Enumeration and molecular detection of Bacillus cereus in local indigenous and imported rice grains
Tóm tắt
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. 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). 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.
Tài liệu tham khảo
Aklilu E, Tukimin EB, Daud NBA, Kyaw T. Enterotoxigenic Bacillus cereus from cooked chicken meat: a potential public health hazard. Malays J Microbiol. 2016;12:112–5.
Ankolekar C, Rahmati T, Labbé RG. Detection of toxigenic Bacillus cereus and Bacillus thuringiensis spores in US rice. Int J Food Microbiol. 2009;128:460–6.
Bavykin SG, Lysov YP, Zakhariev V, Kelly JJ, Jackman J, Stahl DA, Cherni A. Use of 16S rRNA, 23S rRNA, and gyrB gene sequence analysis to determine phylogenetic relationships of Bacillus cereus group microorganisms. J Clin Microbiol. 2004;42:3711–30.
BERNAS. Imported white rice. 2016. www.bernas.com.my/index.php/imported-white-rice.
Bilung LM, Linang V, Noaman YA, Apun K, Lihan S. Presence of Bacillus cereus s.l. from ready-to-eat cereals (RTE) products in Sarawak. Int Food Res J. 2013;20:1031–4.
Budka H, Buncic S, Colin P. Opinion of the scientific panel on biological hazards on Bacillus cereus and other Bacillus spp. in foodstuffs. Eur Food Saf Auth J. 2005;175:1–48.
Delbrassinne L, Andjelkovic M, Dierick K, Denayer S, Mahillon J, Van Loco J. Prevalence and levels of Bacillus cereus emetic toxin in rice dishes randomly collected from restaurants and comparison with the levels measured in a recent foodborne outbreak. Foodborne Pathog Dis. 2012;9:809–14.
Department of Agricultural Sarawak. 2012. www.doa.sarawak.gov.my/modules/web/pages.php?mod=webpage&sub=page&id=690.
Food Standards Australia New Zealand. Guidelines for microbiological examination of ready-to-eat foods. 2001. www.foodstandards.gov.au/publications/Pages/guidelinesformicrobi1306.aspx.
Granum PE. Bacillus cereus. In: Pina LMF, Arun KB, James S, editors. Foodborne pathogens: microbiology and molecular biology. Norfolk: Caister Academic Press; 2005. p. 409–14.
Haque A, Russell NJ. Phenotypic and genotypic characterisation of Bacillus cereus isolates from Bangladeshi rice. Int J Food Microbiol. 2005;98:23–34.
Jawad N, Mutalib SA. Identification of Bacillus cereus isolates from cooked rice by biochemical test and 16 s rDNA sequences. Int J ChemTech Res. 2016;9:469–75.
Lee HY, Chai LC, Tang SY, Jinap S, Ghazali FM, Nakaguchi Y, Nishibuchi M, Son R. Application of MPN-PCR in biosafety of Bacillus cereus s.l. for ready-to-eat cereals. Food Control. 2009;20:1068–71.
Mano H, Morisaki H. Endophytic bacteria in the rice plant. Microbes Environ. 2008;23:109–17.
New Straits Times. 2012. www.nst.com.my.
Public Health England. Guidelines for assessing the microbiological safety of ready-to-eat foods placed on the market. 2009. www.gov.uk/government/publications/ready-to-eat-foods-microbiological-safety-assessment-guidelines.
Sandra A, Afsah-Hejri L, Tunung R, Tuan Zinazor TC, Tang JYH, Ghazali FM, Nakaguchi Y, Nishibuchi M, Son R. Bacillus cereus and Bacillus thuringiensis in ready-to-eat cooked rice in Malaysia. Int Food Res J. 2012;19:829–36.
Wu XY, Walker MJ, Hornitzky M, Chin J. Development of a group-specific PCR combined with ARDRA for the identification of Bacillus species of environmental significance. J Microbiol Methods. 2006;64:107–19.
Wang LT, Lee FL, Tai CJ, Kasai H. Comparison of gyrB gene sequences, 16S rRNA gene sequences and DNA–DNA hybridization in the Bacillus subtilis group. Int J Syst Evolut Microbiol. 2007;57:1846–50.