FIG. 2.

Population transcript accumulations for P. aeruginosa lasR, lasA, lasB, toxA, and algD in sputum from a pediatric CF patient (patient 15). For each sample, 10 μg of the total RNA extracted from the pelleted bacterial population was blotted onto a Nytran membrane (Schleicher and Schuell) and hybridized with the toxA probe. The blots were then washed to remove the probe, and the membrane was rehybridized with the lasB probe. The process was repeated with the lasA, algD, and lasR probes. The relative intensity for the sample was measured from the autoradiograph with a soft laser scanning densitometer. The results represent 10 μg of RNA from equivalent numbers of cells. lasR population transcript accumulation was compared to lasA population transcript accumulation (A), lasB population transcript accumulation (B), toxA population transcript accumulation (C), and algD population transcript accumulation (D). Patient 15 is a male pediatric patient with severe lung disease. Patient 15 was receiving ciprofloxacin and tobramycin on 12/10, ceftazidime on 1/14, ciprofloxacin and tobramycin on 1/24 and 4/8, and ceftazidime again on 4/13 and 4/21.