Lactobacillus endocarditis caused by a probiotic organism.

originated (data not shown), one would perhaps expect to see mutations being lost or gained within the genes potentially affecting quinolone susceptibility. The stability of mutations in genes known to be associated with fluoroquinolone resistance, and the stable MIC values in clonally related MRSA isolates over time, have important implications for quinolone resistance in S. aureus. From this study of clinical MRSA isolates, it seems likely that once acquired, mutations and the decreased susceptibility to quinolones that they confer are highly stable, suggesting that the high prevalence of fluoroquinolone resistance that we are experiencing today in some parts of the world will remain.