TABLE 5.
Fluoroquinolone resistance phenotype and mutations of 138 nalidixic acid-resistant veterinary Salmonella isolates of various serotypes
| MIC (μg/ml)a
|
No. of isolates | No. of isolates (%) with gyrA mutations at codonb:
|
No. of isolates with parC mutations at codon 80 (Ser)c | |||||
|---|---|---|---|---|---|---|---|---|
| Nal | Flu | Enr | Cip | 81 (Gly) | 83 (Ser) | 87 (Asp) | ||
| 128—512 | 8—16 | 0.5—1 | 0.125—0.5 | 132 | None | 74 (56) | 58 (44) | None |
| 512—1,024 | 16—32 | 4 | 1—2 | 5 | None | 5 | None | None |
| 1,024 | 64 | 4 | 2 | 1 | None | 1 | None | None |
a
Nal, nalidixic acid; Flu, flumequine; Enr, enrofloxacin; Cip, ciprofloxacin.
b
AS-PCR-RFLP assay results.
c
HaeII digestion of the parC gene QRDR.