Klebsiella pneumoniae Isolates Stimulated Poorly PMN Bactericidal Responses Compared to Other Opportunistic Bacteria

RODRIGUEZ-RODRIGUES N; GOMEZ S.A.; MARTIRE-GRECO D; FERNÁNDEZ G C; CASTILLO LUIS; LANDONI V.I

MAR DEL PLATA

Congreso; Congreso SAI/SAIC 2016; 2016

Klebsiella pneumoniae (KP) has become a relevant nosocomial pathogen attributed to the production of KP-Carbapanemase (KPC), an enzyme that mediates resistance to carbapenems, the last option of antibiotic treatment. KPC production is associated with higher mortality rates in immunocompromised hospitalized patients. To determine if KPC+ differentially modulates neutrophil (PMN) responses compared to KPC- or other opportunistic pathogens, we evaluated different parameters of PMN activation using a clinical isolates of KPC+ and KPC-, Escherichia coli ATCC 47055 (ECO) and Enterococcus faecalis ATCC 29212 (EFA). We measured CD11b expression and reactive oxygen species (ROS) generation using dihydrorhodamine 123 (DHR) by FACS, NETs formation by confocal microscopy and quimiotaxis. The ratio PMN: Bacteria was 1:20. We did not observe any differences between KPC+ vs KPC- in any of the parameters tested. However, KP species induced lower NETs area and ROS generation compared to ECO and EFA (NETs area mm2 x10-4: KP=0.22±0.06; ECO=2.17±0.22*; EFA=1.59±0.44*; %DHR+ PMN: KP=5.2±0.1; ECO= 39.8±11.3*; EFA=39.3±5.6*; *p