Submitted to: Journal of Clinical Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/13/2012
Publication Date: 6/1/2012
Citation: Pomares, C., Santin, M., Miegeville, M., Espern, A., Albano, L., Marty, P., Morio, F. 2012. A new and highly divergent Enterocytozoon bieneusi genotype isolated from a renal transplant recipient. Journal of Clinical Microbiology. 50(6):2176-2178. Interpretive Summary: Enterocytozoon bieneusi is the most prevalent microsporidian species associated with human disease. This parasite has been identified in water as well as in wild, domestic and food-producing farm animals, raising concerns of water-borne, food-borne and zoonotic transmission. Enterocytozoon bieneusi was identified in a man who received a renal transplant, admitted at Nice University Hospital (France) for abundant liquid diarrhea and dehydration leading to acute renal failure. Molecular characterization of the isolate using the ITS, and comparison with previously published E. bieneusi genotypes revealed only a weak similarity with previously reported genotypes. Therefore, a new and highly divergent E. bieneusi genotype close to a genotype recently identified in horses is here described for the first time. Interestingly, the patient's symptoms began after contact with water contaminated with feces from horses, which is highly suggestive of zoonotic transmission. The data suggest that horses could act as a potential source of human microsporidia infections. These findings must be considered for the management of immunocompromised patients such as HIV-infected patients and solid-organ transplant recipients. In high-risk patients, following prophylactic measures will probably reduce the burden of this neglected disease.
Technical Abstract: Microsporidia are a ubiquitous group of obligate intracellular parasites that infect all major animal groups. Enterocytozoon bieneusi is the most commonly identified microsporidia in humans and has also been reported in animals worldwide. Transmission mainly occurs through fecal-oral routes with sources of infection including other infected humans and animals, contaminated water and food. Microsporidia have emerged as an important cause of opportunistic infection in patients with AIDS and immunocompromised non-HIV-infected individuals, being predominantly associated with wasting and diarrhea. In this study, E. bieneusi was found on a kidney transplant recipient presenting with diarrhea. ITS genotyping of the isolate and comparison with previously published E. bieneusi genotypes revealed a new and highly divergent E. bieneusi genotype that had only a weak similarity with previously reported genotype in horses. This report underlines the pathogenic potential of microsporidia in the immunocompromised hosts.