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DNA Sequence and Comparative Genomics of pAPEC-O2-R, an Avian Pathogenic Escherichia coli Transmissible R Plasmid
Antimicrobial Agents and Chemotherapy
  • Timothy J. Johnson, Iowa State University
  • Kylie E. Siek, Iowa State University
  • Sara J. Johnson, Iowa State University
  • Lisa K. Nolan, Iowa State University
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In this study, a 101-kb IncF plasmid from an avian pathogenic Escherichia coli(APEC) strain (APEC O2) was sequenced and analyzed, providing the first completed APEC plasmid sequence. This plasmid, pAPEC-O2-R, has functional transfer and antimicrobial resistance-encoding regions. The resistance-encoding region encodes resistance to eight groups of antimicrobial agents, including silver and other heavy metals, quaternary ammonium compounds, tetracycline, sulfonamides, aminoglycosides, trimethoprim, and beta-lactam antimicrobial agents. This region of the plasmid is unique among previously described IncF plasmids in that it possesses a class 1 integron that harbors three gene cassettes and a heavy metal resistance operon. This region spans 33 kb and is flanked by the RepFII plasmid replicon and an assortment of plasmid maintenance genes. pAPEC-O2-R also contains a 32-kb transfer region that is nearly identical to that found in the E. coli F plasmid, rendering it transferable by conjugation to plasmid-less strains of bacteria, including an APEC strain, a fecal E. coli strain from an apparently healthy bird, a Salmonella enterica serovar Typhimurium strain, and a uropathogenic E. coli strain from humans. Differences in the G+C contents of individual open reading frames suggest that various regions of pAPEC-O2-R had dissimilar origins. The presence of pAPEC-O2-R-like plasmids that encode resistance to multiple antimicrobial agents and that are readily transmissible from APEC to other bacteria suggests the possibility that such plasmids may serve as a reservoir of resistance genes for other bacteria of animal and human health significance.


This article is from Antimicrobial Agents and Chemotherapy 49, no. 11 (November 2005): 4681–4688, doi:10.1128/AAC.49.11.4681-4688.2005.

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American Society for Microbiology
Date Available
May 6, 2013
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Citation Information
Timothy J. Johnson, Kylie E. Siek, Sara J. Johnson and Lisa K. Nolan. "DNA Sequence and Comparative Genomics of pAPEC-O2-R, an Avian Pathogenic Escherichia coli Transmissible R Plasmid" Antimicrobial Agents and Chemotherapy Vol. 49 Iss. 11 (2005) p. 4681 - 4688
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