Table 1.
Epidemiological and microbiological characteristics of CTX-M-2-producing Salmonella enterica isolates in poultry farms
| Isolate | Serovar | Poultry | Specimena | Yr/stateb | PFGE pulsotypec | MIC (μg/ml)d |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Amp | Caz | Cro | Ctx | Cft | Cpm | Nal | Cip | Eno | Tet | Str | Sut | ||||||
| S721A | Schwarzengrund | Turkey | Drag swab | 2008/SC | A | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S721B | Schwarzengrund | Turkey | Drag swab | 2008/SC | A | >256 | 64 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S778 | Schwarzengrund | Chicken | Drag swab | 2008/PR | A | >256 | 16 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S783 | Untypedf | Chicken | Drag swab | 2008/PR | A | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S779 | Schwarzengrund | Chicken | Drag swab | 2008/PR | A1 | >256 | 16 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S776 | Schwarzengrund | Chicken | Drag swab | 2008/PR | A2 | >256 | 16 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S780e | Schwarzengrund | Chicken | Drag swab | 2008/PR | A2 | >256 | 16 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S782 | Schwarzengrund | Chicken | Drag swab | 2008/PR | A2 | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S784e | Schwarzengrund | Chicken | Drag swab | 2008/PR | A2 | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | >256 | 0.125 |
| S785e | Schwarzengrund | Chicken | Drag swab | 2008/PR | A2 | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 4 | >128 | 128 | 0.125 |
| S791 | Schwarzengrund | Chicken | Carcass | 2008/SC | A3 | >256 | 32 | >256 | >256 | >256 | >512 | >512 | 4 | 2 | >128 | >256 | 0.125 |
| S769e | Agona | Turkey | Carcass | 2008/SC | B | >256 | 16 | >256 | >256 | >256 | >512 | >512 | 8 | 16 | >128 | >256 | >32 |
| S770e | Agona | Chicken | Eggs | 2008/SC | B1 | >256 | 24 | >256 | >256 | >256 | 128 | >512 | 16 | 16 | >64 | >256 | >32 |
Drag swabs were from the rearing facility.
PR, Paraná State; SC, Santa Catarina State.
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.
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).
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.
Flagellar antigens were absent or could not be typed.