In Vitro Antibacterial and Antifungal Activities of Standardized Picralima Nitida Extracts Against Selected Common Clinical Pathogens

Infectious diseases caused by bacteria and fungi remain a significant public health challenge, particularly in developing countries where access to effective antimicrobial agents is limited and resistance to existing drugs is increasing. Medicinal plants provide an important alternative source of bioactive compounds with therapeutic potential. This study investigated the in vitro antibacterial and antifungal activities of the ethanol extract of Picralima nitida seeds against selected pathogens. The test organisms included Staphylococcus aureus , Escherichia coli , Bacillus species, Vibrio cholerae , and Candida albicans . Antimicrobial activities were assessed using the agar well diffusion method, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by standard microbroth dilution techniques. The results showed that the extract exhibited varying degrees of inhibition against all the test organisms. The highest antibacterial activity was observed against Bacillus species with a zone of inhibition of 19.2 mm at 200 mg/ml; in comparison, the lowest activity was observed against Vibrio cholerae with a zone of 10.4 mm at the same concentration. Candida albicans also demonstrated sensitivity, with an inhibition zone of 14.7 mm at 200 mg/ml. The MIC values ranged from 100 to 200 mg/ml, while MBC values were generally higher, indicating bacteriostatic and fungistatic effects at lower concentrations. Compared with standard antibiotics such as chloramphenicol and nystatin, the extract showed moderate but promising antimicrobial potential. The study concludes that P. nitida contains phytochemicals with broad-spectrum antimicrobial activity, making it a candidate for further drug development.