9/18/2016 Sources of C.botulinum Sources of C.botulinum Occurrence in the environment Occurrence in food -Common in soils and sediments -Food surveys focus mostly on meats,fish Number and types vary with locations and infant foods MPN-most probable rumber MPN-most probable rumber 0000000 Sources of C.botulinum Virulence Factors and Mechanisms of ·Occurrence in food Pathogenicity Spores can contaminate fruits and vegetables particularly those that come into contact with Botulinum toxin is called the most poisonous the soil poison known Overall incidence of C botulinum in precut .C.botulinum produces 8 antigenically distinct vegetables is low -0.36% toxins Mushrooms are of concern A,B.C1.C2.D.E,F,and G >grown in compost All are neurotoxins except C2 >favorable to botulinal growth All are similar in structure and mode of >Contain 2,100 type B spores per kg action >Packaging has holes to allow oxygen flow All are heat sensitive >Packaging uses films that allow high oxygen Inactivated by-heating a sample to 80C diffusion for 10 min or bring to a boil completely 9 9/18/2016 10 Sources of C. botulinum • Occurrence in the environment - Common in soils and sediments - Number and types vary with locations MPN – most probable number Sources of C. botulinum • Occurrence in food - Food surveys focus mostly on meats, fish, and infant foods MPN – most probable number Sources of C. botulinum • Occurrence in food - Spores can contaminate fruits and vegetables particularly those that come into contact with th il e so - Overall incidence of C. botulinum in precut vegetables is low – 0.36% - Mushrooms are of concern  grown in compost  f bl t b t li l th favorable to botulinal growth  Contain 2,100 type B spores per kg  Packaging has holes to allow oxygen flow  Packaging uses films that allow high oxygen diffusion Virulence Factors and Mechanisms of Pathogenicity • Botulinum toxin is called the most poisonous poison known • C. botulinum produces 8 antigenically distinct toxins - A, B, C1, C2, D, E, F, and G - All are neurotoxins except C2 - All are similar in structure and mode of action - All are heat sensitive - Inactivated by - heating a sample to 80oC for 10 min or bring to a boil completely