title: Contamination pathways of spore-forming bacteria in a vegetable cannery.
abstract: Spoilage of low-acid canned food during prolonged storage at high temperatures is caused by heat resistant thermophilic spores of strict or facultative bacteria. Here, we performed a bacterial survey over two consecutive years on the processing line of a French company manufacturing canned mixed green peas and carrots. In total, 341 samples were collected, including raw vegetables, green peas and carrots at different steps of processing, cover brine, and process environment samples. Thermophilic and highly-heat-resistant thermophilic spores growing anaerobically were counted. During vegetable preparation, anaerobic spore counts were significantly decreased, and tended to remain unchanged further downstream in the process. Large variation of spore levels in products immediately before the sterilization process could be explained by occasionally high spore levels on surfaces and in debris of vegetable combined with long residence times in conditions suitable for growth and sporulation. Vegetable processing was also associated with an increase in the prevalence of highly-heat-resistant species, probably due to cross-contamination of peas via blanching water. Geobacillus stearothermophilus M13-PCR genotypic profiling on 112 isolates determined 23 profile-types and confirmed process-driven cross-contamination. Taken together, these findings clarify the scheme of contamination pathway by thermophilic spore-forming bacteria in a vegetable cannery.
authors.affiliation: CTCPA, Unité d'Expertise dans la Maitrise du Risque Industriel en Thermorésistants Sporulés, F-84911 Avignon, France.
authors.forename: Loïc
authors.initials: L
authors.lastname: Durand
authors.affiliation: CTCPA, Unité d'Expertise dans la Maitrise du Risque Industriel en Thermorésistants Sporulés, F-84911 Avignon, France.
authors.forename: Stella
authors.initials: S
authors.lastname: Planchon
authors.affiliation: INRA, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France; Avignon Université, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France.
authors.forename: Marie-Hélène
authors.initials: MH
authors.lastname: Guinebretiere
authors.affiliation: CTCPA, Unité d'Expertise dans la Maitrise du Risque Industriel en Thermorésistants Sporulés, F-84911 Avignon, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: André
authors.affiliation: INRA, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France; Avignon Université, UMR408, Sécurité et Qualité des Produits d'Origine Végétale, F-84000 Avignon, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Carlin
authors.affiliation: CTCPA, Unité d'Expertise dans la Maitrise du Risque Industriel en Thermorésistants Sporulés, F-84911 Avignon, France. Electronic address: fabienne.remize@univ-reunion.fr.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Remize
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification; D015169:Colony Count, Microbial; D018552:Daucus carota / Q000382:microbiology*; D005516:Food Microbiology; D057141:Food, Preserved / Q000382:microbiology*; D001411:Geobacillus stearothermophilus / Q000235:genetics / Q000302:isolation & purification; D006358:Hot Temperature; D018532:Pisum sativum / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D013171:Spores, Bacterial / Q000302:isolation & purification; D013242:Sterilization / Q000592:standards
keywords: Canned food; Geobacillus stearothermophilus; Heat-resistance; Moorella thermoacetica; Spore formers; Typing