Comparative Study of Antimicrobial Activities of TiO2 and CdO Nanoparticles against the Pathogenic Strain of Escherichia coli

Background: and Objectives: The aim of this study was to detect the antibacterial properties of 0.01, 0.5 and 1% nano-TiO2 and -CdO against E. coli.Materials and Methods: E. coli was cultured in liquid and agar nutrient medium to evaluate the antibacterial effects of 0.01, 0.05 and 1% of both nano-TiO2 and -CdO via the optical density (OD)and log CFU/ml measurements. Results: Non-significant effect was seen for 0.01% of both nano-specimens. While, 0.05 and 1% ofboth nanoparticles showed considerably decreased bacterial number. A 4.5 and 1.9 times decreasein the OD value was found in the presence of 1 and 0.5% nano-TiO2, respectively (P< 0.001). 1.5and 3.3 times decreased OD was seen in the presence of 0.5 and 1% nano-CdO, respectively, ascompared to control (P<0.001). In the second study, 6.3 log CFU/ml of E. coli were present in thecultures treated with 1% nano-TiO2 and CdO at 4 ºC in water. Control E. coli cells survived for 12 days while complete cell death was seen when 1% nano-TiO2 was applied for 13 hours as comparedto 1% nano-CdO, which showed complete cell death after 15 hours. In the third study, E. coli wasgrown in the agar medium with and without both nanoparticles and suppressed growth (4.5 and 5.6 times; P<0.001) was seen in the presence of 1% nano-CdO and -TiO2, respectively.Conclusion: In spite of the fact that both nanoparticles showed bactericidal activity, nano-TiO2has proven to be more efficient antibacterial agent as compared to nano-CdO.

کلیدواژه ها:

Nanoparticle ، P(2-HMC)-TiO2 ، CDO-MeB ، Bacterial count ، Antibacterial Agent ، Escherichia coli