Genomic diversity and ampicillin/ceftriaxone susceptibility of Enterococcus faecalis from infective endocarditis

Enterococcus faecalis is a leading cause of infective endocarditis (IE), especially among older patients with comorbidities. Here we investigated the genomic diversity and antimicrobial susceptibility of 33 contemporary E. faecalis isolates from definite or probable IE cases at the University of Pittsburgh Medical Center (UPMC) between 2018 and 2020. Isolates belonging to two multi-locus sequence types (STs), ST6 and ST179, were isolated from nearly 40% of IE patients. Overall, we found evidence for diminished in vitro AC efficacy among E. faecalis IE isolates with PBP4 mutations. This study highlights the need to evaluate alternate antibiotic combinations in clinical practice against diverse contemporary E. faecalis IE isolates.