Evaluation of antibacterial activities of graviola (<i>Annona Muricata</i>) leave and stem bark extracts against clinical isolates of <i>Salmonella spp</i> and <i>Escherichia coli</i>

Abstract

Graviola (Annona muricata) Nigeria it is commonly called “Mama” in Hausa language is a tropical plant found in Nigeria in the Sudan- Guinea Savannah vegetation zone has been reported to be used in the treatment of various types of ailments. The present study investigated the antibacterial properties of the stem- bark and leave extracts of the plant against clinical isolates of Escherichia coli and Salmonella spp using agar cup method. Results showed that petroleum ether extract of stem bark and leave had (> 12mm) growth inhibition against E.coli and Salmonella spp. at 50-100 mg/ml concentrations compared to the methanol and aqueous extracts which did not inhibit growth. The minimum inhibitory concentration (MIC) of petroleum ether extract of stem bark and leave was 12.5 mg/ml. It therefore showed that petroleum ether of Annona muricata had antibacterial activities against E.coli and Salmonella spp. thereby justifying its usage ethnopharmacologically in the treatment of infections.

Key words: Annona muricata, E.coli, Salmonella spp, Growth inhibition