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Indirect evidence of cell wall alterations in pseudomonas aeruginosa by immunoglobulin preparations
Abstract:
Ten strains of Pseudomonas aeruginosa isolated from different clinical sources were incubated with immunoglobulin preparations for i.v. use. This resulted in the release of beta-lactamases normally cellbound in the periplasmic space. The amount of released beta-lactamases--depending on the degree of cell wall alteration--was spectrophotometrically determined by the use of nitrocefin as an indicator substance. Beta-lactamase release varies according to strain specificity and depends on the chemical modification of the immunoglobulins used.
Insights
Immunoglobulin preparations triggered the release of cell-bound beta-lactamases from Pseudomonas aeruginosa strains. This release, varying by bacterial strain and immunoglobulin modification, impacts cell wall integrity.
Area of Science:
- Microbiology
- Biochemistry
Background:
- Pseudomonas aeruginosa is an opportunistic pathogen.
- Beta-lactamases are enzymes that hydrolyze beta-lactam antibiotics.
- These enzymes are often located in the periplasmic space, bound to the cell.
Purpose of the Study:
- To investigate the effect of immunoglobulin preparations on beta-lactamase release from Pseudomonas aeruginosa.
- To determine factors influencing beta-lactamase release, including bacterial strain and immunoglobulin modification.
Main Methods:
- Ten clinical isolates of Pseudomonas aeruginosa were incubated with intravenous immunoglobulin preparations.
- Beta-lactamase release was quantified spectrophotometrically using nitrocefin as a substrate.
- Cell wall alteration was assessed as a factor in enzyme release.
Main Results:
- Incubation with immunoglobulin preparations induced the release of cell-bound beta-lactamases.
- The extent of beta-lactamase release varied significantly among different Pseudomonas aeruginosa strains.
- Chemical modifications of the immunoglobulins influenced the degree of beta-lactamase release.
Conclusions:
- Intravenous immunoglobulin preparations can cause the release of periplasmic beta-lactamases from Pseudomonas aeruginosa.
- Bacterial strain specificity and immunoglobulin chemical properties are critical determinants of beta-lactamase release.
- This finding has implications for understanding bacterial response to immunotherapies.