Monitoring of Clostridium botulinum in Poultry and Cattle Manure During Spreading Operations

Animal botulism mainly affects poultry and cattle, with risks of cross-contamination. This study aimed to evaluate Clostridium botulinum contamination in manure and soil following manure spreading on 13 clinically affected farms (10 cattle and three poultry) and 39 clinically unaffected farms (20 cattle and five poultry farms without any previous botulism outbreak, six poultry farms with a history of botulism and eight mixed poultry/cattle farms with an ongoing bovine botulism outbreak). Twelve manure samples, two swabs on a manure pile, 12 soil samples, and two boot swabs from fields were collected before manure spreading. Twelve soil samples and two boot swabs from fields were obtained after manure spreading. C. botulinum types C, D, C/D, and D/C were detected using real-time PCR after an enrichment step. On clinically unaffected poultry and cattle farms with no history of botulism, C. botulinum was detected in 1.4% and 1.8% of samples, respectively. Detection rates reached 8% on poultry farms with a history of botulism and 42.8% on poultry farms with ongoing bovine outbreaks. On clinically affected poultry and cattle farms, 34% and 18.9% of samples were positive, respectively. This study highlights the presence of C. botulinum in manure and soil and emphasizes the importance of biosecurity measures to prevent cross-contamination and disease recurrence.