Evaluation of monoclonal antibody based immunochromatographic strip test for direct detection of Vibrio cholerae O1 contamination in seafood samples

• A strip test for the detection of Vibrio cholerae O1 was developed.
• Detection limit of the bacterium in seafood samples ranged from 5 × 105 to 106 CFU/mL.
• The sensitivity could be improved to 1 CFU/mL after pre-incubation in APW for 12 h.
• The strip test has advantage in speed, simplicity and sample could be directly tested.

A strip test for the detection of Vibrio cholerae O1 was developed using two monoclonal antibodies (MAbs), VC-223 and VC-1226, specific to the lipopolysaccharides of Vibrio cholerae O1 Inaba and Ogawa serovars. The sensitivity of the test was 5 × 105 cfu/mL which was similar to that of dot blot test. The detection limit could be improved to 1 cfu/mL of the original bacterial content after pre-incubation of the bacterium in alkaline peptone water (APW) for 12 h. Detection of V. cholerae O1 in various fresh seafood samples such as shrimp, blood clam, mussel and oyster could be performed directly with sensitivities ranged from 5 × 105 to 106 cfu/mL. After pre-enrichment of the shrimp sample in APW, the detection sensitivities increased to 102 to 10 CFU/mL of the original bacterial content after incubation for 12 and 24 h. However, the detection sensitivities were also depending on the content of the other bacteria that might inhibit the growth of V. cholerae during pre-enrichment step. The V. cholerae O1 strip test has advantages in speed, and simplicity in not requiring sophisticated equipment or specialized skills and the sample could be directly examined without requirement for sample processing.