A. baumannii induction of PTX3 production in monocytic cells. Levels of PTX3 in J774a.1 macrophage cell supernatants were assessed, as previously described in Materials and Methods, 24 h post-challenge with several A. baumannii strains. Error bars represent ±SD for triplicate wells in all graphs. Statistical differences were determined using one-way ANOVA with Holm-Sidak correction; *, P < 0.05; **, P < 0.005; ***, P < 0.0005.