Finding of Anaerococcus hydrogenalis in blood using cell-free DNA technique in a patient with infective endocarditis.

Introduction: The annual incidence of infective endocarditis (IE) is 3-9 cases per 100000 in developed countries and most cases are due to staphylococci and streptococci. IE due to Gram-positive anaerobic cocci (GPAC) is very rare. Case report: We present a case of a 38-year-old female with Anaerococcus hydrogenalis bacteremia and infective endocarditis of the native mitral valve. She presented with fever, chills, and abdominal pain. A computed tomographic scan of the abdomen showed splenic abscesses. Blood cultures and broad-range PCR from the splenic abscess sample were negative. Transthoracic echocardiography showed a mobile filamentous structure on the atrial side of the anterior mitral leaflet which was suggestive for infective endocarditis. Karius test (cell-free microbial DNA testing) showed Gram-positive anaerobic cocci Anaerococcus hydrogenalis. She was successfully treated with antibiotics. Conclusions: In cases of infection with fastidious organisms like GPACs, the use of next-generation sequencing (NGS) can allow the correct identification of culprit pathogens and streamlined treatment.

Mycobacterium avium complex: An unusual cause of hypercalcemia.

Mycobacterium avium-complex (MAC) is an infectious granulomatous disease which is associated with hypercalcemia especially in immunocompromised patients. We present an unusual case of MAC infection in an immunocompetent patient presenting as hypercalcemia.A 76-year-old immunocompetent male was admitted for hypercalcemia of 12.6 mg/dl found on outpatient evaluation for fatigue. PTH level was low 8 pmol/L, Vitamin D 25hydroxy was 29 ng/ml, 1,25 dihydroxy vitamin D (1,25(OH)2 vitamin D) levels was low at 11 pg/ml, PTH related peptide was 1.1 pmol/L. Hypercalcemia resolved with intravenous hydration and bisphosphonate administration. CT chest identified a nodule with central cavity in the right upper lobe. Pathology from percutaneous biopsy of thenodule demonstrated granulomatous inflammation. AFB culture came positive for MAC. Patient was treated with Azithromycin, Rifabutin and Ethambutol for twelve months.Granulomatous diseases like MAC cause hypercalcemia via activation of macrophages which express extrarenal 1- alpha -hydroxylase. It converts vitamin D to its active form 1,25(OH)2 vitamin D causing its excess, leading to hypercalcemia. Interestingly, in our patient calcium level was elevated with appropriately low PTH but 1,25(OH)2 vitamin D level was also low. There are few reported cases of hypercalcemia in granulomatous disease with normal levels of 1,25(OH)2 vitamin D levels, and our case is the first one to have MAC associated hypercalcemia with low 1,25(OH)2 vitamin D levels, suggesting an alternative mechanism for hypercalcemia in these patients.