Antibacterial activity of Ocimum sanctum L. essential oil against multidrug resistance bacteria vaginosis

Abstract

The antibiotic resistance of Bacteria Vaginosis (BV) isolates intensifies vaginal morbidity and genital infections facilitating poor treatment outcome and severe vaginal pathology. The phytochemicals in Ocimum sanctum essential oil (OsEO) were investigated for their antibacterial activity against bacteria vaginosis and major metabolites on multidrug resistance (MDR) strains. Bacteria pathogens isolated from vaginal samples (n = 40) obtained from patients with confirmed BV were analysed for hemolytic activity, biofilm production and profiled for antibiotic resistance. Extracted OsEO was profiled with GC-MS and analysed for antibacterial activity. Of the recovered bacteria pathogens (n = 241) associated with vaginosis including Streptococcus pyogenes (34 %), Staphylococcus aureus (31 %) and Escherichia coli (10 %) and less than 10 % Klebsiella oxytoca, Enterobacter cloaca, Pseudomonas aeruginosa and Citrobacter freundii were identified. Significant rates of 21.6 %, 4.6 % and 2.3 % were weak, mild and strong biofilm producers respectively and overall 26.6 % were hemolytic strains (p < 0.05). More than 60 % resistance to ceftriaxone sulbactam, ampiclox, cefuroxime, cefotaxime, nalidixic acid and cefexime was observed in BV with significant proportion showing MARI>0.2 (p < 0.05). Hierarchical clustering of MDR BV strains provided related clustered bacteria pathogens having a very low susceptibility to iminepem, cefuroxime, and amoxycillin/clavulanate. More than 1.2 % saponin, alkaloids and flavonoids levels in OsEO gave significant inhibitory activities at IC50 (25.0 μg/mL) and IC90 (50.0 μg/mL) and significant inhibitory association with phytochemical compounds (eta = 0.457, p = 0.015). OsEO cyclohexene and methanoazulene metabolites showed significant antibacterial association with BV strains (p < 0.05). The OsEO phytochemical metabolites showed antibacterial activity against multidrug resistance BV and identified cyclohexene and methanoazulene are promising candidates for developing formulations as topical antimicrobial agents for BV treatment.