Mwihia, Stephen K.Ngugi, Mathew P.Maingi, John M.Kamau, James K.Muhuha, Anne W.2019-04-092019-04-092017International Journal of Life Sciences Research. Vol. 5(3), pp; 46-52. Month: July - September 2017, www.researchpublish.com2348313X23483148http://ir-library.ku.ac.ke/handle/123456789/19429Research ArticleInvestigation of plants for phytochemicals and antibacterial effects is essential for discovery of prospective novel complexes for therapeutic use. In the present assay the seed extracts of Annona squamosa were screened for phytochemicals present and antibacterial activities against Salmonella typhi (ATCC 1408), Escherichia coli (ATCC 25922), and Klebsiella pneumonia (ATCC700603) and Shigella flexneri (ATCC 12022). Extraction of the active components was done by the use of organic solvents; methanol, dichloromethane and methanol: dichloromethane blend in soxhlet extractor and concentrated in a rotary evaporator. Phytochemical analysis was done through standard qualitative screening procedures. The antibacterial activities were evaluated through the paper disc diffusion method. Phytochemical analysis exhibited the occurrence of fixed oils, alkaloids, saponins, flavonoids, glycosides, tannins, phenols, steroids and terpenoids which are indicated in antibacterial activity. The methanolic extract was the most efficacious in terms of inhibitory activities, exhibiting a MIC range of 15-31.17mg/ml followed by Methanol: dichloromethane with a MIC range of 16.4-56.57mg/ml while dichloromethane displayed the least bacterial inhibitory activity with a MIC range of 47.50-61.83mg/ml. The antibacterial data obtained was assayed against that of the Ciprofloxacin (reference). Ciprofloxacin activity was significantly higher than all the extracts (p<0.05), though some concentrations exhibited equal activities (p>0.05). The extracts have shown antibacterial effects at their MIC against the microorganisms in the study indicating that with further researches these extracts can be used for treating enteric diseases. Keywords: Annona squamosa, Phytochemical, Antibacterial, Paper disc diffusion method, methanol, dichloromethane extract, enterobacteria.enAnnona squamosaPhytochemicalAntibacterialPaper disc diffusion methodMethanolDichloromethane extractEnterobacteriaArticle