Efficacy of meropenem against ceftazidime-avibactam-resistant Klebsiella pneumoniae producing KPC-31, KPC-33, KPC-90, KPC-106 and KPC-114.

Background: Klebsiella pneumoniae producing KPC variants conferring resistance to ceftazidime-avibactam often remain susceptible to meropenem, suggesting a potential therapeutic use of this antibiotic.

Objectives: In this study, the efficacy of clinically relevant concentrations of meropenem was evaluated against high-risk clones of ceftazidime-avibactam-resistant K. pneumoniae strains producing KPC variants, in a tandem in vitro time-kill/in vivo Galleria mellonella survival model.

Reversion of KPC-114 to KPC-2 in ceftazidime-avibactam- resistant/meropenem-susceptible ST11 is related to low mutation rates.

strains that produce Carbapenemase (KPC) variants displaying resistance to ceftazidime-avibactam (CZA) often remain susceptible to meropenem (MEM), suggesting a potential therapeutic use of this carbapenem antibiotic. However, studies indicate that these sorts of strains can mutate becoming MEM-resistant, raising concerns about the effectiveness of carbapenems as treatment option. We have studied mutation rates occurring from the reversion of MEM-susceptible KPC-114 to MEM-resistant KPC-2, in CZA-resistant belonging to ST11.

Rapid diagnostic of multidrug-resistant sepsis pathogens directly from blood culture bottles using MALDI-TOF and the EUCAST RAST.

In this study, rapid diagnostic of multidrug-resistant (MDR) sepsis pathogens, directly from positive blood culture (BC) bottles, was evaluated by combining MALDI-TOF and the EUCAST Rapid Antimicrobial Susceptibility Testing (RAST). Carbapenemase production in Escherichia coli and Klebsiella pneumoniae isolates was also evaluated by RAST. From 171 positive BC bottles analyzed, 79 (46 %) MDR species, including E.