AUTHOR=Słabisz Natalia , Leśnik Patrycja , Janc Jarosław , Fidut Miłosz , Bartoszewicz Marzenna , Dudek-Wicher Ruth , Nawrot Urszula 

TITLE=Evaluation of the in vitro susceptibility of clinical isolates of NDM-producing Klebsiella pneumoniae to new antibiotics included in a treatment regimen for infections

JOURNAL=Frontiers in Microbiology

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1331628

DOI=10.3389/fmicb.2024.1331628

ISSN=1664-302X

ABSTRACT=<sec id="sec1"><title>Background</title><p>Due to the growing resistance to routinely used antibiotics, the search for new antibiotics or their combinations with effective inhibitors against multidrug-resistant microorganisms is ongoing. In our study, we assessed the <italic>in vitro</italic> drug susceptibility of <italic>Klebsiella pneumoniae</italic> strains producing New Delhi metallo-β-lactamases (NDM) to antibiotics included in the Infectious Diseases Society of America (IDSA) and European Society of Clinical Microbiology and Infectious Diseases (ESCMID) recommendations.</p></sec><sec id="sec2"><title>Methods</title><p>A total of 60 strains of NDM-producing <italic>K. pneumoniae</italic> were obtained from different patients hospitalized at the 4th Military Hospital in Wroclaw between 2019 and 2022 and subjected to drug susceptibility to selected antibiotics, including the effects of drug combinations.</p></sec><sec id="sec3"><title>Results</title><p>Among the tested antibiotics, the highest sensitivity (100%) was observed for cefiderocol, eravacycline (interpreted according to the European Committee on Antimicrobial Susceptibility Testing [EUCAST]), and tigecycline. Sensitivity to intravenous fosfomycin varied depending on the method used. Using the “strip stacking” method, determining cumulative sensitivity to ceftazidime/avibactam and aztreonam demonstrated 100% <italic>in vitro</italic> sensitivity to this combination among the tested strains.</p></sec><sec id="sec4"><title>Conclusion</title><p>The <italic>in vitro</italic> susceptibility assessment demonstrated that, the best therapeutic option for treating infections caused by carbapenemase-producing strains seems to be a combination of ceftazidime/avibactam with aztreonam. Due to the safety of using both drugs, cost effectiveness, and the broadest indications for use among the tested antibiotics, this therapy should be the first-line treatment for carbapenemase-producing <italic>Enterobacterales</italic> infections. Nevertheless, a comprehensive evaluation of the efficacy of treating infections caused by NDM-producing <italic>K. pneumoniae</italic> strains should include not only <italic>in vitro</italic> susceptibility assessment but also an analysis of clinical cases.</p></sec>