Abstract
Background & Objective: The ability of Pseudomonas aeruginosa to form biofilm has an important role in establishment of chronic phase of infections. Biofilm formation can be affected by antibiotics sub-MIC concentrations. The principal aim of the present study was to evaluate the effect of gentamicin at sub-MIC concentrations on biofilm formation in 100 Pseudomonas aeruginosa clinical isolates.Methods: Determination of minimal inhibitory concentration of gentamicin for clinical isolates was done using micro broth dilution method. The amount of biofilm formation in the treated and untreated isolates with gentamicin sub-MIC (1/2&1/4MIC) concentrations was evaluated using microtitre plate assay. pelA and pslA genes were detected in clinical isolates by PCR method.Results: 99% of clinical isolates were biofilm producer. Different changes in amountof biofilm formation were observed in the treated clinical isolates with sub-MIC concentrations of gentamicin. Two dominant changes were observed in 80% of clinical isolates. These concentrations had inhibitory effect on biofilm formation in 46.4% of isolates and caused a significant decrease in its amount. While in 31.3% of the isolates, the biofilm formation was significantly increased. The frequency of pelA and pslA genes among clinical isolates was 100%. Conclusion: gentamicin sub-MIC concentrations cause different changes on biofilm formation of Pseudomonas aeruginosa clinical isolates. Therefore, further studies are needed for discovering new treatment strategies and using sub-MIC concentrations of the antibiotic in prevention and treatment of Pseudomonas aeruginosa infections.
Highlights
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that can form biofilms and cause nosocomial infections, especially in immunocompromised individuals [1,2,3]
The frequency of oprL gene, which is specific to P. aeruginosa gene, as well as pelA and pslA genes that are involved in biofilm formation, was 100% in the studied isolates
The results of our study showed various changes in the biofilm formation of clinical isolates of P. aeruginosa in exposure to sub-Minimal Inhibitory Concentration (MIC) concentrations of gentamicin
Summary
Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that can form biofilms and cause nosocomial infections, especially in immunocompromised individuals [1,2,3]. Extracellular polymeric substance (EPS) or exopolysaccharide is a viscous organic substance which is essential for the formation of biofilm structure. It consists of polysaccharides, proteins and nucleic acids. The psl gene cluster is distributed around the cell surface and strengthens the structural scaffold and improves the establishment of microcolonies It plays a main role in the primary attachment of sessile cells to living and non-living surfaces. The ability of Pseudomonas aeruginosa to form biofilm has an important role in establishment of chronic phase of infections. The principal aim of the present study was to evaluate the effect of gentamicin at sub-MIC concentrations on biofilm formation in 100 Pseudomonas aeruginosa clinical isolates
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
