Antibiotic-resistant threads of Aeromonas hydrophila as a major pathogen in Indonesia freshwater aquaculture

Abstract

Aeromonas hydrophila is a zoonotic, important primary fish pathogen in many economic fish species. Aeromonas acquires and exchanges antimicrobial resistance genes (ARG) and has been widely studied as a potential reservoir of ARGs. This research aims to observe the impact of antibiotics used through the role of Aeromonas hydrophila as a pathogenic bacteria in aquaculture. The tested antibiotics are based on the Minister of Marine Affairs and Fisheries No. 1/2019 Decree, namely tetracycline, oxytetracycline, and enrofloxacin, which the Indonesian government allows to be used in aquaculture. Random sampling was conducted using four to five fishes per farm in West Java, namely Bogor (17 farms) and Sukabumi (10 farms), Central Java at Banyumas (38 farms), and Magelang (25 farms). The test method used is CLSI-2020, an Antimicrobial Sensitivity Test disk diffusion with standard bacteria ATCC Escherichia coli 25922. The results show that A. hydrophila is resistant to tetracycline by 15,06% and oxytetracycline by 54,54%. However, A. hydrophila is sensitive to enrofloxacin by 84%. The aquatic environment acts as a reservoir for antibiotic-resistant A. hydrophila and emphasizes the importance of prudent antimicrobial use and timely AMR surveillance in aquaculture.