Multiple antibiotic resistance gene recruitment onto the enterohemorrhagic Escherichia coli virulence plasmid.
Enterohemorrhagic Escherichia coli (EHEC) strains are zoonotic pathogens responsible for a range of severe human disease. The repertoire of virulence determinants promoting EHEC disease is encoded on both the main chromosome and virulence plasmid. We examined a multiply antibiotic-resistant O26 EHEC strain for carriage of resistance genes on the virulence plasmid. The EHEC virulence plasmid containing a complex antibiotic-resistance gene locus, designated as pO26-CRL, was purified from EHEC O26:H(-) (patient with hemorrhagic colitis) and subjected to shotgun-sequencing and bioinformatic analysis. Determination of the 111,481-bp sequence of pO26-CRL revealed genes encoding a functional enterohemolysin operon (ehxCABD), STEC-specific extracellular serine protease (espP), putative EHEC adhesin (toxB), catalase/peroxidase (katP), and myristoyl transferase (msbB) involved in lipid A synthesis. A 22,609-bp Tn21 derivative is inserted within the conjugal transfer gene traC and encodes resistance to trimethoprim, streptomycin, sulfathiozole, kanamycin, neomycin, beta-lactams, and mercuric chloride. Plasmid pO26-CRL is nonconjugative but is mobilizable. This is the first report of an EHEC virulence plasmid containing a complex antibiotic resistance locus, and raises the concern that antibiotic use will coselect for virulence determinants, leading to increased disease potential in both commensal and pathogenic E. coli populations.-Venturini, C., Beatson, S. A., Djordjevic, S. P., Walker, M. J. Multiple antibiotic resistance gene recruitment onto the enterohemorrhagic Escherichia coli virulence plasmid.
Venturini
Carola
C
School of Biological Sciences, University of Wollongong, Wollongong, NSW, 2522, Australia.
Beatson
Scott A
SA
Djordjevic
Steven P
SP
Walker
Mark J
MJ
D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D054324:Enterohemorrhagic Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D056426:Genetic Loci; D006460:Hemolysin Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009876:Operon / Q000235:genetics; D010957:Plasmids / Q000235:genetics* / Q000378:metabolism
D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C066219:enterohemolysin; C439629:toxB protein, E coli; D002374:Catalase; D000217:Acyltransferases; C097895:MsbB protein, E coli