Quantitative Proteomics Reveal the Inherent Antibiotic Resistance Mechanism against Norfloxacin Resistance in .

Recently, the prevalence of antibiotic-resistant strains has been reported in aquaculture, but its intrinsic antibiotic resistance mechanisms are largely unknown. In the present study, a label-free proteomics technology was used to compare the differential protein abundances in response to norfloxacin (NOR) stress in . The results showed that there were 186 proteins decreasing and 220 proteins increasing abundances in response to NOR stress. Bioinformatics analysis showed that the differentially expressed proteins were enriched in several biological processes, such as sulfur metabolism and homologous recombination. Furthermore, the antibiotic sensitivity assays showed that the deletion of , , and significantly decreased the resistance against NOR, whereas Δ, , Δ, and Δ significantly increased the resistance against NOR. Our results provide insights into NOR resistance mechanisms and indicate that , , , and sulfur metabolism may play important roles in NOR resistance in .