Microbial contamination and antibiotic resistance patterns in locally processed liquid herbal preparations sold in Freetown, Sierra Leone

Background: Herbal medicines are widely used in Sierra Leone due to their cultural acceptance, accessibility, and affordability. However, concerns persist regarding their microbiological safety, especially given poor production hygiene and limited regulatory oversight. This study evaluates the microbial quality and antibiotic resistance profiles of locally processed liquid herbal preparations (LHPs) sold in Freetown and surrounding areas. Objective: To assess the microbial contamination levels and antibiotic susceptibility of bacterial isolates from LHPs in the Western Area of Sierra Leone. Methods: An in-vitro experimental design was employed. Twenty LHP samples were randomly collected from vendors across different locations in Freetown. The samples underwent pH analysis, organoleptic evaluation, total viable count (TVC) estimation, Gram staining, biochemical identification, and antibiotic susceptibility testing using the disc diffusion method. Interpretation followed Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: All 20 samples (100%) were contaminated with bacteria, with TVCs ranging from 9.0 × 10⁴ to 2.7 × 10⁶ CFU/mL well above WHO's permissible limit of 10³ CFU/mL for oral herbal products. The most prevalent organisms were Staphylococcus aureus (30.6%), Pseudomonas aeruginosa (19.4%), Streptococcus spp. (13.9%), Shigella spp. (13.9%), and Salmonella spp. (11.1%). Antibiotic susceptibility testing revealed high resistance rates, particularly among S. aureus isolates, which showed 100% resistance to nitrofurantoin and 91% to amoxicillin-clavulanic acid. P. aeruginosa exhibited multidrug resistance, though most isolates remained sensitive to ciprofloxacin and gentamicin. Conclusion: Locally processed LHPs sold in Freetown are microbiologically unsafe, with widespread contamination by pathogenic and multidrug-resistant bacteria. These findings underscore the urgent need for regulatory enforcement, quality assurance protocols, and public education on the risks associated with unregulated herbal product use.