Ribotyping and increasing trend of antibiotic resistance of Pseudomonas aeruginosa isolated in Iran

Abstract

The trend of antibiotic resistance, ribotyping and serotyping patterns of Pseudomonas aeruginosa collected since 1987 in Iran were investigated. The results showed that among the aminoglycosides, amikacin was the most effective antibiotic against P. aeruginosa with 98.4% susceptibility rate followed by tobramycin (73%) and gentamicin (71%). Of the cephalosporins, susceptibility to ceftazidime was 93%. Among the antibiotics tested in vitro, ciproflaxacin was found to be the most effective against the strains, with 98.4% susceptibility rate. The most predominant monovalent serotype was O:11 (34%). Other dominant serotypes were O:5 (20%), O:1 (16%) and O:6 (15%). Thirteen percent of the isolates showed no agglutination with the tested sera. A high percent of the O:11 serotype isolates (68%) were resistant to ≥ 3 antibiotics. The collected P. aeruginosa isolates were classified into 3 ribotypes using PuvII restriction enzyme. The results suggest that the antibiotic resistance among P. aeruginosa increased significantly rate in Iran in the last decades, with no changes in the ribotype and serotype patterns.