First report of Giardia duodenalis and Enterocytozoon bieneusi in forest musk deer (Moschus berezovskii) in China

Report of Giardia duodenalis in a non-captive chital Axis axis (Erxleben 1777) in Santa Catarina, South of Brazil

Giardiasis is an infection of the small intestine by protozoa of the genus Giardia, which has a wide range of susceptible hosts, including domestic and wild animals and humans. Giardia is a zoonotic agent and represents one of the main human parasites, with high prevalence and great importance in public health. This report aims to describe the parasitism of a non-captive Chital deer (Axis axis) by Giardia duodenalis. The animal, after being rescued by soldiers from the 2nd Platoon of the 2nd Company of the 2nd Battalion of the Environmental Military Police of the State of Santa Catarina, was sent to the Wildlife Studies Center (NEVS) of the University of Western Santa Catarina (UNOESC). During clinical care, an exposed fracture in the left pelvic limb and signs of acute respiratory failure were found. Fecal samples were collected for later parasitological diagnosis. Two techniques were applied: centrifugal flotation with zinc sulfate, to diagnose parasites of the gastrointestinal system, and Baermann, to search for parasitism in the respiratory tract. The investigation revealed the presence of Giardia duodenalis. The animal died on the same day of its arrival due to a cardiorespiratory arrest. The presence of this parasite in an invasive exotic deer species highlights its epidemiological importance, as it can act as a source of infection and spread the disease to humans and other animals.

Molecular cloning, prokaryotic expression and its application potential evaluation of interferon (IFN)-ω of forest musk deer

Forest musk deer (Moschus berezovskii) are currently a threatened species under conservation, and the development of captive populations is restricted by health problems. To evaluate the application potential of interferon (IFN)-ω in the prevention and control of forest musk deer disease, 5 forest musk deer IFN-ω (fmdIFNω) gene sequences were successfully obtained by homologous cloning method for the first time. FmdIFNω5 was selected and recombinant fmdIFNω protein (rIFNω) was successfully expressed by pGEX-6P-1 plasmid and E. coli expression system. The obtained protein was used to stimulate forest musk deer lung fibroblasts cells FMD-C1 to determine its regulatory effect on interferon-stimulated genes (ISGs). In addition, an indirect ELISA method based on anti-rIFNω serum was established to detect endogenous IFN-ω levels in 8 forest musk deer. The results showed that there were 18 amino acid differences among the 5 fmdIFNω subtypes, all of which had the basic structure to exert the activity of type I IFN and were close to Cervus elaphus IFN-ω in the phylogenetic tree. The protein expressed was 48 kDa, and the transcription levels of all ISGs were increased in FMD-C1 cells stimulated by rIFNω, and the amount of transcription accumulation was time-dependent. Meanwhile, Anti-rIFNω serum of mice could react with both rIFNω and forest musk deer serum, and the OD450nm value of forest musk deer serum with the most obvious symptoms was the highest, suggesting that the level of natural IFN-ω in different forest musk deer could be monitored by the rIFNω-based ELISA method. These results indicate that fmdIFNω has the potential as an antiviral drug and an early indication of innate immunity, which is of great significance for the prevention and control of forest musk deer diseases.

Occurrence and Molecular Characteristics of Microsporidia in Captive Red Pandas (Ailurus fulgens) in China

Enterocytozoon bieneusi and Encephalitozoon spp. are microsporidian pathogens with zoonotic potential that pose significant public health concerns. To ascertain the occurrence and genotypes of E. bieneusi and Encephalitozoon spp., we used nested PCR to amplify the internal transcribed spacer (ITS) gene and DNA sequencing to analyze 198 fecal samples from red pandas from 6 zoos in China. The total rate of microsporidial infection was 15.7% (31/198), with 12.1% (24/198), 1.0% (2/198), 2.0% (4/198) and 1.0% (2/198) for infection rate of E. bieneusi, Encephalitozoon cuniculi, Encephalitozoon intestinalis and Encephalitozoon hellem, respectively. One red panda was detected positive for a mixed infection (E. bieneusi and E. intestinalis). Red pandas living in semi-free conditions are more likely to be infected with microsporidia (χ2 = 6.212, df = 1, p < 0.05). Three known (SC02, D, and PL2) and one novel (SCR1) genotypes of E. bieneusi were found. Three genotypes of E. bieneusi (SC02, D, SCR1) were grouped into group 1 with public health importance, while genotype PL2 formed a separate clade associated with group 2. These findings suggest that red pandas may serve as a host reservoir for zoonotic microsporidia, potentially allowing transmission from red pandas to humans and other animals.

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.

Molecular detection and characterization of Enterocytozoon bieneusi in captive alpine musk deer (Moschus chrysogaster) in Central and Eastern of Gansu Province, China

The most ubiquitously diagnosed microsporidian species in animals and humans is Enterocytozoon bieneusi (E. bieneusi). In this case, this work aimed to probe the occurrence and genotypes of this pathogen in captive alpine musk deer (Moschus chrysogaster) in Gansu Province, China. After fecal sample collection (n = 201) from three farms in Gansu, the internal transcribed spacer (ITS) region of the rRNA gene was probed by PCR for detection and genotyping of E. bieneusi. The infection rate of E. bieneusi in alpine musk deer was 6.0% (12/201), with 0% (0/36), 7.7% (5/65) and 7.0% (7/100) in farms 1 to 3, respectively. The infection rate of E. bieneusi in young alpine musk deer (3.2%; 1/31) is lower than that of adults (6.5%; 11/170), with no evident significant differences between age groups (P > 0.05). Three known genotypes D (n = 8), EbpA (n = 3) and BEB6 (n = 1) were identified by sequence analysis. This is the first such scrutiny of E. bieneusi infection in alpine musk deer in China as per our knowledge. Genotypes D and EbpA were common in humans and animals that is suggestive of the plausible zoonotic role in E. bieneusi transmission by alpine musk deer.

Occurrence, genetic diversity and zoonotic potential of Blastocystis sp. in forest musk deer (Moschus berezovskii) in Southwest China

Blastocystis sp. is a common anaerobic protist with controversial pathogenicity that can infect various animals and humans. However, there are no reports of Blastocystis sp. infections in forest musk deer (Moschus berezovskii). The present study was designed to examine the occurrence, subtype distribution and genetic characterization of Blastocystis sp. in forest musk deer in southwestern China, and to assess the potential for zoonotic transmission. A total of 504 fresh stool samples were collected from captive forest musk deer in four distinct areas of southwestern China. Overall, 14.7% of the forest musk deer (74/504) were found to be infected with Blastocystis sp. The highest occurrence of Blastocystis sp. was observed in Dujiangyan (27.5%), followed by Maerkang (23.3%). The occurrence of Blastocystis sp. was 7.9% and 4.1% in Shimian and Hanyuan, respectively. Significant differences in the occurrence of Blastocystis sp. among different areas were observed (p < 0.05), while we did not observe significant differences among animals of different age and sex (p > 0.05). Two known zoonotic subtypes (ST1 and ST5) and three animal-predominant subtypes (ST10, ST13, and ST14) were identified, of which ST10 was the most common (36/74, 48.6%). Our findings highlight that forest musk deer may be potential reservoirs of zoonotic human Blastocystis sp. infections.

Molecular characterizations of Giardia duodenalis based on multilocus genotyping in sheep, goats, and beef cattle in Southwest Inner Mongolia, China

Giardia duodenalis is an important zoonotic parasite that causes economic losses to animal husbandry and threatens public health. In the present study, a total of 1466 fresh fecal samples were collected from sheep (n = 797), goats (n = 561) and beef cattle (n = 108) in Southwest Inner Mongolia, China. Giardia duodenalis was initially screened via nested polymerase chain reaction (PCR) targeting the β-giardin (bg) gene, and bg-positive samples were subjected to PCR amplification targeting the glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) genes. A total of 4.0% of samples (58/1466) were positive for G. duodenalis, with a prevalence of 3.4% in sheep, 3.7% in goats and 5.2% in beef cattle. Three G. duodenalis assemblages (A, B, and E) were identified, with E as the prevalent assemblage. Four and one novel assemblage E sequences were obtained for the gdh and tpi loci, respectively and four assemblage E multilocus genotypes (MLG) were obtained. This study demonstrates high genetic variations in G. duodenalis assemblage E, and provides baseline data for preventing and controlling G. duodenalis infection in livestock in Inner Mongolia.

Changes in Gut Microbiota Composition Associated with the Presence of Enteric Protist Blastocystis in Captive Forest Musk Deer (Moschus Berezovskii)

Blastocystis is a common protistan parasite inhabiting the gastrointestinal tract of a wide range of hosts including humans and domestic and wild animals. Many studies have revealed the associations between Blastocystis and gut microbiome in humans. However, only a few studies have focused on the associations between Blastocystis and gut microbiome of animals, especially in forest musk deer (Moschus berezovskii). We investigated the effects of the Blastocystis colonization on the intestinal bacterial community compositions using amplicon sequencing targeting the V4 variable region of the 16S rRNA. Two subtypes of Blastocystis (ST5 and ST10) and Blastocystis-free (control) were included in this study. We found that compared with the forest musk deer without Blastocystis, ST10-colonized forest musk deer had higher bacterial richness and diversity, while ST5-colonized forest musk deer showed a comparable bacterial diversity. Likewise, beta diversity revealed significant differences in bacterial community structure between ST10-colonized and Blastocystis-free forest musk deer. The proportion of Bacteroidetes were significantly enriched in ST10-colonized forest musk deer. Bacterial community structure between ST5-colonized and Blastocystis-free forest musk deer did not differ significantly. The present study explored the associations between Blastocystis and gut microbial community of forest musk deer for the first time, and revealed ST10 colonization, instead of ST5, is associated with higher bacterial diversity and shifted microbial structure. Our data provides valuable insights into the associations between gut microbiomes and parasites.

IMPORTANCE Forest musk deer is listed as an endangered species by International Union for Conservation of Nature Red List, and the Chinese government has introduced captivity breeding measures to curb the rapid decline of the musk deer population since the 1950s. It has been suggested that Blastocystis colonization can modulate the composition of the host's intestinal microbiota, thereby affecting the host health. The present study investigated the effects of the Blastocystis colonization on the gut microbiota in the feces of forest musk deer in Sichuan Province, China. Two subtypes (ST5 and ST10) have differential effects on the bacterial diversity and community composition, suggesting that the study of Blastocystis should be distinguished at the subtype level. Because the pathogenicity of Blastocystis is controversial, pathogenic, or commensal, continuous monitoring of the impact of Blastocystis colonization on the intestinal microbiota is of great significance to assess its health effects on forest musk deer.

Molecular Epidemiology and Genetic Diversity of Enterocytozoon bieneusi in Cervids from Milu Park in Beijing, China

Simple Summary

Enterocytozoon bieneusi is the most prevalent microsporidian species that can cause significant intestinal diseases in both humans and animals worldwide. This study investigated the overall E. bieneusi prevalence of 21.9% (47/215) in captive and free-ranging deer species in Beijing, China. Thirteen E. bieneusi genotypes including six known and seven novel genotypes were identified. These resources will provide the insights to understand the veterinary and public health and the transmission dynamics between animal environments and human ones.

Abstract

Enterocytozoon bieneusi is the most prevalent microsporidian species that can cause zoonotic diseases in humans and animals. Despite receiving increasing attention in relation to domestic animals, there has been limited information on the infection burden of E. bieneusi in cervids. Altogether, 215 fecal samples collected from four deer species in Beijing, China were examined by nested- Polymerase Chain Reaction (PCR)targeting the internal transcribed spacer (ITS) region. The overall prevalence of E. bieneusi in deer was 21.9% (47/215), with 30.0% (24/80) in Pere David’s deer, 27.3% (15/55) in fallow deer, 12.5% (5/40) in sika deer, and 7.5% (3/40) in Chinese water deer. Thirteen E. bieneusi genotypes were identified, including six known (HLJD-V, MWC_d1, BEB6, CGC2, JLD-XV, and HND-I) and seven novel genotypes (BJED-I to BJED-V, BJFD, and BJCWD). A phylogenetic analysis showed that 38.3% of the isolates belonged to zoonotic Group 1. In addition, E. bieneusi infection was first detected in fallow deer and Chinese water deer, which could act as potential zoonotic reservoirs. Our findings suggest that E. bieneusi circulates in deer and might be of importance to public health.

Multilocus Genotyping of Giardia duodenalis in Alpine Musk Deer (Moschus chrysogaster) in China

Giardia duodenalis is the underlying cause of a significant number of outbreaks of gastrointestinal illness in humans and animals worldwide. The purpose of this study was to elucidate the prevalence and genetic diversity of G. duodenalis in captive alpine musk deer (Moschus chrysogaster) in China. A total of 202 fecal samples were collected from three farms in Gansu Province, China. Identification of G. duodenalis was conducted by nested PCR targeting the genes coding for SSU rRNA, β-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). The overall prevalence of G. duodenalis in captive alpine musk deer in surveyed area was 19.3% (39/202). Two G. duodenalis genetic assemblages were identified, namely assemblage A and E. Mixed genotype infections (A+E) were found in 15.4% (6/39) of positive samples. Multilocus genotyping (MLG) analysis of G. duodenalis isolates revealed six novel assemblage A MLGs formed by two newly-described MLG-subtypes which belonged to sub-assemblage AI. To the best of our knowledge, this is the first report on MLG of G. duodenalis isolates in captive alpine musk deer in China. The presence of zoonotic assemblages and sub-assemblages of G. duodenalis in deer species suggests that these animals may potentially act as a reservoir of this protozoan for humans.

Prevalence and genetic diversity of Enterocytozoon bieneusi in nonhuman primates in Northern and Central China

Background

Enterocytozoon bieneusi is a common enteric pathogen reported in human and many animals. But there are few reports of E. bieneusi in nonhuman primates (NHPs). The aim of this study was to examine the prevalence and molecular characterization of E. bieneusi in NHPs from Northern and Central China.

Results

A total of 299 specimens of NHPs were collected. The overall prevalence rate of E. bieneusi was 9.4% (28/299) in NHPs by ribosomal internal transcribed spacer (ITS) amplification, including 10.0% (16/160) in captive NHPs and 8.6% (12/139) in wild NHPs. In captive NHPs, the infection rate was 9.1% in male, 11.5% in female. Infection rate in juvenile ITS (6.7%) was higher than in the adult ITS (5.6%). In different regions, infection rate in Hubei (14.7%) was higher than in Henan (7.6%) and Beijing (7.9%). Five genotypes were found, including 4 known genotypes (D, HND-Ⅰ, EbpC, SHW2) and a novel genotype named NHP1. Genotype D (8/28) and NHP1 (8/28) were the most prevalent, followed by EbpC (6/28), SHW2 (4/28), and HND-Ⅰ (2/28). All the 5 genotypes belonged to zoonotic Group1.

Conclusion

These findings could deepen our understanding of E. bieneusi prevalence and genotype distribution in NHPs in China. Our study shows that NHPs may be the reservoir of zoonotic E. bieneusi and might present a potential serious threat.

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Enterocytozoon bieneusi was detected in 9.36% fecal specimens of NHPs.

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Four known genotypes (D, HND-Ⅰ, EbpC and SHW2) and a novel genotype NHP1 were detected.

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Genotypes D, HND-Ⅰ, EbpC, SHW2 and NHP1 were classified into zoonotic Group1.

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Nonhuman primates may pose a risk for human transmission.

Chronic Infections in Mammals Due to Microsporidia

Microsporidia are pathogenic organism related to fungi. They cause infections in a wide variety of mammals as well as in avian, amphibian, and reptilian hosts. Many microsporidia species play an important role in the development of serious diseases that have significant implications in human and veterinary medicine. While microsporidia were originally considered to be opportunistic pathogens in humans, it is now understood that infections also occur in immune competent humans. Encephalitozoon cuniculi, Encephalitozoon intestinalis, and Enterocytozoon bieneusi are primarily mammalian pathogens. However, many other species of microsporidia that have some other primary host that is not a mammal have been reported to cause sporadic mammalian infections. Experimental models and observations in natural infections have demonstrated that microsporidia can cause a latent infection in mammalian hosts. This chapter reviews the published studies on mammalian microsporidiosis and the data on chronic infections due to these enigmatic pathogens.

Zoonotic giardiasis: an update

Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common than believed and could be attributed mainly to contact with or contamination from just a few species of animals such as nonhuman primates, equines, rabbits, guinea pigs, chinchillas, and beavers. Future studies should be directed to advanced genetic characterization of isolates from well-designed epidemiological investigations, especially comparative analyses of isolates from humans and animals living in the same household or community. This will likely lead to better understanding of zoonotic transmission of G. duodenalis in different environmental and socioeconomic settings.

Detection of Point Prevalence and Assemblages of Giardia spp. in Dairy Calves and Sika Deer, Northeast China

Giardia lamblia (syn Giardia duodenalis) is an important protozoan parasite that can cause enterocyte damage and loss of brush border of the epithelial cells in the intestine, resulting in shortening of microvilli and altered epithelial barrier function. Many animals have been detected as the hosts of the G. lamblia. However, the information on the epidemiology and molecular detection of G. lamblia in dairy calves and sika deer in northeastern China is limited. To investigate the prevalence and genotypes of dairy calves and sika deer in northeastern China, a total of 321 fecal samples from dairy calves in Heilongjiang Province and 818 fecal samples from sika deer in four provinces (Jilin Province, Heilongjiang Province, Liaoning Province, and Inner Mongolia Autonomous Region) in China were conducted by PCR methods, between September 2017 and April 2018. The overall prevalence of G. lamblia in dairy calves in Heilongjiang Province and sika deer in the four provinces was 4.98% (16/321) and 0.61% (5/818), respectively. In this study, the point prevalence of Giardia spp. in different factor groups was dissimilar. A total of 16 Giardia spp. positive samples in dairy calves were identified as assemblage E based on the triosephosphate isomerase (tpi), β-giardine (bg), and glutamate dehydrogenase (gdh) genes. Furthermore, two positive samples of assemblage A and three positive samples of assemblage E were identified with gdh and bg genes in the sika deer. Assemblage A was zoonotic genotype of G. lamblia, and assemblage E was identified as the predominant assemblage in dairy calves and sika deer. This study reported the prevalence and genotypes of G. lamblia in dairy calves in Heilongjiang Province and sika deer in four provinces in China. These results provided basic information to understand the epidemiology of G. lamblia in dairy calves and sika deer in China.

Effect of probiotics on diversity and function of gut microbiota in Moschus berezovskii

The forest musk deer, Moschus berezovskii, is a nationally protected species of economic importance in China. However, in captive breeding programmes, they usually die as a result of diarrhoea. In this study, six M. berezovskii were randomly selected and divided into two groups: probiotics group (n = 3) and placebo (control) group (n = 3). The two groups were fed a basal diet that included 2 g probiotics (probiotic group) or 2 g whey powder (placebo group) for 30 days. Faecal samples were collected at day 0, 15 and 30 and evaluated for microbial diversity, species richness and metabolic function. Probiotic intervention significantly improved gut health in M. berezovskii by changing the overall community structure of the gut microbiota. Intake of probiotics reduced the relative abundance of pathogenic bacteria such as Escherichia coli and Citrobacter freundii in the intestinal flora and increased the relative abundance of beneficial Bifidobacterium species and other lactic acid bacteria. At the same time, gut microbiota in the probiotics group were involved in regulating degradation of phenylacetic acid and in dTDP-L-rhamnose synthesis; these processes have the potential to enhance immunity in M. berezovskii. This preliminary study revealed the beneficial effects of probiotics on the gut microbiota of M. berezovskii, which the potential to significantly improve the health, wellbeing and economic value of M. berezovskii.

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.

Evidence for Zoonotic Potential of Enterocytozoon bieneusi in Its First Molecular Characterization in Captive Mammals at Bangladesh National Zoo

To determine the occurrence and genotypes of Enterocytozoon bieneusi in captive mammals at Bangladesh National Zoo and to assess their zoonotic significance, 200 fecal samples from 32 mammalian species were examined using a nested PCR and sequencing of internal transcribed spacer (ITS) gene. Enterocytozoon bieneusi was detected in 16.5% (33/200) of the samples. Seven different ITS genotypes were identified, including two known genotypes (D and J) and five new ones (BAN4 to BAN8). Genotype D was the most common genotype being observed in 19 isolates. In phylogenetic analysis, four genotypes (D, BAN4, BAN5, and BAN6), detected in 30 isolates (90.9%), belonged to Group 1 having zoonotic potential. The sequence of genotype J found in a Malayan pangolin was clustered in so-called ruminant-specific Group 2. The other two genotypes BAN7 and BAN8 were clustered in primate-specific Group 5. To our knowledge, this is the first report of molecular characterization of E. bieneusi in Bangladesh, particularly in captive-bred wildlife in this country. The potentially zoonotic genotypes of E. bieneusi are maintained in zoo mammals that may transmit among these animals and to the humans through environmental contamination or contact.

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.

Molecular detection of Cryptosporidium and Enterocytozoon bieneusi in dairy calves and sika deer in four provinces in Northern China

The protistan pathogens Cryptosporidium and Enterocytozoon bieneusi can cause significant intestinal diseases in animals and humans. However, limited information is available regarding prevalence and molecular characterization of Cryptosporidium and E. bieneusi in ruminants in Northern China. In this study, the overall prevalence of Cryptosporidium and E. bieneusi was 19.3% (62/321) and 28.97% (93/321) in dairy calves and 1.10% (9/818) and 13.57% (111/818) in sika deer (Cervus nippon) in four provinces in Northern China, respectively. The prevalence of Cryptosporidium and E. bieneusi in different factor groups was various. Five Cryptosporidium species/genotypes were identified, of which C. parvum, C. ryanae, C. bovis, and C. andersoni were only found in dairy calves, and only Cryptosporidium deer genotype was found in sika deer. Moreover, J, I, and BEB4 ITS genotypes of E. bieneusi were found in dairy calves, and six known genotypes (JLD-III, JLD-IX, JLD-VII, EbpC, BEB6, and I) and ten novel genotypes (namely LND-I and JLD-XV to JLD-XXIII) were found in sika deer in this study. Cryptosporidium parvum and E. bieneusi genotype J were identified as the predominant species/genotypes in dairy calves, whereas the predominance of Cryptosporidium spp. and E. bieneusi in sika deer was Cryptosporidium deer genotype and BEB6, respectively. The present study reported the prevalence and genotypes of Cryptosporidium and E. bieneusi in dairy calves and sika deer in four provinces in northern China. The present findings also suggest that investigated dairy calves and sika deer may play an important role in the transmission of E. bieneusi and Cryptosporidium to humans and other animals, and also in an effort to better understand the epidemiology of these enteric pathogens in China.

Molecular epidemiology of giardiasis from a veterinary perspective

A total of eight Giardia species are accepted. These include: Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia), which infects humans and animals, Giardia agilis, Giardia ardeae, Giardia psittaci, Giardia muris, Giardia microti, Giardia peramelis and G. cricetidarum, which infect non-human hosts including amphibians, birds, rodents and marsupials. Giardia duodenalis is a species complex consisting of eight assemblages (A-H), with assemblages A and B the dominant assemblages in humans. Molecular studies to date on the zoonotic potential of Giardia in animals are problematic and are hampered by lack of concordance between loci. Livestock (cattle, sheep, goats and pigs) are predominantly infected with G. duodenalis assemblage E, which has recently been shown to be zoonotic, followed by assemblage A. In cats and dogs, assemblages A, B, C, D and F are commonly reported but relatively few studies have conducted molecular typing of humans and their pets and the results are contradictory with some studies support zoonotic transmission but the majority of studies suggesting separate transmission cycles. Giardia also infects a broad range of wildlife hosts and although much less well studied, host-adapted species as well as G. duodenalis assemblages (A-H) have been identified. Fish and other aquatic wildlife represent a source of infection for humans with Giardia via water contamination and/or consumption of undercooked fish and interestingly, assemblage B and A predominated in the two molecular studies conducted to date. Our current knowledge of the transmission dynamics of Giardia is still poor and the development of more discriminatory typing tools such as whole genome sequencing (WGS) of Giardia isolates is therefore essential.

Are molecular tools clarifying or confusing our understanding of the public health threat from zoonotic enteric protozoa in wildlife?

Emerging infectious diseases are frequently zoonotic, often originating in wildlife, but enteric protozoa are considered relatively minor contributors. Opinions regarding whether pathogenic enteric protozoa may be transmitted between wildlife and humans have been shaped by our investigation tools, and have led to oscillations regarding whether particular species are zoonotic or have host-adapted life cycles. When the only approach for identifying enteric protozoa was morphology, it was assumed that many enteric protozoa colonized multiple hosts and were probably zoonotic. When molecular tools revealed genetic differences in morphologically identical species colonizing humans and other animals, host specificity seemed more likely. Parasites from animals found to be genetically identical - at the few genes investigated - to morphologically indistinguishable parasites from human hosts, were described as having zoonotic potential. More discriminatory molecular tools have now sub-divided some protozoa again. Meanwhile, some infection events indicate that, circumstances permitting, some "host-specific" protozoa, can actually infect various hosts. These repeated changes in our understanding are linked intrinsically to the investigative tools available. Here we review how molecular tools have assisted, or sometimes confused, our understanding of the public health threat from nine enteric protozoa and example wildlife hosts (Balantoides coli - wild boar; Blastocystis sp. - wild rodents; Cryptosporidium spp. - wild fish; Encephalitozoon spp. - wild birds; Entamoeba spp. - non-human primates; Enterocytozoon bieneusi - wild cervids; Giardia duodenalis - red foxes; Sarcocystis nesbitti - snakes; Toxoplasma gondii - bobcats). Molecular tools have provided evidence that some enteric protozoa in wildlife may infect humans, but due to limited discriminatory power, often only the zoonotic potential of the parasite is indicated. Molecular analyses, which should be as discriminatory as possible, are one, but not the only, component of the toolbox for investigating potential public health impacts from pathogenic enteric protozoa in wildlife.

Prevalence and genotypes of Enterocytozoon bieneusi in wildlife in Korea: a public health concern

Background

Enterocytozoon bieneusi is a unicellular microsporidian fungal pathogen that infects a broad range of animal hosts, including wild and domestic animals and humans. The infection burden of this parasite in wild animals in Korea is largely unknown. In this study, the occurrence and genotypes of E. bieneusi were investigated in wild animal populations in Korea.

Methods

A total of 157 fecal samples (97 from Korean water deer, 48 from raccoon dogs and 12 from other taxa) were collected from wild animals at five wildlife centers in Korea. Genomic DNA was extracted from the samples and screened by nested-PCR targeting the internal transcribed spacer (ITS) region of rRNA, followed by sequence analysis to determine the genotype(s) of E. bieneusi.

Results

The overall prevalence of E. bieneusi was 45.2% (71/157), with rates of 53.6% (52/97) in Korean water deer, 35.4% (17/48) in raccoon dogs and 16.7% (2/12) in other taxa. We detected seven ITS genotypes, including one known (genotype D) and six new genotypes (Korea-WL1–Korea-WL6). Phylogenetically, all detected genotypes clustered with counterparts belonging to group 1, which includes isolates from different animal hosts and humans, suggesting their zoonotic potential.

Conclusions

Our survey results indicate that E. bieneusi circulates widely in wild animals in Korea. These findings address the role of wildlife as a potential source of microsporidiosis in domestic animals and humans.