Survival of some species of Salmonella and Shigella in mukumbi, a traditional Zimbabwean wine

Abstract

Mukumbi is a traditional Zimbabwean wine prepared from a fruit called mapfura by the Shona people of Zimbabwe and amaganu by the Ndebele. The majority of people in Africa call the tree marula (Sclerocarya birrea subspecies caffra). The survival of Salmonella group B, Salmonella enteritidis, Shigella sonnei and Shigella flexneri in unfermented and fermented mapfura (marula) juice (mukumbi) was investigated. It was found that within 30 min of inoculation, there were no longer any viable pathogens in the fermented mapfura juice whilst in the unfermented juice, more than 10 4 cfu/ml were still viable after 8 h. When lactic acid (0.25 mg/ml) was added to the unfermented mapfura juice, more than 10 4 cfu/ml were also still viable after 8 h but none were viable after 24 h. The fermented product, mukumbi, has a rapid antimicrobial effect against the pathogens as compared to the unfermented juice and is therefore safe from contamination with these pathogens. It appears thus that the death of the pathogens was due to other compounds besides the low levels of lactic acid.