Development of a specific immune lateral flow assay for cholera detection

1.Cholera is caused by a pandemic strain of Vibrio cholerae. The strain can have a O1 or a O139 serotype and produces the cholera toxin (Figure 1). Other V. cholerae isolates aren’t O1 or O139 or are O1 but don’t produce the cholera toxin. The complexity is to detect a biomarker that discriminates the pandemic strain from other V. cholerae isolates.

2.Using MALDI-TOF MS a biomarker was found, which is specific for the pandemic V. cholerae strain. Moreover, by using Ferulic Acid as a MALDI matrix a specific protein for the V. cholerae pandemic strain was discovered (Figure 2 and 3).

3.After a band at 35kDa was cut out of a SDS-PAGE gel and analyzed with LC-MS.MS the protein was identified as OmpU. A abundantly expressed outer membrane protein of V. cholerae (Figure 4).

4.Monoclonal antibodies (mABs) were developed and tested. A dotblot of mABs binds specific to the pandemic V, cholerae strain (Figure 4)

5.The immuno-lateral flow assay is currently being developed.

6.After the prototypes are developed its performance will be evaluated in a laboratory against different bacteria. Next, if successful immuno-lateral flow assay’s will be validate in the field, in an area where cholera is endemic.

Using MALDI-TOF MS a specific biomarker for the pandemic V. cholerae strain was detected. The abundantly expressed outer membrane protein OmpU is a promising candidate to develop a imunno-later-flow assay. Therefore, specific monoclonal antibodies were developed against OpmU. The specific mABs are now used to develop a LFA-prototype. Next, the LFA will be evaluated in the lab and if successful field tests will be conducted in areas where cholera is endemic.