Comparison of Conventional Culture Methods and Polymerase Chain Reaction (PCR) for Specific Detection of Pseudomonas Aeruginosa

Pseudomonas aeruginosa (P. aeruginosa), a major gram-negative opportunistic nosocomial pathogen, is notoriously known because of its intrinsic and acquired multiple antibiotic resistances. Different methods are applied in the clinical laboratory to detect Pseudomonas aeruginosa. The aim of this study was to compare culture and molecular diagnostic assays for the detection of Pseudomonas aeruginosa. In this study, 70 Pseudomonas aeruginosa strains isolated from different clinical specimens were used. The specimen was examined for the presence of Pseudomonas aeruginosa by plating onto a combination of culture media (Muller Hinton agar, Blood agar, and McConkey agar) and also basic biochemical testes. In addition, from the culture, genomic bacterial DNA was extracted and was amplified employing sequence-specific target, namely the exotoxin A (ETA) gene locus by polymerase chain reaction (PCR) method. From the total 300 isolates analyzed in this study, 70 were found by phenotypic tests as P. aeruginosa. The ETA gene was found in 66 isolates (94.3%) by PCR with exotoxin A primers. These results suggest that the PCR-method mentioned above can be used to provide a specific, rapid, simple, and highly sensitive detection of Pseudomonas aeruginosa in clinical samples.