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Uropathogenic Escherichia coli strains harboring tosA gene were associated to high virulence genes and a multidrug-resistant profile

Xicohtencatl-Cortes, Juan, Cruz-Córdova, Ariadnna, Cázares-Domínguez, Vicenta, Escalona-Venegas, Gerardo, Zavala-Vega, Sergio, Arellano-Galindo, José, Romo-Castillo, Mariana, Hernández-Castro, Rigoberto, Ochoa, Sara A., Luna-Pineda, Víctor M.
Microbial pathogenesis 2019 v.134 pp. 103593
adhesins, antibiotic resistance, antibiotics, beta-lactamase, beta-lactams, genes, genetic variation, multiple drug resistance, patients, phenotype, phylogeny, polyclonal antibodies, pulsed-field gel electrophoresis, urinary tract diseases, uropathogenic Escherichia coli, virulence
TosA, a putative repeats-in-toxin protein that has recently gained importance as an antigenic molecule, has characteristics of nonfimbrial adhesins and can act as a virulence marker in uropathogenic Escherichia coli (UPEC) strains; however, little is known about the association of this protein with antibiotic resistance profiles in UPEC tosA+ clinical strains. The aim of this study was to evaluate UPEC tosA+ strains, including examining genetic diversity, associations with phylogenetic groups, resistance profiles, virulence genes, adherence assays, integrons, and extended-spectrum beta-lactamase phenotypes. Pulsed-field gel electrophoresis analysis grouped these strains into eight clusters with 62% genetic diversity. These strains were mainly associated with the multidrug-resistant profiles, together with an association with class 1 integron and the extended-spectrum beta-lactamase phenotype. Additionally, the strains exhibited a distribution of ≥96% for core-associated genes, while a variable distribution was identified for pathogenic islands-associated genes. Strong associations between UPEC tosA+ strains and two phylogenetic groups (B2 and D) were identified, including resistance to β-lactam and non-β-lactam antibiotics. The UPEC tosA+ clinical strains exhibited major adherence, which was related to the fitness and virulence genes. A recombinant TosA protein reacted with antibodies from the sera of urinary tract infection patients, and anti-recombinant TosA polyclonal antibodies also detected TosA expression in these strains. In conclusion, strains of UPEC tosA+ belonging to phylogenetic group B2 had a high frequency of fitness and virulence genes associated with class 1 integrons and the extended-spectrum beta-lactamase phenotype, which exhibited a high adherence profile. The TosA protein is expressed during infection with UPEC and is considered an immunogenic molecule.