According to the World Health Organization, cholera affects three to five million people worldwide and causes between 100,000 and 130,000 deaths per year.
The Native Antigen Company prepares a recombinant form of cholera toxin that can be used as a marker for neuronal cells, in addition to specific monoclonal antibodies for detection of the toxin.
Vibrio cholerae Background
The Vibrio genus are highly motile, curved-shaped bacteria, with a single, polar flagellum, used for self-propulsion. Vibrio cholerae is a non-spore-forming, gram-negative, facultative anaerobic bacterium of the Vibrionaceae family. V. cholerae is the causative agent of cholera, which is a diarrhoeal disease of the small intestine. Transmission of V. cholerae to humans occurs via the faecal-oral route and through the ingestion of contaminated water or food (WHO).
There are numerous serogroups of V. cholerae, but until 1992 the only vibrios that caused epidemic cholera were of the serogroup O1. The O1 serogroup is classified as two biotypes, classical and El Tor, and are further classified into two major serotypes, Inaba (AC) and Ogawa (AB). In 1993, a new pathogenic serogroup emerged in Bangladesh that was designated O139 Bengal (Silva AJ).
Cholera is asymptomatic in many cases, but causes severe, watery diarrhoea and dehydration in some individuals, which if untreated can rapidly lead to death. Cholera is reported to be endemic in many countries and seven cholera pandemics have been reported globally. The current pandemic is characterized by the predominance of the O1 serogroup of the El Tor biotype, with sporadic emergence of serogroup O139 (WHO).
The two major virulence factors expressed by V. cholerae O1 and O139, are cholera toxin (CT) and the toxin-coregulated pilus (TCP). Cholera toxin is an oligomeric complex made up of six protein subunits: a single copy of the A subunit and five copies of the B subunit. Subunit B binds to host cell surfaces via GM1 gangliosides. Once bound, the entire toxin complex is endocytosed by the cell and the cholera toxin A1 (CTA1) chain is released by the reduction of a disulphide bridge. Once inside the cell, subunit A activates G protein, which in turn activates adenylate cyclase, eventually leading to enhanced efflux of chloride ions from the intestinal cells and rapid water loss via the intestine.
- World Health Organization: Media centre; Cholera
- Silva AJ, Benitez JA. (2016). Vibrio cholerae Biofilms and Cholera Pathogenesis. PLoS Negl Trop Dis.Feb 4;10(2):e0004330. PMID: 26845681
Vibrio cholerae Antigens
We offer recombinant Cholera toxin subunit B (CTXB) protein, expressed in mammalian cells, which has been used as a marker for neuronal cells, due to its high affinity for the GM1 ganglioside cell surface receptor. CTXB protein has no toxic activity alone and can therefore be used in cell culture. This cholera toxin subunit B comprises Thr22 – Asn124 (accession #P01556) from serotype O1 of Vibrio cholerae and is fused with a polyhistidine tag at the C-terminus.
Vibrio cholerae Antibodies
The Native Antigen Company offer a pair of monoclonal Cholera antibodies that are highly specific for the beta sub-unit of cholera toxin, permitting the development of immunoassays and detection applications for the protein.
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