ASA treatment reduces the host inflammatory response in the liver following systemic bacteremia. (A) Representative IVM images from an uninfected control animal (i) and at 6 hours after IV infection with 2 × 10⁷ CFU of S aureus (ii). (B) Representative images of neutrophil recruitment to the liver of S aureus–infected control mice (i) and S aureus–infected mice pretreated with ASA (ii) or mice treated with ASA 3 hours after infection (iii). (iv) Quantification of the number of neutrophils per field of view (FOV; N = 4-9). (C) Representative images of platelet aggregation in the liver of control mice infected with S aureus (i), ASA-pretreated mice infected with S aureus (ii), or S aureus–infected mice treated with ASA 3 hours after infection (iii). (iv) Quantification of platelet aggregates of indicated sizes in animals from various treatment groups (N = 3-6). (D) Representative images of NET production (extracellular neutrophil elastase [NE] staining) in the liver of control mice infected with S aureus (i), ASA-treated mice infected with S aureus (ii), and mice treated with ASA 3 hours after infection (iii). (iv) Quantification of the area of NE staining (as a percentage of an FOV) within the liver of mice from various treatment groups (N = 3-6). (A-D) Labelling of cellsin vivo was achieved by IV injection of fluorescently-conjugated antibodies against CD49b (platelets; red), Ly6G (neutrophils; yellow), and neutrophil elastase (NE; cyan). Hepatocytes appear as dark green due to autofluorescence. Scale bar, 50 μm. (E) Quantification of the area of extracellular DNA staining (as a percentage of an FOV) within the liver of mice from various treatment groups (N = 3-5). Peripheral blood neutrophil (F) and platelet (G) counts and neutrophil-platelet aggregates (Ly6G⁺CD41⁺ cells) (H) from the different treatment groups (N = 4-5). Values represent the mean obtained from at least 5 FOVs in each animal. Data are represented as mean plus or minus SEM. Statistical analysis was conduced using a 1-way ANOVA with a post hoc Tukey test for panels Biv, Div, E-H and a 2-way ANOVA with a post hoc Bonferroni test for panel Civ. *P < .05, **P < .01, ***P < .001 vs control; #P < .05, ##P < .01, ###P < .001 vs S aureus.