PCR Detection of Thermophilic Spore-Forming Bacteria Involved in Canned Food Spoilage

Abstract

Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

The mechanisms and effect of epigallocatechin gallate (EGCg) on the germination and proliferation of bacterial spores

“…Spores are formed if bacteria experience environmental conditions that are deleterious to growth, such as nutrient limitation, and when conditions are again suitable for growth, the spore germinates to form a vegetative cell that begins to proliferate (Cook & Pierson, 1983;Santo & Doi, 1974). As spores are highly resistant to heat sterilization and to various drugs, control of spores of food poisoning bacteria, such as Clostridium botulinum (Abgueguen et al, 2003), Clostridium perfringens (Valenzuela-Martinez et al, 2010), and Bacillus cereus (Granum & Lund, 1997), and food and beverage spoilage bacteria, such as Bacillus coagulans (Cosentino, Mulargia, Pisano, Tuveri, & Palmas, 1997;Palop, Raso, Pagán, Condón, & Sala, 1999) and Moorella thermoacetica (Prevost, Andre, & Remize, 2010), is an extremely important problem in food and beverage preservation (Brown, 1994).…”

Estimation and evaluation of management options to control and/or reduce the risk of not complying with commercial sterility

“…The model was developed for Clostridium botulinum, Geobacillus stearothermophilus and Bacillus cereus; C. botulinum was chosen as the pathogenic bacteria which has to be considered in priority in a risk assessment of aseptic-UHT-type products (Codex Alimentarius Commission, 1993a), B. cereus was included as a pathogenic bacteria commonly found in milk powder (Becker et al, 1994) and finally, G. stearothermophilus was taken into account because it can survive to very high heat treatment (Rigaux et al, 2013) and has been then often reported as responsible of ambient stable product spoilage (Denny, 1981;Ito, 1981;Prevost et al, 2010). More precisely, André et al (2013) have determined that Geobacillus sp.…”

Detection and Quantification of Thermophilic Spore-Forming Moorella thermoacetica in Canned Beverages Using Real-Time PCR

“…Thermophilic, spore-forming bacteria, later characterized as M. thermoacetica, were detected in the 1970s in Japan in hot vending machines serving canned coffee with milk, soup, and "shiruko" (sweet beverage made from azuki bean powder), all of which were maintained at 55 to 60°C (8,10,22). This species has also been associated with the spoilage of canned food in other countries (1,14). These contaminants result in strong acidification, abnormal odors and colors, pH decrease, and separation and coagulation of milk components (8,23).…”