Streptococcus agalactiae infective endocarditis with large vegetation in a patient with underlying protein S deficiency

More than Garden Variety: Massive Vegetations from Infective Endocarditis

Infective endocarditis classically involves non-sterile vegetations on valvular surfaces in the heart. Feared complications include embolization and acute heart failure. Surgical intervention achieves source control and alleviates valvular regurgitation in complicated cases. Vegetations >1 cm are often intervened upon, making massive vegetations uncommon in modern practice. We report the case of a 39-year-old female with history of intravenous drug abuse who presented with a serpiginous vegetation on the native tricuspid valve and methicillin-resistant Staphylococcus aureus bacteremia. The vegetation grew to 5.6 cm by hospital day two, and she successfully underwent a tricuspid valvectomy. Six weeks of intravenous vancomycin therapy were completed without adverse events. To better characterize other dramatic presentations of infective endocarditis, we performed a systematic literature review and summarized all case reports involving ≥4 cm vegetations.

Clinical strains of Streptococcus agalactiae carry two different variants of pathogenicity island XII

Streptococcus agalactiae or Group B streptococci (GBS) are a common cause of serious diseases of newborns and adults. GBS pathogenicity largely depends on genes located on the accessory genome including several pathogenicity islands (PAI). The present paper is focused on the structure and molecular epidemiological analysis of one of the GBS pathogenicity islands-the pathogenicity island PAI XII (Glaser et al. Mol Microbiol 45(6):1499-1513, 2002). This PAI was found to be composed of three different mobile genetic elements: a composite transposon (PAI-C), a genomic islet (PAI-B), and a pathogenicity island associated with gene sspB1 (PAI-A). PAI-A in GBS has a homolog--PAI-A1 with similar, but a different genetic constellation. PCR-based analysis of GBS collections from different countries revealed that a strains lineage with PAI-A is less common than PAI-A1 and was determined to be present only among the strains obtained from Russia. Our results suggest that PAI-A and PAI-A1 have the same progenitor, which evolved independently and appeared in the GBS genome as separate genetic events. Results of this study reflect specific geographical distribution of the GBS strains with the mobile genetic element under study.

Staphylococcal endocarditis as the first manifestation of heritable protein S deficiency in childhood

A 12-year-old Japanese girl developed infective endocarditis and central nervous system disease. The previously healthy girl showed altered consciousness and abnormal behaviors along with the classical signs of septic emboli. Staphylococcus aureus was isolated from peripheral blood, but not, the pleocytotic cerebrospinal fluid. Diagnostic imaging studies revealed a vegetative structure in the morphologically normal heart, and multiple thromboembolisms in the brain and spleen. Low plasma activity of protein S (12%) and thrombophilic family history allowed the genetic study, demonstrating that she carried a heterozygous mutation of PROS1 (exon 13; 1689C > T, p.R474C). Surgical intervention of the thrombotic fibrous organization and subsequent anticoagulant therapy successfully managed the disease. There are no reports of infective endocarditis in childhood occurring as the first presentation of heritable thrombophilia. Protein S deficiency might be a risk factor for the development or exacerbation of infective endocarditis in children having no pre-existing heart disease.

Successful treatment, despite a non-surgical approach, of severe infective endocarditis

A 60-year-old man with a history of Child-Pugh class B cirrhosis was admitted to the hospital with 4-5 days of nausea, vomiting and altered mental status. Following the development of fever in the intensive care unit and methicillin-sensitive Staphylococcus aureus bacteraemia, a large (15 mm) vegetation was discovered on the anterolateral papillary muscle of the mitral valve. Following a thorough multidisciplinary evaluation, the patient was considered to be a poor surgical candidate due to the significant perioperative complications associated with Child-Pugh class B cirrhosis. The patient was treated with 6 weeks intravenous nafcillin as an outpatient. Echocardiography following the treatment course revealed that the vegetation had completely resolved without any valvular dysfunction. This case report emphasises that medical management remains an effective alternative to surgery in complicated cases of infective endocarditis.

Streptococcus agalactiae endocarditis presenting as acalculous cholecystitis in a previously well woman

This case report describes the unusual presentation of a previously very well woman with Streptococcus agalactiae endocarditis in the emergency department. History, examination and preliminary laboratory and radiological investigations supported a diagnosis of acalculous cholecystitis, for which she was given intravenous broad spectrum antimicrobial therapy. One day following admission, the patient deteriorated and became unresponsive. Subsequent MRI of the brain revealed multiple bihemispheric cerebral emboli and a large, mobile mitral valve thrombus was visualised on her transoesophageal echocardiogram. S agalactiae was cultured from venous blood samples and her antimicrobial cover was adjusted accordingly. Despite her presumed guarded prognosis, this patient made a remarkable recovery. To our knowledge, the association of S agalactiae endocarditis with acalculous cholecystitis has not been previously described.