Abstract
High occurrence of antibiotic resistance in pathogenic bacteria is caused by the use of natural medicinal plants to eliminate risk of infectious diseases. Glycine max is on the most popular and nutritious foods with high antimicrobial effects. The present research was done to study the antibacterial effects of the methanolic extract of G. max against Gram-negative and positive bacteria. G. max seeds of M7 and M9 varieties were purchased and their methanolic extracts were collected. Diameter of the zone of growth inhibition of extracts were measured for pathogenic bacteria using the CLSI guidelines. Antimicrobial effects of G. max extracts were also compared with several antibiotics. Diameter of the inhibition zone of tested bacteria against different treatments of G. max had a ranges of 5.93 ± 0.18 to 22.61 ± 1.80 mm. M7 variety had a higher antimicrobial effects on tested bacteria (p < 0.05). The highest diameter of the zone of growth inhibition was seen for L. monocytogenes (22.61 ± 1.80 mm) and S. aureus (19.33 ± 1.56 mm). Antimicrobial effects of the methanolic extract of the G. max was also dose-dependent (p < 0.05). Diameter of the inhibition zone of tested bacteria against different antibiotic agents had a ranges of 5.94 ± 0.38 to 24.95 ± 2.11 mm. Ciprofloxacin, penicillin G tetracycline, gentamicin and azithromycin antibiotic agents exhibited the highest diameter of zone of the growth inhibition for K. pneumoniae (15.71 ± 1.46 mm), L. monocytogenes (23.94 ± 2.03 mm), L. monocytogenes (20.55 ± 1.95 mm), S. aureus (14.27 ± 1.36 mm) and L. monocytogenes (24.95 ± 2.11 mm), respectively. Formulation of antibiotic agent using the 100 mg/mL concentration of the M7 variety of G. max has been recommended for treatment of the cases of infectious diseases.