DOI: 10.36347/sjavs.2016.v03i03.002

Pages: 172-180

The Antibiotics properties of the aqueous leaf extracts of A. spinosus, A. hybridus, C. esculenta and C. bicolor on four human pathogens, S. aureus, E. coli, Salmonella typhi and Candida albicans was studied using further paper disc diffusion techniques. The minimum inhibitory concentration (MIC) was evaluated for each of the plant extracts on the test organisms. Result showed that there were significant variations in the levels of activity against the test organisms. Finding showed that the inhibition of staphylococcus aureus was in the range of 11.67±1.53d mm in A. hybridus to 18.3± 1.16b mm in C. bicolor while the activity against E.coli was in the range of 10.33± 0.58d mm in A. hybridus to 16.67± 1.53b mm in C. bicolor. Salmonella typhi was inhibited within the range of 10.33± 0.58c.mm in A. hybridus and 14.00± 1.00b mm in B. bicolor and the inhibition was between 11.67±0.58c in C. esculenta and 21.00± 2.65b for Candida albican. The results show that the aqueous extract of C. bicolor was the most potent while A. hybridus extract was the least potent. All the test extracts had activities lower than that of standard antibiotics. The minimum inhibition concentration (MIC) showed that the extracts possess antimicrobial properties at concentrations ranging from > 12.50 mg/ml to > 200 mg/ml respectively. The result obtained in this study suggests that the aqueous leaf extracts of the plants possessed antimicrobial activities against the bacterial isolates at different concentrations. The minimum inhibition concentration was between 12.50 mg/ml and 50 mg/ml against all the test organisms. There were variations in the lowest concentrations of the different plant extracts that caused inhibitions against the different test organisms.