TABLE 2.

Characteristics of the CTX-M-carrying plasmids analyzed in this study

Extended-spectrum β-lactamaseStrainsYr of isolationSpeciesSourceOriginExtra resistance in plasmidbSelf transfercReplicon typing
CTX-M-9C8-VLA1999S. enterica serovar VirchowHumanSpainSUL, TMPYesHI2
C16-VLA2003S. enterica serovar VirchowHumanUnited KingdomSUL, TMPYesHI2
C11-VLA2001S. enterica serovar VirchowHumanBalearicsSUL, TET, TMPNoHI2
C4-VLA1997S. enterica serovar VirchowHumanUnited KingdomSUL, TET, TMPYesHI2
C6-VLA1997S. enterica serovar VirchowHumanSpainNET, SUL, TMPYesHI2
CTX-M-15E162799-HPA2001E. coliHumanUnited KingdomNoneYesI1
E177258-HPA2003E. coliHumanUnited KingdomNoneYesI1
E158740-HPA2001E. coliHumanUnited KingdomNoneYesI1
E172182-HPA2003E. coliHumanUnited KingdomSULYesI1
C1-VLA2001S. enterica serovar AnatumHumanPakistanNoneYesI1
UCM267-VLA2002S. enterica serovar InfantisHumanHondurasNoneYesI1
ESBL3-VLA2000S. enterica serovar OhioHumanUnited KingdomGEN, SUL, TMPYesI1
C12-VLA2002S. enterica serovar TyphimuriumHumanUnited KingdomNoneYesI1
C13-VLA2003S. enterica serovar TyphimuriumHumanUnited KingdomNoneYesI1
C15-VLA2003S. EnteritidisHumanUnited KingdomGENNoFII(1)
E170743-HPA2003E. coliHumanUnited KingdomGENNoFII(1)
E172176-HPA*a2003E. coliHumanUnited KingdomAMK, GEN, KAN, SUL, TET, TMPYesFII(1), FIAd
E177268-HPA2003E. coliHumanUnited KingdomGEN, KAN, STRNoFII(1), FIAd
E172798-HPA2003E. coliHumanUnited KingdomGEN, KAN, TETNoFII(1), FIAd
E177243-HPA2003E. coliHumanUnited KingdomGEN, TETYesFII(1), FIAd
E172172-HPA*2003E. coliHumanUnited KingdomAMK, GEN, KAN, SUL, TET, TMPYesFII(1), FIA, FIBd
E169967-HPA**2002E. coliHumanUnited KingdomNoneYesFII(1), FIA, FIBd
E170681-HPA**2003E. coliHumanUnited KingdomGEN, SUL, TET, TMPYesFII(2), FIAd
E171897-HPA**2003E. coliHumanUnited KingdomGEN, SUL, TET, TMPNoFII(2), FIA, FIBd
E162237-HPA2001E. coliHumanUnited KingdomGEN, SUL, TET, TMPNoFII(2), FIA, FIBd
E177273-HPA2003E. coliHumanUnited KingdomGEN, TET, TMPYesFII(2), FIA, FIBd
E177265-HPA2003E. coliHumanUnited KingdomTMPYesNegative
CTX-M-2E136374-HPA1998E. coliHumanUnited KingdomAMK, GEN, KAN, SULNoA/C
C14-VLAUnknownS. enterica serovar VirchowPoultryIrelandSUL, TET, TMPNoP
CTX-M-14C10-VLA2001S. enterica serovar EnteritidisHumanUnited KingdomNoneYesI1
C159/11-VLA2004E. coliCattleUnited KingdomNoneYesK
Cow 47-VLA2005E. coliCattleUnited KingdomNoneNoNegative
C3-VLA2002S. enterica serovar StanleyHumanThailandNoneYesNegative
CTX-M-3ESBL7-VLA2002S. enterica serovar VirchowHumanUnited KingdomSUL, TMPYesN
ESBL10-VLA2002S. enterica serovar VirchowHumanUnited KingdomSUL, TMPYesN
CTX-M-40E134200 HPA1998E. coliHumanUnited KingdomGENNoN
  • a Two clusters of strains (indicated with single and double asterisks) showed a genetic similarity index of 90% by PFGE (10).

  • b Antimicrobial drugs used were the following: amikacin (AMK), chloramphenicol (CHL), gentamicin (GEN), kanamycin (KAN), netilmicin (NET), sulphonamides (SUL), tetracycline (TET), and trimethoprim (TMP).

  • c For the strains where transfer was not achieved by conjugation, transformation experiments were conducted in ElectroMAX streptomycin resistant DH10B cells (Invitrogen, Paisley, United Kingdom) selecting on cefotaxime (10 μg/ml) MacConkey agar plates.

  • d Multireplicon plasmid; each single replicon was used as a probe in Southern blot hybridization experiments performed on purified plasmids, demonstrating their colocalization on the same plasmid.