Unique report of endocarditis by Priestia megaterium

Abstract

Endocarditis is a serious infection associated with significant morbimortality and can be caused by several microorganisms, most frequently by Enteroccus faecalis, Staphylococcus aureus and Streptococcus sp. Managing patients with severe infective endocarditis is particularly challenging in non-tertiary hospitals. A 26-year-old immunocompetent male was admitted to the hospital with a sudden onset of nausea, followed by a 10-second episode of syncope with unresponsiveness and memory loss. He was submitted to a magnetic resonance of the skull, revealing multiple intraparenchymal nodular lesions with an inflammatory/infectious process. Transesophageal echocardiogram showed prolapse of mitral valves with moderate/severe insufficiency. Eccentric, intense and triangular jet, directed towards the posterior region of the left atrium, with reverse systolic flow in the pulmonary veins. An anomalous, mobile image of 2.6cm x 0.6cm was observed, adhered to the atrial surface of the posterior leaflet of the mitral valve. Sliding of the posterior leaflet over the anterior leaflet is also noted, with an image compatible with partial rupture of the mitral chordae of the posterior leaflet. Antimicrobial empiric therapy with ampicillin, oxacillin, and gentamicin was prescribed. The patient underwent mitral valve replacement with a biological prosthesis. Valve tissue culture results identified Priestia megaterium, and the treatment was replaced by vancomycin, whereas gentamicin was kept. After 14 days, all symptoms were resolved, and the patient was discharged from the hospital. To the best of our knowledge, this is the first report of endocarditis driven by P. megaterium, and the pathogenic potential of P. megaterium warrants be further investigation.