ANTIBACTERIAL SCREENING OF CITRUS AURANTIIFOLIA (CHRISTM) SWINGLE – LIME LEAF METHANOL EXTRACT ON STAPHYLOCOCCUS AUREUS AND ESCHERICHIA COLI

ABSTRACT Antibacterial resistance (ABR) has emerged as a pressing global health concern, threatening the effectiveness of treatments for infectious diseases. The alarming rise of resistant microorganisms has rendered traditional antibacterial therapies increasingly ineffective. Thus the need to find new antibacterial agents of paramount importance.The research aimed to determine phytochemical constituents and antibacterial activity of Citrus aurantiifolia methanol extract. The plant citrusaurantiifolia was collected from within the school premises, the bacteria used wereStaphylococcusaureus and Escherichiacoli, obtained from Sir Yahaya Memorial Hospital BirninKebbi, Kebbi state, Nigeria. The qualitative phytochemical screening was perform using standard methods, Antibiotic Sensitivity profile was assessed using disc diffusion method, antibacterial activity of the extract was determined using Agar well diffusion and minimum inhibitory concentration was determine using serial dilution. Qualitative phytochemical screening revealed the presence of several bioactive compounds, including alkaloids, flavonoids, tannins, steroids, saponins and glycosides, while phenols and anthraquinone was not detected. The antibiotic Sensitivity profile was assessed and Escherichia coli demonstrating susceptibility to CPX, PEF, OFX and AU but resistant to S, CN, AM, SXT, SP and CH while Staphylococcus is susceptible to R, PEF, S, CPX and CN but resistant to APX, Z, E, AM and SXT. The antibacterial activity of the leaf extract used the concentrations of the extract which were in 50mg/ml, 75mg/ml, and 100mg/ml, the zones of inhibition for EscherichiaColi revealed 9.0± 0.58, 13.0 ± 0.29 and 16.5 ± 0.29mm while the zones of inhibition for Staphylococcusaureus revealed 4.7±0.17, 9.3 ± 0.33 and 13.3 ± 0.33mm. Minimum inhibitory concentration (MIC) indicated effective inhibition at concentrations 12.5mg/mL for Staphylococcusaureus and 25mg/ml for Escherichia coli. These findings suggest that Citrus aurantifolia leaf possess significant antibacterial properties and may serve as a promising source for developing natural antibacterial therapies.