Clostridium botulinum produces Botulinum neurotoxins (BoNTs), causing a rare but potentially deadly type of food poisoning called foodborne botulism. This review aims to provide information on the bacterium, spores, toxins, and botulisms, and describe the use of physical treatments (e.g., heating, pressure, irradiation, and other emerging technologies) to control this biological hazard in food. As the spores of this bacterium can resist various harsh environmental conditions, such as high temperatures, the thermal inactivation of 12-log of C. botulinum type A spores remains the standard for the commercial sterilization of food products. However, recent advancements in non-thermal physical treatments present an alternative to thermal sterilization with some limitations. Low- (10 kGy) are required to inactivate BoNTs. High-pressure processing (HPP), even at 1.5 GPa, does not inactivate the spores and requires heat combination to achieve its goal. Other emerging technologies have also shown some promise against vegetative cells and spores; however, their application to C. botulinum is very limited. Various factors related to bacteria (e.g., vegetative stage, growth conditions, injury status, type of bacteria, etc.) food matrix (e.g., compositions, state, pH, temperature, aw, etc.), and the method (e.g., power, energy, frequency, distance from the source to target, etc.) influence the efficacy of these treatments against C. botulinum. Moreover, the mode of action of different physical technologies is different, which provides an opportunity to combine different physical treatment methods in order to achieve additive and/or synergistic effects. This review is intended to guide the decision-makers, researchers, and educators in using physical treatments to control C. botulinum hazards.

Clostridium perfringens is responsible for various diseases. Foodborne outbreaks (FBOs) result from the in situ production of C. perfringens enterotoxin (CPE) by type F strains during sporulation. The cpe gene can be plasmidic (p-cpe) or chromosomal (c-cpe). Strains (c-cpe) exhibit greater heat resistance and are frequently associated with FBO. Strains cpe-negative are considered heat-sensitive. This study investigates the sporulation abilities and heat resistance of eight C. perfringens strains isolated from French foodborne outbreaks. Whole-genome sequencing classified the strains into two clades: the “chromosomal cpe clade,”, mainly composed of cpe-positive strains with c-cpe and some cpe-negative strains, and the “plasmidic cpe clade,”, primarily containing cpe-negative strains and a few with plasmid-borne cpe. Sporulation assays and thermal inactivation kinetics were performed on FBO strains to evaluate the influence of genetic variability on sporulation abilities and heat resistance. Experimental analyses revealed that strains within the “chromosomal cpe clade” exhibited the highest sporulation abilities, regardless of cpe presence, while those in the “plasmidic cpe clade” had low sporulation ability. Moreover, heat-resistant spores were produced exclusively by strains of the “chromosomal cpe clade,” with c-cpe strains exhibiting the highest heat resistance (δ_{95 °C} ≈ 49 min), followed by cpe-negative strains (δ_{95 °C} ≈ 9.5 min). p-cpe strains exhibited a heat-sensitive phenotype, with δ_{85 °C} values of 12 min. A key finding of this study is the identification of a group with intermediate heat resistance, distinct from the highly heat-resistant (c-cpe) and heat-sensitive (p-cpe) strains. This intermediate heat-resistance phenotype, observed in cpe-negative strains within the “chromosomal cpe clade,” offers a new perspective on C. perfringens stress adaptation, suggesting their potential for persistence in food. Their heat resistance, along with the potential for cpe gene transfer, could make these strains a relevant hazard for cooked, cooled, and re-heated meat products.