Resistome analysis of aeromonas veronii strains isolated from diseased outbreak in tilapia farms in Thailand

Abstract

Aeromonas veronii outbreaks in tilapia farming caused relatively high mortality. Moreover, it was resistant to many kinds of antimicrobial used in Thailand aquaculture. According to no CLSI standard, the determination of antimicrobial efficacy has been limited phenotypically; the genomics study is required. This research aims to analyze the resistome of A. veronii isolated from diseased Tilapia in Chainat, Nong Khai and Uttaradit province, Thailand. Twelve isolates of A. veronii were identified base on gyrB sequencing then determined the MIC value to eight antimicrobials (AMP, AML, GEN, ENR, OXO, OXY, SXT, and FFC). According to MIC patterns, five representatives were performed the whole genome sequencing (WGS) and resistome analysis, including 15 isolates from NCBI. All Tilapia isolates are susceptible to FFC but resistant to AML and AMP; OT resistance is the most dominant resistance. For WGS analysis, 4.5 Mbp of A. veronii was characterized, 19 ARGs were detected by resistome analysis and 14 genes were shared among A. veronii population. In conclusion, A. veronii strains isolated from Tilapia exhibit resistant to several antimicrobials and multidrug resistance (MDR) which related to the presence of multiple ARGs. A. veronii shared the ARGs in their population worldwide with the possibility of acquisition and plasmid-mediated.