Use of Carbapenems in the Combined Treatment of Emerging Ceftazidime/avibactam-Resistant and Carbapenem-Susceptible KPC-producing Klebsiella Pneumoniae Infections: Report of a Case and Review of the Literature.

OBJECTIVES:To describe the case of a patient with infection due to a KPC-producing Klebsiella pneumoniae (K. pneumoniae) isolate developing ceftazidime-avibactam resistance with restored carbapenem susceptibility during ceftazidime-avibactam therapy. To review the clinical/microbiological cure and survival rates using carbapenems in other similar case reports and case series.PATIENTS AND METHODS:A patient with an intra-abdominal infection due to K. pneumoniae producing the KPC-48 variant (L169P-A172T) (resistant to ceftazidime/avibactam and susceptible to carbapenems) who was treated with imipenem-cilastatin in combination with tigecycline and gentamicin. The literature was reviewed in order to summarise the in vivo (clinical/microbiological cure and survival rate) use of carbapenems in this emerging scenario.RESULTS:The patient was successfully treated with the indicated regimen. In other reported cases (mostly with pneumonia) all-cause mortality was 50% and clinical cure was 62.5%. Meropenem-vaborbactam has been successful used in an additional case.CONCLUSIONS:A carbapenem-based regimen of combination therapy seems to be an option for treating patients infected with K. pneumoniae resistant to ceftazidime/avibactam and susceptible to carbapenems, at least when the risk of mortality is low.