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BioMed Research International
Volume 2013 (2013), Article ID 679038, 7 pages
http://dx.doi.org/10.1155/2013/679038
Research Article

Development of an Immunochromatographic Test Strip for Detection of Cholera Toxin

1Division of Food Hygiene, Department of Animal and Food Hygiene, Obihiro University of Agriculture and Veterinary Medicine, Nishi 2-11 Inada-cho, Obihiro, Hokkaido 080-8555, Japan
2R&D Center, Nippon Meat Packers, Inc., 3-3 Midorigahara Tsukuba, Ibaraki 300-2646, Japan
3Division of Clinical Microbiology, Saitama Institute of Public Health, Saitama 338-0824, Japan
4Translational Health Science and Technology Institute, Plot no. 496, Phase III, Udyog Vihar, Gurgaon, Haryana 122016, India

Received 4 September 2013; Accepted 8 October 2013

Academic Editor: Hiroshi Asakura

Copyright © 2013 Eiki Yamasaki et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Because cholera toxin (CT) is responsible for most of the symptoms induced by Vibrio cholerae infection, detection of CT is critical for diagnosis of the disease. In this study, we constructed an immunochromatographic test strip for detection of CT (CT-IC) with polyclonal antibodies developed against purified recombinant whole CT protein. The detection limit of the CT-IC was 10 ng/mL of purified recombinant CT, and it could detect the CT in culture supernatant of all 15 toxigenic V. cholerae isolates examined, whereas no false-positive signal was detected in all 5 nontoxigenic V. cholerae isolates examined. The specificity of the CT-IC was examined with recombinant heat-labile toxin (LT), which shares high homology with CT, and it was revealed that the minimum detection limit for LT was 100 times higher than that for CT. In addition, lt gene-positive enterotoxigenic Escherichia coli (ETEC) was examined by CT-IC. The false-positive signals were observed in 3 out of 12 ETEC isolates, but these signals were considerably faint. The CT-IC did not develop false-positive signals with all 7 V. parahaemolyticus isolates. These results showed the high specificity of CT-IC and the feasible use of it for the detection and surveillance of toxigenic V. cholerae.