Effect of highly potent antipseudomonal beta-lactam agents alone and in combination with aminoglycosides against Pseudomonas aeruginosa

• The activities of ticarcillin, cefsulodin, ceftazidime, aztreonam, and imipenem, formerly known as N-formimidoyl thienamycin, were evaluated alone and in combination with aminoglycosides against 56 clinical isolates of Pseudomonas aeruginosa, which were characterized by aminoglycoside susceptibility and content of aminoglycoside-modifying enzymatic activities. All beta-lactam agents were highly active against aminoglycoside-susceptible isolates, and with few exceptions the aminoglycoside-resistant isolates were susceptible to all of the beta-lactam agents except ticarcillin. Combinations of the beta-lactam agents with aminoglycosides frequently acted synergistically, but the effect of different beta-lactam agents in combination with an aminoglycoside against individual strains was unpredictable. The presence or absence of an aminoglycoside-modifying enzymatic activity had no observed effect on synergism with tobramycin. Killing-curve experiments with strains in the presence of concentrations of a beta-lactam and an aminoglycoside that were not bactericidal alone (one-fourth the minimal bactericidal concentration) showed synergistic bactericidal action against four strains that were tested. The results demonstrate the great activity of these newer antipseudomonal beta-lactam agents and their potential for synergism with aminoglycosides.

Ämnesord

NATURVETENSKAP  -- Biologi -- Mikrobiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Microbiology (hsv//eng)

Nyckelord

Aminoglycosides/pharmacology

Anti-Bacterial Agents/*pharmacology

Aztreonam/pharmacology

Cefsulodin/pharmacology

Ceftazidime/pharmacology

Comparative Study

Drug Synergism

Humans

Imipenem

Microbial Sensitivity Tests

Non-U.S. Gov't

Penicillin Resistance

Pseudomonas aeruginosa/*drug effects

Research Support

Thienamycins/pharmacology

Ticarcillin/pharmacology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)