Investigation of the Relationship between the Presence of Genes Producing Toxin and Antibiotic Resistance Pattern in Pseudomonas aeruginosa Strains Isolated from Burn Wounds

Secreted toxins of the burn wounds caused by Pseudomonas aeruginosa play an important role in spreading infection. The antibiotic resistance pattern may have an effect on the increased toxicity of this bacterium. Therefore, the aim of this study was to determine the relationship between the presence of P. aeruginosa toxins isolated from burn wounds and the antibiotic resistance pattern. In this cross sectional-descriptive study, P. aeruginosa isolates were first isolated from the burn wound samples by using biochemical tests. The next step dealt with the investigation of antibiotic resistance pattern based on CLSI (Clinical and Laboratory Standards Institute). The process of identifying the genes responsible for producing toxin was performed by polymerase chain reaction method. Data analysis was performed in SPSS (version 16) using the Chi-square test. Out of 250 strains isolated from burn wounds, 63 isolates (25.2%) were obtained from P. aeruginosa. With regard to resistance, the obtained results revealed that Doripenem, Ertapenem, and Meropenem antibiotics had the highest frequency, whereas, the antibiotics of Piperacillin/Tazobactam and Piperacillin had the lowest frequency. Moreover, resistance to imipenem was observed to be semi-sensitive regarding the minimum inhibitory concentration in three isolates (76.4%). The exoS, toxA, exoT, exoY, and pvdA genes were observed in 40 (63.49%), 31(49.2%), 39 (61.9%), 56 (88.88%), and 50 (79.36%) isolates, respectively. In addition, there was a significant correlation between the antibiotic resistance pattern and distribution of toxin genes (P <0.05). According to the obtained results, it can be concluded that the antimicrobial resistance pattern could play an important role in the distribution of P. aeruginosa toxin genes isolated from burn wounds.