Case Presentation: A 30-year-old male with past medical history of seizure disorder, hepatitis C, depression and intravenous drug abuse presented with fever, progressive generalized myalgia and cough of three days duration. He also endorsed migratory polyarthralgia and a recent dental surgery. He denied any intravenous drug use in the past three years. Physical exam was notable for fever, tachycardia, and significant left lower lobe rales. Pertinent labs include elevated C- reactive protein and erythrocyte sedimentation rate, normocytic anemia (hemoglobin of 10.8 g/dL), thrombocytopenia (platelet count of 127 K/mm3), hematuria and proteinuria. Chest X-ray was unremarkable. Initially suspected with sepsis secondary to pneumonia, he was started on broad spectrum antibiotics and intravenous fluids. Blood cultures drawn at the time of admission grew Pantoea agglomerans and methicillin sensitive Staphylococcus aureus (MSSA). A transthoracic echocardiogram the next day revealed a small 2 mm mobile vegetation on the atrial side of the tricuspid valve. A subsequent transthoracic echocardiogram confirmed the presence of valvular vegetations on tricuspid, mitral and aortic valves and an annular abscess in the aortic valve. Antibiotics were switched to cefazolin and gentamicin based on sensitivity reports. Despite antibiotic therapy and supportive measures, he developed acute respiratory distress syndrome and was transferred to the intensive care unit and later to a tertiary care center. There he underwent aortic valve replacement, as well as mitral and tricuspid valve debridement by a cardiovascular thoracic surgeon, with good post-operative recovery. He was put on a 6 week of intravenous antibiotics regimen, with cefazolin and levofloxacin to cover both MSSA and P. agglomerans respectively.
Discussion: Pantoea agglomerans is a gram-negative, aerobic bacillus belonging to the family Erwiniaceae. Pantoea can be isolated from plants and fecal matter. P. agglomerans strains also occur commonly as symbionts in arthropods. They are motile, ferment lactose and produce a pigment, which imparts the yellow color to the colonies on blood agar. Little is known about the virulence characteristics of these bacteria; they have a capsule offering protection from phagocytosis and possibly contributing to the virulence. P. agglomerans is known to cause disease in cultivable plants. In humans, it is often associated with trauma caused by plant materials, intravenous catheters, as well as contaminated intravenous fluids, and affects blood, soft tissue, bone, joints and urinary tract. Cruz et al, in an extensive case review, observed that almost all cases of septicemia were associated with central venous line. Pantoea endocarditis is a rare entity, with only a few cases reported in literature. There is no characteristic feature specific for Pantoea endocarditis, but the infection tends to severe. Blood cultures and echocardiogram, in addition to clinical signs and symptoms afford the diagnosis. Antibiotic approach is to begin with broad spectrum coverage and subsequent titration based on culture and sensitivity reports. Many of the P. agglomerans infections reported in various case reports required long term antibiotic coverage up to four weeks.
Conclusions: This is a rare case of infective endocarditis caused by Pantoea agglomerans observed in a 30-year-old intravenous drug user. Only a few such cases have been reported so far.