Hu YQ, Huang XH, Guo LQ, Shen ZC, LV LX, Li FX, Zhou ZH, Zhang DF. Rapid and Visual Detection of
Vibrio parahaemolyticus in Aquatic Foods Using
blaCARB-17 Gene-Based Loop-Mediated Isothermal Amplification with Lateral Flow Dipstick (LAMP-LFD).
J Microbiol Biotechnol 2021;
31:1672-1683. [PMID:
34489378 PMCID:
PMC9705909 DOI:
10.4014/jmb.2107.07022]
[Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/22/2021] [Accepted: 09/02/2021] [Indexed: 12/15/2022]
Abstract
Vibrio parahaemolyticus is recognized as one of the most important foodborne pathogens responsible for gastroenteritis in humans. The blaCARB-17 gene is an intrinsic β-lactamase gene and a novel species-specific genetic marker of V. parahaemolyticus. In this study, a loop-mediated isothermal amplification (LAMP) assay combined with a lateral flow dipstick (LFD) was developed targeting this blaCARB-17 gene. The specificity of LAMP-LFD was ascertained by detecting V. parahaemolyticus ATCC 17802 and seven other non-V. parahaemolyticus strains. Finally, the practicability of LAMP-LFD was confirmed by detection with V. parahaemolyticus-contaminated samples and natural food samples. The results showed that the optimized reaction parameters of LAMP are as follows: 2.4 mmol/l Mg2+, 0.96 mmol/l dNTPs, 4.8 U Bst DNA polymerase, and an 8:1 ratio of inner primer to outer primer, at 63°C for 40 min. The optimized reaction time of the LFD assay is 60 min. Cross-reactivity analysis with the seven non-V. parahaemolyticus strains showed that LAMP-LFD was exclusively specific for V. parahaemolyticus. The detection limit of LAMP-LFD for V. parahaemolyticus genomic DNA was 2.1 × 10-4 ng/μl, corresponding to 630 fg/reaction and displaying a sensitivity that is 100-fold higher than that of conventional PCR. LAMP-LFD in a spiking study revealed a detection limit of approximately 6 CFU/ml, which was similar with conventional PCR. The developed LAMP-LFD specifically identified the 10 V. parahaemolyticus isolates from 30 seafood samples, suggesting that this LAMP-LFD may be a suitable diagnostic method for detecting V. parahaemolyticus in aquatic foods.
Collapse