Molecular identification of Pseudomonas aeruginosa recovered from cystic fibrosis patients

OBJECTIVE. Precise identification of various morphotypes of Pseduomonas aeruginosa which developed during cystic fibrosis (CF) is of prime importance. We aimed to identify the isolates of P. aeruginosa recovered from CF patients at the genus and species level through primers targeting oprI and oprL genes via PCR. METHODS. Sputum samples or throat swabs were taken from 100 CF patients and plated on cetrimide agar. All suspected colonies were primarily screened for P. aeruginosa by a combination of phenotypic tests. Molecular identification of colonies was performed using specific primers for oprI and oprL genes. RESULTS. Based on phenotypic tests, P. aeruginosa isolates were recovered from 40% of CF patients. Forty isolates yielded amplicon of oprI gene using genus-specific primers confirming the identity of fluorescent pseudomonads. However, 37 of 40 isolates yielded amplicon of oprL gene using species-specific primers, verifying the identity of P. aeruginosa. CONCLUSION. This study showed that the species-specific PCR targeting oprL gene can be used as accurate test for identification of highly adaptable P. aeruginosa in CF patients. This procedure may provide a simple and reliable method for identification of various morphotypes.