Document Type

Article

Publication Date

8-2006

Journal or Book Title

Journal of Bacteriology

Volume

188

Issue

16

First Page

5975

Last Page

1983

DOI

10.1128/​JB.00204-06

Abstract

Avian pathogenic Escherichia coli (APEC), an extraintestinal pathogenic E. colicausing colibacillosis in birds, is responsible for significant economic losses for the poultry industry. Recently, we reported that the APEC pathotype was characterized by possession of a set of genes contained within a 94-kb cluster linked to a ColV plasmid, pAPEC-O2-ColV. These included sitABCD, genes of the aerobactin operon, hlyF, iss, genes of the salmochelin operon, and the 5′ end ofcvaB of the ColV operon. However, the results of gene prevalence studies performed among APEC isolates revealed that these traits were not always linked to ColV plasmids. Here, we present the complete sequence of a 174-kb plasmid, pAPEC-O1-ColBM, which contains a putative virulence cluster similar to that of pAPEC-O2-ColV. These two F-type plasmids share remarkable similarity, except that they encode the production of different colicins; pAPEC-O2-ColV contains an intact ColV operon, and pAPEC-O1-ColBM encodes the colicins B and M. Interestingly, remnants of the ColV operon exist in pAPEC-O1-ColBM, hinting that ColBM-type plasmids may have evolved from ColV plasmids. Among APEC isolates, the prevalence of ColBM sequences helps account for the previously observed differences in prevalence between genes of the “conserved” portion of the putative virulence cluster of pAPEC-O2-ColV and those genes within its “variable” portion. These results, in conjunction with Southern blotting and probing of representative ColBM-positive strains, indicate that this “conserved” cluster of putative virulence genes is primarily linked to F-type virulence plasmids among the APEC isolates studied.

Comments

This article is from Journal of Bacteriology 188, no. 16 (August 2006): 5975–5983, doi:10.1128/JB.00204-06.

Copyright Owner

American Society for Microbiology

Language

en

File Format

application/pdf