title: Gene detection and toxin production evaluation of hemolysin BL of Bacillus cereus isolated from milk and dairy products marketed in Brazil.
abstract: Bacillus cereusis an ubiquitous, spore-forming bacteria that can survive pasteurization and the majority of the heating processes used in the dairy industry. Besides, it is a pathogen responsible for different types of food poisoning. One type of foodborne disease caused by B.cereusis the diarrheal syndrome, which is caused by the ingestion of vegetative cells producing toxins in the small intestine. One virulence factor for the diarrheal syndrome is the toxin hemolysin BL (HBL), a three-component protein formed by the L1, L2 and B components. In order to evaluate the presence of diarrheal strains isolated from milk and dairy products, 63 B. cereus isolates were obtained from 260 samples of UHT milk, pasteurized milk and powdered milk, sold in commercial establishments and from different brands. The isolates were subjected to the Polymerase Chain Reaction (PCR) for the detection of the encoding genes for the L1, L2 and B components and the toxin production capacity were evaluated with an immunoassay. A total of 23 [36.5%] isolates were identified carrying simultaneously the three tested genes, from which, 20 [86.9%] showed toxigenic capacity. 26 [41.3%] isolates did not carry any of genes tested and the other 14 [22.2%] were positive for one or two of them. The results showed a high toxigenic capacity among the B. cereus isolates able to produce the HBL, indicating a potential risk for consumers.
authors.affiliation: Programa de Pós-Graduação em Engenharia de Alimentos, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Andre L S
authors.initials: AL
authors.lastname: Reis
authors.affiliation: Programa de Pós-Graduação em Engenharia de Alimentos, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Maike T M
authors.initials: MT
authors.lastname: Montanhini
authors.affiliation: Laboratório de Bioengenharia, Universidade Tecnológica Federal do Paraná, Ponta Grossa, PR, Brazil.
authors.forename: Juliana V M
authors.initials: JV
authors.lastname: Bittencourt
authors.affiliation: Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, SP, Brazil.
authors.forename: Maria T
authors.initials: MT
authors.lastname: Destro
authors.affiliation: Programa de Pós-Graduação em Engenharia de Alimentos, Universidade Federal do Paraná, Curitiba, PR, Brazil.
authors.forename: Luciano S
authors.initials: LS
authors.lastname: Bersot
mesh_terms: D000818:Animals; D001409:Bacillus cereus / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000032:analysis* / Q000235:genetics*; D001938:Brazil; D004269:DNA, Bacterial / Q000235:genetics; D003611:Dairy Products / Q000382:microbiology*; D006460:Hemolysin Proteins / Q000032:analysis* / Q000235:genetics*; D007118:Immunoassay; D008892:Milk / Q000382:microbiology*; D016133:Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006460:Hemolysin Proteins; C083961:hemolysin BL protein, Bacillus
keywords: Bacillus cereus; dairy products; detection; milk; pathogenicity