Background: Pseudomonas aeruginosa is a common cause of nosocomial infections. It exhibits innate resistance to a wide range of antibiotics. This study was performed to determine clonal characteristic of P. aeruginosa isolated from clinical specimens, hospital means, and hospital personnel by PCR- ribotyping patterns.
Methods: A total of 104 P. aeruginosa were isolated from clinical and environmental samples (59 clinical, 45 hospital means and hospital personnel). P. aeruginosa was identified by standard bacteriological methods, mucoid colony morphotypes, and antibiotic resistance rate. The genomes of isolates were extracted and all considered species were confirmed by 16S rDNA- based PCR assay. Then all isolates were genotyped by the 16S - 23SrDNA and Hinf1 restriction enzyme technique.
Results: Antibacterial sensitivity pattern of isolates showed clinical and environmental specimens were approximately identical (high antibiotic resistance to Ceftazidime and low antibiotic resistance to Amikacin). Colony morphotypes of specimens revealed that mucoid type of clinical isolates were more than that of environmental isolates. Among clinical and environmental strains P1; (570 bp) was the most prevalence pattern.
Conclusions: Antibiotic resistance, phenotypic characterization, and PCR- ribotyping pattern showed there is clonal relatedness between clinical and environmental isolates and environment could be a main reservoir for P. aeruginosa infections in hospital.
Keywords: Hospital means; Pseudomonas aeruginosa; nosocomial infections.