Detección de genes de virulencia pvl-1 y sec en aislados de Staphylococcus aureus meticilino-resistente (SARM) obtenidos de muestras de leche de bovinos con mastitis subclínica

Abstract

Bovine mastitis caused by Staphylococcus aureus represents the primary problem in dairy production due to the associated economic losses and the potential risk posed by the circulation of MDR strains. In this context, the presence of virulence genes in isolates of methicillin-resistant Staphylococcus aureus (MRSA) is of epidemiological interest, as the combination of resistance and virulence may promote bacterial persistence and increase its pathogenic potential. The present study aimed to determine the presence of the virulence genes pvl-1 and sec in MRSA isolates obtained from milk samples of cattle with subclinical mastitis from different cantons in the province of Tungurahua, Ecuador. For this purpose, 80 samples of previously stored strains were used, which were reactivated and microbiologically verified using conventional phenotypic tests. Subsequently, DNA extraction was performed, followed by molecular detection of the genes of interest via PCR using specific primers. The results obtained showed no amplification for any of the genes analyzed, indicating the absence of pvl-1 and sec in the isolates evaluated. Additionally, a review was conducted of the scientific evidence related to the molecular mechanisms of action of these genes and the interaction between virulence and antimicrobial resistance in S. aureus, highlighting. These findings provide information on the virulence profile of MRSA strains associated with subclinical bovine mastitis in the region.