Clostridium haemolyticum Infection: A Cause of Hemolytic Anemia in a Patient with Bone Marrow Necrosis

Abstract

Clostridium haemolyticum is a sporulating Gram-positive anaerobic rod that is considered to be one of the most fastidious and oxygen-sensitive anaerobes. It is a well-known animal pathogen and the cause of bacillary hemoglobinuria primarily in cattle. To date, human infections caused by C. haemolyticum have been reported in three patients with malignant underlying diseases. We present herein the case of a 30-year-old obese woman with no significant past medical history who developed bacteremia caused by C. haemolyticum with massive intravascular hemolysis associated with bone marrow necrosis and acute renal failure. Because of subculture failure, the diagnosis was made on the basis of 16S rDNA sequencing and next-generation sequencing. The patient, who had been afebrile for 20 days after a 17-day-course of antibiotics, experienced a second bacteremic episode caused by C. haemolyticum. After having been successfully treated for 42 days with clindamycin and amoxicillin-clavulanic acid, the patient developed acute myeloid leukemia as a result of bone marrow regeneration. Although uncommon in humans, infections caused by C. haemolyticum are severe and should be considered in a febrile patient who has severe hemolytic anemia. This case also highlights the importance of using molecular techniques for the identification of this fastidious anaerobic organism.

Keywords: Clostridium haemolyticum; bone marrow necrosis; hemolytic anemia; human infection.

Figure 1

Maximum likelihood (computed by PHYML, model GTR plus gamma distribution and invariant sites) phylogenetic tree based on partial 16S rRNA gene sequences (1420 nt) showing relationships between the strain isolated in our patient (LBN 1021) and related clostridia species. The Paeniclostridium sordellii 16S rRNA gene sequence (AB550230) was used as the outgroup. Numbers at nodes indicate percentages of bootstrap support, based on analysis of 100 replicates. Species represented in single quotes are effectively published but not validly published. Bar, 0.02 substitutions per site.

Figure 2

Colonies of Clostridium haemolyticum on fastidious anaerobe agar.