Potent antimicrobial effect of Ocimum herb essential oil against the drug resistant E. coli and other bacteria found on hand surface

Nowadays the evolution of antimicrobial resistance poses a serious threat to the management of infectious diseases globally. Till the last decade, resistance could be handled by the development of new drugs active against the resistant bacterial strains; however, bacteria seem to be getting smarter, and the emergence of resistant strains leaves the challenge for the pharma industry. In the present scenario, phyto-medicines could well be leveraged to combat antibiotic-resistant strains of bacteria. Here we show the remarkable antimicrobial activity of Ocimum oil (Tulsi, in the Hindi vernacular), tested against sensitive and drug-resistant E. coli (XL10 Gold and Origami strains). The zone of bacterial clearance induced by Ocimum (Tulsi) oil treatment was comparable to the standard of care, polymyxin B. We show that 0.5% Ocimum oil is predominantly bactericidal in nature and could clear bacterial colonies in less than 120 minutes. Additional bacteriostatic properties of Ocimum oil restricted subsequent bacterial growth. Human hands are the primary ‘touch’ organs for interaction with the external world; therefore, they encounter microbes more often. In the present study, we show the antibacterial efficacy of Ocimum oil against the common hand-borne microflora. Finally, community-based microbiology assays confirmed the tested efficacy of Ocimum oil for inhibiting hand-borne microbes, with 90% efficiency. Overall, our findings clearly show that Ocimum oil has antibacterial properties, and it is a strong candidate as an all-herbal hand sanitizer, which is more suitable even against the antibiotic-resistant strain and for skin health also.