TABLE 4.

Contribution of resistance to individual antimicrobial agents to MDR phenotypes in clinical isolates of P. aeruginosa collected from 1999 to 2002

Patient group, specimen source, or collection yra% Isolates (no.)b that had an MDR phenotype% of MDR isolates resistant to:
CeftazidimePiperacillin-tazobactamTicarcillin-clavulanateGentamicinCiprofloxacinImipenemTobramycin
Patient type
    Non-ICU25.4 (6,526)52.847.783.358.677.944.745.4
    ICU29.5 (1,795)59.748.085.660.371.555.950.0
    OP19.4 (3,103)41.739.266.174.171.236.257.1
    NH29.9 (775)45.334.389.354.879.726.344.2
    All24.2 (12,199)50.544.779.662.675.443.049.0
Patient age (yr)
    ≥18-3929.0 (2,463)49.642.568.576.071.942.153.2
    40-4925.2 (1,290)52.946.780.558.574.850.846.4
    50-5927.2 (1,771)55.049.584.358.978.345.250.0
    60-6926.6 (1,817)54.249.986.254.076.848.943.0
    >7021.5 (3,389)50.244.483.957.281.740.247.5
    All25.0 (10,730)51.946.080.461.477.244.248.3
Specimen source
    Blood23.4 (443)54.647.282.465.578.355.156.2
    LRT31.3 (6,264)51.946.377.961.670.445.446.4
    URT5.8 (80)43.740.055.070.062.547.546.3
    Wound20.7 (2,434)56.851.484.956.375.543.246.0
    All26.0 (9,221)53.247.679.860.472.145.346.7
Yr sample collected
    199922.7 (1,462)55.155.978.560.367.040.943.4
    200024.9 (2,536)51.650.376.569.871.146.253.1
    200126.2 (4,366)48.540.878.864.777.141.452.7
    200224.5 (4,753)47.239.582.059.680.846.047.6
    All24.9 (13,117)49.443.979.563.476.243.949.9
  • a Abbreviations: OP, outpatients; NH, nursing home; LRT and URT, lower and upper respiratory tract, respectively.

  • b Total percentage and number of isolates associated with MDR (resistance to ≥3 of the 10 antimicrobial agents).