Prevalence, risk factors and multilocus genotyping of Enterocytozoon bieneusi in farmed foxes (Vulpes lagopus), Northern China

Molecular epidemiology of Enterocytozoon bieneusi from foxes and raccoon dogs in the Henan and Hebei provinces in China

BACKGROUND

Enterocytozoon bieneusi is a zoonotic pathogen widely distributed in animals and humans. It can cause diarrhea and even death in immunocompromised hosts. Approximately 800 internal transcribed spacer (ITS) genotypes have been identified in E. bieneusi. Farmed foxes and raccoon dogs are closely associated to humans and might be the reservoir of E. bieneusi which is known to have zoonotic potential. However, there are only a few studies about E. bieneusi genotype identification and epidemiological survey in foxes and raccoon dogs in Henan and Hebei province. Thus, the present study investigated the infection rates and genotypes of E. bieneusi in farmed foxes and raccoon dogs in the Henan and Hebei provinces.

RESULT

A total of 704 and 884 fecal specimens were collected from foxes and raccoon dogs, respectively. Nested PCR was conducted based on ITS of ribosomal RNA (rRNA), and then multilocus sequence typing (MLST) was conducted to analyze the genotypes. The result showed that infection rates of E. bieneusi in foxes and raccoon dogs were 18.32% and 5.54%, respectively. Ten E. bieneusi genotypes with zoonotic potential (NCF2, NCF3, D, EbpC, CHN-DC1, SCF2, CHN-F1, Type IV, BEB4, and BEB6) were identified in foxes and raccoon dogs. Totally 178 ITS-positive DNA specimens were identified from foxes and raccoon dogs and these specimens were then subjected to MLST analysis. In the MLST analysis, 12, 2, 7 and 8 genotypes were identified in at the mini-/ micro-satellite loci MS1, MS3, MS4 and MS7, respectively. A total of 14 multilocus genotypes were generated using ClustalX 2.1 software. Overall, the present study evaluated the infection of E. bieneusi in foxes and raccoon dogs in the Henan and Hebei province, and investigated the zoonotic potential of the E. bieneusi in foxes and raccoon dogs.

CONCLUSIONS

These findings expand the geographic distribution information of E. bieneusi' host in China and was helpful in preventing against the infection of E. bieneusi with zoonotic potential in foxes and raccoon dogs.

Zoonotic Enterocytozoon bieneusi genotypes in free-ranging and farmed wild ungulates in Spain

Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and other mammals and birds. Data on the epidemiology of E. bieneusi in wildlife is limited. Hence, E. bieneusi was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from five Spanish bioregions. The parasite was detected only in red deer (10.4%, 68/653) and wild boar (0.8%, 3/359). Enterocytozoon bieneusi infections were more common in farmed (19.4%, 63/324) than in wild (1.5%, 5/329) red deer. Eleven genotypes were identified in red deer, eight known (BEB6, BEB17, EbCar2, HLJD-V, MWC_d1, S5, Type IV, and Wildboar3) and three novel (DeerSpEb1, DeerSpEb2, and DeerSpEb3) genotypes. Mixed genotype infections were detected in 15.9% of farmed red deer. Two genotypes were identified in wild boar, a known (Wildboar3) and a novel (WildboarSpEb1) genotypes. All genotypes identified belonged to E. bieneusi zoonotic Groups 1 and 2. This study provides the most comprehensive epidemiological study of E. bieneusi in Spanish ungulates to date, representing the first evidence of the parasite in wild red deer populations worldwide. Spanish wild boars and red deer are reservoir of zoonotic genotypes of E. bieneusi and might play an underestimated role in the transmission of this microsporidian species to humans and other animals.

A Perspective on the Molecular Identification, Classification, and Epidemiology of Enterocytozoon bieneusi of Animals

The microsporidian Enterocytozoon bieneusi is an obligate intracellular pathogen that causes enteric disease (microsporidiosis) in humans and has been recorded in a wide range of animal species worldwide. The transmission of E. bieneusi is direct and likely occurs from person to person and from animal to person via the ingestion of spores in water, food, or the environment. The identification of E. bieneusi is usually accomplished by molecular means, typically using the sequence of the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. Currently, ~820 distinct genotypes of E. bieneusi have been recorded in at least 210 species of vertebrates (mammals, birds, reptiles, and amphibians) or invertebrates (insects and mussels) in more than 50 countries. In this chapter, we provide a perspective on (1) clinical aspects of human microsporidiosis; (2) the genome and DNA markers for E. bieneusi as well as molecular methods for the specific and genotypic identification of E. bieneusi; (3) epidemiological aspects of E. bieneusi of animals and humans, with an emphasis on the genotypes proposed to be zoonotic, human-specific, and animal-specific; and (4) future research directions to underpin expanded molecular studies to better understand E. bieneusi and microsporidiosis.

Enterocytozoon bieneusi Genotypes and Infections in the Horses in Korea

Enterocytozoon bieneusi is a microsporidian pathogen. Recently, the equestrian population is increasing in Korea. The horse-related zoonotic pathogens, including E. bieneusi, are concerns of public health. A total of 1,200 horse fecal samples were collected from riding centers and breeding farms in Jeju Island and inland areas. Of the fecal samples 15 (1.3%) were PCR positive for E. bieneusi. Interestingly, all positive samples came from Jeju Island. Diarrhea and infection in foals were related. Two genotypes (horse1, horse2) were identified as possible zoonotic groups requiring continuous monitoring.

Molecular Detection of Cryptosporidium spp. and Enterocytozoon bieneusi Infection in Wild Rodents From Six Provinces in China

Enterocytozoon (E.) bieneusi and Cryptosporidium spp. are the most important zoonotic enteric pathogens associated with diarrheal diseases in animals and humans. However, it is still not known whether E. bieneusi and Cryptosporidium spp. are carried by wild rodents in Shanxi, Guangxi, Zhejiang, Shandong, and Inner Mongolia, China. In the present study, a total of 536 feces samples were collected from Rattus (R.) norvegicus, Mus musculus, Spermophilus (S.) dauricus, and Lasiopodomys brandti in six provinces of China, and were detected by PCR amplification of the SSU rRNA gene of Cryptosporidium spp. and ITS gene of E. bieneusi from June 2017 to November 2020. Among 536 wild rodents, 62 (11.6%) and 18 (3.4%) samples were detected as E. bieneusi- and Cryptosporidium spp.-positive, respectively. Differential prevalence rates of E. bieneusi and Cryptosporidium spp. were found in different regions. E. bieneusi was more prevalent in R. norvegicus, whereas Cryptosporidium spp. was more frequently identified in S. dauricus. Sequence analysis indicated that three known Cryptosporidium species/genotypes (Cryptosporidium viatorum, Cryptosporidium felis, and Cryptosporidium sp. rat genotype II/III) and two uncertain Cryptosporidium species (Cryptosporidium sp. novel1 and Cryptosporidium sp. novel2) were present in the investigated wild rodents. Meanwhile, 5 known E. bieneusi genotypes (XJP-II, EbpC, EbpA, D, and NCF7) and 11 novel E. bieneusi genotypes (ZJR1 to ZJR7, GXM1, HLJC1, HLJC2, and SDR1) were also observed. This is the first report for existence of E. bieneusi and Cryptosporidium spp. in wild rodents in Shanxi, Guangxi, Zhejiang, and Shandong, China. The present study also demonstrated the existence of E. bieneusi and Cryptosporidium spp. in S. dauricus worldwide for the first time. This study not only provided the basic data for the distribution of E. bieneusi and Cryptosporidium genotypes/species, but also expanded the host range of the two parasites. Moreover, the zoonotic E. bieneusi and Cryptosporidium species/genotypes were identified in the present study, suggesting wild rodents are a potential source of human infections.

Molecular Detection and Genotyping of Enterocytozoon bieneusi in Black Goats (Capra hircus) in Yunnan Province, Southwestern China

Simple Summary

Enterocytozoon bieneusi is one of the most common parasites in human and animals, and a threat to public health. So far, no data are available for E. bieneusi prevalence and genotypes in black goats in Yunnan Province, Southwestern China. Therefore, the objective of this study was to detect the prevalence and genotypes of E. bieneusi by examining 907 fecal samples collected from 5 counties in Yunnan Province. Ninety-three fecal samples (10.3%) were E. bieneusi-positive by PCR amplification. Four new genotypes and 11 known genotypes were identified, and all genotypes considered to be the zoonotic potential. Phylogenetic analysis showed that all of these genotypes were allocated into the zoonotic groups of E. bieneusi indicating its zoonotic potential. These results indicated that effective strategies and measures must be taken to prevent and control E. bieneusi transmission to other animals and humans.

Abstract

Enterocytozoon bieneusi is a fungus-like protist that can parasitize in the intestines of humans and various animals causing a threat to public health. However, there has been no data for E. bieneusi prevalence and genotypes in black goats in Yunnan Province, Southwestern China. In this study, 907 fecal samples were collected from black goats in 5 counties from Yunnan Province. The prevalence and genotypes of E. bieneusi were examined by nested PCR amplification targeting the nuclear internal transcribed spacer (ITS). Multi-locus sequence typing (MLST) was used to further examine the potential occurrence of genetic segregation. The overall prevalence of E. bieneusi in black goats in Yunnan Province was 10.3% (93/907). Statistical analysis revealed that E. bieneusi prevalence was significantly associated with the region, age and gender of black goats (p < 0.001). Four new genotypes (CYG-1, CYG-2, CYG-3, CYG-4) and 11 known genotypes (CHG1, CHG2, CHG3, CHG5, CHG28, J, D, BEB6, Wildboar3, CD6, SDD1) of E. bieneusi were identified. At the microsatellite and minisatellite loci, 15, 2, 17, and 33 sequences were obtained, respectively, forming one new multi-locus genotype (MLG27). Phylogenetic analysis revealed that all 15 genotypes were clustered into group 1 and group 2, with zoonotic potential. This is the first report of E. bieneusi prevalence and genotypes in black goats in Yunnan Province, China. Effective control strategies and measures should be taken to reduce the risk of E. bieneusi transmission between black goats, other animals, and humans.

Zoonotic Genotypes of Enterocytozoon bieneusi in Wild Living Invasive and Native Carnivores in Poland

Wild carnivores, both introduced and native species, are able to adapt well to peri-urban environments, facilitating cross-species pathogen transmission with domestic animals, and potentially humans. The role of wild living reservoir hosts cannot be ignored because of their known carriage of E. bieneusi zoonotic genotypes. In the past decades, populations of wild living carnivores, i.e., native, such as red foxes, and invasive, such as raccoon dogs and raccoons, have increased and adapted to synanthropic environments across Europe, including Poland. The knowledge concerning E. bieneusi genotype identification and distribution in wild carnivores is limited worldwide. A total of 322 individual fecal samples from six carnivore species, i.e., raccoon, raccoon dog, red fox, European badger, pine and beech martens, were collected and then analysed for the presence of E. bieneusi using the nested PCR method. Overall prevalence of the pathogen was estimated to be as high as 27.3%. The infection rates for E. bieneusi varied between the carnivore species, from 13.7% in beech martens to 40.4% in raccoon dogs. Based on sequence analysis of the ITS region of the rRNA gene marker, we detected five known genotypes of E. bieneusi in examined animals. In the invasive species, E. bieneusi NCF2 and D genotypes have been identified, whereas in the native ones, E. bieneusi NCF2, D, C, EbCar2 and Type IV genotypes were identified. All E. bieneusi genotypes recorded in this survey clustered in Group 1, showing their zoonotic potential. Our results provide the first description of the occurrence and genotypes of the microsporidian E. bieneusi in wild living population of raccoon dogs in Europe. Our findings are important for the study of pathogen epidemiology and emphasize the fact that the invasive and the native wild living carnivores, both widely distributed, should be considered more seriously as significant sources of zoonotic pathogens hazardous to domestic and farmed animals and humans.

Molecular detection and genotyping of Enterocytozoon bieneusi in captive foxes in Xinxiang, Central China and its impact on gut bacterial communities

Enterocytozoon bieneusi is a common gastrointestinal parasite that has a broad range of hosts, including birds, mammals, and even humans. The changes of gut bacterial communities have been demonstrated during the course of E. bieneusi. This study aimed to examine the infection status, and assess the zoonotic potential and influence of E. bieneusi on gut bacterial communities of captive foxes in Xinxiang, central China. Fecal samples were collected from 216 captive foxes, and amplification of the internal transcribed spacer (ITS) gene of each sample was performed by nested polymerase chain reaction. E. bieneusi was detected in 48 (22.2%) samples, and five previously reported genotypes CHN-F1 (n = 25), D (n = 18), BEB6 (n = 3), NCF2 (n = 1), and CHN-DC1 (n = 1) were identified, with CHN-F1 being the dominant genotype (25/48, 52.1%). Phylogenetic analysis further revealed that CHN-F1, D, NCF2, and CHN-DC1 genotypes belonged to the zoonotic group 1 of E. bieneusi, whereas BEB6 belonged to group 2. Moreover, sequencing and bioinformatics analysis of the V3-V4 region of 16S rRNA gene in five E. bieneusi-positive and five negative samples showed that gut microbial diversity was higher in the infected animals. In both groups, Firmicutes and Bacteroidetes were the two most abundant phyla, but the Firmicutes/Bacteroidetes ratio was lower in E. bieneusi-positive foxes (7.9:1) as compared with E. bieneusi-negative foxes (5:1). More importantly, at the phylum level, "beneficial bacteria" such as Firmicutes (1.6%) and Bacteroides (5.8%) increased, whereas "opportunistic pathogens" such as Fusobacteria (8.2%) decreased. Similarly, at the genus level, the pathogenic Clostridiaceae_Clostridium (10.0%) decreased, whereas the "beneficial bacteria" Lactococcus (6.6%) increased. These interesting phenomena warrant further investigation.

Distribution and genotypic analysis of Enterocytozoon bieneusi from wild boars in Korea

Enterocytozoon bieneusi, an important microsporidian fungus, causes chronic diarrhea in humans and animals worldwide. Of the 502 fecal samples from wild boars, 13 were positive for the E. bieneusi internal transcribed spacer region, with a prevalence of 2.6%. Six E. bieneusi genotypes, D, EbpC, and four novel KWB1-KWB4, were identified with zoonotic potential. Genotypes D (subgroup 1a) and EbpC (subgroup 1d) were first reported in Korean swine and Korea, respectively; KWB1-KWB4 (subgroup 1e) were most prevalent in this study. Because zoonotic genotypes have been identified, E. bieneusi transmission through wild boars must be closely monitored for proper prevention and treatment, despite their low prevalence.

FIRST REPORT OF ENTEROCYTOZOON BIENEUSI FROM AN AFRICAN LION (PANTHERA LEO) IN A ZOO IN THE REPUBLIC OF KOREA

Enterocytozoon bieneusi is the most common species of microsporidia that infects humans and animals worldwide. However, no information is available on E. bieneusi infection among zoo animals in the Republic of Korea (ROK). Here, we investigated the prevalence of E. bieneusi among animals kept in zoos and the zoonotic potential of the E. bieneusi identified. E. bieneusi was detected only in one African lion (Panthera leo) with diarrhea, using PCR and sequencing analysis of the internal transcribed spacer (ITS) of the rRNA gene. A phylogenetic analysis based on the ITS gene showed that the lion isolate was classified into a novel genotype KPL belonging to Group 2. The KPL genotype identified in this study differed from genotype I in 6 nucleotides and from genotype I-like in 3 nucleotides, respectively, indicating that Group 2 has the capacity to infect a wide range of hosts. This is the first report of the presence of E. bieneusi in an African lion housed in a zoo in the ROK. Further investigation is necessary to study E. bieneusi infection among zoo animals in various regions and to determine the transmission route, in order to control E. bieneusi infection.

Prevalence and new genotypes of Enterocytozoon bieneusi in sheltered dogs and cats in Sichuan province, southwestern China

Enterocytozoon bieneusi is a common intracellular parasite that infects a wide range of hosts, including humans and companion animals, raising concerns of zoonotic transmission. However, there is limited epidemiological information on the prevalence and genotypes of E. bieneusi in sheltered dogs and cats in Sichuan province, southwestern China. A total of 880 fecal samples were collected from shelters in different cities of Sichuan province, including 724 samples from dogs, and 156 samples from cats. Enterocytozoon bieneusi was determined by sequence analysis of the ribosomal internal transcribed spacer (ITS). Overall, the prevalence of E. bieneusi was 18% (158/880), and the parasite was detected in 18.8% (136/724) and 14.1% (22/156) of the dogs and cats examined, respectively. Sequence analysis revealed the presence of five genotypes in dogs, including three known genotypes CD9 (n = 92), PtEb IX (n = 41), and Type IV (n = 1), and two novel genotypes SCD-1 (n = 1) and SCD-2 (n = 1). Similarly, four genotypes were identified in cats, including CD9 (n = 11), Type IV (n = 6), D (n = 4), and PtEb IX (n = 1). Genotypes D and Type IV have previously been identified in humans and are reported in sheltered dogs and cats in the present study, indicating that these animals could be as potential sources of human microsporidiosis infections.

Zoonotic parasites in farmed exotic animals in China: Implications to public health

Several species of wild mammals are farmed in China as part of the rural development and poverty alleviation, including fur animals, bamboo rats, and macaque monkeys. Concerns have been raised on the potential dispersal of pathogens to humans and other farm animals brought in from native habitats. Numerous studies have been conducted on the genetic identity and public health potential of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in these newly farmed exotic animals. The data generated have shown a high prevalence of the pathogens in farmed wildlife, probably due to the stress from the short captivity and congregation of large numbers of susceptible animals. Host adaptation at species/genotype and subtype levels has reduced the potential for cross-species and zoonotic transmission of pathogens, but the farm environment appears to favor the transmission of some species, genotypes, and subtypes, with reduced pathogen diversity compared with their wild relatives. Most genotypes and subtypes of the pathogens detected appear to be brought in from their native habitats. A few of the subtypes have emerged as human pathogens. One Health measures should be developed to slow the dispersal of indigenous pathogens among farmed exotic animals and prevent their spillover to other farm animals and humans.

Molecular detection and genotypes of Enterocytozoon bieneusi in farmed mink (Neovison vison), blue foxes (Alopex lagopus), and raccoon dogs (Nyctereutes procyonoides) in Xinjiang, China

Enterocytozoon bieneusi is a zoonotic pathogen that infects a variety of hosts including humans, livestock, wildlife, companion animals, and birds, as well as being abundant in the environment. Humans and nonhuman animals could be infected with E. bieneusi via consumption of food or water that contains zoonotic and host-adapted genotypes. In this study, 288 fecal specimens were collected from farmed minks, blue foxes, and raccoon dogs, in Xinjiang, China. Enterocytozoon bieneusi was examined by PCR amplification based on sequence analysis of the internal transcribed spacer (ITS) region. The overall infection rate of E. bieneusi was 4.9% (14/288), with mink samples showing the highest infection rate (5.6%, 12/214), followed by blue foxes (2.9%, 1/35), and then raccoon dogs (2.6%, 1/39). Six E. bieneusi genotypes were identified, including D (n = 5), PigEBITS7 (n = 4), EbpA (n = 2), CAM5 (n = 1), WildBoar3 (n = 1), and a novel genotype XJMI-1 (n = 1). Phylogenetic analysis showed that all E. bieneusi genotypes belonged to group 1, which composed of over 300 genotypes and most of them have been identified in human and variety of animals, suggesting a risk of zoonotic transmission from farmed wildlife to humans.

Enterocytozoon bieneusi of animals-With an 'Australian twist'

Enterocytozoon bieneusi is a microsporidian microorganism that causes intestinal disease in animals including humans. E. bieneusi is an obligate intracellular pathogen, typically causing severe or chronic diarrhoea, malabsorption and/or wasting. Currently, E. bieneusi is recognised as a fungus, although its exact classification remains contentious. The transmission of E. bieneusi can occur from person to person and/or animals to people. Transmission is usually via the faecal-oral route through E. bieneusi spore-contaminated water, environment or food, or direct contact with infected individuals. Enterocytozoon bieneusi genotypes are usually identified and classified by PCR-based sequencing of the internal transcribed spacer region (ITS) of nuclear ribosomal DNA. To date, ~600 distinct genotypes of E. bieneusi have been recorded in ~170 species of animals, including various orders of mammals and reptiles as well as insects in >40 countries. Moreover, E. bieneusi has also been found in recreational water, irrigation water, and treated raw- and waste-waters. Although many studies have been conducted on the epidemiology of E. bieneusi, prevalence surveys of animals and humans are scant in some countries, such as Australia, and transmission routes of individual genotypes and related risk factors are poorly understood. This article/chapter reviews aspects of the taxonomy, biology and epidemiology of E. bieneusi; the diagnosis, treatment and prevention of microsporidiosis; critically appraises the naming system for E. bieneusi genotypes as well as the phylogenetic relationships of these genotypes; provides new insights into the prevalence and genetic composition of E. bieneusi populations in animals in parts of Australia using molecular epidemiological tools; and proposes some areas for future research in the E. bieneusi/microsporidiosis field.

Detection of Intestinal Parasites and Genetic Characterization of Enterocytozoon bieneusi in Hedgehogs from China

Microsporidia are a group of unicellular and opportunistic intestinal parasites in which Enterocytozoon bieneusi is a frequent species causing microsporidial infections in humans. Many domesticated and wild animals have been shown to be hosts of E. bieneusi and other microsporidia. The role of hedgehogs in the ecology of microsporidia is unclear; therefore, we investigated the prevalence and genetic diversity of E. bieneusi, Cryptosporidium, and Blastocystis spp. in hedgehogs (Erinaceus amurensis) collected from Hubei Province in Central China. PCR amplification of the internal transcribed spacer region of the ribosomal DNA indicated that 9.8% (4/41) hedgehogs were positive to E. bieneusi, but none (0/41) was positive to Cryptosporidium and Blastocystis spp. Phylogenetic analysis showed the strains detected from the hedgehogs belong to four novel genotypes (EA1-EA4), which were most closely related to type IV of group 1c. This study demonstrated that hedgehogs are hosts of E. bieneusi and may play a role in the transmission of E. bieneusi to humans in the process of being caught and slaughtered.

Multilocus Sequence Typing of Enterocytozoon bieneusi Isolates From Various Mammal and Bird Species and Assessment of Population Structure and Substructure

Enterocytozoon bieneusi is one of the most common intestinal pathogens in humans and animals. E. bieneusi has been confirmed to be complex microsporidian species. Approximately 500 ITS genotypes of E. bieneusi have been defined. With the establishment and application of multilocus sequencing typing and population genetic tools in E. bieneusi, the studies on these aspects have been carried out worldwide, but little information is available. To understand genetic variation of mini-/micro-satellites and the population structure and substructure of E. bieneusi in northeastern China, 305 E. bieneusi DNA specimens composed of 28 ITS genotypes were from 13 mammal species and five bird species in the investigated areas. They were characterized by nested-PCR amplification and sequencing at four mini-/micro-satellite loci (MS1, MS3, MS4, and MS7). At the MS1, MS3, MS4, and MS7 loci, 153 (50.16%), 131 (42.95%), 133 (43.61%), and 128 (41.97%) DNA specimens were amplified and sequenced successfully with 44, 17, 26, and 24 genotypes being identified, respectively. Multilocus genotypes (MLGs) showed a higher genetic diversity than ITS genotypes. 48 MLGs were produced out of 90 ITS-positive DNA specimens based on concatenated sequences of all the five genetic loci including ITS. Linkage disequilibrium (LD) and limited genetic recombination were observed by measuring LD using both multilocus sequences and allelic profile data, indicating an overall clonal population structure of E. bieneusi in the investigated areas. These data will aid in the longitudinal tracking of the attribution of source of infection/contamination and in elucidating transmission dynamics, and will provide valuable information for making efficient control strategies to intervene with and prevent occurrence of microsporidiosis caused by E. bieneusi among animals and transmission of E. bieneusi from animals to humans in the investigated areas. Phylogenetic and network analyses identified three different subgroups, revealing the presence of host-shaped segregation and the absence of geographical segregation in E. bieneusi population. Meanwhile, the MLGs from zoonotic ITS genotypes were observed to be basically separated from the MLGs from host-adapted ones. Assessment of substructure will have a reference effect on understanding of zoonotic or interspecies transmission of E. bieneusi and evolution direction from zoonotic genotypes to host-adapted genotypes.

First identification and genotyping of Enterocytozoon bieneusi and Encephalitozoon spp. in pet rabbits in China

Background

Microsporidia are common opportunistic parasites in humans and animals, including rabbits. However, only limited epidemiology data concern about the prevalence and molecular characterization of Enterocytozoon bieneusi and Encephalitozoon spp. in rabbits. This study is the first detection and genotyping of Microsporidia in pet rabbits in China.

Results

A total of 584 faecal specimens were collected from rabbits in pet shops from four cities in Sichuan province, China. The overall prevalence of microsporidia infection was 24.8% by nested PCR targeting the internal transcribed spacer (ITS) region of E. bieneusi and Encephalitozoon spp. respectively. E. bieneusi was the most common species (n = 90, 15.4%), followed by Encephalitozoon cuniculi (n = 34, 5.8%) and Encephalitozoon intestinalis (n = 16, 2.7%). Mixed infections (E. bieneusi and E. cuniculi) were detected in five another rabbits (0.9%). Statistically significant differences in the prevalence of microsporidia were observed among different cities (χ² = 38.376, df = 3, P < 0.01) and the rabbits older than 1 year were more likely to harbour microsporidia infections (χ² = 9.018, df = 2, P < 0.05). Eleven distinct genotypes of E. bieneusi were obtained, including five known (SC02, I, N, J, CHY1) and six novel genotypes (SCR01, SCR02, SCR04 to SCR07). SC02 was the most prevalent genotype in all tested cities (43.3%, 39/90). Phylogenetic analysis showed that these genotypes were clustered into group 1–3 and group 10. Meanwhile, two genotypes (I and II) were identified by sequence analysis of the ITS region of E. cuniculi.

Conclusion

To the best of our knowledge, this is the first report of microsporidia infection in pet rabbits in China. Genotype SC02 and four novel genotypes were classified into potential zoonotic group 1, suggesting that pet rabbits may cause microsporidiosis in humans through zoonotic transmissions. These findings provide preliminary reference data for monitoring microsporidia infections in pet rabbits and humans.

Prevalence and genotype distribution of Enterocytozoon bieneusi in farmed raccoon dogs (Nyctereutes procyonoides) in Shandong Province, eastern China

Enterocytozoon bieneusi is a common microsporidian species, which can infect humans and various species of animals. However, little is known about E. bieneusi prevalence and genotypes in farmed raccoon dogs (Nyctereutes procyonoides) in Shandong Province, China. In this study, a total of 356 fecal samples were collected from farmed raccoon dogs in Weihai, Weifang, and Yantai cities in Shandong Province, China. A total of 23 (6.5%) samples were E. bieneusi-positive by nested PCR amplification of the internal transcribed spacer (ITS) region of ribosomal DNA. Statistical analysis showed that E. bieneusi prevalence in male raccoon dogs was higher than that in female raccoon dogs, and the highest E. bieneusi prevalence was detected in adult raccoon dogs. Sequence analysis revealed four known E. bieneusi genotypes (D, type IV, CHG1, and Peru8), and type IV (11/23) was the predominant genotype. The genotypes type IV, Peru8, and CHG1 were reported in raccoon dogs for the first time in China. Phylogenetic analysis showed that three human-pathogenic genotypes (D, type IV, and Peru8) were clustered into group 1, and the CHG1 belonged to group 2. These findings expand the current understanding of E. bieneusi prevalence and genotype distribution in raccoon dogs in China. Our study also shows that raccoon dogs are hosts for E. bieneusi belonging to several genotypes, including zoonotic ones, highlighting the possibility of transmission of this pathogen between raccoon dogs and humans.

Molecular detection of porcine Enterocytozoon bieneusi infection in Peninsular Malaysia and epidemiological risk factors associated with potentially zoonotic genotypes

Enterocytozoon bieneusi is an emerging opportunistic pathogen infecting humans, and both domestic and wild pigs are known to harbour zoonotic genotypes. There remains a paucity of information on the prevalence and epidemiology of this enteropathogen in Southeast Asia. The present study was undertaken to determine the molecular prevalence and risk factors associated with E. bieneusi infection among commercially farmed pigs in Malaysia. Faecal samples were collected from 450 pigs from 15 different farms and subjected to nested PCR amplification of the ribosomal internal transcribed spacer (ITS) gene of E. bieneusi. Phylogenetic analysis involved 28 nucleotide sequences of the ITS region of E. bieneusi. An interviewer-administered questionnaire provided information on the animal hosts, farm management systems and environmental factors and was statistically analysed to determine the risk factors for infection. The prevalence of E. bieneusi infection was relatively high (40.7%). The highest prevalence (51.3%) was recorded among the piglets, while the adults showed the lowest level of infection (31.3%). Multivariate analysis indicated that age of the pigs, distance of the farm from human settlement and farm management system were significant risk factors of infection. Three genotypes (EbpA, EbpC and Henan-III) detected among the pigs are potentially zoonotic. The high prevalence of E. bieneusi among locally reared pigs, the presence of zoonotic genotypes and the spatial distribution of pig farms and human settlements warrant further investigation on the possibility of zoonotic transmission.

Novel genotypes and multilocus genotypes of Enterocytozoon bieneusi in two wild rat species in China: potential for zoonotic transmission

Enterocytozoon bieneusi is an opportunistic pathogen in immunodeficient patients. Although this pathogen has been reported in many domestic animals, few data are available about the occurrence of E. bieneusi in wild rats. In the current study, a total of 228 fecal samples from two wild rat species (Leopoldamys edwardsi and Berylmys bowersi) in China were examined by a nested PCR-based sequencing approach employing the internal transcribed spacer (ITS) region of nuclear ribosomal DNA. The overall prevalence of E. bieneusi in wild rats was 33.3% (76/228), with 35.1% (39/111) in L. edwardsi and 31.6% (37/117) in B. bowersi. Ten E. bieneusi genotypes (including four known and six novel genotypes) were identified, with the novel CQR-2 (n = 15) as the predominant genotype. Phylogenetic analysis indicated that ten genotypes in the present study belong to zoonotic group 1, which contains many genotypes in humans. Furthermore, multilocus sequence typing (MLST) analysis showed that 19 ITS-positive samples were successfully amplified at three microsatellites and one minisatellite, forming 18 multilocus genotypes (MLGs). This is the first report of E. bieneusi infection in the wild rats L. edwardsi and B. bowersi. Our findings suggest that wild rats could be a significant source of human infection, including contaminated food and water.

Molecular detection and genotype distribution of Enterocytozoon bieneusi in farmed silver foxes (Vulpes vulpes) and arctic foxes (Vulpes lagopus) in Shandong Province, eastern China

Enterocytozoon bieneusi is an opportunistic enteric pathogen which can infect a wide range of animal species and humans. It is the most diagnosed species of Microsporidia in humans and has an impact on public health. Many infected animals including foxes may be a potential source for transmitting E. bieneusi to humans. However, limited information is available on the E. bieneusi prevalence and genotypes in farmed foxes in China. Therefore, in the present study, 344 fresh fecal samples were collected from farmed foxes (Vulpes vulpes and Vulpes lagopus) in Shandong Province, and the prevalence and genotypes of E. bieneusi were examined based on sequence analysis of the ribosomal internal transcribed spacer (ITS) region. The overall E. bieneusi prevalence was 9% (31/344); of them, 6.5% (9/138) in farmed silver foxes (V. vulpes) and 10.7% (22/206) in farmed arctic foxes (V. lagopus). Moreover, four known (Hum-q1, NCF2, HND-1, and Type IV) and two novel E. bieneusi genotypes (SDF1 and SDF2) were identified in farmed foxes in the present study. All of the E. bieneusi genotypes belonged to the zoonotic group based on phylogenetic analysis. In addition, 2, 4, 0, and 11 samples were successfully amplified at MS1, MS3, MS4, and MS7 loci, respectively. The present study reveals E. bieneusi prevalence and genotype distribution in farmed foxes in Shandong Province and enlarged the host and geographic information of E. bieneusi in China.

Prevalence and multilocus genotypes of Enterocytozoon bieneusi in alpacas (Vicugna pacos) in Shanxi Province, northern China

Enterocytozoon bieneusi is a single-celled obligate pathogen that seriously threatens animal and public health. However, information on the prevalence and genotypes of E. bieneusi in alpacas in China is limited. In the present study, 366 fresh fecal samples from alpacas in Shanxi Province, northern China, were collected to detect E. bieneusi by nested PCR amplification of the internal transcribed spacer (ITS) of nuclear ribosomal DNA (rDNA). The overall prevalence of E. bieneusi in alpacas was 4.4% (16/366), including 3.9% (12/305) in Yangqu County and 6.6% (4/61) in Dai county, respectively. Four known genotypes were identified, namely ALP1, ALP3, P, and SH11, all of which belong to the zoonotic group 1 by phylogenetic analysis. Moreover, ITS-positive samples were further characterized by PCR amplification of other four targets, including three microsatellites (MS1, MS3, and MS7) and one minisatellite (MS4). Multilocus sequence typing (MLST) showed that 5, 2, 3, and 3 types were identified at MS1, MS3, MS7, and MS4 loci, respectively, representing eight multilocus genotypes (MLGs). These findings contribute to the improved understanding of the prevalence and genotypes of E. bieneusi in alpacas in China and have important implications for controlling E. bieneusi infections in animals and humans.

Molecular Detection, Multilocus Genotyping, and Population Genetics of Enterocytozoon bieneusi in Pigs in Southeastern China

Enterocytozoon bieneusi is an important opportunistic pathogen widely distributed in humans and animals that causes diarrhea or fatal diarrhea in immunocompromised hosts. To examine the infection status and molecular characteristics of E. bieneusi in pigs, 725 fecal samples were collected from pigs in six areas of Fujian Province. The E. bieneusi genotypes were identified based on the internal transcribed spacer (ITS) regions of the ribosomal RNA (rRNA) gene by nested PCR, and its population genetics were analyzed by multilocus sequence typing (MLST). The results showed that the infection rate of E. bieneusi was 24.4% (177/725), and 11 known genotypes (EbpC, EbpA, CHN-RR2, KIN-1, CHG7, CHS5, CM11, CHG23, G, PigEBITS, and D) and 2 novel genotypes (FJF and FJS) were identified. All the genotypes were found to be clustered into zoonotic Group 1. Moreover, 52 positive samples were successfully amplified at minisatellite and microsatellite loci and formed 48 distinct multilocus genotypes (MLGs). Further population structure analyses showed strong genetic linkage disequilibrium (LD) and several recombination events (Rm), indicating that E. bieneusi has a clonal population structure. This study is the first to investigate the prevalence and molecular characteristics of E. bieneusi in Fujian Province and could provide baseline data to control E. bieneusi infection in pigs and humans and deepen our understanding of the zoonotic risk of E. bieneusi and its distribution in China.

First report and multilocus genotyping of Enterocytozoon bieneusi from Tibetan pigs in southwestern China

Enterocytozoon bieneusi is a common intestinal pathogen in a variety of animals. While E. bieneusi genotypes have become better-known, there are few reports on its prevalence in the Tibetan pig. This study investigated the prevalence, genetic diversity, and zoonotic potential of E. bieneusi in the Tibetan pig in southwestern China. Tibetan pig feces (266 samples) were collected from three sites in the southwest of China. Feces were subjected to PCR amplification of the internal transcribed spacer (ITS) region. Enterocytozoon bieneusi was detected in 83 (31.2%) of Tibetan pigs from the three different sites, with 25.4% in Kangding, 56% in Yaan, and 26.7% in Qionglai. Prevalence varies according to age group, from 24.4% (age 0-1 years) to 44.4% (age 1-2 years). Four genotypes of E. bieneusi were identified: two known genotypes EbpC (n = 58), Henan-IV (n = 24) and two novel genotypes, SCT01 and SCT02 (one of each). We compare our results with a compilation of published results on the host range and geographical distribution of E. bieneusi genotypes in China. Phylogenetic analysis showed these four genotypes clustered to group 1 with zoonotic potential. Multilocus sequence typing (MLST) analysis of three microsatellites (MS1, MS3, MS7) and one minisatellite (MS4) was successful in 47, 48, 23 and 47 positive specimens and identified 10, 10, 5 and 5 genotypes at four loci, respectively. This study indicates the potential danger of E. bieneusi to Tibetan pigs in southwestern China, and offers basic advice for preventing and controlling infections.

Multilocus Sequence Typing and Population Genetic Analysis of Enterocytozoon bieneusi: Host Specificity and Its Impacts on Public Health

Microsporidia comprise a large class of unicellular eukaryotic pathogens that are medically and agriculturally important, but poorly understood. There have been nearly 1,500 microsporidian species described thus far, which are variable in biology, genetics, genomics, and host specificity. Among those, Enterocytozoon bieneusi is the well-known species responsible for the most recorded cases of human microsporidian affections. The pathogen can colonize a broad range of mammals and birds and most of the animals surveyed share some genotypes with humans, posing a threat to public health. Based on DNA sequence analysis of the ribosomal internal transcribed spacer (ITS) and phylogenetic analysis, several hundreds of E. bieneusi genotypes have been defined and clustered into different genetic groups with varied levels of host specificity. However, single locus-based typing using ITS might have insufficient resolution to discriminate among E. bieneusi isolates with complex genetic or hereditary characteristics and to assess the elusive reproduction or transmission modes of the organism, highlighting the need for exploration and application of multilocus sequence typing (MLST) and population genetic tools. The present review begins with a primer on microsporidia and major microsporidian species, briefly introduces the recent advances on E. bieneusi ITS genotyping and phylogeny, summarizes recent MLST and population genetic data, analyzes the inter- and intragroup host specificity at the MLST level, and interprets the public health implications of host specificity in zoonotic or cross-species transmission of this ubiquitous fungus.

First report of Enterocytozoon bieneusi and Cryptosporidium spp. in peafowl (Pavo cristatus) in China

Enterocytozoon bieneusi and Cryptosporidium spp. are important pathogens causing diarrhea in humans and animals. However, few studies have been conducted on the infection of E. bieneusi and Cryptosporidium spp. in peafowl up to now. The purpose of the present study was to determine the prevalence and the involved genotypes of Cryptosporidium spp. and E. bieneusi in peafowl in Beijing and Jiangxi Province, China. In total, 258 peafowl fecal samples were collected. Overall, both Cryptosporidium spp. and E. bieneusi had the same prevalence, i.e. 6.59% (17/258). Higher infection rates of E. bieneusi and Cryptosporidium spp. were found in the adolescent peafowl. The prevalence of E. bieneusi in Beijing and Jiangxi Province was 5.23% and 8.57% respectively. For Cryptosporidium spp., the prevalence was 4.58% and 9.52% in Beijing and Jiangxi Province, respectively. Three zoonotic genotypes of E. bieneusi were confirmed, including two known genotypes, genotype Peru 6 and D, and one novel genotype, JXP1. Two avian specific species/genotypes of Cryptosporidium, Avian genotype Ⅲ and Goose genotype Ⅰ, were identified. To our knowledge, this is the first report of E. bieneusi and Cryptosporidium spp. occurrence in peafowl in China. The findings suggest that peafowl could be reservoirs of E. bieneusi and Cryptosporidium spp. which could be potentially transmitted to humans and other animals, and the present survey have implications for controlling E. bieneusi and Cryptosporidium spp. infection in peafowl.

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This is the first report of Enterocytozoon bieneusi and Cryptosporidium spp. in peafowl in China.

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The average infection rate was 6.59% and higher prevalence was found in the adolescent peafowl.

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Three zoonotic genotypes of E. bieneusi and 2 avian specific genotypes of Cryptosporidium were identified.

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This study will enrich the epidemiological data of E. bieneusi and Cryptosporidium spp. infection in China.

Multilocus Typing of Enterocytozoon bieneusi in Pig Reveals the High Prevalence, Zoonotic Potential, Host Adaptation and Geographical Segregation in China

Enterocytozoon bieneusi is one of the most frequently diagnosed Microsporidia of humans and most animals. However, there is no information on E. bieneusi infection of pigs in Tibet and Henan, China. In this study, 1,190 fecal samples were collected from pigs in Tibet and Henan and screened for the presence of E. bieneusi. The overall prevalence of E. bieneusi infection was 54.2% (645/1,190), with differences in prevalence observed among geographical areas, ages, and pig breeds. Moreover, 10 E. bieneusi genotypes were identified based on internal transcribed spacer region genotyping, including eight known genotypes (EbpC, EbpA, CHG19, CHC5, Henan-III, I, D, and H) and two novel genotypes (XZP-I and XZP-II). Multilocus sequence typing revealed 18, 7, 17, and 13 genotypes at minisatellite/microsatellite loci MS1, MS3, MS4, and MS7, respectively. Strong linkage disequilibrium (LD) and few numbers of recombination events, suggest a clonal structure of the E. bieneusi population examined in this study. The low pairwise genetic distance (F_ST ) and gene flow (Nm) values indicated limited gene flow in the E. bieneusi population from different hosts, with phylogenetic, structure, and median-joining network analyses all indicating the existence of host and geographical isolation. The identification of isolates belonging to nine human-pathogenic genotypes indicates that pigs play an important role in the dissemination of E. bieneusi, improving our present understanding of E. bieneusi epidemiology in the studied region.

Molecular detection of Enterocytozoon bieneusi from bats in South Korea

Enterocytozoon bieneusi, which has recently been re-classified as a fungus, was identified in 5.2% (3/58) bat intestinal tissues and 1.9% (4/210) bat feces collected in South Korea. The positive cases were classified into six genotypes including four novel genotypes, KBAT1-KBAT4, based on sequence analysis of the E. bieneusi internal transcribed spacer (ITS) region. In addition, a novel genotype, KBAT3, belonged to group 1, which is considered having zoonotic potential by phylogenetic analysis of the E. bieneusi ITS region. This study expands our knowledge of the host range of E. bieneusi.

Prevalence and genotypes of Enterocytozoon bieneusi in pigs in southern China

Enterocytozoon bieneusi is one of the most important causative agents of microsporidiosis, causing diarrhoea the symptoms of enteric disease in humans and animals. Although there is some information on the prevalence and genotypes of E. bieneusi in China, there is still a lack of data in pigs in southern China. In the present study, a total of 396 faecal specimens were collected from pigs in Zhejiang, Guangdong and Yunnan provinces in southern China, and were examined by nested PCR amplification of the ribosomal internal transcribed spacer (ITS) for the prevalence and genotypes of E. bieneusi. The overall prevalence of E. bieneusi in pigs was 31.57% (125/396), forming 15 genotypes, including 9 known genotypes (EbpC, EbpA, D, G, H, PigEBITS5, Henan-IV, KIN-1, CHS5) and 6 novel genotypes (GD1, ZJ1, ZJ2, YN1, YN2 and YN3), which were all clustered into Group 1. Moreover, multilocus sequence typing (MLST) showed that 6, 3, 4 and 5 types were identified in MS1, MS3, MS7 and MS4 loci, respectively, representing four multilocus genotypes (MLGs), designated as MLGs novel-1 to novel-4 in the present study. This is the first detailed study of E. bieneusi using MLST in pigs in southern China, which extended information about the distribution of E. bieneusi genotypes in China.

Prevalence and multi-locus genotypes of Enterocytozoon bieneusi in black-boned sheep and goats in Yunnan Province, southwestern China

Enterocytozoon bieneusi is a common pathogen in sheep and goats worldwide, threatening husbandry development and public health. However, there were few reports on native breeds of sheep and goats in China. In the present study, we investigated the prevalence and multi-locus genotypes (MLGs) of E. bieneusi in two important local breeds, black-boned sheep and goats, in Yunnan province, southwestern China. Of 661 faecal specimens collected from five counties of Yunnan province, 70 (10.59%) were positive for E. bieneusi infection. Infections were found in both black-boned sheep and goats, but no significant difference in prevalence was detected between two species. E. bieneusi was found in all age groups of black-boned sheep, while no infections were observed in 0-2-month black-boned goats. 12 genotypes were identified based on sequence variations of the internal transcribed spacer, including 10 known genotypes (BEB6, COS I, SX1, CM21, CHG3, CHG1, CHS5, EbpC, COS II, PigEb4) and two novel genotypes (named as YNS1 and YSM1), with BEB6 as the prevalent genotype both in black-boned sheep and goats. Phylogenetic analysis indicated that three genotypes of them, namely EbpC, CHS5 and PigEb4, were clustered into the zoonotic group 1, while the remaining nine genotypes were belonged to the host-adapted group 2. Multi-locus sequence typing (MLST) revealed 12 distinct multilocus genotypes (MLGs), with 11 MLGs detected in black-boned sheep and only one found in one black-boned goat. These findings expanded the reservoirs of E. bieneusi and provided fundamental data for controlling E. bieneusi infection in native small ruminants as well as other hosts in this province.

Molecular characterization and new genotypes of Enterocytozoon bieneusi in minks (Neovison vison) in China

Microsporidiosis is an emerging and opportunistic disease, and Enterocytozoon bieneusi is the main cause of this disease in humans. Little information is available on prevalence and genotyping of E. bieneusi in minks. We collected 559 feces samples of minks from Heilongjiang and Jilin provinces in 2017, and studied E. bieneusi prevalence by nested PCR. A total of 23 out of 559 minks (4.1%) were detected as E. bieneusi-positive, and were raised in five of the seven investigated farms. Age was the only risk factor associated with E. bieneusi prevalence in investigated minks through logistic regression analysis. Sequence analysis of the ITS gene revealed that five E. bieneusi ITS genotypes, including Peru11, EbpC, and three novel genotypes (HLJM-1, HLJM-2 and JLM-1) were present, suggesting minks may be a potential source of human microsporidiosis.

Prevalence and genotypes of Enterocytozoon bieneusi in China

Enterocytozoon bieneusi has been considered as the most frequently diagnosed microsporidian species in humans and various animal species, accounting for more than 90% of the cases of human microsporidiosis. Spores of this pathogen excreted from both symptomatic and asymptomatic hosts into environment also would be an important source of waterborne outbreak of microsporidiosis. Due to limited effective drugs available but with too much side effects to mammals (eg. toxic), accurate characterization of E. bieneusi in both humans and animals is essential to implement effective control strategies to this pathogen. In China, E. bieneusi infection was presented in humans and some animals with high prevalence. Analysis of genetic variations of the internal transcribed spacer (ITS) sequences found 361 genotypes in China, and some novel genotypes were identified in some specific hosts. Additionally, associations between infections and some risk factors were also observed. In the present article, we reviewed the current status of prevalence, genotypes, multilocus genotypes (MLGs) in humans, various animals and waters in China. These findings will provide basic information for developing effective control strategies against E. bieneusi infection in China as well as other countries.

New operational taxonomic units of Enterocytozoon in three marsupial species

Background

Enterocytozoon bieneusi is a microsporidian, commonly found in animals, including humans, in various countries. However, there is scant information about this microorganism in Australasia. In the present study, we conducted the first molecular epidemiological investigation of E. bieneusi in three species of marsupials (Macropus giganteus, Vombatus ursinus and Wallabia bicolor) living in the catchment regions which supply the city of Melbourne with drinking water.

Methods

Genomic DNAs were extracted from 1365 individual faecal deposits from these marsupials, including common wombat (n = 315), eastern grey kangaroo (n = 647) and swamp wallaby (n = 403) from 11 catchment areas, and then individually tested using a nested PCR-based sequencing approach employing the internal transcribed spacer (ITS) and small subunit (SSU) of nuclear ribosomal DNA as genetic markers.

Results

Enterocytozoon bieneusi was detected in 19 of the 1365 faecal samples (1.39%) from wombat (n = 1), kangaroos (n = 13) and wallabies (n = 5). The analysis of ITS sequence data revealed a known (designated NCF2) and four new (MWC_m1 to MWC_m4) genotypes of E. bieneusi. Phylogenetic analysis of ITS sequence data sets showed that MWC_m1 (from wombat) clustered with NCF2, whereas genotypes MWC_m2 (kangaroo and wallaby), MWC_m3 (wallaby) and MWC_m4 (kangaroo) formed a new, divergent clade. Phylogenetic analysis of SSU sequence data revealed that genotypes MWC_m3 and MWC_m4 formed a clade that was distinct from E. bieneusi. The genetic distinctiveness of these two genotypes suggests that they represent a new species of Enterocytozoon.

Conclusions

Further investigations of Enterocytozoon spp. from macropods and other animals will assist in clarifying the taxonomy and epidemiology of these species in Australia and elsewhere, and in assessing the public health risk of enterocytozoonosis.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2954-x) contains supplementary material, which is available to authorized users.

Enterocytozoon bieneusi in Minks (Neovison vison) in Northern China: A Public Health Concern

Enterocytozoon bieneusi is the most important causative agent of microsporidiosis and can infect almost all vertebrate and invertebrate hosts, including minks (Neovison vison). In the present study, a total of 298 feces samples (including 79 from Heilongjiang province, 31 from Hebei province, 67 from Jilin province, 90 from Liaoning province, and 31 from Shandong province, Northern China) were examined by nested PCR amplification of the internal transcribed spacer (ITS) region of the rRNA gene. The overall prevalence of E. bieneusi in minks was 10.1%, with 10.5% in Jilin province, 32.3% in Hebei province, 8.9% in Liaoning province, 0% in Shandong province, and 6.3% in Heilongjiang province. Furthermore, multiple logistic regression analysis revealed that region was only risk factors associated with E. bieneusi infection in the investigated minks. Five E. bieneusi ITS genotypes (three known genotypes, namely D, Peru11, and EbpC; two novel genotypes, namely, NCM-1 and NCM-2) were found in the current study. Importantly, genotypes D, Peru11 and EbpC, previously identified in humans, were also found in minks, which suggested that minks are the potential sources of human microsporidiosis. To the best of our knowledge, this is the first report of E. bieneusi infection in minks worldwide. The results of the present survey have implications for the controlling E. bieneusi infection in minks, other animals and humans.

Intestinal microsporidiosis in Strasbourg from 2014 to 2016: emergence of an Enterocytozoon bieneusi genotype of Asian origin

Microsporidia cause opportunistic infections in highly immunodeficient individuals. Few studies on the epidemiology of these infections have been conducted in France. Between 2014 and 2016, we undertook a study to estimate the prevalence and circulating genotypes of this fungus-related micro-organism among the population of Strasbourg University Hospital. Samples were collected from hospitalized patients and analyzed using microscopy and molecular assays. Strains from positive subjects were sequenced for genotyping. Only 7/661 patients (1.1%) were positive for microsporidia, and the only species identified was Enterocytozoon bieneusi. Two patients presented immunodeficiency linked to AIDS, and five transplant recipients presented immunodeficiency linked to immunosuppressive therapies. Only five patients received specific antimicrosporidial treatment, but clinical outcomes were good in all cases. We identified four genotypes: A and D in patients with AIDS, and C and S9 in transplant recipients. To date, genotype S9 has been described only once. This genotype is similar to those found in farm animals in China. Because some of these animals have been introduced to Central Europe, we postulate that this genotype might be of Asian origin. Thus, genotyping microsporidial strains may be of epidemiological and clinical interest to identify potential outbreak sources depending on the infecting strains.

Human-Pathogenic Enterocytozoon bieneusi in Captive Giant Pandas (Ailuropoda melanoleuca) in China

Human and animal infections of Enterocytozoon bieneusi (E. bieneusi) have consistently been reported worldwide, garnering public attention; however, the molecular epidemiology of E. bieneusi in the giant panda remains limited. We surveyed captive giant pandas in China for the presence of E. bieneusi by using PCR and sequence analysis of the ribosomal internal transcribed spacer (ITS) revealing a 34.5% positive rate, with seven known genotypes (SC02, EpbC, CHB1, SC01, D, F, and Peru 6) and five novel genotypes (SC04, SC05, SC06, SC07, and SC08) identified. We similarly analyzed water samples, and E. bieneusi was detected in two samples, with genotype SC02 identified. Phylogenetic analysis revealed that CHB1 did not cluster with any recognized group, while the remaining genotypes belonged to group 1. The predominance of zoonotic group 1 genotypes indicates a public health threat that giant pandas could spread E. bieneusi to humans. The identification of E. bieneusi in water samples suggests giant pandas could contribute to water contamination. Effective control measures are therefore needed to minimize the contamination of the water and prevent a human microsporidiosis outbreak.

Molecular characterization and new genotypes of Enterocytozoon bieneusi in pet chipmunks (Eutamias asiaticus) in Sichuan province, China

BACKGROUND

Enterocytozoon bieneusi, the most commonly identified microsporidian species in humans, is also identified in livestock, birds, rodents, reptiles, companion animals, even wastewater. However, there is no information available on occurrence of E. bieneusi in pet chipmunks. The aim of the present study was to determine the genotypes, molecular characterization of E. bieneusi in pet chipmunks, and assess the zoonotic potential.

RESULTS

A total of 279 fecal specimens were collected from chipmunks from seven pet shops and one breeding facility in Sichuan province, China. The prevalence for E. bieneusi was 17.6% (49/279) based on nested PCR targeting the internal transcribed spacer (ITS) region. The prevalence of E. bieneusi in chipmunks < 90 days of age was significantly higher than that in older chipmunks; however, differences among different sources and between genders were not significant. Eight genotypes of E. bieneusi were identified, including four known genotypes (D, Nig7, CHG9, and CHY1) and four novel genotypes (SCC-1 to 4). Phylogenetic analysis classified these genotypes into four distinct groups as follows: genotypes D and CHG9 clustered into group 1 of zoonotic potential; genotypes Nig7 and CHY1 clustered into group 6 and a new group, respectively; the four novel genotypes (SCC-1 to 4) formed a separate group named group 10.

CONCLUSIONS

To the best of our knowledge, this is the first study reporting the prevalence and genotypes of E. bieneusi in pet chipmunks in China. Genotypes D and Nig7, found in chipmunks in this study, have also been previously identified in humans, which suggests that chipmunks might play a role in the transmission of this pathogen to humans.

Genetic diversity within dominant Enterocytozoon bieneusi genotypes in pre-weaned calves

Background

Cattle are commonly infected with the microsporidian parasite Enterocytozoon bieneusi. Sequence characterization of E. bieneusi in these animals at the ribosomal internal transcribed spacer (ITS) locus had identified I, J and BEB4 as the dominant genotypes. However, current studies on E. bieneusi in dairy cattle are mostly on infection rates and genotype distribution. This study aims to examine the intragenotypic diversity within dominant E. bieneusi genotypes in pre-weaned dairy calves in Shanghai, China.

Methods

Enterocytozoon bieneusi genotypes and subtypes were identified by PCR sequence analysis of ITS and multilocus sequence typing (MLST), based on material from farms. Chi-square test was used to examine differences in E. bieneusi infection rates between farms or age groups.

Results

The overall infection rate of E. bieneusi was 26.5% (214/809), ranging from 12.6% (Farm 5) to 38.5% (Farm 4). Infection rates increased with age during early life, with the peak infection rate (43.0%; 43/100) occurring at six weeks. Four genotypes were present, including J (n = 145, 67.8%), BEB4 (n = 59, 27.6%), CHN4 (n = 4, 1.9%) and CHN15 (n = 1, 0.5%), with the former two belonging to Group 2 and the latter two belonging to Group 1. Differences were detected in the distribution of the dominant genotypes J and BEB4 among five study farms. Altogether, 10 multilocus genotypes (MLGs) were identified in the two dominant ITS genotypes, including MLG-J1 to MLG-J8 of genotype J and MLG-B1 to MLG-B2 of genotype BEB4. MLG-B1 and MLG-B2 were recovered in Farms 1, 2 and 5, whereas MLG-J1 to MLG-J5 and MLG-J6 to MLG-J8 were found in Farms 3 and 4, respectively.

Conclusions

There is extensive genetic heterogeneity within the dominant E. bieneusi genotypes J and BEB4 in dairy calves in Shanghai, China, and MLST should be used in molecular epidemiological studies of E. bieneusi in cattle.

Prevalence, genotypes, and risk factors of Enterocytozoon bieneusi in Asiatic black bear (Ursus thibetanus) in Yunnan Province, Southwestern China

Microsporidiosis is an important zoonotic disease, even leading to severe diarrhea. However, no information about prevalence and genotypes of Enterocytozoon bieneusi infection in Asiatic black bears in southwestern China is available. The objectives of the present study were to investigate the prevalence of E. bieneusi and to characterize their genotypes using the nested PCR amplification of the internal transcribed spacer region of the ribosomal RNA gene cluster and multilocus sequence typing (MLST). The overall prevalence of E. bieneusi was 19.75% (80/405) and the rate of E. bieneusi in Xishuangbanna (33.33%) was significantly higher than that in any other regions (Honghe, 17.65%; Dehong, 13.04%; Kunming, 0; P = 0.01). Sequence analysis revealed that 4 known genotypes (D, n = 2; SC02, n = 10; SC01, n = 5; and CHB1, n = 4) and 13 novel genotypes (designed MJ1-MJ13) were identified. When 17, 5, 14, and 34 sequences at loci MS1, MS3, MS4, and MS7 via MLST analyses, representing 4, 4, 5, and 10 genotypes, respectively, were completed, one multilocus genotype (MLG novel-ABB1) was identified. This is the first report of E. bieneusi in Asiatic black bear in Yunnan province, Southwestern China. The results indicated the potential zoonotic risk of this parasite through the Asiatic black bear in this region and provided foundation data for preventing and controlling E. bieneusi infection of many other animals and humans in these regions.

Molecular Characterization of Enterocytozoon bieneusi in Wild Carnivores in Spain

Microsporidia comprises a diverse group of obligate intracellular parasites that infect a broad range of invertebrates and vertebrates. Among Microsporidia, Enterocytozoon bieneusi is the most frequently detected species in humans and animals worldwide bringing into question the possible role of animal reservoirs in the epidemiology of this pathogen. Although E. bieneusi is an emerging zoonotic pathogen able to infect many domestic and wild mammals that could act as reservoir of infection for humans and other animals, only few studies have documented its occurrence in wild carnivores. To determine the occurrence of E. bieneusi in wild carnivores, we examined 190 wild carnivores collected from different locations in Spain. Twenty-five fecal samples (13.2%) from three host species (European badger, beech marten, and red fox) were E. bieneusi-positive by PCR. Nucleotide sequence analysis of the ITS region revealed a high degree of genetic diversity with a total of eight distinct genotypes including four known (PtEbIX, S5, S9, and WildBoar3) and four novel (EbCar1-EbCar4) genotypes identified. Phylogenetic analysis showed that the four novel genotypes (EbCar1-EbCar4), S5, S9, and WildBoar3 clustered within the previously designated zoonotic Group 1. Our results demonstrate that human-pathogenic genotypes are present in wild carnivores, corroborating their potential role as a source of human infection and environmental contamination.

Population genetics of Enterocytozoon bieneusi in captive giant pandas of China

Background

Most studies on Enterocytozoon bieneusi are conducted based on the internal transcribed spacer (ITS) region of the rRNA gene, whereas some have examined E. bieneusi population structures. Currently, the population genetics of this pathogen in giant panda remains unknown. The objective of this study was to determine the E. bieneusi population in captive giant pandas in China.

Results

We examined 69 E. bieneusi-positive specimens from captive giant pandas in China using five loci (ITS, MS1, MS3, MS4 and MS7) to infer E. bieneusi population genetics. For multilocus genotype (MLG) analysis of E. bieneusi-positive isolates, the MS1, MS3, MS4, and MS7 microsatellite and minisatellite loci were amplified and sequenced in 48, 45, 50 and 47 specimens, respectively, generating ten, eight, nine and five types. We successfully amplified 36 specimens and sequenced all five loci, forming 24 MLGs. Multilocus sequence analysis revealed a strong and significant linkage disequilibrium (LD), indicating a clonal population. This result was further supported by measurements of pairwise intergenic LD and a standardized index of association (I^S_A) from allelic profile data. The analysis in STRUCTURE suggested three subpopulations in E. bieneusi, further confirmed using right’s fixation index (F_ST). Subpopulations 1 and 2 exhibited an epidemic structure, whereas subpopulation 3 had a clonal structure.

Conclusions

Our results describe E. bieneusi population genetics in giant pandas for the first time, improving the current understanding E. bieneusi epidemiology in the studied region. These data also benefit future studies exploring potential transmission risks from pandas to other animals, including humans.

Molecular characterization of Enterocytozoon bieneusi isolates in laboratory macaques in north China: zoonotic concerns

The significance of wild and zoo nonhuman primates (NHPs) as potential sources of human Enterocytozoon bieneusi infections has been increasingly appreciated, while the role of laboratory NHPs in zoonotic transmission of microsporidiosis remains elusive. In this study, the infection rate, genetic characteristic, and zoonotic potential of E. bieneusi were investigated for 205 laboratory macaques in Beijing, north China. The parasite was identified in 37 (18.0%) animals by nested PCR and sequencing of the ribosomal internal transcribed spacer (ITS), with an infection rate of 25.6% in Macaca fascicularis (34/133) and 4.2% in Macaca mulatta (3/72). The differences in infection rate between the two species of macaques and between young macaques aged ≤ 5 years (29.6%, 32/108) and adults aged > 5 years (5.2%, 5/97) were significant (p < 0.01). Analysis of the ITS sequence polymorphisms recognized eight known genotypes (CC4, CM1, CM2, D, Peru8, Peru11, Type IV, and WL21) and two new genotypes (named as CMB1 and CMB2), with well-known human-pathogenic genotypes (D, Peru8, Peru11, and Type IV) most frequently detected. The rest genotypes (CC4, CM1, CM2, WL21, CMB1, and CMB2) were clustered into zoonotic group 1 in phylogenetic analysis. The high diversity and widespread presence of the human-pathogenic or group 1 E. bieneusi genotypes in laboratory NHPs, notably M. fascicularis and the young animals, suggest potential of zoonotic transmission. These findings imply that laboratory rhesus macaques could be significant reservoirs for human microsporidiosis.

Molecular characterization and multi-locus genotypes of Enterocytozoon bieneusi from captive red kangaroos (Macropus Rufus) in Jiangsu province, China

Enterocytozoon bieneusi is the most common pathogen of microsporidian species infecting humans worldwide. Although E. bieneusi has been found in a variety of animal hosts, information on the presence of E. bieneusi in captive kangaroos in China is limited. The present study was aimed at determining the occurrence and genetic diversity of E. bieneusi in captive kangaroos. A total of 61 fecal specimens (38 from red kangaroos and 23 from grey kangaroos) were collected from Nanjing Hongshan Forest Zoo and Hongshan Kangaroo Breeding Research Base, Jiangsu province, China. Using the nested PCR amplification ITS gene of rRNA of E. bieneusi, totally 23.0% (14/61) of tested samples were PCR-positive with three genotypes (i.e. one known genotype, CHK1, and two novel genotypes, CSK1 and CSK2). Multi-locus sequence typing using three microsatellites (MS1, MS3, and MS7) and one minisatellite (MS4) revealed one, five, two, and one types at these four loci, respectively. In phylogenetic analysis, the two genotypes, CHK1 and CSK1, were clustered into a new group of unknown zoonotic potential, and the novel genotype CSK2 was clustered into a separate clade with PtEb and PtEbIX. To date, this is the first report on the presence of E. bieneusi in captive red kangaroos in Jiangsu province, China. Furthermore, a high degree of genetic diversity was observed in the E. bieneusi genotype and seven MLGs (MLG1-7) were found in red kangaroos. Our findings suggest that infected kangaroo may act as potential reservoirs of E. bieneusi and be source to transmit infections to other animal.

Detection of Enterocytozoon bieneusi in White Yaks in Gansu Province, China

Enterocytozoon bieneusi, the most common zoonotic pathogen of microsporidiosis, has been found in various animals and humans, but no information is available concerning the prevalence and genotypes of E. bieneusi in white yaks (Bos grunniens). In the present study, 353 faecal samples from white yaks in Tianzhu Tibetan Autonomous County, Gansu Province, Northwestern China, were collected and examined by PCR amplification of the internal transcribed spacer gene to estimate E. bieneusi prevalence and identify their genotypes. Of the 353 faecal samples, 4 (1.13%) were tested E. bieneusi-positive. Sequences analysis revealed that two known genotypes, namely, I (n = 1) and BEB4 (n = 2), and a novel genotype, namely, WCY1 (n = 1), were found in this study. Among them, genotype WCY1 was clustered into Group 1, and genotypes I and BEB4 belonged to Group 2. The present study firstly indicates the existence of E. bieneusi in yaks in Gansu Province, Northwestern China. This is also the first record of E. bieneusi in white yaks. Effective measures should be taken to control E. bieneusi infection in white yaks, other animals, and humans.

Occurrence of Enterocytozoon bieneusi in Donkeys (Equus asinus) in China: A Public Health Concern

Enterocytozoon bieneusi is an important zoonotic parasite. It can infect virtually all animal species and has a global distribution. However, the prevalence of E. bieneusi in donkeys (Equus asinus) has only been reported in Algeria and Spain, and no information is available concerning genotypes of E. bieneusi in donkeys worldwide. In the present study, a total of 301 donkey fecal samples (48 from Jilin Province, 224 from Shandong Province and 29 from Liaoning Province) were collected and examined by PCR amplification of the internal transcribed spacer (ITS) region. The overall E. bieneusi prevalence was 5.3% (16/301), with 6.3% (3/48) in Jilin Province, 4.9% (11/224) in Shandong Province, and 6.9% (2/29) in Liaoning Province. Prevalence in different age groups ranged from 4.2 to 5.5%. E. bieneusi prevalence in donkeys sampled in different seasons varied from 4.2 to 6.5%. Altogether, four E. bieneusi genotypes were identified in this study, with two known genotypes (J and D) and two novel genotypes (NCD-1and NCD-2). Phylogenetic analysis revealed that genotypes D, NCD-1 and NCD-2 belonged to group 1, while the remaining genotype J was clustered into group 2. These findings revealed the occurrence of E. bieneusi in donkeys in China for the first time. Moreover, the present study also firstly genotyped the E. bieneusi in donkeys worldwide. These findings extend the distribution of E. bieneusi genotypes and provide baseline data for controlling E. bieneusi infection in donkeys, other animals and humans.

First survey of Cryptosporidium, Giardia and Enterocytozoon in diarrhoeic children from Wuhan, China

Intestinal protozoan pathogens cause significant diarrhoeal diseases in children. However, to date, there has been limited genetic study of the intestinal pathogens Cryptosporidium, Giardia and Enterocytozoon in humans in China, with the exception of research in a small number of cities/provinces. In the present study, PCR-based tools were used to detect and characterise these protistan parasites from 500 children with a history of diarrhoea in Wuhan and environs, Hubei province, China. Genomic DNAs from faecal samples were screened for the particular protists by PCR utilising regions in the small subunit (SSU) of the nuclear ribosomal RNA, the 60kDa glycoprotein (gp60), the internal transcribed spacer of nuclear ribosomal DNA (ITS) and/or the triose phosphate isomerase (tpi) genes as markers. Cryptosporidium meleagridis subtype IIIb (10/500, 2.0%), Giardia duodenalis assemblage A (7/500, 1.4%) and Enterocytozoon bieneusi genotype D (1/500, 0.2%) were identified in small percentages of the 500 samples. No significant gender- or age-associated differences in the prevalence of Cryptosporidium and Giardia infections were found. Future studies might focus on the occurrence of these protists in children as well as animals, with an emphasis on Cryptosporidium meleagridis in pets and agriculturally important birds, in different parts of Hubei province.

Presence of zoonotic Cryptosporidium scrofarum, Giardia duodenalis assemblage A and Enterocytozoon bieneusi genotypes in captive Eurasian wild boars (Sus scrofa) in China: potential for zoonotic transmission

Background

Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi are the main causal pathogens of gastrointestinal disease. However, there are limited reports about the prevalence of these organisms in captive Eurasian wild boars worldwide. Therefore, we examined the occurrence and identified the species/assemblages/genotypes of these pathogens in captive Eurasian wild boars, and estimated the zoonotic potential.

Findings

Of 357 fecal samples collected from captive Eurasian wild boars in China, 155 (43.4%) were infected with Cryptosporidium, G. duodenalis and/or E. bieneusi. The infection rates significantly differed in different areas, but did not differ between wild boars kept indoors and outdoors. Three (0.8%), 11 (3.1%) and 147 (41.2%) fecal samples were positive for Cryptosporidium, G. duodenalis and E. bieneusi, respectively. Sequence analysis of SSU rRNA gene revealed that all of the Cryptosporidium strains belonged to C. scrofarum. Based on the sequence analysis of the β-giardia gene of G. duodenalis, assemblages E and A were characterized. Fourteen E. bieneusi genotypes comprising five novel (WildBoar 7–11) and eight known (EbpC, F, CHG19, CHC5, PigEBITS5, D, RWSH4, SC02) genotypes were identified by ITS sequencing. EbpC was the most frequent genotype, detected in 85 specimens. Phylogenetic analysis revealed that all 14 genotypes belonged to Group 1.

Conclusions

This first report on the occurrence of Cryptosporidium, G. duodenalis and E. bieneusi in captive wild boars in China indicates that the presence of zoonotic species/assemblages/genotypes poses a threat to public health. The findings suggest that wild boars could be a significant source of human infection and water pollution.

Molecular characterization and multilocus genotypes of Enterocytozoon bieneusi among horses in southwestern China

Background

Enterocytozoon bieneusi is one of the most prevalent causative species of diarrhea and enteric diseases in various hosts. E. bieneusi has been identified in humans, mammals, birds, rodents and reptiles in China, but few studies have reported E. bieneusi in horses. Therefore, the present study was conducted to assess the prevalence, molecular characteristics and zoonotic potential of E. bieneusi among horses in southwestern China.

Findings

Three hundred and thirty-three fecal specimens were collected from horses on five farms in the Sichuan and Yunnan provinces of southwestern China. The prevalence of E. bieneusi was 22.5 % (75/333), as determined by nested polymerase chain reaction and sequencing analysis of the internal transcribed spacer region of the ribosomal RNA gene of E. bieneusi. Altogether, 10 genotypes were identified among the 75 E. bieneusi-positive samples: four of these genotypes were known (horse1, horse2, SC02 and D) and six were novel (SCH1-4 and YNH1-2). Multilocus sequence typing using three microsatellites (MS1, MS3 and MS7) and one minisatellite (MS4) revealed three, two, three and three genotypes at these four loci, respectively. In phylogenetic analysis, all the genotypes of E. bieneusi obtained in this study were clustered into three distinct groups: D, SC02 and SCH1-3 were clustered into group 1 (zoonotic potential); SCH4 was clustered into group 2 (cattle-hosted); whereas horse2, YNH1 and YNH2 were clustered into group 6 (unclear zoonotic potential).

Conclusions

This is the first report of E. bieneusi among horses in southwestern China. This is also the first multilocus genotyping analysis using microsatellite and minisatellite markers of E. bieneusi in horses. The presence of genotype D, which was previously identified in humans, and genotypes SC02 and SCH1-3, which belong to potential zoonotic group 1, these results indicate that horses are a potential source of human E. bieneusi infections in China.

Cryptosporidium spp. and Enterocytozoon bieneusi in introduced raccoons (Procyon lotor)-first evidence from Poland and Germany

The raccoon (Procyon lotor) carnivore native to North America is a fast spreading, invasive species in the Europe now. At the moment, the highest population occupies areas near the German-Polish border. The data on the occurrence of Cryptosporidium spp. and microsporidia in raccoons is limited to North America's territory and is totally lacking in the case of their introduction to Europe. Therefore, the objective of this study was to investigate the occurrence of microparasites, i.e., Cryptosporidium spp. and microsporidia in the introduced raccoons obtained from localities in Poland and Germany. A PCR-based approach that permitted genetic characterization via sequence analysis was applied to raccoon fecal samples (n = 49), collected during 2012-2014. All fecal samples were simultaneously tested with the use of genetic markers, and DNA of microsporidia and Cryptosporidium spp. was detected among the examined raccoons. The results of our research confirmed the presence of Cryptosporidium skunk genotype and Enterocytozoon bieneusi NCF2 genotype. The results suggest a possible role of raccoons in the contamination of the environment, including urban areas, with pathogens of zoonotic significance as well as their role in the transmission and introduction of new genotypes of microparasites in the areas where P. lotor has not been observed yet. To our knowledge, there has been no literature data on the above genotypes detected previously in humans or animals from the examined study sites so far.

Prevalence, risk factors and molecular characterization of Enterocytozoon bieneusi in raccoon dogs (Nyctereutes procyonoides) in five provinces of Northern China

The disease microsporidiosis is found worldwide and is mainly caused by Enterocytozoon bieneusi. E. bieneusi can infect a wide range of hosts; however, information regarding the prevalence and genotyping of E. bieneusi infection in raccoon dogs (Nyctereutes procyonoides) is limited. Therefore, in 2015, we examined 305 faecel samples from 80 farmed raccoon dogs in Jilin Province, from 54 in Hebei Province, from 72 in Liaoning Province, from 29 in Shandong Province, and from 40 in Heilongjiang Province. The overall prevalence of E. bieneusi infection in farmed raccoon dogs was 22.30%. Logistic regression analysis suggests that age, gender and region of raccoon dogs were highly related to the prevalence of E. bieneusi infection. Moreover, six E. bieneusi internal transcribed spacer (ITS) region sequences, including four known genotypes, namely D, CHN-DC1, NCF2, and CHN-F1, and two novel genotypes (NCR1 and NCR2), were identified in the present study. The present study firstly indicated the existence of E. bieneusi genotypes NCF2, NCR1, NCR2and CHN-F1 in infected raccoon dogs in Northern China. Integrated control strategies should be implemented to limit E. bieneusi infection in farmed raccoon dogs, and to prevent transmission of this disease to other animals and humans.