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. 2011 Jun;3(6):672-7.
doi: 10.3390/toxins3060672. Epub 2011 Jun 20.

Loss of vtx genes after the first subcultivation step of verocytotoxigenic Escherichia coli O157 and Non-O157 during isolation from naturally contaminated fecal samples

Maria-Adelheid Joris  1 , Karen Verstraete, Koen De Reu, Lieven De Zutter
Affiliations

Loss of vtx genes after the first subcultivation step of verocytotoxigenic Escherichia coli O157 and Non-O157 during isolation from naturally contaminated fecal samples

Maria-Adelheid Joris et al. Toxins (Basel). 2011 Jun.

Abstract

Verocytotoxins VT1 and VT2,produced by Verocytotoxigenic Escherichia coli (VTEC), are encoded on temperate bacteriophages. Several studies reported the loss of the vtx genes after multiple subcultivation steps or long preservation. The objective of this study was to determine if the loss of the verocytotoxin genes can already occur during the first subcultivation step. Consequently, the stability of the vtx genes were tested in 40 isolates originating from 40 vtx-positive fecal samples after the first subcultivation step following the isolation procedure. The loss occurred in 12 out of 40 strains tested and was rather rare among the O157 strains compared to the non-O157 strains. This is the first study demonstrating that the loss of the verocytotoxin genes can already occur after the first subcultivation step. This may lead to an underestimation of VTEC positive samples.

Keywords: Escherichia coli; VTEC; loss; vtx genes.

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References

    1. Herold S., Karch H., Schmidt H. Shiga toxin-encoding bacteriophages—genomes in motion. Int. J. Med. Microbiol. 2004;294:115–121. - PubMed
    1. Allison H.E. Stx-phages: Drivers and mediators of the evolution of STEC and STEC-like pathogens. Future Microbiol. 2007;2:165–174. - PubMed
    1. Joris M.A. Cross-sectional survey of EHEC on 12 cattle farms. Unpublished work, 2011.
    1. Karch H., Meyer T., Russmann H., Heesemann J. Frequent loss of Shiga-like toxin genes in clinical isolates of Escherichia coli upon subcultivation. Infect. Immun. 1992;60:3464–3467. - PMC - PubMed
    1. Feng P., Dey M., Abe A., Takeda T. Isogenic strain of Escherichia coli O157: H7 that has lost both Shiga toxin 1 and 2 genes. Clin. Diagn. Lab. Immunol. 2001;8:711–717. - PMC - PubMed

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