Table 1

Epidemiological and microbiological characteristics of CTX-M-2-producing Salmonella enterica isolates in poultry farms

IsolateSerovarPoultrySpecimenaYr/statebPFGE pulsotypecMIC (μg/ml)d
AmpCazCroCtxCftCpmNalCipEnoTetStrSut
S721ASchwarzengrundTurkeyDrag swab2008/SCA>25632>256>256>256>512>51244>128>2560.125
S721BSchwarzengrundTurkeyDrag swab2008/SCA>25664>256>256>256>512>51244>128>2560.125
S778SchwarzengrundChickenDrag swab2008/PRA>25616>256>256>256>512>51244>128>2560.125
S783UntypedfChickenDrag swab2008/PRA>25632>256>256>256>512>51244>128>2560.125
S779SchwarzengrundChickenDrag swab2008/PRA1>25616>256>256>256>512>51244>128>2560.125
S776SchwarzengrundChickenDrag swab2008/PRA2>25616>256>256>256>512>51244>128>2560.125
S780eSchwarzengrundChickenDrag swab2008/PRA2>25616>256>256>256>512>51244>128>2560.125
S782SchwarzengrundChickenDrag swab2008/PRA2>25632>256>256>256>512>51244>128>2560.125
S784eSchwarzengrundChickenDrag swab2008/PRA2>25632>256>256>256>512>51244>128>2560.125
S785eSchwarzengrundChickenDrag swab2008/PRA2>25632>256>256>256>512>51244>1281280.125
S791SchwarzengrundChickenCarcass2008/SCA3>25632>256>256>256>512>51242>128>2560.125
S769eAgonaTurkeyCarcass2008/SCB>25616>256>256>256>512>512816>128>256>32
S770eAgonaChickenEggs2008/SCB1>25624>256>256>256128>5121616>64>256>32
  • a Drag swabs were from the rearing facility.

  • b PR, Paraná State; SC, Santa Catarina State.

  • c PFGE patterns were analyzed using the Dice similarity coefficient and the unweighted-pair group method using the average linkage cluster method (BioNumerics software; Applied Maths, Kortrijk, Belgium). PFGE clusters A and B were assigned based on a <90% similarity of banding patterns. For each PFGE profile, banding patterns with >90% similarity were assigned a numeric subprofile designation.

  • d MICs were determined by the Etest and/or agar dilution method (15, 16). Amp, ampicillin; Caz, ceftazidime; Cro, ceftriaxone; Ctx, cefotaxime; Cft, ceftiofur; Cpm, cefepime; Nal, nalidixic acid; Cip, ciprofloxacin; Eno, enrofloxacin; Tet, tetracycline; Str, streptomycin; Sut, sulfamethoxazole-trimethoprim. ESBL-positive Salmonella isolates were found to be sensitive to kanamycin, gentamicin, amikacin, chloramphenicol, amoxicillin-clavulanic acid, cefoxitin, imipenem, and meropenem, as determined by Kirby-Bauer susceptibility testing (15).

  • e Transformants were obtained with 38.5% of the ESBL-producing strains. The cefotaxime MICs for all transformed E. coli TOP10 strains exhibited a 5-fold increase.

  • f Flagellar antigens were absent or could not be typed.