Enumeration and molecular detection of Bacillus cereus in local indigenous and imported rice grains

• Main Authors: Bilung, Lesley Maurice, Tahar, Ahmad Syatir, Tan, Pei Shze, Jamie, Samantha Valarie Furzanne, Hashim, Hashimatul Fatma, Apun, Kasing, Radu, Son
• Format: Article
• Language: English
• Published: BioMed Central 2016
• Online Access: http://psasir.upm.edu.my/id/eprint/71012/1/Enumeration%20and%20molecular%20detection%20of%20Bacillus%20cereus%20in%20local%20indigenous%20and%20imported%20grains; http://psasir.upm.edu.my/id/eprint/71012/; https://agricultureandfoodsecurity.biomedcentral.com/articles/10.1186/s40066-016-0074-4

Background: Bacillus cereus is frequently related to foodborne illness outbreak. The common food vehicles for transmission of the bacteria are rice, rice products and starchy foods. As rice is a staple food for some countries including Malaysia, knowledge about safety of B. cereus in rice is important. This study was conducted to enumerate and identify B. cereus in local indigenous and imported rice grains. As Malaysia depends on imported rice to complement the food demands, it is crucial to assess on the imported rice besides the locals. Results: Twenty local indigenous and twenty imported rice grains were investigated in this study. All samples showed positive for the presence of B. cereus using polymerase chain reaction targeting the gryB gene (475 bp) which encodes for B protein subunit for DNA gyrase or also known as topoisomerase II. The microbial load of B. cereus in all samples was >1100MPN/g. However, PCR analysis revealed all the samples were contaminated with B. cereus except for three samples of local indigenous rice (LIR 3, LIR 9 and LIR 20). Conclusions: Due to the finding of high prevalence on the samples, it is therefore concluded that the local indigenous and imported rice grains can be one potential source of B. cereus transmission to the public.