摘要：Clostridium botulinum types C and D are related to animal botulism. The disease has been reported in sheep in western Sudan causing economic losses. However, the BoNTs that cause sheep botulism in Sudan have not yet subjected to genetic characterization. The aim of this study is to perform genetic analysis for sheep botulism–related isolates from recent outbreak between January to May 2013 at western Sudan in order to improve the efficiency of control strategies and vaccine development. In this study isolation of Clostridium botulinum from sheep samples was obtained by culture methods and mouse bioassay. Positive samples were confirmed by PCR and DNA sequencing. PCR was used to amplify the BoNTs gene using three sets of primers to differentiate the gene of the mosaic type from the conserved genes of type C and D. The results of polymerase chain reaction with these primers indicated that sheep botulism–related isolates possess the gene for the mosaic form of the neurotoxin. PCR products were sequenced and subjected to genetic analysis. The results provided evidence for close relationships and genetic variation of the isolates and reference strains published on the GenBank. Multiple sequence alignments showed numerous substitutions occurred in heavy chain in the most homologous regions of BoNT/CD and in the light chain of toxin type C and D, respectively. Following sequencing, isolates were compared phylogenetically with reference strains. The close genetic relationship to the strain 193_09 and strain: OFD16 suggests that neurotoxins produced from sheep botulism is BoNT type DC. The present study provides information on genetic classification of BoNTs related to sheep botulism isolates in Sudan.
关键词：Clostridium botulinum; sheep botulism; PCR; DNA sequencing; Sudan
