Figure 3.

HNO₂ sensitivity of 94 different mucoid CF clinical isolates of P. aeruginosa. Aerobic starter cultures of each strain were diluted 100-fold in LB (pH 6.5) supplemented with 15 mM NO₂^–. The CFU in the inoculum versus that after a 4-day anaerobic incubation were determined. The values for log₁₀ [CFU_{after 4 days}/CFU_inoculum] were calculated and are plotted as the viability index. The mucA gene of each isolate was sequenced, and mucoid strains with wild-type mucA alleles and those harboring mucA mutation were shown at left and right, respectively. Arrows indicate clinical isolates that were found to be highly resistant to amikacin, aztreonam, cefepime, ceftazidime, ciprofloxacin, gentamycin, imipenem, and tobramycin.