Desulfovibrio desulfuricans bacteremia: A case report and literature review

Desulfovibrio spp. are sulfate-reducing, anaerobic bacteria that are ubiquitously found in the environment. These organisms infrequently cause human infections, and the clinical characteristics of infection with Desulfovibrio spp. remain unclear. Here, we describe a case of Desulfovibrio desulfuricans bacteremia in an 88-year-old Japanese man with a past medical history of thoracic endovascular aortic repair (TEVAR). His chief complaint was hemoptysis for 2 weeks. A chest contrast-enhanced computed tomography demonstrated an enlarged thoracic aortic aneurysm surrounded by a ring-enhanced lesion, recognized as mediastinal abscess. Gram-negative spiral bacilli were detected in anaerobic blood culture. These bacteria could not be identified using conventional methods, but by analyzing a full base sequence of 16S rDNA, they were identified as D. desulfuricans subsp. desulfuricans. The patient underwent an emergent re-TEVAR, and the infection subsided after being treated with tazobactam/piperacillin and clindamycin, followed by metronidazole. A literature review of previous cases of D. desulfuricans bacteremia suggested that the pathogen was derived from bacterial translocation from the intestine in most cases. Desulfovibrio infection is presumably underestimated due to its infrequency, indolent growth, and difficulty in identification. Desulfovibrio spp. should be suspected when spiral rods are observed in anaerobic culture, and molecular analysis is required for accurate species-level differentiation of the pathogens. To better understand the pathogenicity of these fastidious organisms, further cases based on the exact bacterial identification should be investigated.