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Table 1 Effect of robAYp overexpression on antibiotic susceptibility

From: A multicopy suppressor screening approach as a means to identify antibiotic resistance determinant candidates in Yersinia pestis

  IC50 (μg/ml)a FCc MIC99 (μg/ml)b FC
Y. pestis no plasmid pGEM-4Z pGEM-RobYp   no plasmid pGEM-4Z pGEM-RobYp  
Ofloxacin 0.01 0.01 0.05 5 0.03 0.03 0.7 23
Ciprofloxacin 0.009 0.009 0.04 4 0.02 0.02 0.09 5
Levofloxacin 0.01 0.01 0.04 4 0.02 0.02 0.09 5
Nalidixic Acid 0.5 0.8 2 3 2 2 6 3
Chloramphenicol 0.3 0.4 0.9 2 1 1 3 3
Tetracycline 0.7 1 6 6 1 3 10 3
Doxycycline 0.4 0.5 1 2 0.6 1 3 3
Kanamycin 1 0.9 0.4 0.4 2 2 2 1
Apramycin 2 3 1 0.3 6 6 4 0.7
Streptomycin 1 2 0.8 0.4 3 3 3 1
Gentamicin 0.4 0.4 0.2 0.5 1 0.4 0.4 1
E. coli no plasmid pGEM-4Z pGEM-RobYp   no plasmid pGEM-4Z pGEM-RobYp  
Ofloxacin 0.03 0.04 0.09 2 0.08 0.2 0.4 2
Ciprofloxacin 0.01 0.009 0.04 4 0.05 0.08 0.2 3
Levofloxacin 0.04 0.04 0.1 3 0.2 0.2 0.4 2
Nalidixic Acid 27 26 28 1 83 100 100 1
Chloramphenicol 0.3 0.3 0.8 3 2 2 13 7
Tetracycline 0.8 0.6 2 3 3 3 10 3
Doxycycline 0.3 0.2 0.6 3 1 0.6 3 5
Kanamycin 2 1 2 2 10 6 6 1
Apramycin 3 3 4 1 21 17 21 1
Streptomycin 3 2 3 2 17 13 13 1
Gentamicin 0.9 0.6 2 3 6 5 8 2
  1. a IC50 values were calculated from sigmoidal curves fitted to triplicate sets of dose-response data. b MIC99 values are means of triplicates. c Fold change (FC) values were calculated as the ratio of the IC50 or MIC99 of the pGEM-RobYp transformants to the IC50 or MIC99 of the pGEM-4Z transformants. IC50, MIC99, and FC values <1 and values >1 were rounded to one significant digit and to the nearest non-fractional number, respectively.