| Congresso Brasileiro de Microbiologia 2023 | Resumo: 272-1 | ||||
Resumo:Antimicrobial-resistant pathogens are a growing problem associated with high mortality rates. Pathogenic Pseudomonas aeruginosa strains are frequently related to multidrug resistance and this pathogen is one of the most associated with opportunistic infections in humans, although the metabolic versatility of this species allows it to be found in animals, plants, and the environment. The environment is a significant reservoir and disseminator of antimicrobial resistance determinants, which is amplified by anthropogenic actions. This study aimed to investigate the antimicrobial susceptibility and presence of antimicrobial resistance genes (ARGs) in environmental P. aeruginosa isolates, as well as perform the genomic characterization of a representative isolate. Fifty-eight P. aeruginosa isolates were obtained from waters, soils, sediments, and beach sands of Southeast Brazil and were submitted to antimicrobial susceptibility testing using the agar dilution method for antimicrobials agents of β-lactams, aminoglycosides, fluoroquinolones, and polymyxins classes. A diversity of ARGs was screened by conventional polymerase chain reactions. Whole-genome sequencing followed by genomic analysis was carried out to determine mainly molecular typing, resistome, virulome, and plasmidome. The isolates were resistant mainly to colistin (72%), ciprofloxacin (47%), and gentamicin (41%). In this context, 55% of the isolates were classified as multidrug-resistant (MDR). Only genes encoding aminoglycoside-modifying enzymes [aac(3′)-IIa and aac(6′)Ib] were detected. The MDR BR164 isolate was selected for whole-genome sequencing and bioinformatic analyses revealed that this isolate belonged to the O6/ST900 clone. The resistome showed specific-species genes [aph(3')-IIb, catB7, blaOXA-395, blaPDC-3, and fosA] and a wide virulome, highlighting the exoS+/exoU- genotype. Non-synonymous mutations in PmrB (colistin resistance) and deletions in OprD (carbapenem resistance) were observed. In addition, an unknown mutation in ParC (Q359R) was also detected. A plasmid, named pBR164, with ~ 50 kb was de novo assembled. This plasmid harbored genes associated with replication, partition, conjugative transfer, anti-CRISPR, virulence, and SOS-inhibition. BLASTn analysis showed that pBR164 was most related to three other plasmids from clinical P. aeruginosa isolates from China and Brazil. Furthermore, a Chinese plasmid harbored the blaKPC gene. These results reinforce the presence of antimicrobial-resistant P. aeruginosa isolates in different environmental sources and classifly the O6/ST900 clone as rare, predisposed in acquired ARGs, and potentially pathogenic. Palavras-chave: antimicrobial resistance, environmental sector, genomic analysis, Pseudomonas aeruginosa Agência de fomento:This study was supported by FAPESP (2021/01655-7), CAPES (88887.519091/2020-00 and Finance Code 001), and CNPq (304905/2022-4, 308914/2019-8, 130086/2021-5, 141016/2021-3, and 150712/2022-7). | |||||