title: Rapid detection of Listeria monocytogenes in raw milk with loop-mediated isothermal amplification and chemosensor.
abstract: Loop-mediated isothermal amplification (LAMP) allows a rapid amplification of nucleic acids under isothermal conditions. It can be combined with a rhodamine-based dual chemosensor for much more efficient, field-friendly detection of Listeria monocytogenes. In this report, LAMP was performed at 63 °C for 10 min, followed by a rapid reaction of DNA amplification and the byproduct, pyrophosphate ion, with a rhodamine-based dual chemosensor and Cu(2+) is visualized as a disappearance of red color. The detection limit of L. monocytogenes by the LAMP-chemosensor was 8 to 10 cells per reaction tube, and the total assay time including 10 min for rapid DNA extraction was approximately 30 min. Data on naturally contaminated raw milk samples indicated that the LAMP method was highly specific and sensitive, giving 100% concordance with the ISO 10560 reference method. The results showed that the LAMP-chemosensor method has the advantages of better sensitivity and speed and less dependence on equipment than the standard Polymerase Chain Reaction for specifically detecting low levels of L. monocytogenes DNA, and this can be useful in the field as a routine diagnostic tool.
  
  
  CONCLUSIONS
  The LAMP-chemosensor method reported here provided a powerful tool for detection of L. monocytogenes in raw milk samples due to its specificity, sensitivity, and rapidity.
authors.affiliation: Chemistry and Chemical Industry College, Xuchang Univ., Xuchang 461000, China.
authors.forename: Deguo
authors.initials: D
authors.lastname: Wang
authors.forename: Gaiping
authors.initials: G
authors.lastname: Zhang
authors.forename: Chengping
authors.initials: C
authors.lastname: Lu
authors.forename: Ruiguang
authors.initials: R
authors.lastname: Deng
authors.forename: Aimin
authors.initials: A
authors.lastname: Zhi
authors.forename: Junqing
authors.initials: J
authors.lastname: Guo
authors.forename: Dong
authors.initials: D
authors.lastname: Zhao
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Xu
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods*; D017931:DNA Primers / Q000235:genetics / Q000302:isolation & purification; D008089:Listeria monocytogenes / Q000254:growth & development / Q000302:isolation & purification*; D008892:Milk / Q000382:microbiology*; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D016133:Polymerase Chain Reaction; D012235:Rhodamines / Q000378:metabolism; D012680:Sensitivity and Specificity
chemical_list: D017931:DNA Primers; D012235:Rhodamines