Virulence gene transcription, phylogroups, and antibiotic resistance of cervico-vaginal pathogenic E. coli in Mexico

PLoS One. 2020 Jun 22;15(6):e0234730. doi: 10.1371/journal.pone.0234730. eCollection 2020.

Abstract

The pathogenicity of Escherichia coli strains that cause cervico-vaginal infections (CVI) is due to the presence of several virulence genes. The objective of this study was to define the variability regarding the genotype of antibiotic resistance, the transcription profiles of virulence genes after in vitro infection of the vaginal cell line A431 and the phylogroup composition of a group of cervico-vaginal E. coli strains (CVEC). A total of 200 E. coli strains isolated from Mexican women with CVI from two medical units of the Mexican Institute of Social Security were analysed. E. coli strains and antibiotic resistance genes were identified using conventional polymerase chain reaction (PCR), and phylogroups were identified using multiplex PCR. Virulence gene transcription was measured through reverse-transcriptase real-time PCR after infection of the vaginal cell line A431. The most common antibiotic resistance genes among the CVEC strains were aac(3)II, TEM, dfrA1, sul1, and qnrA. The predominant phylogroup was B2. The genes most frequently transcribed in these strains were fimH, papC, irp2, iroN, kpsMTII, cnf1, and ompT, mainly in CVEC strains isolated from chronic and occasional vaginal infections. The strains showed a large diversity of transcription of the virulence genes phenotype and antibiotic resistance genotype, especially in the strains of phylogroups, B2, A, and D. The strains formed 2 large clusters, which contained several subclusters. The genetic diversity of CVEC strains was high. These strains have a large number of transcription patterns of virulence genes, and one-third of them carry three to seven antibiotic resistance genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cervix Uteri / microbiology*
  • Drug Resistance, Microbial*
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / pathogenicity*
  • Female
  • Humans
  • Mexico
  • Phylogeny*
  • Transcription, Genetic / drug effects*
  • Vagina / microbiology*
  • Virulence / genetics

Grants and funding

This investigation was funded by Universidad Nacional Autónoma de México-Dirección General de Asuntos del Personal Académico-Programa de Apoyo a Proyectos de Investigación e Innovación Tecnológica IN216517 (UNAM-DGAPA-PAPIIT IN216517) and Facultad de Estudios Superiores Iztacala-DIP-Programa de Apoyo a Profesores de Carrera-2016-5 (FESI-DIP-PAPCA-2016-5).