INNATE IMMUNE EVASION MECHANISMS OF A HY- PER-EPIDEMIC CLONE OF KLEBSIELLA PNEUMONIAE RESISTANT TO CARBEPENEMS

CASTILLO, LUIS A.; BIRNBERG WEISS, FEDERICO; MARTIRE-GRECO, DAIANA; BIGI, FABIANA; GOMEZ, SONIA A.; LANDONI, VERONICA I.; FERNANDEZ, GABRIELA C.

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Inmunología 2018; 2018

The emergence and rapid dissemination of Klebsiella pneumo-niae (Kpn) carbapenem resistant has become a relevant problemin health care units, because it has been associated with highermortality in susceptible patients, mainly attributed to Kpn Carbap-enemase (KPC), an enzyme that hydrolyze carbapenems, one ofthe last resources in antibiotic treatment. As Kpn-KPC producershave been successful in terms of dissemination and persistence,we ask if Kpn-KPC could express mechanisms to avoid the innateimmune response, focusing on their interaction with neutrophils(PMN). In this sense, we evaluated if one local isolate of Kpn-KPC,sequence type 258 (a hyper-epidemic clone), induces a differen-tial response in healthy human isolated PMN, compared to anotheropportunistic pathogen as Eschericia coli ATCC 25922 (Eco). Afterevaluating some parameters of PMN activation, no differences wereobserved in the up-regulation of CD11b expression. However, reac-tive oxygen species (ROS) generation, measured by flow cytometryusing dihidrorhodamine-123 (DHR) was lower for Kpn-KPC (ROS,% DHR+ PMN: Kpn-KPC=5.2±0.1; Eco=39.8±11.2, p