Activity of TP-6076 against carbapenem-resistant Acinetobacter baumannii isolates collected from inpatients in Greek hospitals

TP-6076 is a synthetic fluorocycline antibiotic that inhibits bacterial protein synthesis. In this study, carbapenem-resistant Acinetobacter baumannii clinical isolates from 13 Greek hospitals were tested for susceptibility to TP-6076 and comparator antibiotics. Broth microdilution plates were used to determine minimum inhibitory concentrations (MICs). A total of 121 non-duplicate A. baumannii isolates were tested. The MIC50 and MIC90 values of TP-6076 were 0.03 mg/L and 0.06 mg/L, respectively. Tigecycline was the second most active antibiotic (MIC90, 2 mg/L), followed by minocycline (MIC90, 8 mg/L). TP-6076 exhibited MIC90 values that were one dilution lower against tigecycline- and minocycline-susceptible isolates than against resistant isolates. There was no difference in the MIC90 value for colistin-susceptible or -resistant isolates. In conclusion, TP-6076 exhibited greater antimicrobial activity in vitro against carbapenem-resistant A. baumannii than comparator antibiotics.