The role of mobile genetic elements in the typing of nosocomial VREfm outbreak isolates of a successful MLST: ST117 cluster type 24. The role of mobile genetic elements in the typing of nosocomial VREfm outbreak isolates of a successful MLST: ST117 cluster type 24

Vancomycin-resistant Enterococcus faecium (VREfm) is a successful nosocomial pathogen. The rapid emergence of specific VREfm lineages makes it challenging to distinguish outbreak isolates solely based on their core genome. Here, we explored if characterisation of mobile genetic elements could be useful for molecular epidemiology and typing of VREfm isolates belonging to the same genetic background. Conclusions: In case of closely related isolates sharing a similar genetic background, a detailed analysis of mobile genetic elements and the integration point of the vanB-carrying transposon allows to achieve a higher discriminatory power compared to cgMLST alone. Thus, enabling identification of epidemiological links among hospitalised patients.