Anti-biofilm effects and substantively properties of magnetic iron oxide nanoparticles synthesized against clinical isolates for MDR Acinetobacter baumannii and related with expression of gene
Abstract
This study aimed to empirical investigation of influence on biofilm formation and determines the gene expression of Bap gene in this bacterial by manufactured of magnetic iron oxide nanoparticles Fe3O4 antibiofilm drug-like. A total of 10 clinical isolates were collected from different sources included (wounds, burns, urine, sputum, blood and throat) that ability to produce strongly biofilm formation. The Fe3O4 NPs was physical-chemical characterized via UV-visible Absorption Spectroscopy, FT-IR, X-RD, AFM and SEM techniques after synthetics by co-precipitation method, the results showed the Fe3O4 NPs have very fine crystalline sizes reach to 11±1 nm by XRD, with mostly spherical in shape and the average size (40- 47) nm nanoparticles by SEM and AFM respectively. The MIC and sub-MIC tests of synthesis Fe3O4 NPs to effect on biofilm formation of A.baumannii isolates at concentrations (15.75 to 2000) μg/ml the results showed that 125µg/ml were MIC and sub-MIC with a significant difference at p˃0.05 had been reduced bacterial adhesion inhibitory on polystyrene surface of microtiter plates and consequently caused biofilms. Total RNA were extracted with TRIzol while total RNA was converted to cDNA and the gene expression of biofilm formation Bap normalized gene with housekeeping 16SrRNA gene was conducted by using real-time quantitative PCR assay (RT-qPCR) before and after treated with Fe3O4 NPs. The results showed a significant difference at p˃0.05 in Cycle threshold (Ct) values and according to fold regulation equation 2- (ΔΔ CT) for gene expression for Bap gene of the isolates. Therefore these treatment enhance a significant difference were decreased in gene expression levels of Bap gene and up-regulated at physiological biofilm, without changed with 16SrRNA gene because do not appear any variations of expression before and after treated with Fe3O4 NPs. In this study the synthesized magnetic Fe3O4NPs with 125µg/ml gave excellent antibiofilm activities and of inhibitory efficiency against A.baumannii isolates; Synthesized magnetic Fe3O4NPs of the potentiate to down the regulation of gene expression fold for biofilm A.baumannii gene (Bap), leading as a result to have low biofilm production.