Spread of an atypical ESBL-producing Escherichia coli clone in Western Switzerland
We describe the inter-regional spread of a novel ESBL-producing Escherichia coli subclone in long-term care facility residents, general population, and environmental water sources in Western Switzerland between 2017 and 2020. Over the last decades, ESBL-producing Escherichia coli ST131 subclones carrying the fimH30 allele have spread worldwide. Their frequent multidrug-resistant phenotype and potential for urinary tract and bloodstream infections warrant careful surveillance. This study integrates epidemiological and genomic data to estimate the genetic relatedness of identified strains. We also use genomic databases to interpret our findings in an international context. In conclusion, intensified molecular surveillance programs are needed on single strain levels to better monitor the spread and to identify potential reservoirs that may allow the implementation of targeted containment measures.