Clindamycin MRS agar (MRSC)
Commercial MRS agar (Difco e Becton, Dickinson and Company,
Franklin Lakes, USA) was prepared according to manufacturer's
instructions. The rehydrated medium was autoclaved at 121 C for
15 min. For the clindamycin solution, 2 mg Clindamycin hydrochloride
were dissolved in 10 mL distilled water, and sterilized by
filtration through 0.22 mm membrane filter (Millipore, S~ao Paulo,
Brazil). Immediately before use, 0.5 mL clindamycin solution was
added to 1000 mL MRS agar (Christian Hansen, 2007).