Diversity of Bacillus cereus strains in extended shelf life

Loading...
Thumbnail Image

Authors

Mugadza, D.T. (Desmond)
Buys, E.M. (Elna Maria)

Journal Title

Journal ISSN

Volume Title

Publisher

Elsevier

Abstract

Characterisation of 49 Bacillus cereus strains obtained from extended shelf life (ESL) milk and filler nozzles was done using (GTG)5 rep PCR fingerprinting, determining the presence of the virulence genes cytK, nheA, cer and hblA, and discrimination of psychrotrophic and mesophilic strains with 16S rDNA. Fourteen isolates were selected for 16S partial sequencing. Fingerprinting and sequencing showed evidence of filler nozzles contaminating ESL milk despite high heterogeneity existing between the isolates. While there is high prevalence of cer, hblA and nheA; cytK was not widely distributed. There was 100% and 8% prevalence of mesophilic and psychrotrophic signatures, respectively. Despite the large diversity of the B. cereus strains in this study, there is evidence that filler nozzles and raw milk are a source of contamination of B. cereus in ESL milk.

Description

Keywords

Extended shelf life (ESL), Bacteria, Polymerase chain reaction (PCR), Genes, Contamination, Dairy plant, Mesophilic strains, Raw milk, Emetic toxin, Pasteurized milk, Food poisoning toxins, Enterotoxin haemolysin BL (hblA), Emetic toxin cereulide (cer), Nonhemolytic enterotoxin A (nheA), Cytotoxin K (cytK), Bacillus cereus, Milk

Sustainable Development Goals

Citation

Mugadza, D.T. & Buys, E.M. 2017, 'Diversity of Bacillus cereus strains in extended shelf life', International Dairy Journal, vol. 73, no. 144-150.