The vanA operon (including vanA1/vanA2 alleles) encodes modified peptidoglycan precursors (D-Ala-D-Lac) that abolish vancomycin binding, conferring high-level vancomycin resistance in Enterococcus faecium (and faecalis). VanA-type VRE are resistant to vancomycin and teicoplanin. Detection of vanA indicates vancomycin-resistant Enterococcus (VRE), which significantly alters therapy and infection control(Levitus et al. 2023, Arias & Murray 2012, Hourigan et al. 2024).
Arias CA, Murray BE. The rise of the Enterococcus: beyond vancomycin resistance. Nat Rev Microbiol. 2012 Mar 16;10(4):266-78. doi: 10.1038/nrmicro2761. PMID: 22421879; PMCID: PMC3621121.
Levitus M, Rewane A, Perera TB. Vancomycin-Resistant Enterococci. [Updated 2023 Jul 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-.
Hourigan, D., Stefanovic, E., Hill, C., & Ross, R. P. (2024). Promiscuous, persistent and problematic: insights into current enterococcal genomics to guide therapeutic strategy. BMC microbiology, 24(1), 103. https://doi.org/10.1186/s12866-024-03243-2
