| Abstrakt: |
strains TAL2480 and TAL3636 were used to assess outer membrane permeability to various β-lactam compounds. These strains were chosen because they possess β-lactamases capable of hydrolysing all commonly employed β-lactams except monobactams. The β-lactamases are located in the periplasmic space and could be released by sonication and osmotic shock. Permeability was calculated by the method of Zimmerman & Rosselet (1977, , 368–72). The rank order of permeative ability (from fastest to slowest) was as follows: cephaloridine, imipenem, cefotaxime, cefoxitin, cefoperazone, nitrocefin, cephalothin, and latamoxef. Our results showed that ionic charge, hydrophobicity, and molecular weight influenced β-lactam drug uptake by . These results are similar to findings for , where increased negative charge and increased molecular weight are associated with decreased drug uptake. However, unlike , increased drug hydrophobicity, for a given charge and molecular weight of the drug, was associated with increased uptake by . [ABSTRACT FROM PUBLISHER] |
