Publication Date:
2012-07-17
Description:
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, lifethreateningdisease and Stx toxin is an integral virulence factor. The Stx-bacteriophagevB_EcoP-24B, commonly referred to as 24B, is capable of multiply infecting a singlebacterial host cell at a high frequency, with secondary infection increasing the rate at whichsubsequent bacteriophage infections can occur. This is biologically unusual, thereforedetermining the genomic content and context of 24B compared to other lambdoid Stxphages is important to understanding the factors controlling this phenomenon anddetermining whether they occur in other Stx phages. Results: The genome of the Stx2 encoding phage, 24B was sequenced and annotated. The genomicorganisation and general features are similar to other sequenced Stx bacteriophages inducedfrom Enterohaemorrhagic Escherichia coli (EHEC), however 24B possesses significantregions of heterogeneity, with implications for phage biology and behaviour. The 24Bgenome 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 comparisonsystem. Conclusions: The data support the hypothesis that Stx phages are mosaic, and recombination eventsbetween the host, phages and their remnants within the same infected bacterial cell willcontinue to drive the evolution of Stx phage variants and the subsequent dissemination ofshigatoxigenic potential.
Electronic ISSN:
1471-2164
Topics:
Biology
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