Evaluation of Anti-Biofilm Formation Effect of Nickel Oxide Nanoparticles (NiO-NPs) Against Methicillin-Resistant Staphylococcus Aureus (MRSA)

In this project, Nickel oxide nanoparticles (NiO-NPs) have been synthesized by a photolysis method and assessed for their anti-biofilm activity. It is a strategy that is simple and inexpensive. The morphology and the average particle size was investigated by scanning electron microscope (SEM), transmitted electron microscope (TEM) and the crystallite size was calculated by (XRD) analysis. The XRD studies support the existence of NiO-NPs with a high degree of crystallinity. Their nickel oxide particle size was found to be around 13-31 nm. Forty-two samples of medical waste from different hospitals in Baghdad were between 2nd to 12th of October / 2020. Bacterial isolation results recorded fifteen Staphylococcus aureus isolates. Well diffusion method was used to determine of methicillin resistance S. aureus (MRSA), in addition to using the mecA gene as a molecular method to detection of methicillin resistance gene, the results of these both methods showed that the MRSA percentage of these two methods were 53.3% and 73.4% in well diffusion method and PCR respectively. Results of MRSA biofilm formation illustrated that only four isolates (36.3%) hadn’t the ability to produce biofilm by using microtiter plate assay (MTP). In contrast, the other isolates (63.7%) could produce biofilm and they were ranging from strong to week biofilm formation. Antimicrobial activity of different concentrations of NiO-NPs (10, 20, 30, 50, and 100 μg/ml) showed ranging of inhibition zones starting from 0 to 13 mm. In comparison, the MIC concentration was 265 μg/ml (63.7%) of seven MRSA isolates and 530 μg/ml (36.4%) of four isolates. Detection of hemolysis activities of NiO-NPs against human red blood cells (RBCs) was done. The results illustrate that the hemolytic activity was 2.38%, 2.23%, 2.41%, and 2.69% corresponding to 0, 0.01, 0.1, and 1 mg/ml of NiO-NPs.