Staphylococcus argenteus is an emerging species within the Staphylococcus aureus complex, first described in 2006, whose microbiological identification is limited by routine methods. A 56-year-old woman with a history of mitral valve prosthesis due to rheumatic heart disease and prior infective endocarditis (IE), heart failure NYHA class III, and atrial fibrillation was hospitalized with dengue (group C), serotype 1. After fluid resuscitation, she developed acute pulmonary edema and was transferred to the intensive care unit. S. argenteus, susceptible to oxacillin (MIC <0.25), was isolated from blood cultures by mass spectrometry (MALDI-TOF). Oxacillin was prescribed for 28 days. Transesophageal echocardiography showed prosthetic mitral stenosis, tricuspid and aortic regurgitation, and enlargement of both atria and the right ventricle. She developed Broca’s aphasia, left central facial palsy, right hemiplegia, and subconjunctival hemorrhages. CT angiography of the brain revealed left frontal and parietal intracerebral hemorrhages (4.1 × 3.6 × 3.9 cm), perilesional vasogenic edema, mass effect on the left lateral ventricle with rightward midline shift, and an additional 0.3-cm image adjacent to the superior division of the left middle cerebral artery, suggestive of ruptured mycotic aneurysm. Five Duke criteria were identified: one major (positive blood culture) and four minor (fever, prior IE, mitral prosthesis, and mycotic aneurysm). After 30 days, she developed pulmonary congestion, jaundice, and hepatic failure, with total bilirubin 5.2 mg/dL (direct 3.6 mg/dL, indirect 1.6 mg/dL), AST 770 U/L, ALT 297 U/L, GGT 149 U/L, INR 2.7 and BNP 2,260 pg/mL, secondary to volume overload from medical therapy. Abdominal ultrasound showed hepatomegaly and dilated hepatic veins. Despite clinical and laboratory improvement with diuretics, due to severe neurological and cardiovascular compromise, the palliative care team and family opted for limitation of life-sustaining therapy, and the patient died five days later. Vascular and mucocutaneous endothelial damage caused by dengue may explain bacteremia with S. argenteus, which may confer higher risk of death compared with S. aureus bacteremia. In IE, septic emboli may occlude the vasa vasorum, leading to formation of mycotic aneurysms. Bacterial coinfection should be investigated in dengue patients with risk factors for IE, and emerging microorganisms may be associated with increased morbidity and mortality.
Silva et al. (Sun,) studied this question.