From the Research
Pseudomonas aeruginosa secretes several antibiotic-degrading enzymes, with the most significant being beta-lactamase, particularly AmpC beta-lactamase, which hydrolyzes the beta-lactam ring in penicillins, cephalosporins, and related antibiotics, rendering them ineffective 1.
Key Enzymes
- Beta-lactamase: hydrolyzes the beta-lactam ring in penicillins, cephalosporins, and related antibiotics
- Extended-spectrum beta-lactamases (ESBLs): degrade carbapenems, which are often considered last-resort antibiotics
- Metallo-beta-lactamases (MBLs) like IMP and VIM types: also degrade carbapenems
Mechanisms of Resistance
- Enzymatic degradation of antibiotics
- Intrinsic impermeability
- Efflux pump systems
Clinical Implications
- Pseudomonas infections are challenging to treat, often requiring combination antibiotic therapy or newer agents specifically designed to resist enzymatic degradation 2
- The production of beta-lactamases, particularly AmpC beta-lactamase, is a key mechanism of resistance in Pseudomonas aeruginosa 3
Recent Findings
- A study published in 2024 found that acquired beta-lactamases play an important role in beta-lactam resistance in Pseudomonas aeruginosa, and that different beta-lactamases alter susceptibility to different beta-lactam antibiotics 1
- Another study published in 2023 found that ceftazidime/avibactam had better in vitro activity against serine carbapenemase-harbouring Pseudomonas aeruginosa compared to other beta-lactam/beta-lactamase inhibitor combinations 2