RELATIONSHIP BETWEEN OUTER-MEMBRANE PROTEIN PROFILES AND RESISTANCE TO CEFTAZIDIME, IMIPENEM, AND CIPROFLOXACIN IN PSEUDOMONAS-AERUGINOSA ISOLATES FROM BACTEREMIC PATIENTS

Outer membrane protein (OMP) profiles of 122 Pseudomonas aeruginosa is olates recovered from the blood of bacteremic patients were analyzed t o relate alterations in the expression of OMPs with porin activity to resistance to imipenem, ceftazidime, and ciprofloxacin, Imipenem-resis tant isolates lacked or expressed reduced amounts of porin OprD. In co ntrast, alterations of OMP profiles were absent in most ceftazidime-re sistant isolates. Six of 12 ciprofloxacin-resistant isolates had norma l OMP profiles, The remaining isolates showed alterations in the expre ssion of either OprC, OprF, or OprD. In addition, imipenem- and ceftaz idime-resistant isolates displayed a beta-lactamase activity compatibl e with that of a group 1 chromosomal cephalosporinase.