Characterization of unconventional pathogenic Escherichia coli isolated from bloodstream infection: virulence beyond the opportunism

Autor(es)

Santos, Ana Carolina M. ; Santos-Neto, Jose F. ; Trovao, Liana O. ; Romano, Ricardo F. T. ; Silva, Rosa Maria ; Gomes, Tania A. T.

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Microbiology; v. N/A, p. 14-pg., 2022-12-08.

Resumo

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of urinary tract infection worldwide and a critical bloodstream infection agent. There are more than 50 virulence factors (VFs) related to ExPEC pathogenesis; however, many strains isolated from extraintestinal infections are devoid of these factors. Since opportunistic infections may occur in immunocompromised patients, E. coli strains that lack recognized VFs are considered opportunist, and their virulence potential is neglected. We assessed eleven E. coli strains isolated from bloodstream infections and devoid of the most common ExPEC VFs to understand their pathogenic potential. The strains were evaluated according to their capacity to interact in vitro with human eukaryotic cell lineages (Caco-2, T24, HEK293T, and A549 cells), produce type 1 fimbriae and biofilm in diverse media, resist to human sera, and be lethal to Galleria mellonella. One strain displaying all phenotypic traits was sequenced and evaluated. Ten strains adhered to Caco-2 (colon), eight to T24 (bladder), five to HEK-293 T (kidney), and four to A549 (lung) cells. Eight strains produced type 1 fimbriae, ten adhered to abiotic surfaces, nine were serum resistant, and seven were virulent in the G. mellonella model. Six of the eleven E. coli strains displayed traits compatible with pathogens, five of which were isolated from an immune-competent host. The genome of the EC175 strain, isolated from a patient with urosepsis, reveals that the strain belonged to ST504-A, and serotype O11:H11; harbors thirteen VFs genes, including genes encoding UpaG and yersiniabactin as the only ExPEC VFs identified. Together, our results suggest that the ExPEC pathotype includes pathogens from phylogroups A and B1, which harbor VFs that remain to be uncovered. (AU)

• Processo FAPESP: 19/21685-8 - Estudo de marcadores de virulência presentes em cepas de Escherichia coli isoladas da microbiota intestinal de pacientes com infecção urinária
• Beneficiário: José Francisco Santos Neto
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 17/14821-7 - Explorando novas estratégias de virulência em Escherichia coli
• Beneficiário: Tânia Aparecida Tardelli Gomes do Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 18/17353-7 - ANÁLISE COMPARATIVA DE CARACTERÍSTICAS DE VIRULÊNCIA DE Escherichia coli DIARREIOGÊNICA EM CEPAS DE E. coli ISOLADAS DE PACIENTES COM DIFERENTES TIPOS DE INFECÇÃO URINÁRIA
• Beneficiário: Tânia Aparecida Tardelli Gomes do Amaral
• Modalidade de apoio: Auxílio à Pesquisa - Regular