Investigating the antibacterial effects of methanolic extract of Myristica fragrans against broad-spectrum β-lactamase-producing Staphylococcus aureus isolates

The increasing development of antibiotic resistance of bacteria has provided the basis for replacing antimicrobial agents with plant origin and with less side effects. This research is a type of laboratory study that was conducted with the aim of determining the antibacterial effect of Myristica fragrans on staphylococcus isolates beta lactamase producing antibiotics. The methanol extract of the plant was prepared by maceration method. The extract was filtered with Whatman No.1 paper and concentrated by rotary evaporator system. Different concentrations of 200, 100, 80, 40, 20, 10, 5, 2.5, 1.25, 0.625 of the extract were prepared in DMSO: Methanol (1:1v/v) solvent. Identification of beta-lactamase producing isolates was done by phenotypic method with cefotaxime antibiotic discs and cefotaxime / clavulanic acid combined disc. Antibacterial activity against 40 isolates of beta-lactamase-producing isolates was investigated by agar wells diffusion method. After incubation for 24 hours at 37°C, the sensitivity of bacteria was determined by measuring the diameter of the growth inhibition zone. Based on the results, out of 60 Staphylococcus aureus bacteria, 67% of isolates were beta-lactamase producers, respectively. All isolates of Staphylococcus aureus showed sensitivity to Myristica fragrans extract, and the average of minimum growth inhibition concentration to beta-lactamase-producing Staphylococcus aureus was 10 mg/ml. Due to increasing antibiotic resistance, it seems that Myristica fragrans extract can be used against beta-lactam-resistant Staphylococcus aureus strains in controlling infections, and in this regard, isolation and identification of the effective substances of the plant extract it is suggested.