The Eeffects of Silver Nanoparticles Alone and in Combination with Imipenem on Inhibition of Pseudomonas aeruginosa Biofilm Formation

Pseudomonas aeruginosa is an important opportunistic, forming biofilm pathogen. The its biofilm has created the effective barrier against penetration of antimicrobial agents, in result the drug resistance is increased 1000 times in biofilm cells versus planktonic cells .But nanomaterial are good candidates since their use does not lead to the development of resistance .In current study, the ant biofilm effects of silver nanoparticles alone and in combination with imipenem on biofilm producing P. aeruginosa was investigated.
60 isolates of P. aeruginosa were collected from shahid Motahari burn hospital ,Mehr burn hospital and shahid Rajai Cardiovascular hospital in Tehran. 20 strong biofilm-producing isolates were selected to investigate the ant biofilm effects of silver nanoparticles by microdilution plate technique. The combined effects of silver nanoparticles and imipenem was determined through Checkerboard dilution technique on 10 strong biofilm-producing isolates.
In the presence of a dilution series 0/4-50μg /ml silver nanoparticles, reduction of biofilm biomass was different among the studied 20 isolates and was seen the biomass reduction 4 - 95% in 14 isolates. The effects of imipenem in combination with silver nanoparticles on the inhibition of biofilm formation showed synergistic relationships ( ΣFIC ≤ 0/5 ) in majority of the isolates.
This study suggests that the silver nanoparticles can be a promising candidate to inhibit the formation of P.aeruginosa biofilm .Moreover silver nanoparticles in combination with antibiotics such as imipenem can reduce dramatically P.aeruginosa Biofilm formation on surfaces.