Prevalence of protease and elastase production by clinical isolates of Pseudomonas aeruginosa in relation to aeruginocine typing patterns.

Sixty six consecutive P. aeruginosa isolates from heterogeneous clinical specimens were subjected to aeruginocine (pyocine) typing and assayed for in vitro protease and elastase production by a simple and reproducible qualitative test. The 45.4% of the clinical isolates were found to be both protease and elastase (P + E +) producers; 40.9% were only protease producers (P + E -) and 13.6% were non producers (P - E -). Aeruginocine code 7777 strains were found to be predominant among P + E + and P + E - types, as 48.2% and 51.7% isolates belonged to the types, respectively, suggesting thereby the virulence of this aeruginocine type in P. aeruginosa infections and the possible association of protease and elastase production with aeruginocine production.