Comparative Antimicrobial Evaluation of Selected Medicinal Plant Extracts and Conventional Antibiotics Against Clinical Bacterial Pathogens

Antimicrobial resistance among clinical bacterial pathogens has intensified the search for plant-derived alternatives; however, comparative data benchmarking crude extracts against conventional antibiotics remain limited, particularly for Azadirachta indica, Carica papaya, and Ananas comosus. This study comparatively evaluated the antimicrobial efficacy of methanolic neem leaf, methanolic papaya leaf, ethanolic papaya seed, and methanolic pineapple crown extracts against Staphylococcus aureus, Streptococcus spp., Klebsiella pneumoniae, and Escherichia coli, using ciprofloxacin, amoxicillin, ceftriaxone, and gentamicin as comparators. Extracts were prepared by cold maceration and profiled by GC–MS; antimicrobial activity was assessed by agar-well diffusion. MIC and MBC were determined by broth dilution, with antibiotics tested by the Kirby–Bauer method. Neem leaf extract was most active against S. aureus (20.00 ± 0.11 mm), followed by C. papaya seed (16.00 ± 0.10 mm), pineapple crown (15.10 ± 0.10 mm), and C. papaya leaf (14.00 ± 0.09 mm). Activity was concentration-dependent and differed significantly among extracts (p < 0.05), while all antibiotics were significantly more active than the extracts against every isolate (p < 0.05). MIC and MBC values ranged from 25 to 100 mg/mL. The extracts demonstrated promising but inferior activity compared with conventional antibiotics, supporting their potential as adjunctive rather than replacement agents. This study provides comparative baseline data for phytotherapeutic development and antimicrobial stewardship.