TABLE 1

Antibiotic susceptibility of the patient’s multidrug-resistant K. pneumoniae blood isolates

AntibioticMIC, μg/ml (interpretation)a
Day 5Day 54Day 62Day 68
Ampicillin-sulbactam≥32 (R)≥32 (R)≥32 (R)≥32 (R)
Cefazolin≥64 (R)≥64 (R)≥64 (R)≥64 (R)
Ceftriaxone≥64 (R)≥64 (R)≥64 (R)≥64 (R)
Cefepime≥64 (R)≥64 (R)≥64 (R)≥64 (R)
Ceftazidime-avibactam4 (S)4 (S)128 (R)>256 (R)b
Piperacillin-tazobactam≥128 (R)≥128 (R)128 (R)16 (S)
Ertapenem≥8 (R)≥8 (R)>8 (R)≥8 (R)
Meropenem≥16 (R)≥16 (R)2 (I)4 (R)c
Ciprofloxacin≥4 (R)≥4 (R)≥4 (R)≥4 (R)
Gentamicin≤1 (S)≤1 (S)≤1 (S)≤1 (S)
Polymyxin Bd>4 (NI)2 (NI)1 (NI)1 (NI)
Tigecycline≤1 (S)0.5 (S)≤1 (S)≤1 (S)
TMP-SMXe≥4/76 (R)≥4/76 (R)≥4/76 (R)≥4/76 (R)
Meropenem-vaborbactamNPNPNP2 (S)b
  • a S, susceptible; I, intermediate; R, resistant; NI, not interpretable; NP, not performed.

  • b Analysis was performed by disk diffusion and Etest at Cleveland Clinic; MICs determined by broth microdilution at JMI Laboratories were >32 μg/ml for ceftazidime-avibactam and 2 μg/ml for meropenem-vaborbactam.

  • c Confirmed by broth microdilution at JMI Laboratories.

  • d Polymyxin B MICs were determined by the use of a Sensititre GNX2F tray previously validated by comparing to CLSI broth macrodilution.

  • e TMP-SMX, trimethoprim-sulfamethoxazole.