BI-Microbial Gemella Endocarditis Resulting in Septic and Cardiogenic Shock

TOPIC: Critical Care TYPE: Medical Student/Resident Case Reports INTRODUCTION: To our knowledge, there have been no documented reports of infective endocarditis (IE) secondary to bi-microbial bacteremia with dual species of Gemella. CASE PRESENTATION: A 75 year old female with monoclonal gammopathy of undetermined significance (MGUS) & untreated polymyalgia rheumatica (PMR) presented with dyspnea & lower extremity edema. She was emergently intubated on arrival given her respiratory distress. Examination revealed pulmonary crackles & a holosystolic murmur. CT of the chest revealed bilateral pleural effusions & vascular cephalization. She was admitted to the ICU for septic & cardiogenic shock. Cefepime & vancomycin were initiated. Transthoracic echocardiogram was notable for a large vegetation on the posterior mitral leaflet (PML). Transesophageal echocardiogram subsequently revealed an 18mm PML vegetation with a "grossly infected abscess" & severe 4+ mitral regurgitation. Systolic function was normal. Blood cultures grew gemella sanguinis (1/2) & gemella morbillorum (1/2). Emergent mitral valve (MV) repair was performed. The PML was found to be 'torn & destroyed' with secondary perforation of the anterior leaflet. Tissue cultures were negative. The patient demonstrated dramatic clinical improvement shortly thereafter. When able to provide history, She denied intravenous drug use, or recent history of odontogenic manipulation. Her dentition was not poor. Colonoscopy performed 2 years prior was negative for malignancy. No source of infection was identified. DISCUSSION: Gemella species are commensal in the human oropharynx, & the gastrointestinal & urogenital tracts. Pathogenicity is uncommon, & identification often proves difficult [1]. IE is a particularly rare manifestation of true infection. Patients with MGUS should be thoroughly evaluated, given their 2-fold risk of infection (& 3-fold risk of septicemia), in comparison to the general population [2]. This may be due to immunoparesis, or defects in humoral & cell mediated immunity. G. sanguinis is particularly uncommon in the literature, & may be distinctly pathogenic or aggressive [3]. We theorize that MGUS may have prompted a susceptibility to septicemia (though the source remains uncertain). Furthermore, bimicrobial bacteremia with the virulent G. sanguinis likely contributed to the magnitude of the vegetation & perforation of the MV, which is an uncommon occurrence in itself. Ultimately, prompt recognition of IE is paramount, & surgical intervention is often urgently indicated, in concert with a protracted course of antibiotics. CONCLUSIONS: Despite their commensalism, Gemella species have the potential to cause significant morbidity & mortality. A high index of suspicion must be maintained in patients with Gemella bacteremia, particularly if polymicrobial, or if G. sanguinis is isolated. Furthermore, patients with MGUS may succumb to true infection more frequently, with potentially greater degrees of severity. REFERENCE #1: Youssef D, Youssef I, Marroush TS, Sharma M. Gemella endocarditis: A case report and a review of the literature. Avicenna J Med. 2019;9(4):164-168. Published 2019 Oct 3. REFERENCE #2: Kristinsson SY, Tang M, Pfeiffer RM, et al. Monoclonal gammopathy of undetermined significance and risk of infections: a population-based study. Haematologica. 2012; 97(6):854-858 REFERENCE #3: Emmanouilidou G, Voukelatou P, Vrettos I, et al. A Case Report of Successful Conservative Treatment for Infective Endocarditis Caused by Gemella sanguinis. Case Rep Infect Dis. 2019;2019:9382395. Published 2019 Jan 2. DISCLOSURES: No relevant relationships by Karla Avila, source=Web Response No relevant relationships by Huzefa Bhopalwala, source=Web Response No relevant relationships by Tiffany Chomko, source=Web Response No relevant relationships by Nakeya Dewaswala, source=Web Response No relevant relationships by Christopher Siriphand, source=Web Response No relevant relationships by Christopher Wood, source=Web Response