NEUTROPHIL BACTERICIDAL RESPONSE AGAINST PROVIDENCIA SPP.

JOSELYN E. CASTRO; FEDERICO BIRNBERG-WEISS; JOSÉ R. PITTALUG1 ,; GOMEZ, SONIA A.; LANDONI, VERÓNICA; FERNÁNDEZ, GABRIELA CRISTINA;

Congreso; Sociedad Argentina de Inmunologia; 2022

NEUTROPHIL BACTERICIDAL RESPONSE AGAINST PROVIDENCIA SPP.Joselyn E. Castro1, Federico Birnberg-Weiss1, Jose R. Pittaluga1, Sonia Gómez2, Verónica I. Landoni1, Gabriela C. Fernández1.1 Laboratorio de Fisiología de los Procesos Inflamatorios, Instituto de Medicina Experimental (IMEX)-CONICET/Academia Nacional de Medicina, Buenos Aires, Argentina. 2 Servicio de Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas Dr. Carlos G. Malbrán (INEI), Administración Nacional de Laboratorios e Institutos de Salud (ANLIS), Buenos Aires, ArgentinaAntimicrobial resistance is a significant problem for the treatment of infectious diseases worldwide. Providencia spp. are Gram-negative opportunistic bacteria that are becoming extremely relevant in hospitalized patients. P. stuartii (Ps) and P. rettgeri (Pr) cause urinary tract infections, followed by pneumonia, septicemia, and others. The innate immune response against these pathogens has not been investigated. The aim of this study was to determine whether Ps and Pr are able to trigger the bactericidal response in neutrophils (PMN), one of the most relevant cells for the innate immunity. For this purpose, we evaluated two main mechanisms of PMN, the respiratory burst by flow cytometry using Dihydrorhodamine, and neutrophil extracellular trap (NETs) formation by release of double strand DNA and confocal microscopy in isolated human PMN (n=7) challenged with clinical multi-resistant isolates of Ps and Pr, and used E. coli (Ec) ATCC as a positive control (PMN:bacteria ratio of 1:10). We found that both Ps and Ec triggered the respiratory burst similarly, whereas Pr did not (p