Nuclear magnetic resonance biosensor for rapid detection of Vibrio parahaemolyticus

BACKGROUND: Vibrio parahaemolyticus is a Gram-negative bacterium widely distributed in marine environments and a well-recognized invertebrate pathogen frequently isolated from seafood. V. parahaemolyticus may also spread into humans, via contaminated, raw, or undercooked seafood, causing gastroenteritis and diarrhea. METHODS: A Nuclear Magnetic Resonance (NMR)-based detection system was used to detect pathogenic levels of this microorganism (10(5) CFU/ml) with Molecular Mirroring using iron nanoparticles coated with target-specific biomarkers capable of binding to DNA of the target microorganism. The NMR system generates a signal (in milliseconds) by measuring NMR spin–spin relaxation time T(2), which correlates with the amount of microorganism DNA. RESULTS: Compared with conventional microbiology techniques such as real-time PCR (qPCR), the NMR biosensor showed similar limits of detection (LOD) at different concentrations (10(5)–10(8) CFU/ml) using two DNA extraction methods. In addition, the NMR biosensor system can detect a wide range of microorganism DNAs in different matrices within a short period of time. CONCLUSION: NMR biosensor represents a potential tool for diagnostic and quality control to ensure microbial pathogens such as V. parahaemolyticus are not the cause of infection. The “hybrid” technology (NMR and nanoparticle application) opens a new platform for detecting other microbial pathogens that have impacted human health, animal health and food safety.