Molecular analysis of subtilase cytotoxin genes of food-borne Shiga toxin-producing Escherichia coli reveals a new allelic subAB variant

BMC Microbiology

Herbert Schmidt¹  Elisabeth Hauser¹  Helen Stoeber¹  Joschua Funk¹ 

[1] Department of Food Microbiology, Institute of Food Science and Biotechnology, University of Hohenheim, Garbenstraße 28, Stuttgart, D-70599, Germany

关键词: Phylogenetic heterogeneity;    Complete open reading frames;    New variant;    Deer;    subAB;    Shiga toxin-producing Escherichia coli;    Subtilase cytotoxin;   

Others  :  1142890
DOI  :  10.1186/1471-2180-13-230

 received in 2013-08-08, accepted in 2013-10-10,  发布年份 2013

【 摘 要 】

Background

The open reading frames of subAB genes and their flanking regions of 18 food-borne Shiga toxin-producing E. coli (STEC) strains were analyzed.

Results

All but one subAB open reading frames (ORF) were complete in all STEC strains. The subAB₁ genes of nine STEC strains were located on large plasmids. The subAB₂ allele (here designated subAB_2-1), which was recently described by others to be present in the Subtilase-Encoding PAI (SE-PAI) was found in 6 STEC strains. A new chromosomal subAB₂ variant, designated subAB_2-2 was detected in 6 strains and was linked to a chromosomal gene hypothetically encoding an outer membrane efflux protein (OEP). Three STEC strains contained both subAB₂ variants. DNA analysis indicated sequence conservation in the plasmid-located alleles and sequence heterogeneity among the chromosomal subAB₂ genes.

Conclusions

The results of this study have shown that 18 subAB-PCR positive STEC strains contain complete subAB open reading frames. Furthermore, the new allelic variant subAB_2-2 was described, which can occur in addition to subAB_2-1 on a new chromosomal locus.

【 授权许可】

   
2013 Funk et al.; licensee BioMed Central Ltd.

【 图 表 】

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