WHOLE GENOME SEQUENCING UNRAVELS ANTIBIOTIC RESISTANCE PROFILES AND MUTATIONS THAT MIGHT AFFECT DRUG SUSCEPTIBILITY IN LEGIONELLA PNEUMOPHILA AND AEROMONAS SPECIES FROM MUNICIPAL WASTEWATER

Antimicrobial resistance has emerged as a significant global health issue. Wastewater treatment plants (WWTPs) contain diverse bacterial communities, including pathogens, and have been identified as crucial reservoirs for the emergence and dissemination of antimicrobial resistance. The present study aimed to identify antibiotic resistance genes (ARGs) and screen for the presence of mutations associated with antibiotic resistance in Legionella pneumophila and Aeromonas spp. strains from municipal wastewater. Whole genome sequencing (WGS) was used to characterise the genomes of L. pneumophila and Aeromonas spp. and elucidate the molecular mechanisms of antibiotic resistance in these genomes. A total of 138 nonsynonymous single nucleotide variants (SNVs) in seven genes associated with drug resistance and one deletion mutation in the lpeB gene were identified in L. pneumophila. In Aeromonas spp. strains, two (aph(6)-Id and aph(3)-Ib) and five (blaMOX-4, blaOXA-1143, blaOXA-724, cepH, and imiH) ARGs conferring resistance to aminoglycosides and b-lactams were identified, respectively. Moreover, this study presents b-lactam resistance genes, blaOXA-1143 and blaOXA-724, for the first time in Aeromonas spp. strains from a municipal WWTP. In conclusion, these findings shed light on the molecular mechanisms through which clinically relevant pathogenic bacteria such L. pneumophila and Aeromonas spp. found in natural environments like municipal wastewater, acquire drug resistance.