KU Center for Food Safety, College of Veterinary Medicine, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, Republic of Korea.
Food Microbiol. 2012 Oct;32(1):217-22. doi: 10.1016/j.fm.2012.06.003. Epub 2012 Jun 19.
Sunsik, a ready-to-eat food in Korea, is comprised of various agricultural and marine products, and has been an important concern in Bacillus cereus food poisoning. The aim of this study was to investigate the toxin profiles, genotypic and phenotypic patterns as well as antibiotic resistance of B. cereus strains isolated from Sunsik. A subtyping method known as automated repetitive sequence-based PCR system (DiversiLab™) was used to assess the intraspecific biodiversity of these isolates. Thirty-five B. cereus strains were isolated from 100 commercial Sunsik samples, all of which harbored at least 1 enterotoxin gene. The detection rates of nheABC, hblCDA, cytK, and entFM enterotoxin gene among all isolates were 97%, 86%, 77%, and 100%, respectively. Most strains also produced corresponding enterotoxins such as HBL (83%) and NHE (94%). One strain (2.9%) carried the emetic toxin genes, including ces and EM1, and was positive for the HEp-2 cell emetic toxin assay. Most strains were positive for various biochemical tests such as salicin hydrolysis (86%), starch fermentation (89%), hemolysis (89%), motility test (100%) and lecithinase hydrolysis (89%). All isolates were susceptible to most antibiotics although they were highly resistant to β-lactam antibiotics. By using the automated rep-PCR system, all isolates were successfully differentiated, indicating the diversity of B. cereus strains present in Sunsik.
在韩国，Sunsik 是一种即食食品，由各种农产品和海产品组成，一直是蜡样芽胞杆菌食物中毒的重要关注点。本研究旨在调查从 Sunsik 中分离出的蜡样芽胞杆菌菌株的毒素谱、基因型和表型模式以及抗生素耐药性。一种称为自动重复序列基序 PCR 系统（DiversiLab™）的分型方法用于评估这些分离物的种内生物多样性。从 100 份商业 Sunsik 样品中分离出 35 株蜡样芽胞杆菌，所有这些菌株都至少携带 1 种肠毒素基因。在所有分离株中，nheABC、hblCDA、 cytK 和 entFM 肠毒素基因的检出率分别为 97%、86%、77%和 100%。大多数菌株还产生了相应的肠毒素，如 HBL（83%）和 NHE（94%）。一株（2.9%）携带呕吐毒素基因，包括 ces 和 EM1，并对 HEp-2 细胞呕吐毒素检测呈阳性。大多数菌株对各种生化试验呈阳性，如水杨素水解（86%）、淀粉发酵（89%）、溶血（89%）、运动试验（100%）和卵磷脂酶水解（89%）。虽然所有分离株对β-内酰胺类抗生素高度耐药，但对大多数抗生素仍敏感。通过使用自动重复序列 PCR 系统，所有分离株均成功区分，表明 Sunsik 中存在的蜡样芽胞杆菌菌株具有多样性。
