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.

Abstract Objectives (i) To describe a case of a patient with infection due to a KPC-producing Klebsiella pneumoniae isolate developing ceftazidime-avibactam resistance with restored carbapenem susceptibility during ceftazidime-avibactam therapy; (ii) to review 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-3 variant L169P-A172 T (resistant to ceftazidime/avibactam and susceptible to carbapenem) who was treated with imipenem-cilastatin in combination with tigecycline and gentamicin. We reviewed the literature in order to summarize 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 (most with pneumonia) all-cause mortality was 50% and clinical cure was 62.5%. Meropenem-vaborbactam has been successful used in an additional case. Conclusions Carbapenem-based regimen of combination therapy, seems to be an option to treat patients infected withKlebsiella pneumoniae resistant to ceftazidime/avibactam and susceptible to carbapenem, at least when the risk of mortality is low.