Toxin production potential and the detection of toxin genes among strains of the Bacillus cereus group isolated along the dairy production chain

• Published in: International dairy journal Vol. 17; no. 10; pp. 1201 - 1208
• Main Authors: Svensson, Birgitta, Monthán, Amanda, Guinebretière, Marie-Hélène, Nguyen-Thé, Christophe, Christiansson, Anders
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.10.2007; Elsevier Science
• Subjects: Bacillus cereus; Bacillus weihenstephanensis; bacterial contamination; bacterial toxins; Biological and medical sciences; cattle production; dairy cattle; dairy industry; detection; Emetic toxin; Enterotoxins; food contamination; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; genes; genetic polymorphism; Methods of analysis, processing and quality control, regulation, standards; Milk; Milk and cheese industries. Ice creams; pasteurized milk; Psychrotrophic; strain differences; toxigenic strains; toxin genes; Toxin production; Emetic toxin; Psychrotrophic; Bacillus cereus; Toxin production; Enterotoxins; Milk; Dairy product; Bacillaceae; Strain; Toxin; Enterotoxins; Emetic toxin; Toxin production; Psychrotrophic; Milk; Analysis method; Bacillales; Gene; Dairy industry; Production; Enterotoxin; Bacteria; Control method; Detection
• ISSN: 0958-6946; 1879-0143
• DOI: 10.1016/j.idairyj.2007.03.004

Isolates of the Bacillus cereus group (396 in total) from farms, silo tanks and production lines for pasteurised milk were tested for toxin production potential, and by polymerase chain reaction (PCR) for the presence of toxin genes. Comparison between the tests indicated the presence of gene polymorphisms. Highly toxigenic strains, based on production of subunit A of the nonhemolytic enterotoxin, NHE (NheA) and subunit C of the haemolytic enterotoxin, HBL (HblC), were less common among dairy isolates compared with farm and silo isolates. No producer of high levels of both toxins was found among 156 psychrotrophic dairy isolates ( B. weihenstephanensis) and only 3% of all psychrotrophs were high producers of NheA. Psychrotrophic B. cereus from pasteurised milk appeared to have a low enterotoxin production potential, and they were not producers of emetic toxin or cytotoxin K and therefore may be less likely to cause illness than mesophilic strains.