title: Method for rapid detection and identification of chaetomium and evaluation of resistance to peracetic acid.
abstract: In the beverage industry, peracetic acid has been increasingly used as a disinfectant for the filling machinery and environment due to merits of leaving no residue, it is safe for humans, and its antiseptic effect against fungi and endospores of bacteria. Recently, Chaetomium globosum and Chaetomium funicola were reported resistant to peracetic acid; however, little is known concerning the detail of peracetic acid resistance. Therefore, we assessed the peracetic acid resistance of the species of Chaetomium and related genera under identical conditions and made a thorough observation of the microstructure of their ascospores by transmission electron microscopy. The results of analyses revealed that C. globosum and C. funicola showed the high resistance to peracetic acid (a 1-D antiseptic effect after 900 s and 3-D antiseptic effect after 900 s) and had thick cell walls of ascospores that can impede the action mechanism of peracetic acid. We also developed specific primers to detect the C. globosum clade and identify C. funicola by using PCR to amplify the β-tubulin gene. PCR with the primer sets designed for C. globosum (Chae 4F/4R) and C. funicola (Cfu 2F/2R) amplified PCR products specific for the C. globosum clade and C. funicola, respectively. PCR with these two primer sets did not detect other fungi involved in food spoilage and environmental contamination. This detection and identification method is rapid and simple, with extremely high specificity.
authors.affiliation: Global R&D Safety Science, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-Gun, Tochigi 321-3497, Japan.
authors.forename: Motokazu
authors.initials: M
authors.lastname: Nakayama
authors.forename: Kouichi
authors.initials: K
authors.lastname: Hosoya
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tomiyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsugukuni
authors.forename: Tetsuhiro
authors.initials: T
authors.lastname: Matsuzawa
authors.forename: Yumi
authors.initials: Y
authors.lastname: Imanishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yaguchi
mesh_terms: D001628:Beverages / Q000382:microbiology*; D002597:Chaetomium / Q000187:drug effects / Q000302:isolation & purification; D015169:Colony Count, Microbial; D017931:DNA Primers; D025141:Drug Resistance, Fungal; D005506:Food Contamination / Q000032:analysis*; D005519:Food Preservation; D005520:Food Preservatives / Q000494:pharmacology*; D006801:Humans; D010463:Peracetic Acid / Q000494:pharmacology*; D016133:Polymerase Chain Reaction / Q000379:methods; D013172:Spores, Fungal; D014404:Tubulin / Q000235:genetics
chemical_list: D017931:DNA Primers; D005520:Food Preservatives; D014404:Tubulin; D010463:Peracetic Acid