Antimicrobial Activity of Crude Extract of Grewia mollis Smith (Malvaceae) on Clinical Isolates of Escherichia coli from Cases of Diarrhoea

Abstract

Background: Escherichia coli is one of the leading causes of primary intestinal infections, particularly diarrhoea and other types of opportunistic infections of humans. The antimicrobial, phytochemical contents and minimum inhibitory concentration of Grewia mollis Smith (Malvaceae) were determined in a quest to evaluate their potentials as sources of alternative medicine for the treatment of diarrhoea. Methods: The bacteriological investigation was carried out on 25 clinical isolates of Escherichia coli from cases of diarrhoea which includes; sub-culturing onto eosin methylene blue agar and incubated at 370C for 24 hours. Gram staining, lactose fermentation, indole formation from tryptophan, gelatin liquefaction and Voges–Proskauer test were carried out on the isolates. The antimicrobial, phytochemical analysis and minimum inhibitory concentration (MIC) of Grewia mollis extract were determined using Evans and Trease method. Results: Grewia mollisleave methanol, ethyl acetate and N- hexane extracts gave extraction yield 8.40, 3.86 and 2.55 respectively. Tannins, saponins, flavonoids and alkaloids were detected as bioactive compounds from the leave of Grewia mollis investigated. The minimum inhibitory and minimum bactericidal concentration of the extract elicited remarkable antimicrobial activity in correlation to the polarity of each solvent. Conclusion: Therefore, Grewia mollis leave extracts hold the potential for clinical application.