Characterising Enterococcus faecium and defining its role in diabetic wound infections

Abstract

Chronic wound infections, particularly in diabetic patients, are frequently colonized by Enterococci, with vancomycin-resistant E. faecium emerging as a critical global pathogen. This study aimed to elucidate E. faecium infection dynamics and fitness factors in diabetic wounds, addressing a significant research gap. Using a low-dose streptozocin-induced diabetic mouse model, we observed stable E. faecium colonization in all mice, with impeded clearance in diabetic subjects. Despite robust immune activity, E. faecium persisted in wounds, modulating host innate immunity. The study also explored mixed-species infections with S. epidermidis, revealing complex interactions. Through transposon directed insertion site sequencing (TraDIS), several genetic factors contributing to E. faecium fitness were identified, including mprF_1, bceB_2, pepC, mgs, and c1s_A. Notably, a novel hypothetical protein (Efm_01217) was found to uniquely contribute to E. faecium fitness in diabetic wounds. This comprehensive investigation provides valuable insights into E. faecium pathogenesis in diabetic wounds and establishes a foundation for future studies on mono and polymicrobial infections.