Pyocyanin and Biofilm Formation in Pseudomonas aeruginosa Isolated from Burn Infections in Baghdad, Iraq

摘要

Pseudomonas aeruginosa is emerging as important hospital pathogenic bacteria, which can persist in the environment for extended periods of time. Sixty-three isolates belonging to the P. aeruginosa were isolated from different clinical sources. The antimicrobial susceptibility test was performed by the disk diffusion method, and the biofilm formation was assayed by the micro titer plate. Pyocyanin was extracted from the culture supernatants, and the absorbance values were measured using a spectrophotometer. The percentage of resistance shown by the isolates were 87.3 % for cefotaxime, 52.38 % carbenicillin, 39.68 % imipenem, 11.11 % colistin, and 7.93 % Piperacillin-tazobactam. About 9.09 % exhibited positive results for the phenotypic production of extended spectrum β-lactamase, whereas 40 % of the imipenem-resistant isolates were Metallo-β lactamase (MBLs) producers. Among the burn isolates, 22.22 % formed moderate biofilms and 6.35 % formed strong biofilms. 34.92 % of the burn isolates were pyocyanin producers. All the pyocyanin-producer isolates carried phenazine biosynthetic operon phzA-G gene. The results of this study revealed a high prevalence of pyocyanin production and biofilm formation in the P. aeruginosa isolates from burn infections.