An Investigation into the Effect of Aqueous ExtractofGarlic (Allium-sativum) on Growth Inhibition of Escherichia coli Isolated from calveswith Diarrheain Kazerun

Diarrhea in calves is one of the most prevalent diseases the veterinarians encounter in practice. Diarrhea is responsible for major economic damages in livestock husbandries. Escherichia coli (E.coli) has been regarded as the main factor that causes white diarrhea in calves’ first three weeks of life. Antimicrobial treatment of E. coli is difficult since these bacteria naturally show resistance against most antibiotics. The aim of the present study is to investigate the antibacterial activity of aqueous extract of garlic on Escherichia coli isolated from calves with diarrhea. This descriptive cross-sectional study was carried out to investigate the effect of aqueous extract of garlic on 100 samples of calves with diarrhea collected from traditional and industrial livestock husbandries crops in Kazerun during February and March 2016 and April 2017. The isolates susceptibility to different antibiotics was tested by the disc diffusion method and the antibacterial activity of garlic extract was measured by MIC and MBC methods. In this study, the highest resistance was seen against ampicillin and tetracycline (0±0.4 mm, 0±0.5 mm) and the lowest resistance was against ciprofloxacin (40±2/54 mm). The halo diameter formed by aquatic extract of garlic was similar to streptomycin (15 ± 1/00 mm). In general, the results showed that garlic has the potentiality to be used as an antimicrobial drug, especially in the treatment of E. coli-induced diarrhea in calves.