Nanogold‐based immunochromatographic strip test for rapid detection of clinical and environmental strains of Vibrio cholerae

• Published in: Journal of food safety Vol. 41; no. 1
• Main Authors: Pengsuk, Chalinan, Wangman, Pradit, Chaivisuthangkura, Parin, Sithigorngul, Paisarn, Longyant, Siwaporn
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.02.2021; Blackwell Publishers Inc
• Subjects: Bacteria; Epidemiology; Food safety; Monoclonal antibodies; Peptones; Seafood; Sensitivity; Strains (organisms); Strip; Vibrio cholerae; Waterborne diseases
• ISSN: 0149-6085; 1745-4565
• DOI: 10.1111/jfs.12874

A nanogold‐based immunochromatographic strip test (VCG strip test) for the detection of all 70 isolates of Vibrio cholerae including O1, O139, and non‐O1/O139 (NVCs) was developed using two monoclonal antibodies (MAbs), namely VC‐63 and VC‐201, which bound specifically to 10 and 15 kDa proteins. Direct detection of V. cholerae in experimentally spiked fresh seafood samples such as shrimp, blood clam, mussel, and oyster could be achieved with sensitivities of 107 CFU/ml, which was similar to that of the dot blotting test using each MAb. The detection sensitivity could be improved to 103 or 10 or 1 CFU/ml of original bacterial content after preincubation of the sample in alkaline peptone water for 6, 12, and 24 hr consecutively. However, the detection sensitivities were also dependent on the content of other bacteria in the sample that might compete or inhibit the growth of V. cholerae during the preenrichment step. Due to its broad specificity, simplicity and rapid result generation, the VCG strip test can be used for the preliminary detection of V. cholerae at point of care for both environmental and clinical strains to assist appropriate decision or epidemiological surveillance of virulent V. cholerae strains (including NVC strains), which are ubiquitous in the environment and seafood. A strip test for the detection of all serotypes of Vibrio cholerae was developed. Detection limit of the bacterium in seafood samples was 107 CFU/ml. The sensitivity could be improved to 1 CFU/ml after pre‐incubation in APW for 24 h. Due to its simplicity and rapidity, the sample could be directly tested at point of care.