Molecular characterization of bacteremic Escherichia coli belonging to the serogroups O4, O6, O18 and O75
Authorship
A.G.S.
Degree in Biochemistry
A.G.S.
Degree in Biochemistry
Defense date
07.16.2024 10:00
07.16.2024 10:00
Summary
E. coli is the main causative agent of bacteremia in humans, which has been increasing significantly worldwide in recent decades. In addition, this clinical concern is compounded by the emergence of high-risk clones that present multiple antimicrobial resistance and complicate the clinical treatment of patients. In this work, phenotypic (serotyping and antibiogram) and molecular (conventional PCR and Sanger sequencing) characterization of 53 bacteremic strains isolated in the HULA between 2020 and 2022 has been carried out. The results indicate that serogroups O4, O6, O18 and O75 strains have a significant prevalence among bacteremic E.coli in our healthcare area in the period 2020-2022, with serogroup O6 strains being the most numerous. Comparing these data with the previous study conducted at the LREC-USC between 1989 and 2011, we observed no significant differences in terms of the prevalence of these four serogroups. The level of antimicrobial resistance detected in serogroups O4, O6 and O18 strains is relatively low, and only O75 strains stand out for their significant resistance to quinolones. In contrast, the vast majority of the strains of these four serogroups possess a high number of virulence genes typical of the ExPEC pathotype, reflecting a significant pathogenicity potential undoubtedly responsible for their success as pathogens. In addition, the presence of the emerging clone ST1193 among the strains belonging to serogroup O75 studied in this work supports other previous studies, but it does not seem to have a significant prevalence in our health area. The high incidence of serogroups O4, O6, O18 and O75 strains, together with their high number of virulence genes, fully justifies their inclusion in preventive vaccines against ExPEC.
E. coli is the main causative agent of bacteremia in humans, which has been increasing significantly worldwide in recent decades. In addition, this clinical concern is compounded by the emergence of high-risk clones that present multiple antimicrobial resistance and complicate the clinical treatment of patients. In this work, phenotypic (serotyping and antibiogram) and molecular (conventional PCR and Sanger sequencing) characterization of 53 bacteremic strains isolated in the HULA between 2020 and 2022 has been carried out. The results indicate that serogroups O4, O6, O18 and O75 strains have a significant prevalence among bacteremic E.coli in our healthcare area in the period 2020-2022, with serogroup O6 strains being the most numerous. Comparing these data with the previous study conducted at the LREC-USC between 1989 and 2011, we observed no significant differences in terms of the prevalence of these four serogroups. The level of antimicrobial resistance detected in serogroups O4, O6 and O18 strains is relatively low, and only O75 strains stand out for their significant resistance to quinolones. In contrast, the vast majority of the strains of these four serogroups possess a high number of virulence genes typical of the ExPEC pathotype, reflecting a significant pathogenicity potential undoubtedly responsible for their success as pathogens. In addition, the presence of the emerging clone ST1193 among the strains belonging to serogroup O75 studied in this work supports other previous studies, but it does not seem to have a significant prevalence in our health area. The high incidence of serogroups O4, O6, O18 and O75 strains, together with their high number of virulence genes, fully justifies their inclusion in preventive vaccines against ExPEC.
Direction
Flament Simon, Saskia Camille (Tutorships)
BLANCO ALVAREZ, MIGUEL (Co-tutorships)
Flament Simon, Saskia Camille (Tutorships)
BLANCO ALVAREZ, MIGUEL (Co-tutorships)
Court
BARCIA VIEITEZ, RAMIRO (Chairman)
REGAL LÓPEZ, PATRICIA (Secretary)
VERA RODRIGUEZ, MANUEL (Member)
BARCIA VIEITEZ, RAMIRO (Chairman)
REGAL LÓPEZ, PATRICIA (Secretary)
VERA RODRIGUEZ, MANUEL (Member)