The study included the isolation, cultural characteristics, molecular identification of bacterial isolated from land snail Achatina achatina and the enhanced antibacterial potential of Xylopia aetiopica extracts in consortium with alum on some bacteria isolated from Achatina achatina (land snail). Isolates associated with the intestine of the snails were isolated using standard microbiological methods and subjected to standard microbiological procedures such as, culturing isolation, identification; the cultural characteristics of all isolated bacterial strains were elucidated on International Streptomyces Project media (ISP2-ISP-7). 16S rRNA marker gene was used for molecular identification using 27F and 1492R universal primers and sensitivity testing using alum and plant extracts (Agar well Diffusion method). Tube dilution method was used to determine the Minimum Inhibitory Concentration (MIC) using double-fold serial dilutions at concentrations 62.5mg/ml to 400 mg/ml. The bacterial isolates identified were; Escherichia coliMW46885, Bacillus cereus AP007209, S. aureus CP051191 and Salmonella typhimurium AE006468. The result of phytochemical component present in X. aethiopica were; Tannin Alkaloid, Flavonoid, and Saponin with values, 2.22±0.08, 5.55±0.78, 6.55±0.21, and 10.55±0.07mg/kg respectively. Results of the inhibitory activity of the extracts and alum were dose-dependent. Methanolic extract of X. aethiopica were more active on E. coli24.50±0.71 at 250mg/ml, Aqueous extract of X. aethiopica were more active on E. coli and Salmonella typhi (21.0±0.00mm), at 250mg/ml and Staphylococcus aureus (20.0±0.00mm) at 125mg/ml and 62.5mg/ml concentrations respectively. Alum were more active on Staphylococcus aureus (25.0±0.00mm) at 250mg/ml concentrations. The result of the combination methanol extract of X. aethiopica and alum showed it more effect on Bacillus cereus (22.0±0.00) at 250mg/ml concentrations. The combination effect of aqueous extract of X. aethiopica and alum revealed the inhibitory effect were more on Bacillus cereus (21.0±0.00) at 250mg/ml concentrations while it was more active on Staphylococcus aureus (15.5±0.71mm) at 62.5mg/ml conc. The result of the combination treatments of methanolic, aqueous extracts of X. aethiopica, and alum showed that the inhibitory effect was more on E, coli and Staphylococcus aureus (18.0±0.00) at 250mg/ml conc., E. coli and Salmonella typhi (15.0±0.00) at 125mg/ml conc. and Salmonella typhi (14.0±0.00mm) at 62.5mg/ml conc. and ciprofloxacin which serves as control has higher inhibition potentials. Xylopia aetiopica has been reported to possess anticancer, antidiabetic, antimalarial, antioxidant, enzyme inhibitory and antibacterial properties. Tube dilution method was used to determine the Minimum Inhibitory Concentration (MIC) using double-fold serial dilutions at concentrations 62.5mg/ml to 400 mg/ml. statistically, there was a significant difference (p≤0.05) in the antibacterial activity of the alum, methanol, and aqueous extracts of X. aethiopica. The minimum inhibitory concentrations at which the extracts were effective against the bacterial isolates was at the 400mg/ml to 300mg/ml concentrations. The MICs values of the extracts and their combinations revealed significantly the inhibitory activities. The study has revealed some level of antibacterial activity and antibacterial activity of the extracts on these bacterial isolates is promising as the extracts could be used as a cheap antibacterial for the treatment of infections caused by these bacteria.

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