title: Detection of toxigenic Bacillus cereus strains isolated from vegetables in Mexico City.
abstract: 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.
authors.affiliation: 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.
authors.forename: Karen A
authors.initials: KA
authors.lastname: Flores-Urbán
authors.affiliation: 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.
authors.forename: Iván
authors.initials: I
authors.lastname: Natividad-Bonifacio
authors.affiliation: 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.
authors.forename: Carlos R
authors.initials: CR
authors.lastname: Vázquez-Quiñones
authors.affiliation: 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.
authors.forename: Carlos
authors.initials: C
authors.lastname: Vázquez-Salinas
authors.affiliation: 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. elsairma46@yahoo.com.mx.
authors.forename: Elsa Irma
authors.initials: EI
authors.lastname: Quiñones-Ramírez
mesh_terms: D001409:Bacillus cereus / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000302:isolation & purification; D047630:Depsipeptides / Q000235:genetics; D004768:Enterotoxins / Q000302:isolation & purification; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D006460:Hemolysin Proteins / Q000235:genetics; D008800:Mexico; D014675:Vegetables / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D047630:Depsipeptides; D004768:Enterotoxins; D006460:Hemolysin Proteins; C089294:cereulide; C083961:hemolysin BL protein, Bacillus