RESUMEN
BACKGROUND/AIM: ß-Lactamase production is considered one of the most important resistance mechanisms amongvirulent Pseudomonas aeruginosa isolates. The aim of this study was to compare the production and antimicrobial resistance patterns of some virulence factors in extended spectrum ß-lactamase (ESßL)-producing and nonproducing P. aeruginosa clinical isolates. MATERIALS AND METHODS: Out of 183 different clinical specimens, 104 Pseudomonas aeruginosa isolates were recovered. The isolates were screened for ESßL production using the double disk diffusion test and phenotypic confirmatory disk diffusion test. All isolates were tested for susceptibility to 25 antimicrobials, as well as for expression of various virulence factors including pigment, hemolysin, gelatinase, protease, lipase, rhamnolipids, biofilm, and cell surface hydrophobicity. The results of ESßL producers and honproducers were statistically compared. RESULTS: All isolates showed a high frequency of multiple resistance to at least 14 and up to 25 of the tested antimicrobials. Nevertheless, most virulence factors were produced at higher rates in ESßL-producing than in ESßL-nonproducing Pseudomonas aeruginosa isolates. CONCLUSION: The results of this study suggest a correlation between ESßL phenotype and the production of some factors that are reported to be involved in the virulence of P. aeruginosa.
