摘要:
Ciprofloxacin is a second-generation of fluoroquinolone,broad-spectrum antibiotic with bactericidal activity against Gram-positive and Gram-negative organisms.It is one of the most widely used antibiotics,because of its efficacy,safety,and relatively low cost.Ascorbic acid(vitamin C)is water-soluble monosaccharide antioxidant;it is essentially required by the body for its various biochemical and physiological processes.S.aureus is Gram-positive cocci;widely distributed in the environment,it is a member of the normal flora of the body.S.aureus is not always pathogenic;it is a common cause of skin infections including abscesses,respiratory infections such as sinusitis,and food poisoning.E.coli is Gram-negative bacteria,found in the environment,foods,and intestines.Most E.coli strains are harmless;it is part of the normal microbiota of the gut.However,some serotypes of E.coli cause serious food poisoning in their hosts;it can cause diarrhea,while others cause urinary tract infections,respiratory illness and pneumonia,and other illnesses.Method:Cup cut diffusion method was applied.Experiment I:is carried out to choose the concentration of vitamin C to be used in experiment II.The negative control is normal saline,added in cup in each plate,vitamin C(100 mg/mL,200 mg/mL,400 mg/mL)was added,the volume in each cup was 100μL.Experiment II:Eight groups of treatments were applied.The first is the negative control(1%normal saline),the second group is the positive control of vitamin C(200 mg/mL).The third,fourth and fifth groups are ciprofloxacin with different concentrations(10 mg/mL,20 mg/mL,40 mg/mL);the sixth,seventh and eighth are the combination of vitamin C with each concentration of ciprofloxacin(10 mg/mL,20 mg/mL,40 mg/mL).Each group includes six petri dishes.Bacterial plates were incubated at 37 oC for 24 h and 48 h.Zone of inhibition is measured in mm.Results and conclusion:Ciprofloxacin produces dose dependent increase in zone of inhibition of S.aureus and E.coli growth,after 24 and 48 hours incubation.While vit