Within a sufficiently large bacterial population, some members will naturally adopt an alternate, metabolically-active state that favors small molecule synthesis over cell division. These isogenic "tolerant" subpopulations have variable responses during antibiotic exposure and can remain viable in the presence of typically bactericidal concentrations. In this study, we determine the ability of typical and atypical antistaphylococcal therapies to reduce the viability of mupirocin-induced tolerant Staphylococcus aureus bacteria. Overall, tolerance-induced staphylococci exhibited a markedly decreased rate and extent of killing following antibiotic exposure. However, oritavancin remained effective at maintaining a similar extent of killing. Further studies to investigate the role of oritavancin against recurrent or relapse staphylococcal infection are warranted.
Keywords: MRSA; lipoglycopeptide; oritavancin; persistence; tolerance.