Microbiological Characterization and Pathogenicity Assessment of Bacteria Isolated from Medicinal Plant Powders Sold in Abidjan, Côte d’Ivoire

Abstract

Introduction: Medicinal plant powders are widely used in sub-Saharan Africa, especially in Côte d’Ivoire, as accessible alternatives to conventional medicine. However, their informal trade, often lacking sanitary regulation, promotes microbial contamination. This study aimed to identify bacterial species present in medicinal plant powders sold in Abidjan markets and assess their pathogenic and antimicrobial resistance profiles. Methods: One hundred (100) medicinal powder samples were collected from markets across Abidjan. Bacteria were isolated and identified using MALDI-TOF mass spectrometry. A small amount of bacterial culture is deposited on a target with a chemical matrix and then ionized by a laser. The generated ions are accelerated in a vacuum tube, and their time of flight is measured. The resulting mass spectrum is compared to a database to identify the bacterial species. Pathogenicity was evaluated through an extensive literature review focusing on virulence factors and resistance mechanisms. Results: Seventy-four (74) bacterial isolates representing 16 pathogenic and opportunistic species were identified, including Enterobacter hormaechei (30), Escherichia coli (18), Klebsiella pneumoniae (2), Proteus mirabilis (2), Pseudomonas aeruginosa (5), and various Staphylococcus species. Rare isolates such as Cronobacter sakazakii and Alcaligenes faecalis were also detected. Literature data indicate that these species possess multiple virulence factors (biofilm, urease, siderophores, toxins) and exhibit multidrug resistance, particularly to β-lactams (ESBLs, carbapenemases), fluoroquinolones, aminoglycosides, and polymyxins. Conclusion : The presence of bacteria in medicinal powders sold in Abidjan could pose a major health risk to consumers. These results highlight the need to establish strengthened quality control measures and appropriate regulations to protect consumer health.