Variation in Macrophage Phagocytosis of Streptococcus agalactiae Does Not Reflect Bacterial Capsular Serotype, Multilocus Sequence Type, or Association with Invasive Infection

Group B Streptococcus (GBS) is an encapsulated Gram-positive coccus that is an important cause of infections in adults with chronic medical conditions, pregnant women, and neonates. GBS causes a range of clinical syndromes, from asymptomatic colonization to deep-seated invasive and highly lethal infections. Macrophages are important sentinels of innate immunity, protecting host tissues from infection when bacteria advance beyond cutaneous or mucosal barriers. We hypothesized that the capacity for macrophages to phagocytose unopsonized GBS would vary across distinct clinical strains, and such differences would reflect serotype diversity