Clonal Complexes 23, 10, 131 and 38 as Genetic Markers of the Environmental Spread of Extended-Spectrum β-Lactamase (ESBL)-Producing E. coli

Abstract

In accordance with the global action plan on antimicrobial resistance adopted by the World Health Assembly in 2015, there is a need to develop surveillance programs for antimicrobial resistant bacteria. In this context, we have analyzed the clonal diversity of Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (E. coli) isolated from aquatic environments and human and food samples in Spain, with the aim of determining possible clonal complexes (CCs) that act as markers of the potential risk of transmission of these resistant bacteria. The phylogenetic groups, sequence types (STs) and CCs were determined by different Polymerase Chain Reaction (PCR) and Multilocus Sequence Typing (MLST) techniques. Phylogroup A was prevalent and was mainly present in food and water strains, while human strains were mostly associated with phylogroup B2. According to the observed prevalence in the different niches, CC23 and CC10 are proposed as markers of phylogroups A and C, related with the spread of blaCTX-M1 and blaCTX-M15 genes. Similarly, CC131 and CC38 could be associated to the dissemination of pathogenic strains (phylogroups B2 and D) carrying mainly blaCTX-M14 and blaCTX-M15 genes. Some strains isolated from wastewater treatment plants (WWTPs) showed identical profiles to those isolated from other environments, highlighting the importance that water acquires in the dissemination of bacterial resistance. In conclusion, the detection of these genetic markers in different environments could be considered as an alert in the spread of ESBL.

High Emergence of Multidrug-Resistant Sequence Type 131 Subclade C2 among Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli Isolated from the University Hospital Bratislava, Slovakia

“…In addition, the elevation in MDR strains is correspondingly related to the overall increase in the administration of antimicrobial agents, which affects the composition of the microbiota in humans [3]. Escherichia coli (E. coli) strains have been recognized as some of the most prevalent ESBL-producing Gramnegative pathogens [4][5][6] from the Enterobacterales order. The prevalence of ESBL-producing E. coli strains has increased in clinical samples to more than 10% in 22 European countries in previous years.…”