Identification of bacterial contaminants in polyherbal medicines used for the treatment of tuberculosis in Amatole District of the Eastern Cape Province, South Africa, using rapid 16S rRNA technique

Abstract

Background: Polyherbal medicines are used for the treatment of many diseases in many African and Asian communities. With the increasing use of these remedies, several investigations have shown that they are associated with a broad variety of residues and contaminants. This study investigates the presence of bacteria in the polyherbal medicines used for the treatment of tuberculosis (TB) in the Eastern Cape Province of South Africa. Methods: Bacterial DNA was extracted from the polyherbal medicines, and a fragment of the bacterial 16S rRNA gene was amplified by PCR with universal primers 27F and 518R. The amplicons were visualised on agarose gel electrophoresis, followed by end repair and adaptor ligation. They were further purified and quantified using Library Preparation kit NEBNext® UltraT DNA Library Prep Kit for Illumina, and the amplicons were run on illumina's MiSeq platform. Results: Different bacterial species were identified in all each of the polyherbal medicines. Generally, the most prominent and common bacteria recovered from all the samples were Bacillus sp., Enterobacter sp., Klebsiella sp., Rahnella sp., Paenibacillus sp., Clostridium sp. and Pantoea sp. Others are Pseudomonas sp., Raoultella ornithinolytica, Salmonella enterica and Eubacterium moniliforme. Conclusions: This study, thus, revealed the presence of pathogenic and non-pathogenic bacteria in the polyherbal medicines used for the treatment of tuberculosis in the study area. The implications of the findings are discussed in relation to the health care of the patients of tuberculosis in the study area, having in mind that they are immunocompromised individuals.