Multi-locus sequence typing and virulence profile in Bacillus cereus sensu lato strains isolated from dairy products

Ital J Food Saf. 2021 Jan 18;9(4):8401. doi: 10.4081/ijfs.2020.8401. eCollection 2020 Dec 3.

Abstract

Members of Bacillus cereus group are important food contaminants and they are of relevant interest in food safety and public heath due to their ability to cause two distinct forms of food poisoning, emetic and diarrhoeal syndrome. In the present study, 90 strains of B. cereus isolated from dairy products, have been typed using Multilocus Sequence Typing (MLST) analysis and investigated for the occurrence of 10 enterotoxigenic genes (hblA, hblC, hblD, nheA, nheB, nheC, cytK, entFM, entS and bceT) and one emetogenic gene (ces), to determine their genetic diversity. A total of 58 sequence types were identified and among these 17 were signalled as new profiles. Among the virulence genes, the majority of our strains carried the entS (92%), entFM (86%), nhe (82%) and cytK (72%) genes. All remaining genes were identified in at least one strain with different prevalence, stressing the genetic diversity, how even the different grade of pathogenicity of B. cereus isolated from dairy products.

Keywords: Bacillus cereus; Multi-locus Sequence Typing; food poisoning; toxin genes.

Grants and funding

Funding: Fondi Ricerca Corrente Ministero della Salute IZS PB 04/16 RC.