Article Figures & Data
Figures
- FIG. 1.
CLUSTAL W alignment of QnrA, QnrB1, QnrB2, and QnrS.
- FIG. 2.
Maps of cloned qnrB genes. The sizes of the cloned fragments vary, as indicated by the 1-kb reference bars. Orf1 resembles pspF, Orf2 is related to genes of unknown function in various gram-negative bacteria, and Orf3 resembles sapA.
- FIG. 3.
QnrB1 protection of DNA gyrase from ciprofloxacin inhibition of supercoiling. Reaction mixtures of 30 μl were analyzed by agarose gel electrophoresis. Reaction mixtures contained 0.2 μg relaxed pBR322 DNA (lanes 1 to 14), 6.7 nM gyrase (lanes 2 to 14), 2 μg/ml ciprofloxacin (lanes 3 to 14), and QnrB-His6 fusion protein at 25 μM (lane 4), 5 μM (lane 5), 2.5 μM (lane 6), 0.5 μM (lane 7), 50 nM (lane 8), 5 nM (lane 9), 0.5 nM (lane 10), 50 pM (lane 11), 5 pM (lane 12), or 0.5 pM (lane 13).
Tables
- TABLE 1.
Properties of QnrB plasmids
Plasmid Species or strain found in: Location β-Lactamase(s) Other resistancesa Orf1005 pMG298 K. pneumoniae 17 Southern India CTX-M-15 Cm Gm Km Sm Su Tc Tm Tp + K. pneumoniae 21 Southern India SHV-1 and SHV-12 Tra− − pMG299 K. pneumoniae 24 Southern India CTX-M-15 Ak Gm Km Sm Su Tm Tp + pMG300 K. pneumoniae 25 Southern India SHV-12 Gm Km Sm Tm + pMG301 C. koseri Long Beach, CA SHV-12 Gm Sm Su Tp − pMG302 E. cloacae Philadelphia, PA SHV-12 Cm Gm Km Sm Su Tm Tp − pMG303 E. cloacae St. Louis, MO SHV-12 Cm Km Sm Su Tc Tp − pMG304 E. coli St. Louis, MO SHV-12 Cm Km Sm Su − ↵a Resistance abbreviations: Ak, amikacin; Cm, chloramphenicol; Gm, gentamicin; Km, kanamycin; Sm, streptomycin; Su, sulfonamide; Tc, tetracycline; Tm, tobramycin; Tp, trimethoprim.
- TABLE 2.
Susceptibility of E. coli J53 transconjugants to various quinolones
Plasmid in E. coli J53 Qnr protein MIC (μg/ml) Nalidixic acid Ciprofloxacin Gatifloxacin Levofloxacin Moxifloxacin R− 4 0.015 0.03 0.03 0.06 pMG252 QnrA 32 0.5 0.5 1 1 pHSH4-3 QnrA 16 0.25 0.5 0.5 0.5 pMG298 QnrB1 16 1 1 0.5 2 pMG299 QnrB1 16 0.25 0.5 0.5 1 pMG300 QnrB1 16 0.25 0.5 0.25 1
