Prevalence and persistence of listeria monocytogenes in dairy and other ready-to-eat food products in Africa

Abstract

Worldwide, L. monocytogenes bacteria are frequently associated with illness in humans, where immunocompromised individuals and pregnant women are at high risk of contracting listeriosis. The pathogen most often spreads through food consumption, so it is a major concern in most food-processing environments. In Africa, however, research on L. monocytogenes is scarce, making data on listeriosis limited. This is problematic because in Africa, traditionally produced foods have poor microbial quality. On average, 5.1 % of dairy and ready-to-eat foods are contaminated with L. monocytogenes. The pathogen has been isolated from milk, local cheese (“wara”), yogurt, ice cream, “kunu,” and ready-to-eat meat products during and after processing. Furthermore, it is resistant to one or more antibiotics and can also form biofilms on various surfaces that contact food. So, while L. monocytogenes is persistent in food-processing environments in Africa, the serotypes of its circulating strains are largely unknown. This study therefore expounds the characteristics of L. monocytogenes and listeriosis associated with consuming contaminated diary and ready-to-eat foods in Africa. We also present the prevalence and persistence of the pathogen in most food environments as well as the safety measures that can limit its ability to contaminate foods/surfaces and spread.