acid,neutral and weak base simulated aquaculture systems,respectively.Enrofloxacin residues in water less than 5?g/L;weak alkaline sediment in the system as high as 2689.52?g/kg,elimination half-life up to96 d.Enrofloxacin is more likely to accumulate in the internal organs,so the residuals have tissue differences.pH greater impact on the distribution of enrofloxacin in water,sediments and hornwort and elimination;less impact on the Chinese mitten crab and snails and other organisms.Enrofloxacin residues in the distribution phase of the weak acid simulations were greater than those in the neutral and weak alkaline culture systems.The contents of enrofloxacin in Eriocheir sinensis aquculture system were: weak acid system?neutral system?weak base system.Following enrofloxacin treatment,a total of 1,327 DEGs were found to be upregulated and 1,468 DEGs were downregulated in E.sinensis.The results showed that metabolic and signal transduction pathways were significantly enriched.Furthermore,we found that gshB and the CYP450 enzyme system plays a role in the metabolism of enrofloxacin in the hepatopancreas of E.sinensis.This study identified differential unigenes related to transmembrane transport and drug metabolism in Eriocheir sinensis which could help us developing our understanding of the molecular basis of enrofloxacin metabolism in this economically important aquaculture species.After enrofloxacin treatment,218 transcripts were deemed to be differentially expressed genes(DEGs),135 genes were upregulated and 83 genes were downregulated.This study identified enrofloxacin treatment affects multiple biological functions of A.hydrophila.Enrofloxacin resistance in A.hydrophila is closely related to the reduction of intracellular drug accumulation caused by ABC transporters and increased expression of topoisomerase ?.