Mechanisms of Resistance to Glycopeptides in Staphylococcus aureus
Maribel Castellano González,
Armindo Perozo Mena
Affiliations
Maribel Castellano González
Cátedra de Bacteriología General. Escuela de Bioanálisis. Universidad del Zulia.
Armindo Perozo Mena
Cátedra de Práctica Profesional de Bacteriología. Escuela de Bioanálisis. Universidad del Zulia. Venezuela. Centro de Referencia Bacteriológica –Servicio Autónomo Hospital Universitario de Maracaibo. Venezuela.
Glycopeptides (vancomycin and teicoplanin) are an alternative therapeutic in the treatment of severe infections by methicillin-resistant S. aureus strains. However, two resistance mechanisms of S. aureus have already been described: low-level resistance, characterized by an abnormal thickening of the cellular wall, present in the VISA strains, and high-level resistance, mediated by the vanA operon, which causes the replacement of D-ala - D-ala terminal residues by D-ala-D-lac, decreasing its affinity for the antibiotic. This review summarizes the history of the emergence of glycopeptide resistance in S. aureus and considers the mechanisms that determine the resistance in these organisms as a background for understanding the need and potential roles of new agents of this kind.