title: Cytolethal distending toxin-producingEscherichia colistrains causing severe diarrhoea in young Mexican children.
abstract: Introduction.Cytolethal distending toxins (CDTs), encoded bycdtgenes, have DNase activity leading to cellular and nuclear distension, resulting in irreversible cell cycle arrest and apoptosis of target cells.cdt-positiveEscherichia colistrains have been isolated from children with diarrhoea. There is, however, scant information on the prevalence and clinical presentation of diarrhoeal disease caused by these strains. Furthermore, toxin production ofcdt-positive strains is rarely confirmed. We report five young children with diarrhoea caused by CDT-producingE. coliin whom stools were negative for other bacterial or enteric pathogens.Case presentation.On admission to hospital, all children presented watery diarrhoea with high stool output (range 7-20 stools/24 h); five had fever of 38 °C or more and four presented vomiting. Dehydration was present in four patients, one of whom had hypovolaemic shock; one child also presented hyponatraemia and hypokalaemia. In two children,cdt-positive strains were classified as typical and atypical enteropathogenicE. coli, and the remaining three harbouredcdt-positive strains that did not belong to any diarrhoeagenic pathogroup. Onecdt-positive strain from each case was characterized by a CDT cytotoxic assay and acdttype-specific PCR. All strains produced the characteristic cellular intoxication due to CDT. Two strains carried thecdt-I, onecdt-III, onecdt-IV, and one concurrently hadcdt-I, cdt-IIandcdt-IIIgenes.Conclusion.Our results suggest that CDT-producingE. colistrains are an infrequent, albeit significant, cause of severe diarrhoeal illness in children. Future research should measure the true burden ofcdt-positiveE. colidiarrhoea among children.
authors.affiliation: Department of Molecular Biomedicine, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Mario
authors.initials: M
authors.lastname: Meza-Segura
authors.affiliation: Infectious Diseases Research Unit, Hospital General O'Horan, Merida, Mexico.|Department of Epidemiology and Biostatistics, Michigan State University, Lansing, MI, USA.
authors.forename: Mussaret Bano
authors.initials: MB
authors.lastname: Zaidi
authors.affiliation: Department of Molecular Biomedicine, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Samantha
authors.initials: S
authors.lastname: Maldonado-Puga
authors.affiliation: Department of Cell Biology, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Jazmin
authors.initials: J
authors.lastname: Huerta-Cantillo
authors.affiliation: Department of Cell Biology, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Lucia
authors.initials: L
authors.lastname: Chavez-Dueñas
authors.affiliation: Department of Cell Biology, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Fernando
authors.initials: F
authors.lastname: Navarro-Garcia
authors.affiliation: Department of Molecular Biomedicine, CINVESTAV-IPN, Mexico City, Mexico.
authors.forename: Teresa
authors.initials: T
authors.lastname: Estrada-Garcia
keywords: CDT-Positive Escherichia coli; children; severe diarrhoea