Fitness costs associated with carriage of a large staphylococcal plasmid are reduced by subinhibitory concentrations of antiseptics

Pathogenic bacteria often carry large plasmids that contain multiple resistance genes; individually, these elements coselect for additional resistance genes that are genetically linked by the plasmid. In this short communication, we demonstrate increased triclosan resistance can be conjugatively transferred inStaphylococcus aureus. Furthermore, in a competition assay, we show subinhibitory concentrations of antiseptics abrogate the fitness cost of a large multidrug resistance plasmid inS. aureus, thus coselecting for the numerous antimicrobial resistance genes present on the plasmid. AbstractStaphylococcus aureus carries a collection of mobile genetic elements that often harbor virulence and antimicrobial resistance genes. Since the introduction of antibiotics, plasmids have become a major genetic element responsible for the distribution of antimicrobial resistance. Under antimicrobial selection, resistance plasmids are maintained within bacterial populations as a means to ensure survival. However, in the absence of selection, large plasmids can be lost due to the fitness costs associated with harboring these genetic elements. pC02 is a previously identified multidrug resistance, conjugative plasmid that is found inS. aureus. In addition to antibiotic resistance, pC02 also carries genes known to be associated with antiseptic resistance. Among these, we previously characterized the contribution ofqacA to pC02 mediated reduced chlorhexidine susceptibility. Herein, we demonstrat...
Source: MicrobiologyOpen - Category: Microbiology Authors: Tags: ORIGINAL ARTICLE Source Type: research