Volume 17, Number 6—June 2011
Dispatch
Salmonella enterica Serotype Typhi with Nonclassical Quinolone Resistance Phenotype
Table 1
Characteristics of the 674 Salmonella enterica serovar Typhi isolates belonging to subpopulations A, C, and D, France, 2007–2009*
Subpopulation |
No. isolates |
Nal MICs,† μg/mL | Cip MICs,† μg/mL | QRDR mutation (no./no. tested) |
|||||
---|---|---|---|---|---|---|---|---|---|
MIC50 |
MIC90 |
Range |
MIC50 |
MIC90 |
Range |
||||
A | 554 | 4 | 4 | 1–8 | 0.008 | 0.025 | 0.002–0.08 | WT (75/77) | |
gyrB Leu465 (2/77) | |||||||||
C | 119 | >256 | >256 | 128–>256 | 0.25 | 0.5 | 0.06–0.5 | gyrA Phe83 (24/44) | |
gyrA Tyr83 (12/44) | |||||||||
gyrA Asn87 (4/44) | |||||||||
gyrA Gly87 (2/44) | |||||||||
gyrA Phe83 and parE Asn420 (2/44) | |||||||||
D | 1 | >256 | 8 | gyrA Phe83, gyrA Asn87, and parC Ile80 |
*Nal, nalidixic acid; Cip, ciprofloxacin; QRDR, quinolone resistance–determining region of the gyrA, gyrB, parC, and parE genes; WT, wild type.
†MICs of Nal and Cip were determined by Etest strips. MIC50, 50% below; MIC90, 90% below.
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