title: Combined high pressure and thermal processing on inactivation of type E and nonproteolytic type B and F spores of Clostridium botulinum.
abstract: The aim of this study was to determine the resistance of multiple strains of the three nonproteolytic types of Clostridium botulinum (seven strains of type E, eight of type B, and two of type F) spores exposed to combined high pressure and thermal processing. The resistance of spores suspended in N-(2-acetamido)-2-aminoethanesulfonic acid (ACES) buffer (0.05 M, pH 7) was determined at a process temperature of 80°C with high pressures of 600, 650, and 700 MPa using a laboratory-scale pressure test system. Spores of C. botulinum serotype E strains demonstrated less resistance than nonproteolytic spores of type B or F strains when processed at 80°C and 600 MPa for up to 15 min. All C. botulinum type E strains were reduced by . 6.0 log units within 5 min under these conditions. Among the nonproteolytic type B strains, KAP 9-B was the most resistant, resulting in reductions of 2.7, 5.3, and 5.5 log, coinciding with D-values of 7.7, 3.4, and 1.8 min at 80°C and 600, 650, and 700 MPa, respectively. Of the two nonproteolytic type F strains, 610F was the most resistant, showing 2.6-, 4.5-, and 5.3-log reductions with D-values of 8.9, 4.3, and 1.8 min at 80°C and 600, 650, and 700 MPa, respectively. Pulsed-field gel electrophoresis was performed to examine the genetic relatedness of strains tested and to determine if strains with similar banding patterns also exhibited similar D-values. No correlation between the genetic fingerprint of a particular strain and its resistance to high pressure processing was observed.
authors.affiliation: U.S. Food and Drug Administration, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA. guy.skinner@fda.hhs.gov.
authors.forename: Guy E
authors.initials: GE
authors.lastname: Skinner
authors.affiliation: U.S. Food and Drug Administration, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA. kristin.marshall@fda.hhs.gov.
authors.forename: Kristin M
authors.initials: KM
authors.lastname: Marshall
authors.affiliation: U.S. Food and Drug Administration, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.
authors.forename: Travis R
authors.initials: TR
authors.lastname: Morrissey
authors.affiliation: Institute for Food Safety and Health, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.
authors.forename: Viviana
authors.initials: V
authors.lastname: Loeza
authors.affiliation: Institute for Food Safety and Health, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Patazca
authors.affiliation: U.S. Food and Drug Administration, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA. rukma.reddy@fda.hhs.gov.
authors.forename: N Rukma
authors.initials: NR
authors.lastname: Reddy
authors.affiliation: U.S. Food and Drug Administration, Institute for Food Safety and Health, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.
authors.forename: John W
authors.initials: JW
authors.lastname: Larkin
mesh_terms: D003014:Clostridium botulinum / Q000502:physiology*; D015169:Colony Count, Microbial; D016521:Electrophoresis, Gel, Pulsed-Field; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology / Q000379:methods*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D011312:Pressure; D013045:Species Specificity; D013171:Spores, Bacterial / Q000502:physiology*