TABLE 3.

Microdilution MIC values for N315 and Mu3 strains

StrainPlasmidChromosomal phenotypea,bPlasmid phenotypeMIC (μg/ml)c of:
TGCEtBrTPPDMG-MINODMG-DMDOTIPM
N315MepR MepA0.254160.1250.1252
N315pCLL3436MepR MepAMepA++116640.250.1251
N315pCLL3432MepR MepATet M++0.54160.1250.1252
N315_mut1MepRT++ MepA++0.516640.50.250.25
N315_mut1pCLL3434MepRT++ MepA++MepR++0.1258320.1250.1252
N315_mut2MepRT++ MepA++2326410.250.125
N315_mut3MepRT++ MepA++4326420.50.125
N315_mut3pCLL3434MepRT++ MepA++MepR++283210.250.5
N315_mut3pCLL3432MepRT++ MepA++Tet M++4326420.50.125
Mu3MepR MepA0.51285120.51128
Mu3pCLL3436MepR MepAMepA++212851211128
Mu3pCLL3432MepR MepATet M++11285120.51128
Mu3_mut1MepRT++ MepA++112851212128
Mu3_mut1pCLL3434MepRT++ MepA++MepR++0.1251285120.51128
Mu3_mut2MepRT++ MepA++41285122264
Mu3_mut2pCLL3434MepRT++ MepA++MepR++212851210.5128
Mu3_mut2pCLL3432MepRT++ MepA++Tet M++41285122264
Mu3_mut3MepRT++ MepA++ Tet M++81285122464
Mu3_mut4MepRT++ MepA++ Tet M++161285124464
Mu3_mut4pCLL3434MepRT++ MepA++ Tet M++MepR++812851222128
  • a MepRT refers to the truncated MepR product resulting from the introduction of a premature stop codon in the mepR gene of N315 and Mu3 mutants.

  • b The MepA phenotype refers to wild-type levels of mepA expression. MepA++, Tet M++, and MepR++ describe the phenotypes when mepA, tet(M), or mepR, respectively, is overexpressed from the chromosome or plasmid as indicated.

  • c TGC, tigecycline; EtBr, ethidium bromide; TPP, tetraphenylphosphonium bromide; DMG-MINO, 9-N,N-dimethylglycylamido-minocycline; DMG-DMDOT, 9-N,N-dimethylglycylamido-6-demethyl-6-deoxytetracycline; IPM, imipenem.