NO release and arginase activity at 96 h after infection. (A) Immediately after 4 h of infection, cells were stimulated with LPS (1 μg/ml) and nitrite levels in culture supernatants harvested 96 hours later were determined using Griess assay method. (B) Non-stimulated cells were lysed and the total arginase activity was determined. Data are presented as mean ± SD and are representative of three different experiments with similar results. *P <0.05 indicates significant differences between BCN150 and the other isolates; ns, not significant.