title: Quantifying viable Vibrio parahaemolyticus and Listeria monocytogenes simultaneously in raw shrimp.
abstract: A novel TaqMan-based multiplex real-time PCR method combined with propidium monoazide (PMA) treatment was firstly developed for the simultaneous quantification of viable Vibrio parahaemolyticus and Listeria monocytogenes in raw shrimp. The optimization of PMA concentration showed that 100 μM was considered optimal to effectively inhibit 10(8) CFU/mL dead cells of both bacteria. The high specificity of this method was confirmed on tests using 96 target and non-target strains. The optimized assay could detect as low as 10(1)-10(2) CFU/g of each strain on the artificially contaminated shrimp, and its amplification efficiencies were up to 100 and 106 % for V. parahaemolyticus and L. monocytogenes, respectively. Furthermore, this assay has been successfully applied to describe the behavior of these two pathogens in raw shrimps stored at 4 °C. In conclusion, this PMA TaqMan-based multiplex real-time PCR technique, where the whole procedure takes less than 5 h, provides an effective and rapid tool for monitoring contamination of viable V. parahaemolyticus and L. monocytogenes in seafood, improving seafood safety and protecting public health.
authors.affiliation: College of Food Science and Technology, Shanghai Ocean University, 999# Hu Cheng Huan Road, Shanghai, 201306, China.
authors.forename: Zhaohuan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Haiquan
authors.initials: H
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Lou
authors.forename: Lili
authors.initials: L
authors.lastname: Xiao
authors.forename: Chao
authors.initials: C
authors.lastname: Liao
authors.forename: Pradeep K
authors.initials: PK
authors.lastname: Malakar
authors.forename: Yingjie
authors.initials: Y
authors.lastname: Pan
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D003080:Cold Temperature; D005516:Food Microbiology / Q000379:methods*; D061353:Food Storage; D008089:Listeria monocytogenes / Q000302:isolation & purification* / Q000502:physiology; D050296:Microbial Viability; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D017747:Seafood / Q000382:microbiology*; D012680:Sensitivity and Specificity; D013696:Temperature; D013997:Time Factors; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification* / Q000502:physiology