Antibiotic Resistance and Virulence in Enterococci

Enterococci are Gram-positive, facultative anaerobic cocci that colonise the gastrointestinal tracts of humans and animals yet have emerged as leading causes of multidrug-resistant hospital-acquired infections. Among the genus, Enterococcus faecalis and Enterococcus faecium pose greatest clinical concern, driven by the accumulation of mobile genetic elements carrying antibiotic resistance determinants and virulence factors such as aggregation substance, biofilm-forming proteins and cytolysins. Intrinsic tolerance to β-lactams and aminoglycosides is compounded by acquired resistance to glycopeptides, oxazolidinones and last-line agents. The interplay between resistance mechanisms and virulence attributes underpins treatment failures and transmission among community, nosocomial and environmental reservoirs. A One-Health perspective emphasises the global distribution of resistant enterococci and the need for integrated surveillance, novel diagnostics and therapeutic strategies to mitigate their impact.

Research from Nature Portfolio

High-resolution structural studies have elucidated how clinical variants of penicillin-binding protein 5 (PBP5) in Enterococcus faecium accelerate β-lactam hydrolysis through expanded surface loops and reduced side-chain bulk, thereby enhancing antibiotic turnover and resistance. Complementary genomic surveillance across human, animal and environmental samples has revealed distinct clustering of enterococcal species according to their ecological niches, with accessory gene content reflecting antimicrobial usage patterns. Such One-Health analyses demonstrate how specific resistance genes and mobile elements circulate among reservoirs, informing risk assessment and guiding targeted interventions to curb the spread of resistance in enterococci.

Antibiotic Resistance and Virulence in Enterococci publication trend

The graph below shows the total number of articles in antibiotic resistance and virulence in enterococci across all publications each year (not limited to Nature Index journals).

Technical terms

Antibiotic resistance: The ability of bacteria to survive exposure to an antibiotic to which they were previously susceptible.

Virulence factor: A molecule produced by a microbe that contributes to its ability to cause disease by facilitating colonisation, immune evasion or tissue damage.

Penicillin-binding protein (PBP): Enzymes that catalyse bacterial cell-wall synthesis and serve as targets for β-lactam antibiotics; alterations in PBPs can confer resistance.

Whole-genome sequencing (WGS): A method for determining the complete DNA sequence of an organism’s genome, enabling comprehensive detection of resistance and virulence determinants.

Vancomycin-resistant enterococci (VRE): Enterococcal strains that possess genetic elements conferring high-level resistance to vancomycin, often mediated by van gene clusters.

Horizontal gene transfer: The movement of genetic material between organisms by mechanisms other than inheritance, facilitating the spread of resistance and virulence genes.

References

1. Molecular basis of β-lactam antibiotic resistance of ESKAPE bacterium E. faecium Penicillin Binding Protein PBP5. Nature Communications (2023).
2. Surveillance of Enterococcus spp. reveals distinct species and antimicrobial resistance diversity across a One-Health continuum. Scientific Reports (2020).
3. Antibiotic resistance determination using Enterococcus faecium whole-genome sequences: a diagnostic accuracy study using genotypic and phenotypic data. The Lancet Microbe (2024).
4. Mapping the widespread distribution and transmission dynamics of linezolid resistance in humans, animals, and the environment. Microbiome (2024).
5. Conjugation of Polycationic Peptides Extends the Efficacy Spectrum of β‐Lactam Antibiotics. Advanced Science (2024).