title: An enrichment medium for increasing a very small number of vibrio parahaemolyticus cells to the detection limit of the loop-mediated isothermal amplification (LAMP) assay.
abstract: We developed an enrichment medium for use with the loop-mediated isothermal  amplification (LAMP) assay (enrichment media + LAMP assay) to quickly increase a very small number  of Vibrio parahaemolyticus cells to the detection limit of the assay. Thirty-nine different  enrichment media were prepared based on evaluating 12 potential ingredients. From our assessment  of the 39 media, enrichment medium #36, which contained 2% sodium chloride, 1% proteose peptone  no. 2, 0.1% trehalose, 0.5% α-ketoglutaric acid, 0.25% pyruvic acid, and 0.5% yeast extract (pH  8.6), was found to be most effective at enhancing the proliferation of V. parahaemolyticus during  incubation for 3 h at 40ºC. We compared the detection limits of the LAMP assay, the enrichment  medium #36 + LAMP assay, and the cultivation method using bacterial cell and spiked shrimp sample  tests. The detection limits of the LAMP assay, the medium #36 + LAMP assay, and the cultivation  method were 10(3), 10(0)-10(-1), and 10(-1) CFU ml(-1), respectively. Enrichment medium #36 promoted  a 10(3)- to 10(4)-fold increase in the bacterial population, and the detection limit of the enrichment  media + LAMP assay was the same as that of the cultivation method.
authors.affiliation: Laboratory of Microbiology, Aichi Prefectural Kinuura-Tobu Health Center, Kariya 448-0857, Japan.
authors.forename: Mitsugu
authors.initials: M
authors.lastname: Yamazaki
authors.forename: Hidemi
authors.initials: H
authors.lastname: Aoki
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Iwade
authors.forename: Masakado
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yamada
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Reiji
authors.initials: R
authors.lastname: Hiramatsu
authors.forename: Hiroko
authors.initials: H
authors.lastname: Minagawa
mesh_terms: D000818:Animals; D001431:Bacteriological Techniques / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D057230:Limit of Detection; D021141:Nucleic Acid Amplification Techniques / Q000379:methods*; D013696:Temperature; D013997:Time Factors; D014735:Vibrio Infections / Q000175:diagnosis* / Q000382:microbiology; D014736:Vibrio parahaemolyticus / Q000302:isolation & purification*
chemical_list: D003470:Culture Media