Plant material are used throughout developed and developing countries as home remedies, over the counter drug products and raw materials for the pharmaceutical industry and represent a substantial proportion of the global drug market. Medicinal plant materials normally carry a great number of bacteria and moulds, often originating in soil, while a large range of bacteria and fungi form the naturally occurring micro flora of herbs, aerobic spore-forming bacteria frequently predominate [1].
Eighty five herbal teas and sixteen herbal medicinal products obtained from different suppliers were examined for microbial contaminants. The maximum acceptable limits were determined according to European pharmacopoeia [2]. The microbiological examination was carried out in accordance with the Ph.Eur. The total aerobic plate counts for herbal teas were about 105 CFU/g, so the limits were met. The same applied to the moulds and yeasts whose aggregate values reached 104 CFU/g. While none of the herbal tea samples contained Salmonella spp., six samples exceeded the limit of 102 CFU/g for E. coli.
The total aerobic plate counts for herbal medicinal products were about 102 CFU/g.
References: [1] Beckmann, K. et al. (2003) Pharmeuropa 15: 291–298. [2] European Pharmacopoeia. (2005) Council of Europe. Strasbourg.
