Antibacterial activity of aqueous extracts of some Nigerian chewing sticks

Objectives: The study aimed at determining the antibacterial activity in extracts obtained various Nigerian chewing sticks. Ultimately such identified extracts may serve as chemotherapeutic agents in the management of orofacial infections Methods: Whole roots, stem and twigs of seventeen different plants as well as the fruits of Cnestis ferruginea were collected, identified and extracted. Test organisms consisted of four reference strains as well as twenty-four bacterial isolates (13 facultative anaerobes and 11 obligate anaerobes) obtained from orofacial infections.All the extracts were screened for antimicrobial activity by the plate method of Lamikanra et al against the type cultures. (Lamikanra et al 1999). Subsequently the minimum inhibitory concentrations (MICs) of these extracts against the test strains were determined by the agar dilution method (Okeke 1999) Results: Eleven of the 18 extracts examined demonstrated varying degrees of activity against the type cultures for preliminary screening. Results from further evaluation of the 11 extracts against isolates from orofacial infections showed that anaerobic isolates were particularly susceptible to all the extract with the exception of Citrus sinensis with MIC °Ý 2.5/ml. Similarly the extracts were effective against aerobic gram-positive cocci of the genera Staphylococcus and Streptococcus. (MIC °Ü 2.5mg/ml). Generally the gram-negative organisms were less susceptible to the activity of the extracts though impressive activity was noted with extracts of Bridellia ferruginea, Anogeissus leicocarpus and Terminalia glaucescens. Conclusion: The results demonstrated antibacterial activity in a number of plants used as chewing sticks in Nigeria. Further studies need to be carried out to test the potential of these substances in the chemotherapy of bacterial infections