Ampicillin-resistant and vancomycin-susceptible Enterococcus faecium bacteremia: a clinical narrative review

• Published in: Expert review of anti-infective therapy Vol. 21; no. 7; p. 759
• Main Authors: Echeverria-Esnal, Daniel, Sorli, Luisa, Navarrete-Rouco, María Eugenia, Prim, Nuria, Barcelo-Vidal, Jaime, Conde-Estévez, David, Montero, María Milagro, Martin-Ontiyuelo, Clara, Horcajada, Juan Pablo, Grau, Santiago
• Format: Journal Article
• Language: English
• Published: England 03.07.2023
• Subjects: Ampicillin - pharmacology; Ampicillin - therapeutic use; Anti-Bacterial Agents - adverse effects; Bacteremia - drug therapy; Bacteremia - epidemiology; Daptomycin - adverse effects; Enterococcus faecium; Gram-Positive Bacterial Infections - drug therapy; Gram-Positive Bacterial Infections - epidemiology; Humans; Treatment Outcome; Vancomycin - pharmacology; Vancomycin - therapeutic use; teicoplanin; Enterococcus faecium; linezolid; oritavancin; daptomycin; vancomycin; bloodstream infection; Bacteremia
• ISSN: 1744-8336
• DOI: 10.1080/14787210.2023.2223977

is a commensal microorganism that can cause infections such as bacteremia. Incidence of ampicillin-resistant and vancomycin-susceptible (EfARSV) bacteremia is on the rise, and the mortality rate is high. Despite much data, the most appropriate treatment remains a question. This article mostly reviews the relevant aspects of EfARSV bacteremia: microbiology, gastrointestinal tract colonization and invasion, antibiotic resistance, epidemiology, risk factors, mortality, and treatment, including pharmacologic components of employed agents and related clinical evidence. A literature search was conducted on PubMed on 31 July 2022, which was updated on 15 November 2022. EfARSV bacteremia presents high mortality. However, it is uncertain whether mortality is attributable to or a marker of severity/comorbidities. Considering its antibiotic resistance pattern, EfARSV is considered a difficult-to-treat microorganism. Glycopeptides have been used to treat EfARSV, with linezolid and daptomycin serving as potential alternative agents. Yet, the use of daptomycin is controversial due to a higher risk of treatment failures. Clinical evidence on this issue is scarce, unfortunately, and subject to many limitations. Despite increased incidence and mortality, EfARSV bacteremia presents multiple aspects to be addressed in well-conducted studies.