Antibacterial Activity of the Hydro-Alcoholic Extract of Juglans regia L. Stem Bark on Human Bacterial Infection

Aims Bovine mastitis continues to be the most costly disease to the dairy farmers. It dominates in Iran as one of the most prevalent diseases in dairy cattle among the dairy farms. Mastitis treatment with antibiotics leads to the development of antibiotic resistant strains and consumer health problem.This study was performed for the first time to analyze in vitro effects of hydro-alcoholic extract of Juglans regia L. stem bark on 6 mastitis pathogens. Materials Methods the susceptibility of 6 strains of bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus spp., Pasteurella multocida and Mannheimia haemolytica) were analyzed against hydro-alcoholic extract of Juglans regia L. stem bark with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) methods. Findings Hydro-alcoholic extract did not have antibacterial effects on E. coli and K. pneumoniae. Minimum inhibitory concentration for S. aureus, P. multocida, M. haemolytica and Streptococcus spp. was 62.5mg/ml of hydro-alcoholic extract. There was not any significant response with concentrations below 100mg/disc on S. aureus, Streptococcus species, P. multocida and M. haemolytica. Minimum bactericidal concentration of this extract was 100mg/ml in all isolates. Conclusion Juglans regia L. have some antibacterial effects on S. aureus, P. multocida, M. haemolytica and Streptococcus species.