NBEAL2 and pneumonia: - Higher prevalence of App, Ss, and Gps following PRRSV infection. - Increased severity of clinical signs and Mhp-like pneumonia following an PRRSV infection or vice versa. - PRRSV infection was entirely hindered following an infection with App or App cell-free culture supernatant in SJPL and PAM cells. - Pigs that infected with PRRSV and S. Choleraesuis and received dexamethasone inducing stress had the most severe clinical signs, significantly longer and larger amount of S. Choleraesuis shedding in feces and PRRSV titers in sera.