Enterocytozoon bieneusiin human and animals, focus on laboratory identification and molecular epidemiology

Abstract

ummary :Human microsporidian infections have emerged following the onset of the AIDS pandemic. Microsporidia are unicellular eukaryotic parasites that form spores. They are an exceptionally diverse group of parasites that infect a wide range of eukaryotic cells in numerous invertebrate and vertebrate hosts. Of the 14 species newly described as pathogens in human, Enterocytozoon bieneusi, which causes gastrointestinal diseases, is the most common agent of human infections. In the past fifteen years, E. bieneusi was also identified in environmental sources, especially in surface water, as well as in wild, domestic and farm animals. These findings raised concerns for waterborne, foodborne and zoonotic transmission. Molecular analyses of the 243-bp internal Transcribed spacer-(ITS) of the rRNA gene have revealed a considerable genetic variation within E. bieneusi isolates of human and animal origins, supporting the potential for zoonotic transmission. The focus of this revue is to present and discuss recent advances in diagnosis and zoonotic potential of E. bieneusi infections.

Molecular Epidemiologic Characterization of Enterocytozoon bieneusi in HIV-Infected Persons in Benin City, Nigeria

“…Phylogenetically, most of the study participants were infected with genotypes belonging to the initially described human pathogenic group 10 or the recently renamed Group 1 ( Figure 1). 1,12 All six known genotypes and two new genotypes belonged to this group. The latter had one nucleotide difference (G to A substitution) from genotype A or two nucleotide differences (T to C and G to A) from genotype IV, and they were named as Nig1 and Nig2, respectively.…”

“…1,10 Indeed, at least one case of zoonotically transmitted E. bieneusi infection has been reported. 14 In this study, however, contact with animals was not identified as a risk factor in E. bieneusi infection, although two of three major genotypes found in this study, D and IV, are common in domestic animals and wild mammals in many areas.…”

“…7 The use of molecular diagnostic techniques in the characterization of E. bieneusi has led to the identification of extensive genetic diversity of this pathogen in humans and animals and better understanding of the role of animals in the transmission of microsporidiosis in human. 1,5,8 There is a dearth of data on genotype diversity of E. bieneusi in developing countries. Although microsporidiosis has been identified in humans in Nigeria by microscopy, 9 there is no molecular characterization of E. bieneusi in Nigeria.…”

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“…Among over 100 E. bieneusi ITS genotypes identified in humans and animals thus far, several unique groups (Groups II-V) of genotypes are found in specific groups of animals, thus have less public health importance. Nevertheless, a large group (Group I) of ITS genotypes have been found in both humans and animals [16,17]. These observations need to be substantiated by sequence characterization of other genetic markers [18].…”

Deforestation and Water Borne Parasitic Zoonoses

“…Diarrhea is the most frequent health problem caused, mainly in immunocomopromised people. The transmission routes indicated are via airborne, person-to-person, zoonotic, and waterborne means (Didier, 2005;Theiller, Breton, 2008).…”