In our study, the protein expression levels of actin-related protein 2/3 complex subunit 5 (ARPC5) and neural Wiskott-Aldrich syndrome protein (WASL), both of which are involved in Fc γ R-mediated phagocytosis, and bacterial invasion of epithelial cells and Salmonella infection (Kolb-Mäurer et al. 2001), were significantly increased in BALF and serum in the early infection stage. This evidence concerns the gene FCGR2A and infection.