KLEBSIELLA PNEUMONIAE ST258 DIFFERENTIALLY MODULATES NEUTROPHIL FUNCTIONS

FEDERICO BIRNBERG-WEISS; LUIS A. CASTILLO; JOSÉ R. PITTALUGA; DAIANA MARTIRE GRECO; FLORENCIA SABBIONE; IRENE KEITELMAN; JOSÉ L. MARIN FRANCO; LUCIANA BALBOA; ANALIA TREVANI; VERONICA LANDONI; GABRIELA FERNÁNDEZ

Congreso; LXIX Reunión Anual de la Sociedad Argentina de Inmunología (SAI); 2021

Klebsiella pneumoniae carbapenemase (Kp)-producing bacteria are associated with significant mortality in immunocompromised patients. We have previously reported that neutrophils (PMN) failed to release neutrophil-extracellular-traps (NET) when challenged with Kp. Our aim was to deepen the study of evasive mechanisms of PMN responses, mediated by Kp. For this purpose, we determined NETosis on purified PMN in response to a Kp MOI 10 and/or PMA 50nM, a potent NET inducer. NET release was quantified after 3 h using confocal microscopy after DNA and Elastase staining. Also, NET-associated DNA released by nuclease treatment was measured in the supernatants.We found that Kp was able to decrease NETosis induced by PMA (NETs area, μm2: Ctrl=944±326, Kp=1250±605, PMA=78781±21065*; PMA+Kp= 34513±13420# ; Released DNA, ng/mL:Ctrl=137,9±19,4, Kp=155,7±12,7, PMA=448,9±85,2*; PMA+Kp=299,8±54,6# ; *p