Flores-Urbán Karen A, Natividad-Bonifacio Iván, Vázquez-Quiñones Carlos R, Vázquez-Salinas Carlos, Quiñones-Ramírez Elsa Irma
Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Calle Carpio y Plan de Ayala s/n, C.P. 11340, Mexico City, Mexico.
Departamento de Biotecnología, División de Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, Avenida San Rafael Atlixco 186, Colonia Vicentina, C.P. 09340, Mexico City, Mexico.
J Food Prot. 2014 Dec;77(12):2144-7. doi: 10.4315/0362-028X.JFP-13-479.
Bacillus cereus can cause diarrhea and emetic syndromes after ingestion of food contaminated with it. This ability is due to the production of enterotoxins by this microorganism, these being the hemolysin BL complex, which is involved in the diarrheal syndrome, and cereulide, which is responsible for the emetic syndrome. The detection of genes associated with the production of these toxins can predict the virulence of strains isolated from contaminated food. In this paper, we analyzed 100 samples of vegetables, 25 of each kind (broccoli, coriander, carrot, and lettuce) obtained from different markets in Mexico City and its metropolitan area. B. cereus was isolated in 32, 44, 84, and 68% of the samples of broccoli, carrot, lettuce, and coriander, respectively. The hblA gene (encoding one of the three subunits of hemolysin BL) was amplified in 100% of the B. cereus isolates, and the ces gene (encoding the cereulide) could not be amplified from any of them. This is the first report of B. cereus isolation from the vegetables analyzed in this work and, also, the first report in Mexico of the isolation from vegetables of strains with potential virulence. The results should serve as evidence of the potential risk of consuming these foods without proper treatment.
蜡样芽孢杆菌在摄入被其污染的食物后可引发腹泻和呕吐综合征。这种能力归因于该微生物产生的肠毒素，即参与腹泻综合征的溶血素BL复合物，以及导致呕吐综合征的蜡样毒素。检测与这些毒素产生相关的基因可以预测从受污染食物中分离出的菌株的毒力。在本文中，我们分析了从墨西哥城及其大都市区不同市场获取的100份蔬菜样本，每种蔬菜各25份（西兰花、香菜、胡萝卜和生菜）。蜡样芽孢杆菌分别在西兰花、胡萝卜、生菜和香菜样本中的分离率为32%、44%、84%和68%。溶血素BL三个亚基之一的编码基因hblA在100%的蜡样芽孢杆菌分离株中得以扩增，而蜡样毒素的编码基因ces在所有分离株中均未扩增出来。这是关于从本研究分析的蔬菜中分离出蜡样芽孢杆菌的首次报道，也是墨西哥首次从蔬菜中分离出具有潜在毒力菌株的报道。这些结果应作为未经适当处理就食用这些食物存在潜在风险的证据。
