珠三角黄颡鱼细菌性疾病的流行特点及耐药现状研究OA

To elucidate the epidemiological characteristics and antibiotic resistance profiles of bacterial diseases in the yellow catfish(Pelteobagrus fulvidraco)in the Pearl River Delta region,a systematic investigation and analysis were conducted on 375 diseased fish samples collected from March 2022 to September 2023.The results indicated a bacterial disease incidence rate of 56.0%,peaking in spring.The main pathogens included Aeromonas spp.(34.8%,predominantly Aeromonas veronii),Streptococcus spp.(33.8%,predominantly Streptococcus iniae),and Edwardsiella spp.(14.3%).Aeromonas spp.exhibited resistance rates exceeding 39.0%to florfenicol,thiamphenicol,and sulfamethoxazole-trimethoprim,but remained sensitivity to enrofloxacin(11.7%resistance)and doxycycline(1.3%resistance).Edwardsiella spp.showed resistance rates above 40.0%to florfenicol and thiamphenicol.Vibrio spp.were only sensitive to doxycycline(0%resistance).Multidrug-resistance analysis revealed that 39.5%of the strains were resistant to multiple antimicrobial agents(MARI 0.5～1),with 1.68%resistance to all tested drugs.The MIC50/MIC90 ratios revealed significant differences in antimicrobial susceptibility among pathogens,indicating an increased risk of resistance in certain bacterial populations.Cluster analysis confirmed that some highly resistant strains may share common resistance mechanisms or genetic backgrounds.In conclusion,enhanced monitoring and early intervention during spring and summer,together with the regulated antimicrobial usage,can help to promote the green and sustainable development of the yellow catfish aquaculture.