ANTIBACTERIAL ACTIVITY OF Cassia occidentalis WHOLE PLANTEXTRACT AGAINST MDR-Salmonella SPECIES

ABSTRACT This study investigated the antibacterial activity of Cassia occidentalis (Coffee Senna) whole plant extracts against multidrug-resistant (MDR) Salmonella species isolates obtained from Ahmadu Bello University Teaching Hospital (ABUTH), Zaria. The isolates were subjected to gram staining and biochemical screening, antibiotic susceptibility testing was conducted on Mueller Hintons agar and the AMR status of the isolates was established. Phytoconstituents screening of the ethanolic and aqueous extracts revealed the presence of alkaloids, flavonoids, tannins, saponins, glycosides, and phenolic compounds, with steroids detected only in the ethanolic extract. Antibacterial assays conducted using the agar well diffusion method showed concentration-dependent inhibition, with the ethanolic extract exhibiting stronger activity than the aqueous extract. The ethanolic extract produced zones of inhibition up to 40 mm at 300 mg/mL, while the aqueous extract reached 34 mm at the same concentration. Minimum inhibitory concentration (MIC) values ranged from 9.38–18.75 mg/mL for the ethanolic extract and 18.75–37.5 mg/mL for the aqueous extract. Minimum bactericidal concentration (MBC) values ranged from 37.5–75 mg/mL. These results confirm the bacteriostatic and bactericidal effects of C. occidentalis, highlighting its potential as a source of novel antimicrobial agents. The findings support its ethnomedicinal use and suggest its possible application in developing alternative therapies for managing drug-resistant Salmonella infections.