Antimicrobial resistance, biofilms and others virulence factors in clinical and marine isolates of Enterococcus spp.

Rojas F.; Huamán-Reyes A.; Rosas K.; Alvarado D. · Anales de la Facultad de Medicina (2026) · DOI: 10.15381/anales.v87i1.31427

Resumen

Introduction. Enterococcus is a Gram-positive coccus opportunistic pathogen, reservoir of antibiotic resistance genes, due to its genomic plasticity it adapts selectively to environmental stressors. Objective. Detection of antimicrobial resistance, biofilm formation and presence of virulence genes in clinical and marine isolates of Enterococcus faecalis and Enteorococcus faecium. Methods. Strains of E. faecalis and E. faecium and other Enterococcus species from the marine environment (n=34) and hospital samples (n=33) were studied. Antimicrobial resistance was determined by the diffusion disk method. Biofilm production was quantified with crystal violet. The esp, gelE, cyl, hyl genes were identified by polymerase chain reaction (PCR). Results. Clinical isolates showed greater resistance to antimicrobials than those from a marine environment. Seven molecular profiles of virulence determinants were observed against three from the marine group. Gamma hemolysis occurred in both groups, but beta hemolysis only in clinical isolates. Stronger biofilm was obtained in enterococci of clinical origin. Conclusions. These results reveal that marine and clinical enterococci differ in antibiotic resistance, biofilm formation and presence of virulence genes, with the marine environment as a reservoir of antibiotic resistance and virulence genes. © (2026), (Universidad Nacional Mayor de San Marcos, Facultad de Medicina), All Rights Reserved.

Instituciones: Universidad Nacional Mayor de San Marcos