Linezolid-resistant (Tn6246::fexB-poxtA) Enterococcus faecium strains colonizing humans and bovines on different continents: similarity without epidemiological link

• Tipo: Artigo em Revista Científica Internacional
• Data: 2020

Autores

Freitas, AR (Autor) Outra; Tedim, AP (Autor) Outra; Duarte, B (Autor) Outra; Elghaieb, H (Autor) Outra; Abbassi, MS (Autor) Outra; Hassen, A (Autor) Outra; Read, A (Autor) Outra; Alves, V (Autor) Outra; Novais, Carla (Autor) FFUP; Luisa Peixe (Autor) FFUP

Revista

Título: Journal of Antimicrobial Chemotherapy

Vol. 75

Páginas: 2416-2423

ISSN: 0305-7453

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 1 Citação

Scopus - 9 Citações

Outras Informações

ID Authenticus: P-00S-MKZ

DOI: 10.1093/jac/dkaa227

Abstract (EN): Objectives: poxtA is the most recently described gene conferring acquired resistance to linezolid, a relevant antibiotic for treating enterococcal infections. We retrospectively screened for poxtA in diverse enterococci and aimed to characterize its genetic/genomic contexts. Methods: poxtA was screened by PCR in 812 enterococci from 458 samples (hospitals/healthy humans/wastewater/animals/retail food) obtained in Portugal/Angola/Tunisia (1996-2019). Antimicrobial susceptibility testing was performed for 13 antibiotics (EUCAST/CLSI). poxtA stability (similar to 500 generations), transfer (filter mating), clonality (SmaI-PFGE) and location (S1-PFGE/hybridization) were tested. WGS (Illumina-HiSeq) was performed for clonal representatives. Results: poxtA was detected in Enterococcus faecium from six samples (1.3%): a healthy human (rectal swab) in Porto, Portugal (ST32/2001); four farm cows (milk) in Mateur, Tunisia (ST1058/2015); and a hospitalized patient (faeces) in Matosinhos, Portugal (ST1058/2015). All expressed resistance to linezolid (MIC = 8 mg/L), chloramphenicol, tetracycline and erythromycin, with variable resistance to ciprofloxacin and streptomycin. ST1058poxtA-carrying isolates from Tunisia and Portugal differed by two SNPs and had similar plasmid content. poxtA, located in an IS1216-flanked Tn6246-like element, co-hybridized with fexB on one or more plasmids per isolate (one to three plasmids of 30-100 kb), was stable after several generations and transferred only from ST1058. ST1058 strains carried resistance/virulence genes (Efmqnr/acm) possibly induced under selective quinolone treatment. Conclusions: poxtA has been circulating in Portugal since at least 2001, corresponding to the oldest description worldwide to date. We also extend the reservoir of poxtA to bovines. The similar linezolid-resistant poxtA-carrying strains colonizing humans and livestock on different continents, and without a noticeable relationship, suggests a recent transmission event or convergent evolution of E. faecium populations in different hosts and geographic regions.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8