Estimation of outer membrane permeability of carbapenem antibiotics to Pseudomonas aeruginosa.
The outer membrane permeability of carbapenems (imipenem [IPM], panipenem [PAPM], meropenem [MEPM], and biapenem [BIPM]) and ceftazidime (CAZ) to Pseudomonas aeruginosa was determined by the Zimmermann and Rosselet method. The permeability coefficients of beta-lactams tested at 50 &mgr;M concentration of substrates ranged from (0.40 +/- 0.10) x 10-6 cm/s for CAZ to (2.33 +/- 0.33) x 10-6 cm/s for IPM, indicating that the outer membrane permeability of carbapenems to P. aeruginosa was high in comparison with that of CAZ. In particular, IPM and BIPM showed a higher rate of penetration than MEPM and PAPM.
Iyobe
S.
S
Laboratory of Drug Resistance in Bacteria, Gunma University School of Medicine, 3-39-22 Showa-machi, Maebashi, Gunma 371-8511, Japan. siyobe@akagi.sb.gunma-u.ac.jp
Watanabe
Masato
M
Mitsuhashi
Susumu
S
Inoue
M.
M