Prevalence and new genotypes of Enterocytozoon bieneusi in wild rhesus macaque (Macaca mulatta) in China: A zoonotic concern

Occurrence and genotyping of Enterocytozoon bieneusi in flying squirrels (Trogopterus xanthipes) from China

Enterocytozoon bieneusi is an obligate intracellular microsporidian parasite with a worldwide distribution. As a zoonotic pathogen, E. bieneusi can infect a wide range of wildlife hosts through the fecal-oral route. Although the feces of flying squirrels (Trogopterus xanthipes) are considered a traditional Chinese medicine (as "faeces trogopterori"), no literature is available on E. bieneusi infection in flying squirrels to date. In this study, a total of 340 fresh flying squirrel fecal specimens from two captive populations were collected in Pingdingshan city, China, to detect the prevalence of E. bieneusi and assess their zoonotic potential. By nested PCR amplification of the ITS gene, six specimens tested positive, with positive samples from each farm, with an overall low infection rate of 1.8%. The ITS sequences revealed three genotypes, including known genotype D and two novel genotypes, HNFS01 and HNFS02. Genotype HNFS01 was the most prevalent (4/6, 66.7%). Phylogenetic analysis showed that all genotypes clustered into zoonotic Group 1, with the novel genotypes clustering into different subgroups. To our knowledge, this is the first report of E. bieneusi infection in flying squirrels, suggesting that flying squirrels could act as a potential reservoir and zoonotic threat for E. bieneusi transmission to humans in China.

Widespread distribution of human-infective Enterocytozoon bieneusi genotypes in small rodents in northeast China and phylogeny and zoonotic implications revisited

Enterocytozoon bieneusi features high genetic diversity among host species and environmental sources and over 500 genotypes in 11 phylogenetic groups have been defined. Here we investigated 291 small rodents in Heilongjiang province, northeast China, for the presence of E. bieneusi by PCR of the ribosomal internal transcribed spacer (ITS). Nine of 60 (15.0 %) gray squirrels from a park in Harbin, 120 of 201 (59.7 %) guinea pigs from a pet shop in Harbin, and two of 30 (6.7 %) peridomestic rats from a pasture in Qiqihar were positive for the parasite. Six known genotypes (EbpB, SCC-1, SCC-2, D, S7 and HLJ-CP1) and two novel genotypes (NESQ1 and NEGP1) were identified by sequence analysis of the ITS, with EbpB, SCC-1, SCC-2 and NESQ1 found in squirrels, D, S7 and NEGP1 in guinea pigs, and EbpB and HLJ-CP1 in rats. Widespread distribution of human-infective Group 10 genotype S7 and Group 1 genotype D in guinea pigs raised our concerns about the importance of pet animals as zoonotic reservoirs of microsporidiosis. Co-occurrence of Group 1 genotypes D and HLJ-CP1 in cancer patients and rodents in Heilongjiang indicated a possibility of zoonotic transmission. The host range of Group 1 genotype EbpB previously considered pig-adapted was extended. A potential variant of genotype S7, namely NESQ1, went into the existing Group 10 in phylogenetic analysis. The other new genotype, NEGP1, was clustered in an undefined clade we proposed as Group 15. With the emerging epidemiologic evidence, the host specificity of existing E. bieneusi genotypes is now being challenged.

First report on the molecular detection of Enterocytozoon bieneusi in livestock and wildlife around Qinghai Lake in the Qinghai-Tibetan Plateau area, China

Enterocytozoon bieneusi is considered to be a microsporidial species of humans and animals in the worldwide. Limited data have been reported on the prevalence and genotypes of E. bieneusi in livestock and wild animals around Qinghai Lake in the Qinghai-Tibetan Plateau area, which shares water sources, grasslands, and harsh climate with high altitudes. In this study, fecal samples from 110 Tibetan sheep, 128 yaks, 227 wild birds, 96 blue sheep (Pseudois nayaur) and 268 Przewalski's gazelle (Procapra przewalskii) around Qinghai Lake were collected, and then tested for E. bieneusi by PCR and sequencing analysis based on the ribosomal internal transcribed spacer. Among them, ten (9.09%) samples from Tibetan sheep, five (3.91%) from yaks, five (2.20%) from wild birds, one (1.04%) from wild blue sheep and two (0.75%) from Przewalski's gazelle were positive for E. bieneusi. Among sheep, there were nine E. bieneusi genotypes, including two known genotypes (BEB6 and J), and seven novel genotypes (named CHS18-CHS24). From yaks, four genotypes were identified, including two known ones (BEB4 and J) and two novel genotypes (named CHN15 and CHN16). While in wild animals, eight genotypes were found, including five different genotypes from wild bids, with three known genotypes (EbpC, J and NCF2), two novel genotypes (named CHWB1 and CHS24), and two genotypes from Przewalski's gazelle, with one known genotype J and one novel genotype CHWPG1, and one novel genotype CHWBS1 from blue sheep. According to the phylogenetic analysis, five isolates belonged to group 1, and the others were clustered into group 2. This study provides unique data on the epidemiological reports and potential risk factors for E. bieneusi in both domesticated livestock and wild animals around Qinghai Lake in the Qinghai-Tibetan Plateau area; it is important to better understand the molecular epidemiology and zoonotic potential of E. bieneusi in the Qinghai-Tibetan Plateau area.