Community-acquired pneumonia and sepsis caused by a multiresistant Staphylococcus aureus strain resulting in a severe and long-lasting multiple organ inflammatory involvement

An exceptional case report of community-acquired, disseminated infection caused by a methicillin-resistant Staphylococcus aureus strain, responsible for pneumonia, sepsis, and scattered septic embolism, and accompanied by diffuse polyvisceritis and thrombophlebitis as signs of an overwhelming extensive activation of the immune system, is reported and discussed on the grounds of the most recent evidence in literature. The striking features of a severe, multiresistant S. aureus polyvisceral disease associated with multiple immune-mediated focal manifestations are in contrast with the community-acquired origin of infection and the apparent absence of supporting factors for both antimicrobial resistance and the unexpected, exaggerated immune activation occurred in an otherwise healthy man. The extensive immune activation status (as demonstrated by a proportionally maintained absolute lymphocyte cont and a T-cell subset study pointing out an increased quote of CD4+, CD34+, and CD4-CD8- cells, compared with a proportional decrease of CD8+ T-lymphocytes) probably had a prominent role in prompting several focal clinical features of our patient, which apparently were not directly related to bacterial invasion, such as the polyvisceritis, the massive pleuric and pericardial effusion, the myocarditis-pericarditis, and the thrombophlebitis occurring in multiple and remote body sites, as compared with to the initial respiratory localization. This case report raises multiple questions regarding the epidemiology, pathogenesis, clinical manifestations, and management of complicated S. aureus infection, including the role of novel antimicrobial agents and corticosteroids.