Proximate, Phytochemical and Antibacterial Analysis of Persea americana Obtained from Nigeria

The proximate analysis and antimicrobial activities of Persea Americana seed (Avocado pear) against pathogenic Escherichia coli and Staphylococcus aureus was carried out to ascertain the unique properties that makes it confer antibacterial effect. This research work was carried out in the Microbiology Project Laboratory of Chukwuemeka Odumegwu Ojukwu University, Uli. The organisms used were obtained from urine samples of students and characterized using microbiological and biochemical tests. The phytochemical and proximate analysis of the seed extract of the plant was determined quantitatively using chemical and spectrophotometric methods. The inhibitory activity test was carried out using agar well diffusion method also tube dilution technique using double-fold serial dilution method was employed for assaying the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) at various concentrations (31.25, 62.5, 125, 250 and 500 mg/ml). The phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, saponins, phenols, cyanogenic glycosides and steroids. The proximate content revealed that the seed contained more of moisture than fat and fibre. The ethanolic extract of Persea americana seed showed a pronounced activity (11.00 mm and 9.40 mm) against Escherichia coli and Staphylococcus aureus were significantly higher (P<0.05) than that of the aqueous extract (5.90 mm) which showed for only Escherichia coli. This activity differed significantly (P>0.05) from that of Ciprofloxacin (22.10 mm and 16.40 mm). The results of MIC for the ethanolic extract against E. coli and S. aureus were 500 mg/ml and 250 mg/ml respectively, while the MBC result was pronounced for only E. coli at 500 mg/ml. The spectra of antimicrobial activities displayed by the extracts could be attributed to the presence of these phytochemicals and signifies the potential of Persea americana as a source of therapeutic agent