KLEBSIELLA PNEUMONIAE AFFECTS NEUTROPHIL ELASTASE DYNAMICS

FEDERICO BIRNBERG- WEISS; JOSE RAMÓN PITTALUGA; JOSELYN CASTRO; LUIS CASTILLO MONTAÑEZ; MARTIRE GRECO, DAIANA; FEDERICO FUENTES; FABIANA BIGI; SONIA GOMEZ; VERONICA INÉS LANDONI; GABRIELA C. FERNÁNDEZ

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Congreso; Reunion conjunta anual 2022; 2022

SAI/SAIC

The importance of neutrophil elastase (NE) in the bactericidal response of neutrophils (PMN) relies on different mechanisms. NE contained in azurophilic granules (AzG) can kill bacteria after fusion with phagosomes. Also, NE translocation from AzG to the nucleus is a key step for neutrophil-extracellular-traps (NET) formation, and depends on NE activity. Klebsiella pneumoniae carbapenemase (Kp)-producing bacteria are associated with significant mortality in immunocompromised patients. We have previously reported that PMN failed to release NET when challenged with Kp, whereas Escherichia coli (Eco) was a high NET inducer. Our aim was to deepen the study of the lack of NET formation in the presence of Kp focusing on NE dynamics.To determine whether Kp directly affects NE activity, we used a PMN lysate as a source of NE, and determined NE activity using a commercial kit after 1 h incubation with Kp or Eco. We found that neither Kp or Eco affected NE activity (p