FIG. 2.

Comparison of ica operon expression, PIA/PNAG production, and biofilm regulation in 16 MRSA clinical isolates grown in BHI medium or in BHI supplemented with 4% NaCl or 1% glucose (Glu). Laboratory strain RN4220 and its isogenic Δica mutant were used as positive and negative controls, respectively. Transcription of gyrB (control) and icaA was measured by RT-PCR using RNA prepared from cultures grown at 37°C to an A₆₀₀ of 2.0. PIA/PNAG was measured in cell extracts from overnight cultures. Biofilm formation in tissue culture-treated 96-well plates was measured three times, and representative results are shown.