Streptococcus agalactiae mural infective endocarditis in a structurally normal heart

Group B Streptococcus (Streptococcus agalactiae)

Invasive disease due to group B Streptococcus infection (Streptococcus agalactiae) results in a wide spectrum of clinical disease. In North America, serotypes Ia, Ib, II, III, and V are most frequently associated with invasive disease. Group B Streptococcus remains a continuing source of morbidity and mortality in high-risk populations, including pregnant women, neonates, and the elderly; an increasing incidence of invasive disease has been observed in nonpregnant adults. Group B Streptococcus remains the most common culture-confirmed neonatal bacterial infection in the United States and is a significant source of neonatal morbidity globally. Intrapartum antibiotic prophylaxis has reduced the incidence of early-onset neonatal disease without a notable impact on the incidence of late-onset neonatal disease. Penicillin G remains the mainstay of therapy, although reduced penicillin susceptibility has been observed in select isolates. Increased frequency of resistance to non-beta-lactam antibiotics, including clindamycin, erythromycin, and fluoroquinolones, has been observed, with some isolates demonstrating resistance to vancomycin. The development and implementation of strategies to identify hosts, treat judiciously with antimicrobials with the narrowest spectra, and prevent invasive disease, with vaccines, are essential to reduce the burden of group B Streptococcus disease.

Right-sided infective mural endocarditis complicated by septic pulmonary embolism and cardiac tamponade caused by MSSA

The appearance of right-sided mural infective endocarditis has rarely been reported. Here, we report the case of a 40-year-old male with a history of alcoholic liver disease who presented with a partial loss of consciousness and fever. Chest computed tomography scans showed multiple pulmonary infiltration sites and cavities. A repeat transthoracic echocardiogram detected a vegetation on the right ventricular surface of the interventricular septum middle segment, as well as pericardial effusion. Blood, pericardial fluid, sputum, and scalp effusion cultures were positive for methicillin-sensitive Staphylococcus aureus. We diagnosed the patient with infective mural endocarditis complicated by septic pulmonary embolism, pericardial effusion, and cardiac tamponade. The patient was successfully treated with pericardiocentesis and appropriate antibiotics. Right-sided mural endocarditis complicated by pericardial effusion and cardiac tamponade is an uncommon condition in clinical practice. This case confirms the usefulness of transthoracic echocardiography in the early recognition of primary mural endocarditis and its associated complications.