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Transposition of the heat-stable toxin astA gene into a gifsy-2-related prophage of Salmonella enterica serovar Abortusovis.
- Source :
-
Journal of bacteriology [J Bacteriol] 2004 Jul; Vol. 186 (14), pp. 4568-74. - Publication Year :
- 2004
-
Abstract
- The horizontal transfer and acquisition of virulence genes via mobile genetic elements have been a major driving force in the evolution of Salmonella pathogenicity. Serovars of Salmonella enterica carry variable assortments of phage-encoded virulence genes, suggesting that temperate phages play a pivotal role in this process. Epidemic isolates of S. enterica serovar Typhimurium are consistently lysogenic for two lambdoid phages, Gifsy-1 and Gifsy-2, carrying known virulence genes. Other serovars of S. enterica, including serovars Dublin, Gallinarum, Enteritidis, and Hadar, carry distinct prophages with similarity to the Gifsy phages. In this study, we analyzed Gifsy-related loci from S. enterica serovar Abortusovis, a pathogen associated exclusively with ovine infection. A cryptic prophage, closely related to serovar Typhimurium phage Gifsy-2, was identified. This element, named Gifsy-2AO, was shown to contribute to serovar Abortusovis systemic infection in lambs. Sequence analysis of the prophage b region showed a large deletion which covers genes encoding phage tail fiber proteins and putative virulence factors, including type III secreted effector protein SseI (GtgB, SrfH). This deletion was identified in most of the serovar Abortusovis isolates tested and might be dependent on the replicative transposition of an adjacent insertion sequence, IS1414, previously identified in pathogenic Escherichia coli strains. IS1414 encodes heat-stable toxin EAST1 (astA) and showed multiple genomic copies in isolates of serovar Abortusovis. To our knowledge, this is the first evidence of intergeneric transfer of virulence genes via insertion sequence elements in Salmonella. The acquisition of IS1414 (EAST1) and its frequent transposition within the chromosome might improve the fitness of serovar Abortusovis within its narrow ecological niche.<br /> (Copyright 2004 American Society for Microbiology)
- Subjects :
- Animals
Bacterial Proteins genetics
Bacterial Proteins metabolism
Colony Count, Microbial
DNA, Bacterial chemistry
DNA, Bacterial isolation & purification
Escherichia coli genetics
Gene Deletion
Gene Dosage
Gene Transfer, Horizontal
Genes, Bacterial
Genes, Viral
Intestines microbiology
Liver microbiology
Lymph Nodes microbiology
Molecular Sequence Data
Prophages isolation & purification
Salmonella Infections, Animal microbiology
Salmonella enterica isolation & purification
Salmonella enterica pathogenicity
Sheep Diseases microbiology
Spleen microbiology
Viral Tail Proteins genetics
Bacterial Toxins genetics
DNA Transposable Elements
Prophages genetics
Salmonella enterica genetics
Salmonella enterica virology
Virulence Factors genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9193
- Volume :
- 186
- Issue :
- 14
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 15231789
- Full Text :
- https://doi.org/10.1128/JB.186.14.4568-4574.2004