ANTIBACTERIAL ACTIVITY OF ANNONA MURICATA LEAF BIOFRACTIONS AGAINST PSEUDOMONAS AERUGINOSA ISOLATED FROM WOUND INFECTIONS

Abstract

Wound infections caused by drug-resistant Gram-negative bacteria constitute a major global health concern, with Pseudomonas aeruginosa recognized as a leading etiological agent due to its intrinsic and acquired resistance mechanisms. The burden of antimicrobial resistance (AMR) associated with this pathogen exceeds 300,000 deaths annually, highlighting the urgent need for alternative therapeutic approaches. This study investigated the antibacterial activity of solvent-partitioned biofractions of Annona muricata (soursop) leaves against clinical isolates of P. aeruginosa obtained from wound infections. Fresh leaves were pulverized, extracted with methanol, and subsequently partitioned sequentially using n-hexane, ethyl acetate, and methanol. Ten isolates were confirmed using standard biochemical tests, while antibiotic susceptibility was determined using the disc diffusion method following Clinical and Laboratory Standards Institute (CLSI) guidelines. The antibacterial activity of the biofractions was evaluated at concentrations ranging from 100–400 μg/mL, and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using the broth microdilution method. Ethyl acetate yielded the highest extract (49.64%), followed by methanol (46.52%) and n-hexane (3.84%). All isolates exhibited multidrug resistance, although ciprofloxacin and gentamicin showed comparatively higher effectiveness. Both ethyl acetate and methanol fractions demonstrated concentration dependent antibacterial activity, with the ethyl acetate fraction showing slightly superior efficacy. MIC values ranged from 300–400 μg/mL, while MBC values were predominantly 400 μg/mL, indicating bactericidal effects. These findings support the potential of A. muricata leaf biofractions as promising candidates for the development of plant-based antimicrobial agents against resistant wound pathogens.