Microbial Contamination of the Stem Bark of Mitragyna ledermannii, A Commercially Available Medicinal Plant in the District of Abidjan (Cote d'Ivoire)

Raw plant material sold on markets may constitute hazardous risk to population due to storage conditions. This study aimed at assessing the microbial quality of Mitragyna ledermannii an important medicinal plant being used in Cote d’Ivoire for treating malaria and other diseases. A total of 188 samples of stem barks of M. ledermannii were purchased from markets in 3 settings (Abobo, Adjamé, Yopougon) over a period of 3 months. The samples were analyzed using standard microbiological methods. Also, some physicochemical parameters were measured. The moisture of the samples varied from 5.3 to 61.18%, pH was 4.88-6.35 and temperature 24.5-31°C. The samples showed high rate of contamination to mesophilic aerobic bacteria (100%), total coliforms (99.50%), thermotolerant coliforms (99.50%), Escherichia coli (10%), Staphylococcus aureus (98.93%), Enterococci (85.56%), Pseudomonas (61%), yeasts and moulds (93%). Any Salmonella was found in all samples. Average loads of microorganisms ranged from 2.6 x10³ to 8.7 x10⁷ CFU/g for mesophiles, 4.0 x10³ to 3.4 x10⁷ CFU/g for total coliforms, 1 x10³ to 6.6 x10⁶ CFU/g for thermotolerant coliforms, 8.0 x10⁴ to 4 x10⁸ CFU/g for Staphylococcus aureus, from 3.2 x10³ to 2.2 x10⁸ CFU/g for Enterococci, and 2.0 x10⁴ to 4.4 x10⁷ CFU/g for yeasts and moulds. Most of samples had unsatisfactory microbiological quality compared to WHO standards. This study demonstrates population exposure to health risk and the great need to carry out microbiological tests frequently in these medicinal plants marketed in Abidjan. Keyword: Medicinal plants; markets; storage; microbiology; quality; Cote d’Ivoire