title: Survival of Clostridium difficile spores at low water activity.
abstract: Clostridium difficile is frequently found in meat and meat products. Germination efficiency, defined as colony formation, was previously investigated at temperatures found in meat handling and processing for spores of strain M120 (animal isolate), R20291 (human isolate), and DK1 (beef isolate). In this study, germination efficiency of these spore strains was assessed in phosphate buffered saline (PBS, aw∼1.00), commercial beef jerky (aw∼0.82/0.72), and aw-adjusted PBS (aw∼0.82/0.72). Surface hydrophobicity was followed for spores stored in PBS. After three months and for all PBS awlevels tested, M120 and DK1 spores showed a ∼1 decimal reduction in colony formation but this was not the case when kept in beef jerky suggesting a protective food matrix effect. During storage, and with no significant aweffect, an increase in colony formation was observed for R20291 spores kept in PBS (∼2 decimal log increase) and beef jerky (∼1 decimal log increase) suggesting a loss of spore superdormancy. For all strains, no significant changes in spore surface hydrophobicity were observed after storage. Collectively, these results indicate that depending on the germination properties of C. difficile spores and the media properties, their germination efficiency may increase or decrease during long term food storage.
authors.affiliation: Food Process Engineering Group, Department of Food Science & Technology, 100 Wiegand Hall, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Deng
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, 216 Dryden Hall, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Prabhat K
authors.initials: PK
authors.lastname: Talukdar
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, 216 Dryden Hall, Oregon State University, Corvallis, OR 97331, USA; Department of Microbiology, College of Science, Oregon State University, 216 Dryden Hall, Corvallis, OR 97331, USA.
authors.forename: Mahfuzur R
authors.initials: MR
authors.lastname: Sarker
authors.affiliation: Department of Biomedical Sciences, College of Veterinary Medicine, 216 Dryden Hall, Oregon State University, Corvallis, OR 97331, USA; Microbiota-Host Interactions and Clostridia Research Group, Departamento de Ciencias Biológicas, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile; Center for Bioinformatics and Integrative Biology, Facultad de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile. Electronic address: daniel.paredes.sabja@gmail.com.
authors.forename: Daniel
authors.initials: D
authors.lastname: Paredes-Sabja
authors.affiliation: Food Process Engineering Group, Department of Food Science & Technology, 100 Wiegand Hall, Oregon State University, Corvallis, OR 97331, USA; Tecnológico de Monterrey, Emerging Technologies and Nutrigenomis Group, School of Engineering & Sciences, Av. Eugenio Garza Sada 2501 Sur, Col. Tecnológico, Monterrey, NL 64849, Mexico. Electronic address: dr.j.antonio.torres@gmail.com.
authors.forename: J Antonio
authors.initials: JA
authors.lastname: Torres
mesh_terms: D058491:Bacterial Load; D016360:Clostridioides difficile / Q000187:drug effects / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D005516:Food Microbiology; D057927:Hydrophobic and Hydrophilic Interactions; D013171:Spores, Bacterial / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology*; D013696:Temperature; D014867:Water
chemical_list: D003470:Culture Media; D014867:Water
keywords: Clostridium difficile; Spore hydrophobicity; Spore survival; Water activity