The mechanism of resistance of pseudomonas aeruginosa to β-lactam antibiotics and clinical significance

Abstract

To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ-lactam antibiotics, the outer membrane permeability rate of 30 P. aeruginosa strains to 5β-lactam antibiotics was measured and their production ofβ-lactamase and theβ-lactamase genes they carried detected. Furthermore, the relationship between the permeability,β-lactamase and the clinical effects ofβ-lactam antibiotics was observed. By using¹⁴C-penicillin and liquid-scintillant isotope assay, the affinity of penicillin binding proteins (PBPs) was measured and their roles in the resistant mechanism studied. It was revealed that the permeability rate was higher in sensitive strains than in resistant ones (P<0.05). All strains harbored 1–4β-lactamase genes and producedβ-lactamase. Higher permeability rate and higher degree of stability toβ-lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the permeability andβ-lactamase. These results suggested that the permeability of outer membrane andβ-lactamase, but not PBPs, played important roles in the resistant mechanism of P. aeruginosa toβ-lactam antibiotics and affected the clinical therapeutic effectiveness of some patients.

Keywords

Pseudomonas aeruginosa / β-lactamase / antibiotics / outer membrane

References

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