Antimicrobial susceptibilities of rough, smooth, and mucoid colony types of Pseudomonas isolated from cystic fibrosis patients.

Minimal inhibitory concentrations of carbenicillin, chloramphenicol, tetracycline, gentamicin, tobramycin, and trimethoprim- sulfamethoxazole 
were determined for rough, smooth, and mucoid Pseudomonas sp. isolates from 
sputa collected from 40 cystic fibrosis patients. Ninety-four percent of the 
minimal inhibitory concentrations obtained by using mixed inocula of colonies of 
different morphological types fell within one serial dilution of the most 
resistant minimal inhibitory concentration obtained when each colony type was tested 
separately. 