Biofilm Formation and Determination of Antimicrobial Resistance Pattern in Pseudomonas aeruginosa Clinical Isolates

Pseudomonas aeruginosa is one of the most important pathogens in hospitals. One of the therapeutic problems of this bacterium is antibiotic resistance to common antibiotic treatments associated with biofilm production. This study was conducted to find out the relationship between antibiotic resistance and biofilm formation on P. aeruginosa isolated from 50 clinical specimens of patients referring to Milad Hospital in Tehran. Biochemical and differential tests were carried out to identify and isolate P. aeruginosa. The resistance of the strains was determined by antibiogram test and the ability of biofilm strain formation was investigated by microtiterplate method. The results showed that the highest resistance to antibiotics was ticarcillin (48%) and imipenem (36%) and 17 strains (34%) had multiple drug resistance. Also, the ability to form biofilms of strains showed that 52% of them had strong biofilms and among 17 strains of P. aeruginosa with multiple drug resistance, 12 strains had the ability to form a strong biofilm. According to the results, a significant percentage of MDR strains have the ability to produce strong biofilms. Regarding the role of biofilms in reducing the penetration of the drug into cell, biofilm-producing bacteria have a high drug resistance, which is a warning to the medical community.