TABLE 1.

Characteristics of E. coli and S. enterica isolates tested for the presence of putative transposable elements bearing blaCMY-2

Strain IDSpecies or Salmonella serotypeSourceYrblaCMY-2-bearing plasmid (kb)aResistance patternbStructure typec
R57E. coliCow2002150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFII
H4HE. coliCow2002150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFI
R98E. coliCow2002150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFI
W1539E. coliCat2001160AMP-CHL-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFI
6615NewportCow2000150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFI
6668NewportCow2000150AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFI
7486NewportCow2001150AMP-CHL-GEN-KAN-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFII
7591NewportHuman2000150AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFI
7594NewportHuman2000140AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFI
7658NewportCow2002150AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFI
7651MuensterCow2002150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFI
8200TyphimuriumCow2003160AMP-KAN-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFII
8201TyphimuriumCow2003150AMP-CHL-KAN-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFII
8238TyphimuriumCow2003140AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFI
8240TyphimuriumCow2003150AMP-CHL-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFII
9639TyphimuriumCow2004160AMP-CHL-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFII
8232DublinCow2003150AMP-CHL-GEN-KAN-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFIII
8274DublinCow2003150AMP-CHL-GEN-KAN-TSU-TET-AMC-CEF-CAZ-FOX-CTFIII
8991DublinCow2004150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFIII
9155DublinCow2004150AMP-CHL-GEN-KAN-STR-TSU-TET-AMC-CEF-CAZ-FOX-CTFIII
9640DublinCow2004150AMP-CHL-GEN-KAN-STR-TSU-SXT-TET-AMC-CEF-CAZ-FOX-CTFIII
  • a Each DH10B transformant carried only one large plasmid, ranging in size from approximately 140 to 160 kb. Plasmid sizes were estimated by comparison with a supercoiled DNA ladder containing DNA bands of 8 to 165 kb (BAC-Tracker supercoiled DNA ladder; Epicentre, Madison, Wis.). All blaCMY-2 plasmids were classified as the “type C” plasmid based on a PCR typing scheme described by Giles et al. (10).

  • b Resistance patterns were determined by the Kirby-Bauer disk diffusion assay on Mueller-Hinton agar for 13 antimicrobials, including ampicillin (AMP), chloramphenicol (CHL), gentamicin (GEN), kanamycin (KAN), streptomycin (STR), triple sulfa (TSU), trimethoprim-sulfamethoxazole (SXT), tetracycline (TET), amoxicillin-clavulanic acid (AMC), cephalothin (CEF), ceftazidime (CAZ), cefoxitin (FOX), and ceftiofur (CTF).

  • c Structure types indicate the genetic context of blaCMY-2 regions as determined by PCR mapping, as shown in Fig. 1.