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Mutation of Pseudomonas aeruginosa to piperacillin resistance mediated by beta-lactamase production
Abstract:
Piperacillin-resistant mutants were detected in each of ten strains of Pseudomonas aeruginosa. The resistance was associated with constitutive production by the strains of high levels of beta-lactamase which was similar in character to the induced chromosomal Id beta-lactamase of the parent strains. This type of mutation to piperacillin-resistance occurred at a low frequency. The beta-lactamase production and piperacillin-resistance were stable on repeated subculture and prolonged storage of the strains.
Insights
Ten Pseudomonas aeruginosa strains developed piperacillin resistance due to high beta-lactamase production. This stable resistance mutation occurred infrequently but was consistently observed in the tested strains.
Area of Science:
- Microbiology
- Molecular Biology
- Antimicrobial Resistance
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen known for its intrinsic and acquired resistance mechanisms.
- Beta-lactamase enzymes are a primary defense against beta-lactam antibiotics like piperacillin.
Purpose of the Study:
- To investigate the emergence and characteristics of piperacillin-resistant mutants in Pseudomonas aeruginosa.
- To understand the role of beta-lactamase in conferring piperacillin resistance.
Main Methods:
- Isolation and characterization of ten Pseudomonas aeruginosa strains.
- Detection and analysis of beta-lactamase production in resistant mutants.
- Assessment of the stability of resistance and beta-lactamase production.
Main Results:
- All ten strains exhibited piperacillin resistance.
- Resistance correlated with constitutive high-level beta-lactamase production.
- The identified beta-lactamase resembled the inducible chromosomal enzyme of parent strains.
- This resistance mutation occurred at a low frequency.
- Piperacillin resistance and beta-lactamase production were stable upon subculture and storage.
Conclusions:
- Constitutive high-level beta-lactamase production is a key mechanism for piperacillin resistance in Pseudomonas aeruginosa.
- The emergence of such resistant mutants, though infrequent, poses a significant challenge due to their stability.