Abstract
In order to estimate the resistance of each 50 clinical isolates of Pseudomonas cepacia and Achromobacter xylosoxidans together with 5 P. cepacia strains from natural sources against 17 antimicrobics, the maximum growth allowance concentration of these drugs was determined by serial agar dilution technique. The concentration of each drug ranged from 3.13 to 1,600 mend with the exception of tobramycin which ranged from 3.13 to 200 μg/ml.
P. cepacia strains were highly resistant to β-lactam (PCG, ABPC, CBPC, SBPC, and CER) and aminoglycoside (SM, KM, DKB, GM, and TOB) antimicrobics. Thirty nine of 55 strains (70%) were resistant to streptomycin 1,600 μg/ml, and all 55 strains grew in the presence of CER 1,600 μg/ml. P. cepacia strains were sensitive to MNC, CP, NA, and NB. No significant difference was seen in antimicrobic resistance between 50P. cepacia strains of clinical origin and 5 of natural origin.
Most of the 50 A. xylosoxidans strains were highly resistant to aminoglycoside antibiotics, especially 38 strains (76%) grew in the presence of 1,600 μ/ml SM, whereas they were rather sensitive to ABPC, CBPC, SBPC, and MNC.
