Interspecies transmission of Enterozytozoon bieneusi supported by observations in laboratory animals and phylogeny

Abstract

Enterocytozoon bieneusi is emerging as an important cause of chronic diarrhoea in AIDS patients. Its reservoirs and transmission patterns are unknown. In this study, we have examined E. bieneusi sequences from four Rhesus macaques of different origin, which were kept at one animal facility. The sequences were identical in all animals, which suggested that infection had occurred within the facility. Full sequence agreement of E. bieneusi from macaques was found with an E. bieneusi genotype that occurs frequently in humans. To clarify, the relevance of possible inter-species transmission from man to macaque, a phylogenetic analysis was conducted including all sequences of E. bieneusi deposited in GenBank. The hitherto used system of diverse nomenclatures could be reduced to an outlier group and three main lineages, one of which could be further sub-divided into five subgroups. Based in this phylogeny, an association of parasites and host species could be observed for main lineages 2 and 3, as well as for most of the subgroups of main lineage 1. For confirmation, the phylogeny of main lineage 1 was reconstructed with an alternative method of distance estimation, yielding essentially the same parasite-host associations. Zoonotic potential of E. bieneusi is thus supported on a phylogenetic basis.

New Highly Divergent rRNA Sequence among Biodiverse Genotypes ofEnterocytozoon bieneusiStrains Isolated from Humans in Gabon and Cameroon

“…2 and 3). As seen in previous studies (12,40), four main groups, numbered 1 to 4, are segregated from the most divergent sequence, EntCanA, which was isolated from dogs (28). Group 1 contains most of the sequences previously published as well as the new sequences CAF1, CAF2, and CAF3 (53 out of 66 sequence) (Fig.…”

“…2). To provide a more comprehensive classification of group 1 E. bieneusi genotypes, the simplified nomenclature of Drosten et al (12) was used, i.e., subgroups 1a to 1f, and subgroup 1g was added. The identities within this group are high: 79.4% of the nucleotides (193/243) are conserved among the 53 sequences.…”

“…E. bieneusi also has been isolated from a large number of domestic and wild mammals, as well as birds (29). The potential of zoonotic transmission is supported by phylogenetic studies showing that several genotypes can infect humans as well as animals (9,12,26,37,(39)(40)(41).…”

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

“…The remaining genotype, named D, is very widespread: it was first found in human in Germany, then in other countries in Americas, Asia and Africa. It was also found in numerous and various animals (swine, cattle, macaque, muskrat, raccoon, beaver, fox, dog and falcon) (Breton et al, 2007;Buckholt et al, 2002;Drosten et al, 2005;Espern et al, 2007;Green et al, 2004;Lee, 2007;Leelayoova et al, 2006;Lobo et al, 2006a;Rinder et al, 1998;Sadler et al, 2002;Santin et al, 2006;Sulaiman et al, 2003aSulaiman et al, , 2003b (Table I). Type D was commonly reported in HIV-positive patients in Thailand (leelayoova et al, 2006) andin Peru Sulaiman et al, 2003a), and in two isolated cases in Europe (Rinder et al, 1998;Sadler et al, 2002).…”

“…The development of new tools for diagnosis and especially molecular methods have shown that E. bieneusi was present in a large number of domestic and wild mammals as well as birds (Haro et al, 2006;Haro et al, 2005;Kondova et al, 1998;and reviewed in Mathis et al, 2005). Thanks to molecular methods again, the potential of zoonotic transmission was quickly supported by phylogenetic studies showing that several genotypes can infect humans as well as animals (Curry, 1999;Dengjel et al, 2001;Drosten et al, 2005;Lobo et al, 2006a;Santin et al, 2006;Sulaiman et al, 2003a;Sulaiman et al, 2003b;Sulaiman et al, 2004). The focus of this revue is to present and discuss the more recent advances on diagnosis and zoonotic potential of Enterocytozoon bieneusi infections.…”