Isolation of three Klebsiella pneumoniae carrying KPN and NDM carbapenemases from a transplanted patient in Argentina

COSTA, AGUSTINA; CALZA YANINA; PEÑA LAURA; GUTKIND GABRIEL; DI CONZA JOSÉ

Chicago

Congreso; ASM Microbe 2020; 2020

ASM

options for treatment of infected patients. KPC and NDM enzymes can confer resistance to β-lactams, including penicillin, cephalosporins and carbapenems. While KPC producers can hydrolyze monobactams and can be inhibited by common inhibitors such as avibactam (AVI), NDM producers remain susceptible to aztreonam (AZT) but can resist the presence of AVI. The co-existence of these two carbapenemases in clinical isolates is a public health issue as it confers resistance to ceftazidime (CAZ), AZT and carbapenems alone or in combination with AVI. The aim of this study was to characterize 3 carbapenem-resistant Klebsiella pneumoniae isolates recovered from a transplanted patient.Three clinical isolates, designated as 338 (rectal swab), 705 (clot) and 728 (peritoneal liquid) were sequentially recovered from a transplanted patient who attended the Instituto de Cardiología de Corrientes (Corrientes Province, Argentina). Identification was carried out by MALDI-TOF MS and susceptibility testing was performed by disk diffusion tests and MIC determination. Phenotypic screening for KPC and metallo-β-lactamases was performed by synergy tests using phenylboronic acid (BOR) (300 µg), EDTA (1 µmol), meropenem (10 µg) and imipenem (10 µg) containing disks. PCR assays were carried out for carbapenemase detection and ST258 recognition. REP and ERIC PCRs were performed to evaluate clonal relationship among isolates.The 3 isolates were identified as K. pneumoniae (scores >2.400) and were resistant to all tested antibiotics (cephalosporins, carbapenems, gentamicin and AZT) excepting amikacin. Sinergy was observed between EDTA and meropenem disks in isolate 705, and between BOR and meropenem disks in isolates 338 (MIC CAZ/AVI >256 µg/ml) and 728 (MIC CAZ/AVI 1µg/ml). Isolate 338 resulted positive for blaKPC and blaNDM; isolate 705 rendered positive for blaNDM; and isolate 728 resulted positive for blaKPC. None of these isolates belonged to ST258. According to REP-ERIC, isolates 338 and 728 displayed the same amplification pattern, which was different from isolate 705.To our knowledge, KPC and NDM co-producing Klebsiella pneumoniae are emerging in inpatients in our country. We described the co-existence of blaKPC and blaNDM in a Klebsiella pneumoniae clinical isolate, which alerts about the importance of resistance mechanisms detection in order to implement a proper antibiotic treatment in this high-risk resistance scenario.