| Congresso Brasileiro de Microbiologia 2023 | Resumo: 332-1 | ||||
Resumo:Resistance mechanisms mediated by mobile genetic elements are considered the main drivers of the spread of antimicrobial resistance and wastewater are identified as critical environments for horizontal gene transfer (HGT). In this context, we aimed to characterize the plasmid associated with resistance genes in an Escherichia coli isolate from an environmental source. A total of 137 Escherichia coli isolates were obtained from wastewater treatment plants in Porto Alegre, RS, Brazil. Identification at species level was confirmed by mass spectrometry technique using the VITEK®MALDI-TOF MS (bioMérieux, France) and the antimicrobial susceptibility profile was determined by disk diffusion test. One isolate resistant to ciprofloxacin was selected to whole genome sequencing (WGS) performed by Illumina MiSeq (2 x 250 bp paired-end reads). Genomic DNA was extracted using a QIAamp DNA Mini Extraction Kit (QIAGEN®), the concentration was determined by Qubit (Thermo Fisher Scientific) and the quality by NanoDrop™. The paired-end library was constructed with the Nextera XT DNA Library Prep Kit (Illumina). Raw data were assembled using CLC Genomic Workbench 23 and antimicrobial resistance genes were identified using QIAGEN Microbial Insight-Antimicrobial Resistance database (QMI-AR). Multilocus Sequence Typing (MLST) and plasmid typing were performed using the MLST 2.0 and PlasmidFinder 2.1, respectively. Mobile genetic elements were identified using the MobileElementFinder (MGE). Comparative genomic analysis was performed using Geneious Prime 9.0.5 and BRIG. The susceptibility profile resulted in a resistant phenotype to quinolones and tetracyclines (according to BrCAST). The total sequence length was 4,781,351 bp and De novo assembly resulted in a set of 128 contigs, GC content of 50.8% and N50 of 140,230. Escherichia coli strain was typed as ST442 and the qnrS1 [100% ID], tetA [100% ID], blaTEM-1B [100% ID] antimicrobial resistance genes were found in the bacterial genome. These genes encode resistance to tetracyclines, beta-lactams and fluoroquinolones, classes of antimicrobials that are critically important for human medicine, mainly to treat urinary tract infections. Furthermore, the ST442 is highly virulent and usually associated with hemolytic uremic syndrome (HUS) in humans.
The PlasmidFinder identified just one plasmid, the IncR [100% ID], co-harboring blaTEM-1B and qnrS1 genes in the same contig. In addition, comparative genomic analysis determined that the IncR plasmid contains the conjugative transfer genes (tra). The presence of tra genes in the IncR plasmid reveals that it is conjugative and can be transferred between different bacteria. Moreover, the IncR plasmid harbored the blaTEM-1b and qnrS1 genes, reinforcing the idea that mobile genetic elements play an important role in the acquisition of antimicrobial resistance.The spread of strains resistant to fluoroquinolones and beta-lactams is a worldwide concern and poses a high risk to the effectiveness of clinical treatment. Therefore, surveillance programs and adequate management of wastewater are important to mitigate risks to human health and reduce the spread of antimicrobial resistance. Palavras-chave: Antimicrobial resistance, blaTEM-1b, Escherichia coli, IncR plasmid, qnrS1 Agência de fomento: CAPES/CNPQ/FAPERGS | |||||