title: Novel Combinations of Synthesized ZnO NPs and Ceftazidime: Evaluation of their Activity against Standards and New Clinically IsolatedPseudomonas aeruginosa.
abstract: BACKGROUND
  Antibiotic resistant bacteria can be considered as a main problem in infection management. Zinc oxide nanoparticles (ZnO NPs), individually or in combination with antibiotics, can be considered as good candidates for struggling against drug resistant bacteria.
  
  
  METHODS
  In this study, Zinc oxide nanoparticles were synthesized using sol-gel method in low temperature as a cost effective procedure and characterized by X-ray diffraction and Scanning Electron Microscopy. Antibacterial activity of 9 new combinations of Zinc oxide nanoparticles and ceftazidime was assessed against standards and new clinically isolated multi drug resistantPseudomonas aeruginosa(P. aeruginosa), in order to evaluate enhancement effect of synthesized Zinc oxide nanoparticles on antibacterial activity of ceftazidime.
  
  
  RESULTS
  The results indicated that desirable effects can be seen at 6 and 7mMof Zinc oxide nanoparticles (60 to 100% inhibition). Moreover, after evaluation of 9 new combinations with various concentrations of both components, it was demonstrated that Zinc oxide nanoparticles can enhance the antibacterial activity of ceftazidime, against some bacterial strains ofP. aeruginosa. The highest activity was observed with the concentration of 20μg/mlceftazidime in the presence of 5, 6 or 7mMof Zinc oxide nanoparticles.
  
  
  CONCLUSIONS
  Zinc oxide nanoparticles in appropriate concentrations can be proposed as new and promising candidates for overcoming bacterial resistance.
authors.affiliation: Department of Microbiology, Afzalipour Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Isaei
authors.affiliation: Department of Microbiology, Afzalipour Faculty of Medicine, Kerman University of Medical Sciences, Kerman, Iran.
authors.forename: Shahla
authors.initials: S
authors.lastname: Mansouri
authors.affiliation: Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Mohammadi
authors.affiliation: Department of Plant Breeding and Biotechnology, Faculty of Plant Production, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan, Iran.
authors.forename: Sadegh
authors.initials: S
authors.lastname: Taheritarigh
authors.affiliation: Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Mohammadi
keywords: Antibiotic resistance; Ceftazidime; Pseudomonas aeruginosa; ZnO NPs