The Effect of Different Doses of Silver Nanoparticles on Escherichia coli genome Using Randomly Amplified Polymorphic DNA (RAPD) Molecular Markers
Subject Areas : Biotechnology and Applied Microbiology journal
Keywords: silver nanoparticles, E. coli, RAPD-PCR, Genetic change,
Abstract :
Silver is one of the most important antimicrobial material in the world. In recent years, there has been a growinginterest in silver nanoparticles due to its unique properties. Considering the toxicity of silver nanoparticles onmicroorganisms, they are used to treat infections. In the present study, the effect of growth inhibition of silvernanoparticles on different doses and exposure time was recorded. To do so, the model gram-negative bacteriumEscherichia coli O157: H7 was selected. To study the effect of silver nanoparticles, first stock solution of silvernanoparticles prepared and different concentrations of 75 and 90 μg/ml of stock solution of nanoparticles in eachof the tubes containing the bacteria were inoculated. After 1, 2 and 24 hours of incubation in a shaking incubator,the DNA treated samples was extracted. The RAPD-PCR technique was used to assess the genetic diversity.RAPD markers were analyzed using NTSYS-PC software. A similarity matrix was calculated and treated cellswere compared with that of controls. The results showed that the genetic variation between control and treatedcells is relatively high. Many mechanisms have been proposed about the effects of silver nanoparticles onmicroorganisms. In this study, the genotoxic approach is used. The results showed that the mentionedconcentrations have a severe inhibitory effect on the growth of Gram-negative bacterium Escherichia coli after24 hours treatment. Also the mechanisms of antimicrobial silver nanoparticles revealed changing in the sequenceof bacterial DNA
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