Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

Vol 23, Issue 1, 2021; Page No.(31-41)

DETERMINATION OF IN VITRO ANTIMICROBIAL ACTIVITY OF STEVIA REBAUDIANA (BERTONI) LEAF EXTRACTS AGAINST ANTIBIOTIC RESISTANT MICROORGANISMS

SADIA AFRIN, KAZI ASMA AHMED SHAMIMA, MD. AMIRUL HOQUE, ASHISH KUMAR SARKER, MD. ABDUS SATTER MIAH AND MOHAMMAD NAZRUL ISLAM BHUIYAN1

Abstract

Antimicrobial activity of Stevia rebaudiana (Bertoni), well known as stevia plant which leaves extracts were investigated against a large number of microorganisms, but not yet evaluated its activity against resistant microorganisms. The aim of this study was to evaluate the antimicrobial proficiency of stevia against antibiotic resistant microorganisms (10 bacteria, 6 fungi and 16 yeast species) using Kirby- Bauer disc diffusion technique. Extracts were obtained from the stevia powder of leaves using different solvents like as n-hexane, petroleum ether, acetone, ethanol and water. Among different extracts of stevia, n-hexane, petroleum ether and acetone extracts were more potentially effective with variable efficiency against both gram positive and gram negative resistance bacteria compared to ethanolic and water extracts, respectively. Maximum zone of inhibition (21.0±0.5 mm) was observed with n-hexane extracts against Bacillus cereus and minimum zone of inhibition (7.5±0.5 mm) was specified by the water extracts against Listeria monocytogenes. The n-hexane extracts inhibited significant number of mycelial growth of tested fungi compared to other solvents extracts. Likely as, extracts with n-hexane exhibited more efficacies against most of the tested yeasts, particularly for Candida species. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) were also determined. The results of present study indicate that the stevia leaf extracts have inhibitory efficacy against microorganisms and further study will reveal the possibility of employing them in medicines for the treatment of infectious diseases caused by the test microorganisms.