Crude pineapple extract inhibits WHO priority groups bacteria that are causing skin and soft tissue infections: A cost-effective alternative in the fight against AMR

Background: The escalating global crisis of antimicrobial resistance (AMR) has rendered many frontline antibiotics ineffective, particularly against multidrug-resistant (MDR) bacteria such as carbapenem-resistant Pseudomonas aeruginosa (CarbR), extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, and methicillin-resistant Staphylococcus aureus (MRSA). With limited new antibiotics entering the pipeline and high costs of drug development, there is growing interest in affordable, eco-friendly alternatives from plant-derived compounds. Pineapple (Ananas comosus), particularly its bromelain-rich peel and crown, contains bioactive phytochemicals with reported antibacterial properties. This study evaluated the antibacterial activity of crude pineapple extracts against MDR pathogens associated with skin and soft tissue infections (SSTIs). Methodology: This laboratory-based experimental study (May–July 2025) utilized 15 archived clinical isolates of CarbR P. aeruginosa (5), ESBL E. coli (5), and MRSA (5) from the Bugando Medical Centre. Isolates were revived, re-characterized, and tested for susceptibility following CLSI guidelines. Crude bromelain extracts were prepared from pineapple fruit, peel, and crown using ethanol maceration followed by rotary evaporation, and finally drying. Extracts were tested for antibacterial activity via broth micro-dilution assays to determine minimum inhibitory concentrations (MICs), with experiments performed in triplicate. Results: Peel extract exhibited the strongest antibacterial activity with MICs of 12.5% for CarbR P. aeruginosa and 25% for both ESBL E. coli and MRSA. While crown extract showed MICs of 12.5%, 25%, and 50% against the same pathogens, while fruit extract demonstrated weaker activity, requiring 100% concentration against ESBL E. coli and MRSA. Conclusion: Crude pineapple peel and crown extracts demonstrated potent antibacterial activity against WHO-priority MDR pathogens. Further work should isolate and characterize bioactive compounds from crude pineapple peel and crown extracts for clinical translation.