title: Active Shiga-Like Toxin Produced by SomeAeromonasspp., Isolated in Mexico City.
abstract: Shiga-like toxins (Stx) represent a group of bacterial toxins involved in human and animal diseases. Stx is produced by enterohemorrhagicEscherichia coli, Shigella dysenteriaetype 1,Citrobacter freundii, andAeromonasspp.; Stx is an important cause of bloody diarrhea and hemolytic uremic syndrome (HUS). The aim of this study was to identify thestx1/stx2 genes in clinical strains and outer membrane vesicles (OMVs) ofAeromonasspp., 66 strains were isolated from children who live in Mexico City, and Stx effects were evaluated in Vero cell cultures. The capacity to express active Stx1 and Stx2 toxins was determined in Vero cell cultures and the concentration of Stx was evaluated by 50% lethal dose (LD50) assays, observing inhibition of damaged cells by specific monoclonal antibodies. The results obtained in this study support the hypothesis that thestxgene is another putative virulence factor ofAeromonas, and since this gene can be transferred horizontally through OMVs this genus should be included as a possible causal agents of gastroenteritis and it should be reported as part of standard health surveillance procedures. Furthermore, these results indicate that theAeromonasgenus might be a potential causative agent of HUS.
authors.affiliation: Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Palma-Martínez
authors.affiliation: Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico.
authors.forename: Andrea
authors.initials: A
authors.lastname: Guerrero-Mandujano
authors.affiliation: Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio Central de Análisis Clínicos Unidad Médica de Alta Especialidad Hospital de Pediatría "Silvestre Frenk Freund," Centro Médico Nacional Siglo XXIMexico City, Mexico.
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Ruiz-Ruiz
authors.affiliation: Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico; Laboratorio de Bioquímica Microbiana, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico NacionalMexico City, Mexico.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Hernández-Cortez
authors.affiliation: Departamento de Salud Pública, Facultad de Medicina, Universidad Nacional Autónoma de México Mexico City, Mexico.
authors.forename: José
authors.initials: J
authors.lastname: Molina-López
authors.affiliation: Centro de Biotecnología Genómica, Instituto Politécnico Nacional Reynosa, Mexico.
authors.forename: Virgilio
authors.initials: V
authors.lastname: Bocanegra-García
authors.affiliation: Laboratorio de Bacteriología Médica, Departamento de Microbiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional Mexico City, Mexico.
authors.forename: Graciela
authors.initials: G
authors.lastname: Castro-Escarpulli
keywords: Aeromonas spp.; Shiga-like toxin; diarrhea; outer membrane vesicles; uremic hemolytic syndrome