Prevalence of the resistance genes to extended-spectrum β-lactam antibioticsin P. aeruginosa strains collected from different parts of Tonekabon ShahidRajai hospital in north of Iran, using PCR technique

Pseudomonas aeruginosa is among the best known hospital pathogens. This organism is the most common opportunistic pathogen with an innate resistance to many antibiotics. Its inborn resistance to many antimicrobial agents and its ability to develop multidrug resistance imposes a serious therapeutic issue. Resistance of this bacterium against different antibiotics has been reported from various regions. The purpose of this study was to clarify the presence of resistance genes to ESBL antibiotics in Pseudomonas aeruginosa strains isolated from different parts of Tonekabon Shahid Rajai hospital in North of Iran using PCR technique. In this study, 35 strains of Pseudomonas aeruginosa were collected from different wards of Tonekabon Shahid Rajai Hospital within 2011- 2012. To determine the resistance of strains, antibiogram test was performed by the disk diffusion method. Specific primers were used to detect the presence of the studied genes, and the PCR technique was applied to amplify the above genes. the strains showed different levels of resistance to antibiotics including, 42.8% to Tobramycin, 20% to Ceftazidime, and 2.8% to Imipenem. All Pseudomonas aeruginosa isolates did not show any resistance to Ciprofloxacin and Amikacin. Of total 35 studied strains, PstS, and blaoxa -50 genes were observed, in 35 (100%) and 34 (97.1%) strains, respectively. Regarding the high percentage of resistance of isolated Pseudomonas aeruginosa to the antibiotics of the ESBL, the accurate performance of antibiogram tests before the prescription of antibiotics seems to be an unavoidable necessity in the treatment of infections resulted from these bacteria. This study is the first report of presence of PstS and blaOXA type genes in P. aeruginosa isolates, in Tonekabon Shahid Rajai hospital in North of Iran