Molecular Characterization and Toxin Profile of Bacillus cereus Strains Isolated from Ready-to-eat Foods

Abstract

Toxin-producing Bacillus cereus is the causative agent of two different types of food poisoning: the emetic and the diarrheal types. This study was conducted to investigate the presence of enterotoxin and emetic toxin genes in 263 B. cereus isolated from 619 different ready-to-eat food items. Hemolytic enterotoxins hblA, hblC, and hblD were detected in 85.6, 41.1, and 76.8%, respectively, of the B. cereus isolates. About 67.0% (175/263) of the isolates presented all of three genes. Non-hemolytic enterotoxins nheA, nheB, and nheC were detected in 100, 97.0, and 68.4% of the isolates, respectively. Approximately 90.0% (236/263) of the isolates presented all of these three non-hemolytic enterotoxin genes. Emetic toxin gene, CER, was detected in 132 of 263 (50.2%) isolates. Computer-assisted cluster analysis of Rep-PCR profiles showed a high genetic diversity among the isolates. All B. cereus isolates from food samples tested in this study carried at least 6 of 10 toxin genes.

Antimicrobial Activity of Foreign Plant Extracts Against Foodborne Pathogens

“…유래의 항생물질에 대한 연구가 지속적으로 증가하고 있으며 (Kim et al, 2009), 식물의 자기방어 기전과 관련되어 생 산하는 플라보노이드, 스테로이드, 페놀류 등 이차 대사산물들의 항생효과가 보고되고 있다 (Agrios, 1988;Mitscher et al, 1980). 식품 유해균으로 알려진 Bacillus cereus는 식중독, 곡류 부패 및 변질을 일으키고 (Kim et al, 2014), Listeria monocytogenes는 임산부에게 유산을 유발시키며, 성인에게는 폐렴, 결막염 등의 리스테리아증을 초래하는 것으로 보고되었다 (Farber et al, 1991). 황금추출물 (Cho et al, 2001), 소나무 에탄올 추출물 (Cho and Kim, 2001) 등의 식물 추출물은 L. monocytogenes 균주에 대하여 생육억제 효과를 나타내는 것으로 보고된 바 있다.…”