Design and Validation of a Novel Multiplex Real-Time PCR Assay for VibrioPathogen Detection

Three species—Vibrio cholerae, Vibrio parahaemolyticus,and Vibrio vulnificus—account for the majority of vibrio infections in humans. Rapid and accurate identification of Vibriospecies has been problematic because phenotypic characteristics are variable within species. Additionally, biochemical identification and confirmation require 2 or more days to complete. Rapid and sensitive molecular techniques for the detection of vibrio pathogens would be useful for the surveillance and management of outbreaks. To facilitate the identification of human-pathogenic species, we designed and validated a highly sensitive, specific, and robust multiplex real-time PCR assay to identify V. cholerae, V. parahaemolyticus,and V. vulnificususing a four-dye configuration in a convenient lyophilized format. Multiple Vibriostrains were sequenced to verify candidate target TaqMan sites. Several individual assays within the multiplex contain multiple primers or probes to ensure detection of polymorphic variants. V. cholerae, V. parahaemolyticus,and V. vulnificuswere detected either individually or in mixtures at ≤ 30 genomic copies. V. choleraewas specifically detected in the presence or absence of Vibrio mimicus.The Vibriomultiplex assay showed 100% specificity to all targets analyzed and no detection of nearest neighbor strains. Each assay exhibited 100% ± 10% efficiency. Multiplex real-time PCR can simplify pathogen detection and reduce costs per test since three species can be analyzed in a single reaction tube. Rapid and accurate detection of pathogenic vibrios in shellfish or seawater samples will improve the microbiological safety of seafood for consumers.