Open AccessInvestigation of Botulinum Neurotoxin Types from Clostridium botulinum Causing A Recent Outbreak in Vietnam
Author(s) -
Lã Thị Huyền,
Nguyễn Thùy Linh,
Nguyễn Trung Thành,
Phạm Hải Yến
Publication year - 2021
Publication title -
tạp chí khoa học đại học quốc gia hà nội: khoa học tự nhiên và công nghệ (vnu journal of science:natural sciences and technology)
Language(s) - English
Resource type - Journals
eISSN - 2615-9317
pISSN - 2588-1140
DOI - 10.25073/2588-1140/vnunst.5332
Subject(s) - clostridium botulinum , botulism , toxin , neurotoxin , outbreak , gene , typing , biology , strain (injury) , microbiology and biotechnology , clostridiaceae , botulinum toxin , virology , genetics , biochemistry , anatomy , neuroscience
Clostridium botulinum is one of the causes of undiagnosed sudden deaths in humans due to the lethal botulinum neurotoxins (BoNTs). Foodborne botulism rarely occurs in developed countries because of being closely monitored, in opposite to developing countries including Vietnam. In the August 2020 food poisoning outbreak in Vietnam, presence of Clostridium botulinum and BoNTs was identified by culture and mouse bioassay, however, information regarding the possible toxin types was unclear. To examine the types of toxin, we designed primers for specific amplification of gene regions encoding the light chain (LC) domains for both BoNT/A and BoNT/B. After optimization, the expected PCR products were sent for sequencing. The results showed that the sequence of gene encoding BoNT/A LC was 99.2% identical to the CB-27 strain. The sequence of gene encoding BoNT/B LC was approximately 98.8% identical to reference strains. Additionally, we analyzed the sequences of the inferred proteins and identified a substitution that resulted in an early stop codon as previously found in a defective form of BoNT/B. Collectively, we provided the first evidence for C. botulinum strain possessing A(b) type in this studied outbreak. Further enzyme activity and neutralization assays are necessary to validate this preliminary toxin typing.