``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli

Details ``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli ``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli

Mar 1998

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1998pnas...95.3943m&link_type=abstract

Proceedings of the National Academy of Sciences of the United States of America, Volume 95, Issue 7, pp. 3943-3948

Computer Science

4

Scientific paper

Plasmids, bacteriophages, and pathogenicity islands are genomic additions that contribute to the evolution of bacterial pathogens. For example, Shigella spp., the causative agents of bacillary dysentery, differ from the closely related commensal Escherichia coli in the presence of a plasmid in Shigella that encodes virulence functions. However, pathogenic bacteria also may lack properties that are characteristic of nonpathogens. Lysine decarboxylate (LDC) activity is present in ≈ 90% of E. coli strains but is uniformly absent in Shigella strains. When the gene for LDC, cadA, was introduced into Shigella flexneri 2a, virulence became attenuated, and enterotoxin activity was inhibited greatly. The enterotoxin inhibitor was identified as cadaverine, a product of the reaction catalyzed by LDC. Comparison of the S. flexneri 2a and laboratory E. coli K-12 genomes in the region of cadA revealed a large deletion in Shigella. Representative strains of Shigella spp. and enteroinvasive E. coli displayed similar deletions of cadA. Our results suggest that, as Shigella spp. evolved from E. coli to become pathogens, they not only acquired virulence genes on a plasmid but also shed genes via deletions. The formation of these ``black holes,'' deletions of genes that are detrimental to a pathogenic lifestyle, provides an evolutionary pathway that enables a pathogen to enhance virulence. Furthermore, the demonstration that cadaverine can inhibit enterotoxin activity may lead to more general models about toxin activity or entry into cells and suggests an avenue for antitoxin therapy. Thus, understanding the role of black holes in pathogen evolution may yield clues to new treatments of infectious diseases.

Affiliated with

Also associated with

No associations

Rating

``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with ``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and ``Black Holes" and Bacterial Pathogenicity: A Large Genomic Deletion that Enhances the Virulence of Shigella spp. and Enteroinvasive Escherichia coli will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-932928