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

AUTOR(ES)

Preheim, L C

RESUMO

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 beta-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.

Documentos Relacionados

• Principal beta-lactamases responsible for resistance to beta-lactam antibiotics in urinary tract infections.
• Development of beta-lactam resistance and increased quinolone MICs during therapy of experimental Pseudomonas aeruginosa endocarditis.
• Inoculum effect of new beta-lactam antibiotics on Pseudomonas aeruginosa.
• Penetration of the outer membrane of Pseudomonas aeruginosa by synergistic combinations of beta-lactam and aminoglycoside antibiotics.
• Emergence of fluoroquinolone resistance in Bacteroides fragilis accompanied by resistance to beta-lactam antibiotics.