Development of colloidal gold-based immunochromatographic strip test using two monoclonal antibodies for detection of Vibrio parahaemolyticus

A rapid and sensitive colloidal gold-based immunochromatographic test strip (ICTS) for the detection of Vibrio parahaemolyticus (VP) was developed. It was based on sandwich principle with two monoclonal antibodies (Mabs), namely H7 and C9. The Mab H7 gold nanoparticle (AuNPs-Mab H7) conjugate was transferred onto a glass fiber pad as conjugate pad. Mab C9 containing 1% (M/V) bovine serum albumin and the goat anti-mouse immunoglobulinG (IgG) antibody were sprayed onto a nitrocellulose membrane in strips at T and C line positions, respectively. The ICTS was assessed for the ability to detect VP, 50 l aliquot of test sample was applied to the sample pad. The results were observable within 10 min after adding the sample. The sensitivity of the test was determined to be 10(4) CFU/ml. Detection of VP after 25-week storage could be accomplished with similar sensitivities. The positive rate was 100% in seafood with the ICTS. The VP ICTS provided several advantages over other detection methods, including the short time, low cost, convenient to use, and not requiring sophisticated equipment. Furthermore, the results could be imaged and transformed into a two-dimensional bar code by using a smart cell phone for more vividly, clearly and permanently being observed. Practical applicationsDuring the past two decades, Vibrio parahaemolyticus (VP) has been one of the most common causes of the bacterial foodborne outbreaks, which caused abdominal cramps, vomiting, nausea, headaches, fever, and chills. Therefore, the detection of VP is crucial to public food safety. This study obtained two different monoclonal antibodies (Mabs; Mab H7 and C9) of VP with high specificity and no cross-reactions were found with other foodborne pathogens. The AuNPs-based immunochromatographic test strip (ICTS) was developed with the Mabs (Mab H7 and C9) and the ICTS was evaluated with high sensitivity, high specificity, low cost, and rapid speed for VP detection. The accuracy rate of immunochromatographic strip for detection VP was 100% in seafood samples.