Email updates

Keep up to date with the latest news and content from BMC Genomics and BioMed Central.

Open Access Highly Accessed Research article

Comparative genomics of Shiga toxin encoding bacteriophages

Darren L Smith1, David J Rooks1, Paul CM Fogg1, Alistair C Darby1, Nick R Thomson2, Alan J McCarthy1 and Heather E Allison1*

Author Affiliations

1 Microbiology Research Group, Institute of Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, UK

2 Pathogen Genomics, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK

For all author emails, please log on.

BMC Genomics 2012, 13:311  doi:10.1186/1471-2164-13-311

Published: 16 July 2012

Abstract

Background

Stx bacteriophages are responsible for driving the dissemination of Stx toxin genes (stx) across their bacterial host range. Lysogens carrying Stx phages can cause severe, life-threatening disease and Stx toxin is an integral virulence factor. The Stx-bacteriophage vB_EcoP-24B, commonly referred to as Ф24B, is capable of multiply infecting a single bacterial host cell at a high frequency, with secondary infection increasing the rate at which subsequent bacteriophage infections can occur. This is biologically unusual, therefore determining the genomic content and context of Ф24B compared to other lambdoid Stx phages is important to understanding the factors controlling this phenomenon and determining whether they occur in other Stx phages.

Results

The genome of the Stx2 encoding phage, Ф24B was sequenced and annotated. The genomic organisation and general features are similar to other sequenced Stx bacteriophages induced from Enterohaemorrhagic Escherichia coli (EHEC), however Ф24B possesses significant regions of heterogeneity, with implications for phage biology and behaviour. The Ф24B genome was compared to other sequenced Stx phages and the archetypal lambdoid phage, lambda, using the Circos genome comparison tool and a PCR-based multi-loci comparison system.

Conclusions

The data support the hypothesis that Stx phages are mosaic, and recombination events between the host, phages and their remnants within the same infected bacterial cell will continue to drive the evolution of Stx phage variants and the subsequent dissemination of shigatoxigenic potential.