Volume 14, Number 2—February 2008
Letter
Plasmid-mediated Quinolone Resistance in Salmonella enterica, United Kingdom
, Martin Day*, and E. John Threlfall*
Table
Isolates of Salmonella enterica with plasmid-mediated qnr genes, United Kingdom, October 2006–April 2007
| Salmonella serotype | Phage type* | No. isolates | VNTR profile† | Ciprofloxacin MIC (μg/mL)‡ | Additional resistance to antimicrobial drugs§ | qnr identified |
|---|---|---|---|---|---|---|
| Corvallis | – | 1 | – | 0.25 | S, Su, T | qnrS1 |
| Corvallis | – | 2 | – | 0.38 | S, Su, T | qnrS1 |
| Corvallis | – | 1 | – | 1.0 | S, Su, T ,Cf | qnrS1 |
| Corvallis | – | 1 | – | 0.25 | None | qnrS1 |
| Corvallis | – | 1 | – | 0.38 | None | qnrS1 |
| Schwarzengrund | – | 1 | – | 0.25 | T | qnrB5 |
| Typhimurium | DT120 | 4 | 1–6-0–0-3 | 0.38 | S, Su, T | qnrS1 |
| Typhimurium | DT120 | 3 | 1–6-0–0-3 | 0.50 | S, Su, T | qnrS1 |
| Typhimurium | DT120 | 3 | 1–4-0–0-3 | 0.38 | S, Su, T | qnrS1 |
| Typhimurium | DT120 | 1 | 1–4-0–0-3 | 0.50 | S, Su, T | qnrS1 |
| Typhimurium | DT120 | 1 | 1–4-0–0-3 | 0.38 | None | qnrS1 |
| Typhimurium | DT120 | 1 | 1–5-0–0-3 | 0.38 | S, Su, T | qnrS1 |
| Typhimurium | DT193 | 1 | 1–6-0–0-3 | 0.50 | S, Su, T | qnrS1 |
| Typhimurium | DT193 | 1 | 1–4-0–0-3 | 0.38 | C, S, Su, Sp, T, Tm | qnrS1 |
| Typhimurium | DT193 | 1 | 1–4-0–0-3 | 0.38 | S, Su, T | qnrS1 |
| Typhimurium | DT193 | 2 | 1–5-0–0-3 | 0.38 | S, Su, T | qnrS1 |
| Typhimurium | DT193 | 1 | 1–4-0–0-3 | 0.50 | A, Su | qnrS1 |
| Typhimurium | 49b | 1 | 1–4-19–1-3 | 0.25 | A, G, Ne, K, S, Su, Sp, T, Tm, Ak, Cx, Cr, Cf, Cn, Ct | qnrB2 |
| Typhimurium | NC | 1 | 1–4-0–0-3 | 0.25 | S, Su, T | qnrS1 |
| Typhimurium | UT | 1 | 3–8-19–1-2 | >32 | A, C, G, S, Su, Sp, T, Tm, Fu, Nx | qnrS1 |
| Virchow | 43 | 5 | – | 1.0 | A, Fu, Nx | qnrS1 |
| Virchow | 43 | 2 | – | 1.5 | A, Fu, Nx | qnrS1 |
| Virchow | 25a | 1 | – | 0.75 | Tm | qnrS1 |
| Virchow | 11 | 1 | – | 1.0 | A, Fu, Nx | qnrS1 |
| Virchow | NC | 1 | – | 1.5 | A, C, G, Ne, K, S, Su, Sp, T, Tm, Fu, Nx, Cx, Cr, Cf, Cn, Ct | qnrS1 |
*DT, definitive type; NC, does not conform to a recognized pattern; UT, untypeable.
†VNTR, variable number tandem repeat. Loci of the VNTR profiles are presented in the following order: STTR9-STTR5-STTR6-STTR10pl-STTR3. The number 0 in the VNTR profile represents cases with no amplification of PCR product.
‡Determined by Etest.
§Antimicrobial drugs (breakpoint final concentrations): S, streptomycin (16 mg/L); Su, sulfonamide (64 mg/L); T, tetracycline (8 mg/L); Cf, cefuroxime (16 mg/L); C, chloramphenicol (8 mg/L); Sp, spectinomycin (64 mg/L); Tm, trimethoprim (2 mg/L); A, ampicillin (8 mg/L]; G, gentamicin (4 mg/L); Ne, neomycin (8 mg/L) K, kanamycin (8 mg/L); Ak, amikacin (4 mg/L); Cx, cefalexin (16 mg/L); Cr, cefradine (16 mg/L); Cn, ceftriaxone (1 mg/L); Ct, cefotaxime (1 mg/L); Fu, furazolidone (8 mg/L); Nx, nalidixic acid (16 mg/L).