الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 185 |  |  |
| | | from | 185 | | |
Abstract
Pseudomonas aeruginosa causes numerous human illnesses as a result of its drug resistance. Biofilms increase the pathogenicity of P. aeruginosa by evading the immune system and causing persistent infections that are challenging to treat. This study aimed to evaluate the antibacterial and antibiofilm activities of chitosan against clinically isolated P. aeruginosa. Twenty P. aeruginosa isolates were collected from different clinical sources including urine, sputum, blood, pus and wounds. The susceptibility of these isolates to different antibiotics showed that eleven isolates exhibited multi-drug resistance (MDR), while 9 isolates were non-MDR. However, the assessment of biofilm formation exhibited different levels of production, with no significant variations detected between MDR and non-MDR P. aeruginosa isolates. In addition, PCR technique was performed to detect three essential genes (PsL, GacA, and PeLF) involved in biofilm formation among P. aeruginosa isolates. It was found that PslA and GacA genes was observed in all isolates, while PelF gene was absent in few ones. Statistical analysis showed that there is no correlation between biofilm formation and drug resistance. Chitosan at a concentration of 5mg/ml did not exhibit any antibacterial effects, but it strongly suppressed the formation of biofilm by P. aeruginosa isolates. Also, Scanning Electron Microscopy (SEM) showed individually separated cells with fewer bacterial number in treated samples with chitosan compared to untreated ones. The combination of chitosan and gentamicin demonstrated a potent antibacterial and antibiofilm effect. Also, chitosan-gentamicin significantly suppressed the expression of PsL, GacA, and PeLF genes. The findings of our study indicate that chitosan has the potential to be a valuable supplement for current antibiotics in the treatment of P. aeruginosa infections.