title: Application of a simple method using minute particles of amorphous calcium phosphate for recovery of norovirus from cabbage, lettuce, and ham.
abstract: In this study, the amorphous calcium phosphate (ACP) method developed previously for calicivirus concentration from water was applied for norovirus detection from food. The viral recovery from cabbage, lettuce, or ham (10g of each) was firstly examined in seeding experiments with feline caliciviruses (FCVs). The viruses were concentrated by viral adsorption to ACP particles (0.3g) in the eluent solution (40ml) from foods, collection of the particles by centrifugation, followed by dissolution of the particles with 3.3M citric acid (3ml). In ham, FCV recovery was improved by addition of ascorbic acids into the eluent solution before ACP-particle adsorption. Quantitative real-time reverse transcription-PCR (qRT-PCR) revealed that FCV recoveries were 32-33%, 50-55%, and 37-46% from cabbage, lettuce, and ham, respectively, when seeded with 10(3)-10(4) viruses, and detection limits were estimated ∼10(3) genomic copies in all 3 foods. Subsequently, the ACP-concentration method was evaluated for norovirus (NoV) detection from these 3 foods. The recoveries and detection limit of NoVs determined by qRT-PCR were 12-41% and 10(3) (genomic copies) from cabbage, 30-57% and 10(3) from lettuce, and 20-26% and 10(4) from ham, when seeded with 10(3)-10(5) viruses. This simple method may be suitable for NoV detection from these foods.
authors.affiliation: Virus Division, Saitama Institute of Public Health, 639-1 Kamiokubo, Sakura-ku, Saitama-shi, Saitama, Japan.
authors.forename: Michiyo
authors.initials: M
authors.lastname: Shinohara
authors.forename: Kazue
authors.initials: K
authors.lastname: Uchida
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Shimada
authors.forename: Kyoko
authors.initials: K
authors.lastname: Tomioka
authors.forename: Noriko
authors.initials: N
authors.lastname: Suzuki
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Minegishi
authors.forename: Sachie
authors.initials: S
authors.lastname: Kawahashi
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yoshikawa
authors.forename: Norio
authors.initials: N
authors.lastname: Ohashi
mesh_terms: D001937:Brassica / Q000821:virology*; D002130:Calcium Phosphates / Q000737:chemistry*; D017250:Caliciviridae Infections / Q000175:diagnosis / Q000821:virology; D017927:Calicivirus, Feline / Q000302:isolation & purification; D005516:Food Microbiology; D005759:Gastroenteritis / Q000175:diagnosis / Q000821:virology; D006801:Humans; D018545:Lactuca / Q000821:virology*; D008460:Meat / Q000821:virology*; D029322:Norovirus / Q000302:isolation & purification*; D012367:RNA, Viral / Q000032:analysis / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002130:Calcium Phosphates; D012367:RNA, Viral; C519480:amorphous calcium phosphate