Solithromycin Can Specifically Induce Macrolide-Lincosamide-Streptogramin B Resistance.

Solithromycin is a fluoroketolide that is considered to be a noninducing antibiotic for macrolide-lincosamide-streptogramin B resistance mediated by genes. The exact activity of solithromycin to induce gene expression remains to be determined. The potential of solithromycin to induce (A), (C), and (B) gene expression was examined using a reporter assay, double-disk diffusion test, and determination of the minimal inhibitory concentration after incubation with subinhibitory concentration of different antibiotics. Neither solithromycin nor the ketolides telithromycin and cethromycin induced (A) or (C) gene expression. However, solithromycin could significantly induce (B) gene expression at levels greater than that seen for cethromycin and clindamycin, but less than that for erythromycin, rokitamycin, and telithromycin. Solithromycin does not induce (A) and (C) gene expression, but does induce (B) gene expression, although to a weaker extent than that seen for macrolides.