Antibacterial Activity of Hunteria umbellata (Madaci Seed) against Multidrug-Resistant Staphylococcus aureus Isolated from Patients in Dutsin-Ma, Katsina State, Nigeria

Abstract

Background: Urinary tract infections (UTIs) caused by Staphylococcus aureus are increasingly reported in Nigerian healthcare settings, with multidrug resistance (MDR) posing a major therapeutic challenge. The search for alternative antibacterial agents from medicinal plants has therefore gained renewed attention. Hunteria umbellata (Madaci), widely used in traditional medicine in Northern Nigeria, is reputed for its antimicrobial properties, yet evidence against MDR uropathogenic S. aureus remains limited. Objective: This study evaluated the in vitro antibacterial activity of Hunteria umbellata seed extracts against multidrug-resistant Staphylococcus aureus isolated from urine samples of patients attending General Hospital Dutsin-Ma, Katsina State, Nigeria. Methods: Fifty urine samples were collected from patients with suspected UTIs. Staphylococcus aureus was isolated and identified using standard phenotypic and biochemical methods. Antimicrobial susceptibility testing was performed by the Kirby–Bauer disc diffusion method in accordance with CLSI guidelines. Multidrug resistance was defined as r resistance to ≥1 agent in ≥3 antimicrobial classes. Ethanol and aqueous seed extracts of H. umbellata were phytochemically screened and evaluated for antibacterial activity using agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. Results: Twenty-two (44.0%) urine samples yielded S. aureus, with a higher prevalence among females (63.6%). High resistance rates were observed to cefoxitin (81.8%), ciprofloxacin (77.3%), and ampicillin (72.7%), while all isolates were susceptible to vancomycin. Multidrug resistance was detected in 81.8% of isolates. The ethanol extract demonstrated strong, concentration-dependent antibacterial activity against MDR isolates (mean inhibition zone: 21.6 ± 2.1 mm at 100 mg/mL), with MIC values predominantly between 6.25 and 12.5 mg/mL. The aqueous extract showed moderate, largely bacteriostatic activity. Conclusion: Hunteria umbellata seed extracts, particularly the ethanol extract, exhibit significant in vitro activity against MDR Staphylococcus aureus from UTIs, supporting their potential as sources of alternative antibacterial agents.