Polymicrobial endocarditis involving Veillonella parvula in an intravenous drug user: case report and literature review of Veillonella endocarditis

Abstract

Veillonella spp. are strictly anaerobic, Gram-negative cocci able to ferment various substrates (pyruvate and lactate) that usually present as commensals in the oral, gastrointestinal, and female genital tract microflora [1]. This genus has been reported to be pathogenically involved in periodontitis, periodontal abscess, and various acute oral conditions. In addition, Veillonella spp. may be exceptionally involved in severe infections, including meningitis, osteomyelitis, or prosthetic joint infection [2]. Infective endocarditis (IE) constitutes one of the most serious, albeit uncommon, complications of bloodstream infection (BSI) by Veillonella spp. in patients with predisposing conditions such as valvular heart disease or intravenous (IV) drug abuse [3]. Here we describe a case of IE due to V. parvula in an IV drug user (IDU) and review the scarce literature on this entity. A 35-year-old man presented to the Emergency Department (ED) of our hospital with fever, chills, purulent sputum, and pleuritic pain for about 48 h. He was a current smoker (index of 20 pack-years) and acknowledged a history of active IV drug abuse (heroine and cocaine). His temperature was 39 C, blood pressure was 120/70 mmHg, and his respiratory rate was 24 breaths per minute (bpm). Physical examination revealed a poor oral hygiene with periodontal disease, venipuncture marks in the upper extremities, and basal crackles over the right lung, with no audible cardiac murmurs. Laboratory data showed a mild normocytic anemia (hemoglobin 11.3 g/dL) and white cell count (WCC) of 9.8 9 10/L. A chest X-ray was unremarkable. Because of our clinical suspicion of IE, we initiated empiric treatment with IV ceftriaxone, cloxacillin, and gentamicin. A transthoracic echocardiography (TTE) revealed two oscillating masses (1.5 9 0.5 and 1.5 9 0.4 cm, respectively) on the tricuspid valve with mild regurgitation, and a thoracic computed tomography (CT) showed multiple cavitating nodules compatible with pulmonary septic embolisms. Viridans group Streptococcus was identified by the semiautomated WIDER system (Francisco Soria Melguizo S.A., Madrid, Spain) in four out of four aerobic bottles of blood cultures (BCs) taken at admission and processed using the BacT/Alert System (bioMerieux, Marcy l’Etoile, France). The isolate was not identified to species and was sensitive to penicillin, cefotaxime, ceftriaxone, erythromycin, clindamycin, levofloxacin, trimethoprim–sulfamethoxazole, and vancomycin; therefore, treatment with cloxacillin was discontinued. The patient initially became afebrile, but after 14 days of treatment with ceftriaxone and gentamicin persistent daily fever reappeared. Before the results of repeated BCs were available, the patient had left the hospital ward without medical authorization. He returned 3 days later to the ED complaining of fever (38.8 C) and left pleuritic chest pain a few hours after an IV heroin injection. He was hemodynamically stable, and tachypneic (18 bpm), and the abdominal examination was remarkable for the identification of a 2-cm tender hepatomegaly and 4-cm splenomegaly that had not been noted on the previous admission. The WCC M. A. Perez-Jacoiste Asin I. Serrano-Navarro S. Prieto-Rodriguez Department of Internal Medicine, University Hospital ‘‘12 de Octubre’’, Instituto de Investigacion Hospital ‘‘12 de Octubre’’ (i?12), Universidad Complutense, Madrid, Spain