title: DNA sequence analysis of the composite plasmid pTC conferring virulence and antimicrobial resistance for porcine enterotoxigenic Escherichia coli.
abstract: In this study the plasmid pTC, a 90 kb self-conjugative virulence plasmid of the porcine enterotoxigenic Escherichia coli (ETEC) strain EC2173 encoding the STa and STb heat-stable enterotoxins and tetracycline resistance, has been sequenced in two steps. As a result we identified five main distinct regions of pTC: (i) the maintenance region responsible for the extreme stability of the plasmid, (ii) the TSL (toxin-specific locus comprising the estA and estB genes) which is unique and characteristic for pTC, (iii) a Tn10 transposon, encoding tetracycline resistance, (iv) the tra (plasmid transfer) region, and (v) the colE1-like origin of replication. It is concluded that pTC is a self-transmissible composite plasmid harbouring antibiotic resistance and virulence genes. pTC belongs to a group of large conjugative E. coli plasmids represented by NR1 with a widespread tra backbone which might have evolved from a common ancestor. This is the first report of a completely sequenced animal ETEC virulence plasmid containing an antimicrobial resistance locus, thereby representing a selection advantage for spread of pathogenicity in the presence of antimicrobials leading to increased disease potential.
authors: Veterinary Medical Research Institute of the Hungarian Academy of Sciences, Budapest, Hungary.
authors: Péter Z
authors: PZ
authors: Fekete
authors: Elzbieta
authors: E
authors: Brzuszkiewicz
authors: Gabriele
authors: G
authors: Blum-Oehler
authors: Ferenc
authors: F
authors: Olasz
authors: Mónika
authors: M
authors: Szabó
authors: Gerhard
authors: G
authors: Gottschalk
authors: Jörg
authors: J
authors: Hacker
authors: Béla
authors: B
authors: Nagy
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001427:Bacterial Toxins / Q000235:genetics; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D054307:Enterotoxigenic Escherichia coli / Q000187:drug effects / Q000235:genetics* / Q000472:pathogenicity; D004768:Enterotoxins / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology*; D029968:Escherichia coli Proteins / Q000235:genetics; D056426:Genetic Loci; D006801:Humans; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*; D013752:Tetracycline / Q000494:pharmacology; D013753:Tetracycline Resistance / Q000235:genetics*; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; D037521:Virulence Factors; C034151:heat stable toxin (E coli); D013752:Tetracycline