TABLE 1.

Antimicrobial susceptibility profiles of K. pneumoniae clinical isolates 231-21D and 234-49C, the E. coli K-12 strain carrying the conjugative plasmid p231-21D, and the recipient E. coli K-12 strain

Antimicrobial agentMIC (μg/ml)
K. pneumoniae 234-49CK. pneumoniae 231-21DE. coli K-12 (p231-21D)E. coli K-12
Ampicillin>16>16>164
Piperacillin-tazobactam>64>64322
Aztreonam8>16>160.06
Cefoxitin>16>16>164
Cefotaxime>16>164≤0.25
Ceftazidime>32>32320.25
Ceftriaxone16>32320.06
Cefepime8840.06
Imipenem4840.03
Meropenem8820.03
Ertapenem4>8>80.06
Amikacin≤4>32>32≤4
Gentamicin≤2>8>8≤2
Ciprofloxacin0.5>40.250.06
Levofloxacin0.5>40.250.06
Tigecycline0.50.50.120.06
Colistin≤0.5≤0.5≤0.5≤0.5
Polymyxin B1≤0.5≤0.5≤0.5