Incidence of enteric pathogens in ugba, a traditional fermented food from African oil bean seeds (Pentaclethra macrophylla)

Abstract

Abstract Background The lack of good production practices and probable post-fermentation contaminations contribute to bacterial pathogen load in ugba, a fermented food made from African oil been seeds (Pentaclethra macrophylla Benth). Some of these bacteria are not easily detected using standard culturing techniques. The study used molecular-based approaches involving PCR, cloning and sequencing as well as culture-based methods to investigate the occurrence of pathogenic bacteria within the microbiome of ugba. Six samples (OK1-OK6) were purchased from different local markets within Lagos and Abia States in Nigeria and used in the study. Results A total of 14 pathogenic bacteria were identified among the bacteria diversity found in ugba. Two pathogens (11%) were uniquely identified by cultural and biochemical characteristics, 12 pathogens (67%) were uniquely identified by culture-independent (PCR-clone-based) method and 4 pathogens (22%) were found in both methods. Enteric pathogens were common and Bacillus sp. was conspicuously absent. Escherichia coli and Staphylococcus aureus detected by cultural method in this study and elsewhere were not picked up by culture-independent method. This is the first report of the presence of Acinetobacter baumanii, Clostridium sartagofum, Enterococcus casseliflavus, Comamonas testosteronii, and Aeromonas sp. in ugba as identified by PCR-clone-based techniques. Though the genera Salmonella and Proteus have been associated with ugba in previous studies, the species-level identities were determined in this research by the culture-independent method used. Conclusions This study highlights the importance of using appropriate technologies and correct species identification strategies in studying microbiological quality and food safety issues in fermented foods in a developing country like Nigeria.

Keywords

• Food safety
• Pathogenic bacteria
• Fermented foods
• African oil bean seeds
• Ugba