Evaluation Antibacterial behavior of Silver nanoparticles ongeneral escherchia uropathogenic

Background and Aim : Urinary tract infection (UTI) is a big problematic issue in Health Systems.Members of Enterobacteriaceae family are the main causes of UTIs and Escherichia coli has beenreported as the most important involved microorganism,. Escherichia coli , a rod-shaped Gramnegativebacterium is the causative of ۸۰- ۹۰ percent cases of UTIs. Antibitic resistancephenotypes amongst the uropathogenic strains of E,coli makes it difficult to cure UTIs. This studywas conducted to investigate the influences of Silver nanoparticles to prevent and combatantibiotic resistance in E. coli.Methods : In this study silver nanoparticles with an approximate size of ۵ nm was prepared by theChemistry Department. Serial dilutions of nanoparticles were prepared in Nutrient broth mediumand ۱۰ microbial suspension equal to ۰.۵ McFarland, was added to it. A۵er ۲۴ hours of incubationat temperature of ۳۷°C was transferred to Mueller- Hinton agar,trough dilution and with secondincubation(۲۴ hours,۳۷ degrees centigrade),intended colonies are counted for determination ofMIC and MBC. Also bacterium sensitivity to silver nanoparticles is studied by disc diffusion andwell diffusion methods.Results : According to the result of this study ,MIC and MBC amounts for ۵ nm silvernanoparticles are determined az ۱۲۵۰۰ ppm and ۲۵۰۰۰ppm.Also disc diffusion method can makezone of (growth) inhibition with size of ۸-۱۰ milimeters,for E.coli from ۵nm silver nanoparticles,using ۲۰ μL fron the ۲۵۰۰۰ppm concentration in every discConclusion : The results show E,coli is sensitive to silver nanoparticles and there is no resistancefor silver nanoparticles in resistant Pathogen microbes against drugs

کلیدواژه ها:

E.coli ، silver nanoparticles.MIC and MBC