Molecular Characterization of Microsporidia Indicates that Wild Mammals Harbor Host-Adapted Enterocytozoon spp. as well as Human-Pathogenic Enterocytozoon bieneusi

Abstract

Over 13 months, 465 beavers, foxes, muskrats, otters, and raccoons were trapped in four counties in eastern Maryland and examined by molecular methods for microsporidia. A two-step nested PCR protocol was developed to amplify a 392-bp fragment of the internal transcribed spacer region of the rRNA gene of Enterocytozoon spp., with the use of primers complementary to the conserved regions of published nucleotide sequences. Fifty-nine PCR-positive samples were sequenced. Multiple alignments of these sequences identified 17 genotypes of Enterocytozoon spp. (WL1 to WL17); of these, 15 have not been reported before. Most of the genotypes were found in multiple species of wildlife and belonged to a major group consisting of all the previously described Enterocytozoon bieneusi genotypes from human and domestic animals. Some of the isolates from muskrats and raccoons formed two distinct groups. Results of this study indicate that fur-bearing mammals, especially those closely associated with surface water, can be a potential source of human-pathogenic E. bieneusi. However, there are also host-adapted Enterocytozoon genotypes in wildlife, which may represent species different from E. bieneusi and have no apparent public health significance. This is the first report of E. bieneusi in wildlife.

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

“…In our analysis this group is clearly subdivided in eight major clades named subgroup 1a to 1 h. Within subgroup 1a, eight genotypes were found only in HIV infected patients in Gabon, Peru and Thailand (Breton et al, 2007;Leelayoova et al, 2005;Sulaiman et al, 2003a). Eight again were isolated from animals only, domestic such as swine, cattle and cat but also wild such as beaver (Buckholt et al, 2002;Dendjel et al, 2001;Jeong et al, 2007;Mathis et al, 1999;Santin et al, 2005;Santin et al, 2006;Sulaiman et al, 2003b). More interestingly, three genotypes were found both in human and animals.…”

“…Group 4 is to date host specific and found only in raccoon (Sulaiman et al, 2003b). Group 3 is composed of three genotypes isolated from muskrat in USA and one isolated from a cat in Portugal (Lobo et al, 2006a;Sulaiman et al, 2003b). Group 2 consisted of genotypes isolated in farm animals, almost exclusively from cattle (10 genotypes), with one genotype also found in chicken (Dengjel et al, 2001;Fayer et al, 2007;Lee, 2007;Lobo et al, 2006a;Reetz et al, 2002;Rinder et al, 2000;Santin et al, 2005;Sulaiman et al, 2004).…”

“…The other major clusters named Group 2, Group 3 and Group 4 are composed of genotypes only found in animals. Group 4 is to date host specific and found only in raccoon (Sulaiman et al, 2003b). Group 3 is composed of three genotypes isolated from muskrat in USA and one isolated from a cat in Portugal (Lobo et al, 2006a;Sulaiman et al, 2003b).…”

“…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.…”

Ocorrência de Giardia, Cryptosporidium e microsporídios em animais silvestres em área de desmatamento no Estado de São Paulo, Brasil

“…Com relação aos animais silvestres, Encephalitozoon cuniculi foi isolado de ratos silvestres na Europa (MÜLLER-DOBLIES et al, 2002). SULAIMAN et al (2003) encontraram 12,69% de amostras fecais positivas para o microsporídio Enterocytozoon bieneusi em castores, raposas, pequenos roedores, lontras e guaxinins, no Sudeste dos Estados Unidos. A comparação das freqüências de microsporídios em animais silvestres de regiões geográficas distintas é dificultada pela diferença de espécies de hospedeiro.…”