Identification of Clostridium botulinum from Drinking and Food Processing Water Source in a Rural Area in Enugu, Nigeria

Abstract

Background: Clostridium botulinum is responsible for the toxin-mediated disease, botulism. It is a food-borne disease, occurring globally with high mortality, especially in children. Gastrointestinal form, which is common in developing countries, is associated with ingestion of spore containing food. Many studies have reported animal botulism caused by ingestion of spore contaminated water. Such studies are scarce in humans. We here report incidental isolation of Clostridium botulinum in a river that is used for drinking and food processing in a community in Enugu Nigeria. Method: A descriptive study to ascertain the microbial content of Adada River that ran through Uzo-Uwani- and Igbo-Etiti Local Government Areas of Enugu State. The sampling sites were at the six differently determined geographical coordinates (stations 1-6) along the Aku bank of the Adada River flow. The sampling stations were selected according to the vegetation’s cover and river use. Standard water sample processing for Clostridium perfringens was followed and the isolated organism was characterized phenotypically and using 16SrRNA gene sequencing. Result: Clostridium botulinum was isolated from station 2 in June 2016 (rainy season), and in February 2017 (dry season). The organism was a Gram-positive motile rod with oval subterminal spores which was confirmed using a 16S rRNA sequence. The sequence shows 96.8% identical to Clostridium botulinum strain AM1195 chromosome, complete genome (NCBI accession number CP013701). Conclusion: Such organism in the drinking water and water used for home food processing could cause gastrointestinal botulism, especially in children. There is a need to provide potable water for rural dwellers in Enugu, and for the concerned authorities to monitor the water used by local food processors.