Emergence of resistance to β-lactam and aminoglycoside antibiotics during moxalactam therapy of Pseudomonas aeruginosa infections

L. C. Preheim, R. G. Penn, C. C. Sanders, Richard V. Goering, D. K. Giger

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In four patients with Pseudomonas aeruginosa infections, the infecting strain developed resistance to moxalactam during therapy with this drug. In addition, P. aeruginosa isolates from two of these four patients showed increased resistance to aminoglycosides. Isolates from a third patient acquired cross-resistance to other antipseudomonal β-lactams. In three of the cases, disk susceptibility tests failed to detect the resistance that was demonstrated in broth dilution assays. Isolate identities were confirmed by serotyping. No new plasmids were found by agarose gel electrophoresis. The mechanisms for this resistance did not involve enzymatic antibiotic degradation. These findings suggest that currently available expanded-spectrum cephalosporin derivatives should probably not be used alone for most serious infections due to P. aeruginosa. They also suggest that strains with multiple antibiotic resistance may become more prevalent in hospitals if these drugs are used extensively.

Original languageEnglish
Pages (from-to)1037-1041
Number of pages5
JournalAntimicrobial Agents and Chemotherapy
Issue number6
Publication statusPublished - 1982
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Pharmacology (medical)

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