SBIR-STTR Award

The long-term objective is to develop a rapid enzyme linked immunoassay for toxigenic Clostridium difficile, C. difficile is the most frequent cause of antibiotic-associated diarrhea and colitis, and the most frequently identified cause of enteric disease in industrialized nations. Single treatment of patients with virtually any antibiotic can induce an overgrowth of intestinal microflora by C. difficile and cause disease. A very reliable diagnostic procedure which detects an exotoxin. Toxin B, already exists but requires 48 hours to perform and a sophisticated cell culture facility. Although effective therapy exists for C. difficile, it is usually withheld until the results of the cellular assay are known, because a majority of samples assayed lack toxin. An alternative assay should require less time while preserving specificity for Toxin B. We have developed a panel of murine monoclonal antibodies specific for Toxin B, high titered Toxin B specific antisera and purification methods for Toxin B. The research plan will make use of conventional immunological methods to develop an antigen capture test using these reagents as we have previously done with adenovirus and rotavirus.Awardee's statement of the potential commercial applications of the research:The research and technology will be used to develop a kit which will be used in clinical laboratories to rapidly identify C. difficile Toxin B in stool samples. It is expected that this assay will substantially reduce the delay in applying appropriate treatment for C. difficile.National Institute of Allergy and Infectious Diseases (NIAID)

We will apply technology developed in Phase I to create a rapid, simple diagnostic for C. difficile diarrhea which can be used in the field thereby widening the user base and facilitating improved patient care. This program will develop a monoclonal antibody based latex immunoassay for the detection of Toxin A and Toxin B in human fecal samples. The assay will be adapted to capillary slide technology that combines the ease of use and speed of latex tests with the control of an instrumented system for on site testing. This patented technology, the slide immunoassay (SIA) has been devised at Cambridge Biotech. For agglutination to occur two monoclonals are required. The results of the new system will be compared with the cellular cytotoxicity test and the FDA approved Enzyme Immunoassay developed in Phase I (Cytoclone A+B).Sensitivities and the elimination of non-specific reactions will be a major challenge of this effort. The need for a universal set of reference standards will be addressed. Reliable reference standards that will ensure the routine quality of testing and enable meaningful comparison of multicenter data will be developed. These standards will be used to determine the performance of the new SIA will respect to the currently available toxin based assays. Extensive testing of the SIA will be conducted in the field. A study of the prevalence of symptomatic and asymptomatic C. difficile infections in pre-school children attending day care centers will be undertaken. A testing algorithm will be developed to aid the diagnosis of C. difficile disease.Awardee's statement of the potential commercial applications of the research:These efforts will result in rapid, simple and inexpensive medical diagnostic products for the detection of C.difficile toxins in stool samples. The availability of such an instrument controlled rapid test will allow quality testing for this disease outside the major laboratory.National Institute of Allergy and Infectious Diseases (NIAID)