Potential of selected infant food formulas for production of Bacillus cereus emetic toxin, cereulide

• Published in: International journal of food microbiology 2006-04, Vol.107 (3), p.287-294
• Main Authors: Shaheen, Ranad, Andersson, Maria A., Apetroaie, Camelia, Schulz, Anja, Ehling-Schulz, Monika, Ollilainen, Veli-Matti, Salkinoja-Salonen, Mirja S.
• Format: Article
• Language: English
• Subjects: B. cereus; Bacillus cereus; Bacillus cereus - metabolism; bacterial toxins; Biological and medical sciences; Cereulide; Colony Count, Microbial; Consumer Product Safety; Depsipeptides - biosynthesis; Emetic toxin; emetics; food contamination; Food Contamination - analysis; Food Contamination - prevention & control; Food Handling - methods; Food Handling - standards; Food industries; food intoxication; Food microbiology; food pathogens; Fundamental and applied biological sciences. Psychology; Humans; Infant; Infant food; Infant Food - analysis; infant formulas; reconstituted foods; ribopathern; Ribopattern; ribotypes; Sperm micro assay; Temperature; Time Factors; toxigenic strains
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2005.10.007

Cereulide producing Bacillus cereus was isolated from randomly chosen commercial infant foods. The cereulide production in infant food formulas was investigated. When the reconstituted foods were inoculated with > 10 5 cfu ml − 1 of cereulide producing B. cereus, 2 to 200 μg of cereulide per 100 ml of food accumulated during 24 h of non-refrigerated storage. The amount of cereulide measured in the foods by the accurate chemical assay (LC-MS) matched with that found by sperm micro assay, proving the cereulide was the sole heat stable toxin in the foods and present in its toxic form. The infant formulas containing both cereal and dairy ingredients were the most supportive for cereulide production. Cereulide accumulation was affected by the infant food composition as well as by the handling of the food. Diluting the reconstituted food with water resulted in increased toxin production expressed as μg per volume. More cereulide was accumulated when the food was incubated stationary compared with moderate shaking. The amount of cereulide accumulated within 24 h at room temperature per 100 ml of cereal and dairy or in rice–nondairy reconstituted infant formulas, inoculated with ≥ 10 5 cfu ml − 1 of B. cereus strain F4810/72, was higher or similar to the amounts reported for foods implicated in emetic type of food poisonings. Thus mishandling and temperature abuse of infant foods may cause food poisoning when emetic B. cereus is present.