Molecular Characterization of Vancomycin-Resistant spp. from Clinical Samples and Identification of a Novel Sequence Type in Mexico.

spp. is the third leading cause of healthcare-associated infections in the American continent, often because of the virulence factors that protect the bacterium against host defenses and facilitate tissue attachment and genetic material exchange. In addition, vancomycin, considered a last-resort treatment, has shown reduced efficacy in spp. strains. However, the relationship between bacterial resistance and virulence factors remains unclear. This study intends to evaluate the prevalence of glycopeptide-resistant genotypes and virulence factors in spp. strains. Over six months, 159 spp. strains causing nosocomial infections were analyzed. Multiplex PCR was performed to identify species, glycopeptide-resistant genotypes, and 12 virulence factors. The most abundant species identified were and . Vancomycin resistance was observed in 10.7% of the isolates, and the genotype was present in 47% of resistant samples. The main virulence factors detected were (54%), which is related to cell adhesion; gel E (66%), a metalloproteinase linked to tissue damage; and the sex pheromones (64%) and (84%), which are involved in horizontal gene transfer. A significant association was found between the prevalence of , , and in VRE isolates, indicating the potential dissemination of genes to emerging strains via horizontal gene transfer. In addition, a new , which displayed five virulence factors and harbored the sequence type, was identified and registered as ST2700. and are clinically critical due to multidrug resistance and virulence factors like , which aids host colonization. Genes and promote resistance spread via horizontal transfer, while the emerging ST2700 strain requires urgent monitoring to curb its virulent, drug-resistant spread.