Cytolethal distending toxins in Shiga toxin-producing Escherichia coli: alleles, serotype distribution and biological effects.

Department of Hygiene, Microbiology and Social Medicine, Innsbruck Medical University and Austrian Reference Laboratory for Enterohaemorrhagic Escherichia coli, Schöpfstrasse 41, A-6020 Innsbruck, Austria.
Journal of Medical Microbiology (Impact Factor: 2.27). 12/2006; 55(Pt 11):1487-92. DOI: 10.1099/jmm.0.46666-0
Source: PubMed

ABSTRACT To assess the prevalence of cytolethal distending toxin (CDT) among Shiga toxin-producing Escherichia coli (STEC), 202 STEC strains were investigated using PCRs targeting various cdt alleles (cdt-I to cdt-V). Seven of the 202 strains contained cdt-III and an additional seven contained cdt-V. All 14 cdt-positive strains produced biologically active CDT, as demonstrated by a progressive distension of cultured Chinese hamster ovary cells. The CDT-positive STEC belonged to eight different serotypes, including sorbitol-fermenting O157 : NM (non-motile). The data demonstrate that CDT is present in some STEC serotypes only. However, more studies are required to evaluate whether CDT presence is associated with severe disease.

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