Genomic diversity and virulence genes among clinical isolates of Pseudomonas aeruginosa.

BACKGROUND Typing of nosocomial pathogens is necessary to determine the source of an outbreak. The aim was to determine the genomic variability among Pseudomonas aeruginosa (P. aeruginosa) by random amplification of polymorphic DNA (RAPD) and enterobacterial repetitive intergenic consensus (ERIC) methods. METHODS Fifty P. aeruginosa isolates were obtained from the hospitals. The source of these isolates were burn wound and urinary tract infections. After detection of P. aeruginosa by biochemical methods, chromosomal deoxyribonucleic acid (DNA) was extracted by a DNA extraction kit. ERIC-PCR and RAPD- PCR was done by standard methods. The polymerase chain reaction (PCR) products were run and visualized in 1.5% agarose gels stained with ethidium bromide. RESULTS Fifty P. aeruginosa isolates were analyzed by ERIC-PCR and RAPD-PCR methods. Multiple PCR fragment sizes generated by two PCR methods and PCR product size were between 200-3500 bp, and 10 and 7 different PCR patterns were detected by ERIC-PCR and RAPD-PCR, respectively. Eleven isolates were not detected by ERIC-PCR method. Fifteen isolates were typed to a single genotype by the RAPD-PCR method. CONCLUSIONS We suggested that ERIC and RAPD PCR are equally suitable, inexpensive, fast, reproducible, and discriminatory as rapid DNA typing tools for effective epidemiological surveillance of P. aeruginosa isolates. Our results suggest that these DNA typing tools could be used in routine epidemiological surveillance, outbreak surveillance, and in the identification of the source of transmission of P. aeruginosa.