Subtyping of Cryptosporidium cuniculus and genotyping of Enterocytozoon bieneusi in rabbits in two farms in Heilongjiang Province, China

Iberian wild leporidae as hosts of zoonotic enteroparasites in Mediterranean ecosystems of Southern Spain

Wild lagomorphs including rabbits and hares can act as natural carriers or reservoirs of bacterial and parasitic zoonotic diseases. However, little is known on the epidemiology and potential public health significance of intestinal eukaryotes in wild leporids. We examined faecal samples from European wild rabbits (Oryctolagus cuniculus, n = 438) and Iberian hares (Lepus granatensis, n = 111) collected in the Autonomous Region of Andalusia in southern Spain during 2012-2021. We searched for the presence of DNA from the main intestinal protist and microsporidial pathogens of veterinary and public health concerns using molecular methods (PCR followed by Sanger and next-generation sequencing). Giardia duodenalis was the most prevalent species found (27.8%, 153/550; 95% CI: 24.1-31.8), followed by Cryptosporidium spp. (1.3%, 7/550; 95% CI: 0.5-2.6), Blastocystis sp. (1.1%, 6/550; 95% CI: 0.4-2.4) and Encephalitozoon intestinalis (0.2%, 1/550; 95% CI: 0.0-10.1). All samples tested negative for Enterocytozoon bieneusi. Sequence analyses revealed the presence of sub-assemblage BIV (n = 1) within G. duodenalis, and Cryptosporidium cuniculus (n = 6) and Cryptosporidium andersoni (n = 1) within Cryptosporidium. The presence of ruminant-adapted C. andersoni is indicative of a potential cross-species transmission event, although a spurious infection (mechanical carriage) cannot be ruled out. Samples assigned to C. cuniculus belonged to the gp60 subtype families Va (n = 3) and Vb (n = 2). The six Blastocystis-positive samples were identified as ST2 (n = 3) and ST1 + ST2 (n = 3). Our molecular results suggest that wild rabbits and hares were primarily infected by leporid-adapted species of eukaryotic pathogens. However, the occasional findings of zoonotic G. duodenalis sub-assemblage BIV, Blastocystis sp. ST1 and ST2, and Encephalitozoon intestinalis could be of public health relevance.

Molecular Detection of Microsporidia in Rabbits (Oryctolagus cuniculus) in Tenerife, Canary Islands, Spain

Enterocytozoon bieneusi and Encephalitozoon spp. are microsporidia with zoonotic potential that have been identified in humans, as well as in a large group of wild and domestic animals. Several wildlife species have been studied as reservoirs of zoonotic microsporidia in mainland Spain, including the European rabbit (Oryctolagus cuniculus). Due to a lack of data on microsporidia infection in wildlife on the Canary Islands, the aim of this work was to analyze the prevalence and identify the species of microsporidia in rabbits in Tenerife. Between 2015 and 2017, a total of 50 fecal samples were collected from rabbits in eight municipalities of Tenerife, Canary Islands, Spain. Seven of the fifty samples (14%) were amplified using nested polymerase chain reaction (PCR) targeting the partial sequence of the 16S rRNA gene, the internal transcribed spacer (ITS) region, and the partial sequence of the 5.8S rRNA gene. Sanger sequencing reveals the presence of Encephalitozoon cuniculi genotype I in two samples (4%), and undescribed microsporidia species in five samples (10%). This study constitutes the first molecular detection and genotyping of E. cuniculi in rabbits in Spain.

Molecular Detection of Cryptosporidium cuniculus in Rabbits (Oryctolagus cuniculus) from Tenerife, Canary Islands, Spain

Cryptosporidium cuniculus is a zoonotic parasite responsible for cryptosporidiosis cases and outbreaks in both humans and rabbits. Since there are no molecular Cryptosporidium spp. infection data in rabbits (Oryctolagus cuniculus) from Spain, our aim was to gather information about this parasite in wild European rabbits from Tenerife, Canary Islands (Spain). A total of 100 faecal samples were collected from rabbits from eight municipalities of Tenerife. Microscopic analysis showed that 4.0% of the samples presented structures compatible with Cryptosporidium oocyst. A nested polymerase chain reaction (PCR) targeting 18S ribosomal RNA (rRNA) gene fragments was carried out, and sequencing confirmed the identity of C. cuniculus in one sample (1.0%). The sample was successfully subtyped using nested PCR analysis of the 60-kDa glycoprotein (gp60) gene as the subtype VbA26R3. This study confirms the presence of C. cuniculus in wild rabbits from Tenerife, providing new information on the occurrence of this zoonotic parasite. Further studies are required to better understand the epidemiology of Cryptosporidium spp. in wild rabbits in Spain and their possible public health repercussions.

First genotyping of Enterocytozoon bieneusi in plateau pikas (Ochotona curzoniae) from the Qinghai Plateau, Northwest China

Enterocytozoon bieneusi is considered the most common microsporidian species and is frequently detected in humans and various animals worldwide. However, information on E. bieneusi infection in plateau pikas (Ochotona curzoniae) is somewhat limited. Therefore, this study was conducted to determine the infection status and genotype characteristics of E. bieneusi in plateau pikas in China. A total of 33 fresh fecal samples were collected from plateau pikas captured on the Qinghai Plateau. By PCR assay and DNA sequencing of the ITS gene, 5 (15.2%, 5/33) isolates were diagnosed as positive. Sequence analysis revealed the presence of one known sheep-derived genotype, CHS17 (4/5), and a novel E. bieneusi genotype, CHPP1 (1/5), with maximum shared identity with the CHS17 genotype. Phylogenetically, these isolates were clustered into subgroup 1i of zoonotic group 1 with genotypes CHS17 and CHN14 from plateau ruminants, but the new CHP1 genotype formed a cluster separate from those genotypes. This is the first report of E. bieneusi in plateau pikas. The findings suggested that these animals might be potential reservoirs of zoonotic E. bieneusi, and transmission of the pathogen between plateau pikas and sheep probably occurs in the region.

Genetic Characterization of Cryptosporidium cuniculus from Rabbits in Egypt

Rabbits are increasingly farmed in Egypt for meat. They are, however, known reservoirs of infectious pathogens. Currently, no information is available on the genetic characteristics of Cryptosporidium spp. in rabbits in Egypt. To understand the prevalence and genetic identity of Cryptosporidium spp. in these animals, 235 fecal samples were collected from rabbits of different ages on nine farms in El-Dakahlia, El-Gharbia, and Damietta Provinces, Egypt during the period from July 2015 to April 2016. PCR-RFLP analysis of the small subunit rRNA gene was used to detect and genotype Cryptosporidium spp. The overall detection rate was 11.9% (28/235). All 28 samples were identified as Cryptosporidium cuniculus. The 16 samples successfully subtyped by the sequence analysis of the partial 60 kDa glycoprotein gene belonged to two subtypes, VbA19 (n = 1) and VbA33 (n = 15). As C. cuniculus is increasingly recognized as a cause of human cryptosporidiosis, Cryptosporidium spp. in rabbits from Egypt have zoonotic potential.

Cryptosporidium species and subtypes in river water and riverbed sediment using next-generation sequencing

This study uncovered the prevalence, harboured species, and subtype diversity of Cryptosporidium species in river water and its sediment from the Apies River in South Africa. Cryptosporidium spp. concentrations in freshwater and its sediment were determined using Ziehl-Neelsen staining and quantitative Polymerase Chain Reaction (qPCR) techniques. Next-generation sequencing (NGS) targeting the 60 kDa glycoprotein (gp60) gene of Cryptosporidium spp. was performed to reveal the species, subtype families and subtypes harboured in freshwater and its sediment. Although the results revealed that water samples had a higher prevalence (30%) compared with sediment (28%), the number of observable Cryptosporidium spp. oocysts in sediment samples (ranging from 4.90 to 5.81 log₁₀ oocysts per 1 Liter) was higher than that of river water samples (ranging from 4.60 to 5.58 log₁₀ oocysts per 1 L) using Ziehl-Neelsen staining. The 18S ribosomal ribonucleic acid (rRNA) gene copy of Cryptosporidium in riverbed sediments ranged from 6.03 to 7.65 log₁₀, whereas in river water, it was found to be between 4.20 and 6.79 log₁₀. Subtyping results showed that in riverbed sediments, Cryptosporidium parvum accounted for 40.72% of sequences, followed by Cryptosporidium hominis with 23.64%, Cryptosporidium cuniculus with 7.10%, Cryptosporidium meleagridis with 4.44% and the least was Cryptosporidium wrairi with 2.59%. A considerable percentage of reads in riverbed sediment (21.25%) was not assigned to any subtype. River water samples had 45.63% of sequences assigned to C. parvum, followed by 30.32% to C. hominis, 17.99% to C. meleagridis and 5.88% to C. cuniculus. The data obtained are concerning, as Cryptosporidium spp. have intrinsic resistance to water treatment processes and low infectious doses, which can pose a risk to human health due to the various uses of water (for human consumption, leisure, and reuse).

Identification and genotyping of Enterocytozoon bieneusi in wild Himalayan marmots (Marmota himalayana) and Alashan ground squirrels (Spermophilus alashanicus) in the Qinghai-Tibetan Plateau area (QTPA) of Gansu Province, China

Background

Enterocytozoon bieneusi is the most frequently detected microsporidian species in humans and animals. Currently, to the best of our knowledge, no information on E. bieneusi infection in Himalayan marmots (Marmota himalayana) and Alashan ground squirrels (Spermophilus alashanicus) is available worldwide. The aim of the present study was to understand the occurrence and genetic characterizations of E. bieneusi in Himalayan marmots and Alashan ground squirrels in the Qinghai-Tibetan Plateau area (QTPA), Gansu Province, China.

Methods

A total of 498 intestinal contents were collected from 399 Himalayan marmots and 99 Alashan ground squirrels in QTPA. These samples were screened for the presence of E. bieneusi by using nested polymerase chain reaction and sequencing of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene. The ITS-positive sequences were aligned and phylogenetically analyzed to determine the genotypes of E. bieneusi.

Results

The average infection rate of E. bieneusi was 10.0% (50/498), with 11.8% (47/399) in Himalayan marmots and 3.0% (3/99) in Alashan ground squirrels. A total of 7 distinct E. bieneusi genotypes were confirmed: 1 known genotype, YAK1 (n = 18) and 6 novel genotypes, named as ZY37 (n = 27), HN39 (n = 1), HN96 (n = 1), SN45 (n = 1), XH47 (n = 1) and ZY83 (n = 1). All the genotypes obtained in the present study were classified into group 1.

Conclusions

To our knowledge, this is the first report of E. bieneusi in Himalayan marmots and Alashan ground squirrels in China. The identification of genotype YAK1 in the two rodent species expanded the host range of this genotype. All the seven genotypes were clustered into zoonotic group 1, suggesting that these animal species can be potential epidemiological vectors of zoonotic microsporidiosis caused by E. bieneusi and pose a threat to ecological security. It is necessary to strengthen management practices and surveillance in the investigated areas to reduce the risk of E. bieneusi infection from the two rodent species to humans.

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.

Molecular detection of Enterocytozoon bieneusi in farm-raised pigs in Hainan Province, China: infection rates, genotype distributions, and zoonotic potential

Enterocytozoon bieneusi is a zoonotic fungal pathogen with a high degree of host diversity that can parasitize many animals, including humans. Pigs may play an important role in the epidemiology of E. bieneusi as reservoir hosts. Nevertheless, the genotypes of E. bieneusi in pigs in China remain poorly understood. The aim of this study was to determine the prevalence of E. bieneusi infection amongst pigs raised on farms from four cities of Hainan Province, using nested polymerase chain reaction (PCR) of the partial small subunit of the ribosomal RNA gene, and to identify genotypes of E. bieneusi isolates based on sequence analysis of the ribosomal internal transcribed spacer (ITS) region. Among 188 stool samples, E. bieneusi was detected in 46.8% (88/188). Eight genotypes including four known (EbpA, CS-4, MJ14, and CHG19) and four novel (HNP-I – HNP-IV) genotypes were identified. Using phylogenetic analysis, genotypes EbpA, CS4, CHG19, HNP-III, and HNP-IV were clustered into zoonotic Group 1, while the remaining three genotypes (MJ14, HNP-I, and HNP-II) clustered into Group 10. The high prevalence of zoonotic genotypes of E. bieneusi among pigs suggests that pig farming is a potential source of human infection. Additionally, this is the first identification of genotypes in Group 10 in pigs indicating unique epidemic features of E. bieneusi in pigs in Hainan Province, the southernmost part of China.

Prevalence and Genotype Distribution of Giardia duodenalis in Rabbits in Shandong Province, Eastern China

Giardia duodenalis is a zoonotic enteric parasite that can infect humans and a number of animal species including rabbits with a worldwide distribution. Infection with G. duodenalis can cause serious public health problems and significant economic losses to animal husbandry. So accurate understanding of the prevalence and genotype distribution of G. duodenalis in rabbits is necessary. In the present study, a total of 616 fecal samples were collected from rabbits in Shandong province, eastern China, and examined in G. duodenalis prevalence and genotypes by nested PCR amplification of β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) gene loci of G. duodenalis. Sixty-nine (11.2%) of the examined rabbit fecal samples were G. duodenalis-positive. Of them, the prevalence of G. duodenalis is 8.4% (41/490) in Rizhao city and 22.2% (28/126) in Weihai city. Breeds, region, and feeding modes were highly correlated with G. duodenalis infection in rabbits. Moreover, three genotypes (assemblages A, B, and E) were identified in rabbits at three gene loci, and the assemblage E was the dominant genotype, while the assemblage A was reported in rabbits in China for the first time. It is noticeable that two rabbits were found to be infected with two different G. duodenalis assemblages (assemblages A and E, assemblages B and E, respectively). These findings enrich the genotype distribution of G. duodenalis in rabbits and provide baseline data for preventing and controlling G. duodenalis infection in rabbits in eastern China.

Identification of Enterocytozoon bieneusi and Cryptosporidium spp. in farmed wild boars (Sus scrofa) in Beijing, China

Enterocytozoon bieneusi and Cryptosporidium spp. are opportunistic pathogen that can infected humans and other animals. However, the data on the prevalence and genotypes of the parasites in captive wild boars is not available in Beijing, China. In this study, a total of 257 fecal specimens of wild boars were collected. The overall prevalence of E. bieneusi and Cryptosporidium spp. was 42.0% (108/257) and 5.8%, respectively. Higher infection rate of E. bieneusi was discovered in the wild boar ≤2 months old (58.3%). The differences between the feeding pattern and gender were not significant. Furthermore, eight genotypes of E. bieneusi were determined by analyzing the internal transcribed spacer (ITS) of the rRNA gene, including seven known genotypes and one novel genotype. Phylogenetic analysis revealed that all the eight genotypes belonged to the zoonotic potential Group 1. For Cryptosporidium spp., no significant differences were found between groups of gender, age and feeding pattern. Only C. scrofarum was identified in the investigated samples. The findings suggest that wild boar could be reservoirs of E. bieneusi and C. scrofarum which could be potentially transmitted to humans and other animals.

First survey of Enterocytozoon bieneusi and dominant genotype Peru6 among ethnic minority groups in southwestern China's Yunnan Province and assessment of risk factors

BACKGROUND

Enterocytozoon bieneusi is the most common microsporidian species causing diarrhea and other intestinal disorders in humans and animals. Like other infectious diseases, microsporidiosis usually disproportionately affects poor populations. In China, some ethnic minority areas remain poor. Currently, no information of E. bieneusi infection is available in minority populations. The present aims were to understand occurrence and genetic characterizations of E. bieneusi in ethnic minority groups from a poverty-stricken ethnic township in Yunnan Province, and to assess risk factors for E. bieneusi infection.

METHODOLOGY/PRINCIPAL FINDINGS

289 fecal specimens were collected from Yao people (one specimen each) with and without diarrhea, in Yunnan Province. E. bieneusi was identified and genotyped by PCR and sequence analysis of the ITS region of the rRNA gene. An average prevalence of 8.30% (24/289) was observed and four genotypes were identified-genotype Peru6 (n = 21) and three novel genotypes (one each). Genotype Peru6 was detected in two family members in each of three families. In a phylogenetic analysis, all of four genotypes fell into group 1 with zoonotic potential. The people owning individual pit toilets had a statistically higher prevalence of E. bieneusi (16.67%, 12/72) than those using public pit toilets (6.06%, 12/198).

CONCLUSIONS/SIGNIFICANCE

This is the first report on occurrence and genetic characteristics of E. bieneusi in ethnic minority groups in China. Genotype Peru6 was found in humans in China for the first time and showed dominance in Yao people. The same genotype was found in some family members and all the genotypes fell into group 1, suggesting the possibility of anthroponotic and zoonotic transmissions. The majority (83.33%, 20/24) of E. bieneusi positive individuals did not present diarrhea. In any case, it is important to recognize their existence and the importance that asymptomatic individuals to E. bieneusi may have from an epidemiological point of view, as transmitters of this pathogen. The analysis of risk factors provides scientific evidence for the development of effective strategies for prevention and control of E. bieneusi infection.

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.

Detection and Genotyping Study of Enterocytozoon bieneusi in Sheep and Goats in East-central China

BACKGROUND

Enterocytozoon bieneusi, the dominant zoonotic species of microsporidia, has been reported in various animals and humans. However, relatively little information is available concerning the worldwide prevalence and genotypes of E. bieneusi in ruminants, such as sheep and goats. The present study was conducted to evaluate the prevalence and genetic characteristics of E. bieneusi in sheep and goats in east-central China.

METHODS

Fresh fecal samples from 832 sheep and 781 goats were evaluated for the presence of E. bieneusi using PCR and sequencing of the ribosomal internal transcribed spacer.

RESULTS

28 sheep specimens (3.4%) and 32 goat specimens (4.1%) were positive for E. bieneusi. A total of 12 ITS genotypes were identified, including 7 known genotypes (COS-I, OEB1, BEB6, CHG1, CHG3, COS-II, and CHC8) and 5 novel genotypes (named AHS1, AHS2, JSS1, AHG1, and AHG2). The dominant genotypes in sheep and goats were BEB6 and CHG3, respectively. Phylogenetic analysis revealed that all genotypes obtained in this study belonged to the so-called "cattle-specific" Group 2.

CONCLUSIONS

These findings show a relatively low occurrence and genetic diversity of E. bieneusi in sheep and goats in east-central China. Further studies are required to elucidate the role of sheep and goats in the epidemiology of microsporidia.

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.

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.

Molecular characterizations of Cryptosporidium spp. and Enterocytozoon bieneusi in brown rats (Rattus norvegicus) from Heilongjiang Province, China

Background

Cryptosporidium spp. and Enterocytozoon bieneusi are prevalent zoonotic pathogens responsible for the high burden of diarrheal diseases worldwide. Rodents are globally overpopulated and are known as reservoirs or carriers of a variety of zoonotic pathogens including Cryptosporidium spp. and E. bieneusi. However, few data are available on genetic characterizations of both pathogens in rodents in China. The aim of the present work was to determine the prevalence and genetic characterizations of Cryptosporidium spp. and E. bieneusi in brown rats (Rattus norvegicus) from Heilongjiang, China.

Methods

A total of 242 wild brown rats were captured in Heilongjiang Province of China. A fresh fecal specimen was collected directly from the intestinal and rectal content of each brown rat. All the fecal specimens were examined for the presence of Cryptosporidium spp. and E. bieneusi by PCR and sequencing of the partial small subunit (SSU) rRNA gene and the internal transcribed spacer (ITS) region of the rRNA gene of the two pathogens, respectively.

Results

The infection rate was 9.1% (22/242) for Cryptosporidium spp. and 7.9% (19/242) for E. bieneusi. Sequence analysis confirmed the presence of C. ubiquitum (1/22, 4.5%) and three genotypes of Cryptosporidium, including Cryptosporidium rat genotype I (14/22, 63.6%), Cryptosporidium rat genotype IV (6/22, 27.3%) and Cryptosporidium suis-like genotype (1/22, 4.5%). Meanwhile, two E. bieneusi genotypes were identified, including D (17/19, 89.5%) and Peru6 (2/19, 10.5%).

Conclusions

To the best of our knowledge, Enterocytozoon bieneusi genotype Peru6 was identified in rodents for the first time globally and Cryptosporidium rat genotype I and Cryptosporidium rat genotype IV were found in rats in China for the first time. The finding of zoonotic C. ubiquitum and C. suis-like genotype, as well as E. bieneusi genotypes, suggests that brown rats pose a threat to human health. It is necessary to control brown rat population in the investigated areas and improve local people’s awareness of the transmission risk of the two pathogens from brown rats to humans.

Molecular Characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in Rabbits in Xinjiang, China

A total of 321 rabbit fecal samples were collected from 10 farms in the Xinjiang Uyghur Autonomous Region, China. The prevalence of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in the samples was 3.4% (11/321), 1.9% (6/321), and 2.8% (9/321), respectively. Small subunit ribosomal RNA (SSU rRNA) gene sequence analysis identified all 11 Cryptosporidium-positive samples as C. cuniculus. Further subtyping based on the 60-kDaglycoprotein locus (gp60) identified five of the C. cuniculus isolates as subtype VbA24. G. duodenalis genotypes were determined by multilocus sequence typing of the SSU rRNA, triosephosphate isomerase, β-giardin and glutamate dehydrogenase loci, which confirmed that six G. duodenalis isolates belonged to subtype BIV of assemblage B. Analysis of the internal transcribed spacer region, showed that five, three, and one E. bieneusi isolates belonged to genotypes J, BEB8, and Type IV, respectively. These results suggest that Cryptosporidium spp., G. duodenalis, and E. bieneusi isolates from rabbits in China have zoonotic potential.

Dominance of the Enterocytozoon bieneusi genotype BEB6 in red deer (Cervus elaphus) and Siberian roe deer (Capreolus pygargus) in China and a brief literature review

Enterocytozoon bieneusi is the most frequently diagnosed microsporidian species in humans and is also found in a wide range of animals. It is considered to be an important but neglected zoonotic pathogen. With the development of deer bred in captivity, the number of deer has been increasing in recent years in China and there are more people involved in this work. The aims of this study were to determine prevalence and genotypes of E. bieneusi in red deer (Cervus elaphus) and Siberian roe deer (Capreolus pygargus), and to assess their potential zoonotic transmission. A total of 122 fecal specimens were collected from 104 red deer and 18 roe deer from three deer farms in Heilongjiang and Jilin Provinces, China. Enterocytozoon bieneusi was detected and genotyped by PCR and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. The average infection rate was 8.2% (10/122), with 7.7% (8/104) for red deer and 11.1% (2/18) for roe deer. Two genotypes were identified: a known genotype BEB6 (n = 9) and a novel genotype named HLJD-VI (n = 1). This is the first report of E. bieneusi infection in Siberian roe deer. The fact that genotype BEB6 was detected previously in one human case of microsporidiosis, and that genotype HLJD-VI fell into zoonotic group 1, suggest the possibility of transmission to humans. A brief review of E. bieneusi genotypes in deer worldwide shows that 40 genotypes have been found in seven deer species, with genotype BEB6 being predominant.

Genotyping of Enterocytozoon bieneusi and Subtyping of Blastocystis in Cancer Patients: Relationship to Diarrhea and Assessment of Zoonotic Transmission

Enterocytozoon bieneusi (E. bieneusi) and Blastocystis are common pathogens responsible for diarrhea in humans, especially in immunocompromised individuals. The number of cancer patients has been increasing and diarrhea is a common clinical symptom in the treatment of cancers. To understand the prevalences and genotypes/subtypes of E. bieneusi and Blastocystis in cancer patients in China, to track the infection sources, and to explore the relationships between E. bieneusi and Blastocystis infections and diarrhea, 381 fecal specimens were collected from cancer patients. Each of them was analyzed for the presence of E. bieneusi and Blastocystis by PCR amplifying and sequencing the ITS region of the rRNA gene and the barcode region of the SSU rRNA gene, respectively. 1.3 and 7.1% of cancer patients were positive for E. bieneusi and Blastocystis, respectively. No statistical differences were observed in the infection rates between the groups by age, gender, and residence. E. bieneusi and Blastocystis were both significantly more common in cancer patients with diarrhea, and significant relationship of Blastocystis to diarrhea was found in chemotherapy group. Two E. bieneusi genotypes (D and a novel one named as HLJ-CP1) and two Blastocystis subtypes (ST1 and ST3) were identified with three novel ST1 sequences. This is the first report of occurrence and molecular characterizations of E. bieneusi and Blastocystis in cancer patients in China. E. bieneusi genotype D and Blastocystis ST1 and ST3 have been identified in humans and animals while one novel E. bieneusi genotype falling into zoonotic group 1, implying a potential of zoonotic transmission.

Molecular Epidemiology of Cryptosporidiosis in China

Molecular epidemiology of cryptosporidiosis is an active research area in China. The use of genotyping and subtyping tools in prevalence studies has led to the identification of unique characteristics of Cryptosporidium infections in humans and animals. Human cryptosporidiosis in China is exemplified by the high diversity of Cryptosporidium spp. at species and subtype levels, with dominant C. hominis and C. parvum subtypes being rarely detected in other countries. Similarly, preweaned dairy calves, lambs, and goat kids are mostly infected with non-pathogenic Cryptosporidium species (C. bovis in calves and C. xiaoi in lambs and goat kids), with C. parvum starting to appear in dairy calves as a consequence of concentrated animal feeding operations. The latter Cryptosporidium species is dominated by IId subtypes, with IIa subtypes largely absent from the country. Unlike elsewhere, rodents in China appear to be commonly infected with C. parvum IId subtypes, with identical subtypes being found in these animals, calves, other livestock, and humans. In addition to cattle, pigs and chickens appear to be significant contributors to Cryptosporidium contamination in drinking water sources, as reflected by the frequent detection of C. suis, C. baileyi, and C. meleagridis in water samples. Chinese scientists have also made significant contributions to the development of new molecular epidemiological tools for Cryptosporidium spp. and improvements in our understanding of the mechanism involved in the emergence of hyper-transmissible and virulent C. hominis and C. parvum subtypes. Despite this progress, coordinated research efforts should be made to address changes in Cryptosporidium transmission because of rapid economic development in China and to prevent the introduction and spread of virulent and zoonotic Cryptosporidium species and subtypes in farm animals.

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.

First description of Cryptosporidium ubiquitum XIIa subtype family in farmed fur animals

This study investigated the prevalence of Cryptosporidium in farmed fur animals in the Czech Republic and Poland. A total of 480 faecal samples were collected from fur animals, including 300 American mink (Mustela vison), 60 silver foxes (Vulpes vulpes), 50 long-tailed chinchillas (Chinchilla lanigera), and 70 nutrias (Myocastor coypus), at 14 farms. Samples were examined for the presence of Cryptosporidium using microscopy (following aniline-carbol-methyl violet staining) and sequence analysis of PCR amplified products. Three mink and two chinchillas from two different farms tested positive for Cryptosporidium ubiquitum DNA. The presence of C. ubiquitum DNA was not associated with diarrhoea. Subtyping of C. ubiquitum isolates by sequence analysis of the 60-kDa glycoprotein gene showed that isolates belonged to the XIIa subtype family, which was previously restricted to humans and ruminants. This suggests that C. ubiquitum subtype XIIa has a broader host range than previously reported.

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.