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Published on: May 4, 2018
[Peptidase activity and toxicity of strains of Pseudomonas aeruginosa]
1Istituto di Chimica Biologica, Facoltà di Medicina e Chirurgia, Università di Sassari.
Abstract:
Pseudomonas aeruginosa is a microorganism of the terrestrial and aquatic environment which may cause pulmonary, urinary and corneal infections. The pathogenesis of Pseudomonas-induced diseases seems to be linked to the production of extracellular substances such as exotoxins, hemolysins, leukocidins and hydrolytic enzymes, including various peptidases. Anyway there is not a clear view on the role other proteases have in the mechanism of pathogenesis, and even if their activity may always be associated to the toxicity of the microorganism. We have therefore determined the activity of a number of eso- and endopeptidases in 17 strains of P. aeruginosa isolated from patients with urinary pathologies. Four of these peptidase activities, namely elastase, neutral protease, aminopeptidase I and leucine aminopeptidase show a positive correlation with three parameters selected as indices of toxicity, i.e. the mucoid appearance, the gentamicin resistance and the adhesivity of colonies.
Insights
Certain Pseudomonas aeruginosa peptidases, including elastase and neutral protease, correlate with increased bacterial toxicity in urinary tract infections. This finding helps understand Pseudomonas aeruginosa pathogenesis and virulence factors.
Area of Science:
- Microbiology
- Pathogenesis
- Enzymology
Background:
- Pseudomonas aeruginosa is a versatile pathogen causing infections in pulmonary, urinary, and corneal sites.
- Pathogenesis is linked to extracellular substances like toxins and hydrolytic enzymes, including peptidases.
- The specific roles of various proteases in Pseudomonas aeruginosa pathogenesis remain unclear.
Purpose of the Study:
- To investigate the activity of exo- and endopeptidases in Pseudomonas aeruginosa strains from urinary infections.
- To determine the correlation between specific peptidase activities and indicators of bacterial toxicity.
Main Methods:
- Analysis of 17 Pseudomonas aeruginosa strains isolated from patients with urinary pathologies.
- Quantification of various exo- and endopeptidase activities.
- Assessment of mucoid appearance, gentamicin resistance, and colony adhesivity as toxicity indices.
Main Results:
- Four peptidase activities demonstrated a positive correlation with toxicity parameters.
- Specifically, elastase, neutral protease, aminopeptidase I, and leucine aminopeptidase activities were linked to increased mucoid appearance, gentamicin resistance, and colony adhesivity.
- These findings suggest a role for these specific peptidases in Pseudomonas aeruginosa virulence.
Conclusions:
- Specific peptidases (elastase, neutral protease, aminopeptidase I, leucine aminopeptidase) are associated with increased virulence in Pseudomonas aeruginosa strains from urinary infections.
- These enzymes may contribute to the pathogenesis of urinary tract infections caused by Pseudomonas aeruginosa.
- Further research is warranted to elucidate the precise mechanisms by which these peptidases contribute to Pseudomonas aeruginosa toxicity.
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