The search for alternative natural antibiotics to replace or compliment synthetic antibiotics is on the increase. This is due to the side effects produced by synthetic drugs, some of which are irreversible and the rise of antimicrobial resistance. The objectives of this research were to investigate the antimicrobial activity of Chrysolobalanus Icaco and Thymus Vulgaris against selective pathogens and to ultimately develop a natural antimicrobial medication for microbial infections. The Completely Randomised Block Approach (CRBA), consisting of three blocks: Experimental Samples, Control and Reference were used in all cases. The aqueous and ethanolic extract of Chrysolobalanus Icaco and Thymus Vulgaris were investigated for their antimicrobial activity against selective pathogens, E.coli, S. aureus, K. pneumoniae and C. albicans, using the Disc Diffusion assay under asceptic conditions. The diameterof zone of inhibition, DZOI, measured with a rule was used as the indicator of the plant extract antimicrobial activity at a concentration of 0.5g/ml. Experiments were done in triplicates and data were collected after 24 and 48hrs for bacterial and fungal species respectively. Data were analysed for the mean diameter of zone of inhibition (MDZI) with standard deviation, area of zone of inhibition, AZOI and significant differences, in MDZI, between the varying fruit extracts concentrations, using two way ANOVA. For the ethanolic extract of C.icaco, the largest DZOI was obtained against E.coli (34.25 ± 0.96 mm), whereas the least was obtained against C.albicans (7 mm ± 5 mm). For T. vulgaris, the largest DZOI of (23.42 ± 3.0 mm) was obtained for the ethanolic extract against C. albicans and the lowest DZOI of (11.25 ± 1.5 mm) was obtained against S.aureus. Smaller DZOI were obtained for the aqueous extracts of both plant parts in comparison to the ethanolic. This range from 11mm to 23.50mm. The combination of both plants ethanolic and aqueous extract showed variation in antimicrobial potency with respect to each plant parts. Selective antimicrobial activity was also evident as C.icaco extracts was selective against E.coli and T.vulgaris was selective against C. albicans. The ethanolic and aqueous extracts of Chrysolobalanus Icaco (fat poke) and Thymus Vulgaris (Thyme) are effective against E.coli and C. albicans infections. Furthermore, the research addresses the lack of data on the antimicrobial activity of Chrysolobalanus Icaco and Thymus Vulgaris extracts, in Guyana. The populace are encouraged to continually use Thymus Vulgaris (Thyme) as a food seasoning ingredient and the possibility of using the ethanolic extract of Chrysolobalanus Icaco as an antibacterial skin and antifungal agent.
Hinds S. *Jagessar R. (Fri,) studied this question.