Detection of toxigenic Clostridium perfringens and Clostridium botulinum from food sold in Lagos, Nigeria

Food-borne diseases contribute to the huge burden of sickness and death globally and in the last decade, have become more frequently reported in Africa. In line with this, food safety is becoming a significant and growing public health problem in Nigeria. Diarrhoea is a common problem in Nigeria and has been reported but there has been little data on the possibility of clostridia as aetiological agents. Clostridium species are ubiquitous in the environment and in the gastrointestinal tract of man and animals and can serve as a marker for faecal contamination. We set out to determine the potential of these foods to transmit Clostridium species. A total of 220 food commodities from six local governments in Lagos State were sampled. Isolates obtained were identified based on cultural, morphological and biochemical characteristics. Toxinotyping was done using multiplex-PCR with primers specific for alpha, beta, epsilon and iota-toxin genes, enterotoxigenic cpe gene and neurotoxigenic BoNt gene. Fifty (22.7%) clostridial species were isolated of which 29 (58%) were identified as C. perfringens. Toxinotyping of the 29 strains showed that 28 (96.6%) were toxin producing C. perfringens type A while one (3.4%) was C. perfringens type D. Two (4%) C. botulinum species were isolated and identified by 16S rRNA sequencing, both harbouring BoNt/A gene. The contamination rates of food with Clostridium species show that food hygiene is a problem and Clostridium species may be a source of food borne disease in Lagos State, Nigeria.