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

Detection and genotyping of zoonotic microsporidia in the endangered Iberian lynx (Lynx pardinus)

Microsporidia is a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most frequently reported species in humans. Limited information is available about the presence and molecular diversity of microsporidian species in the endangered Iberian lynx (Lynx pardinus). Presence of Enterocytozoon bieneusi and Encephalitozoon spp. was investigated by molecular methods in wild and captive Iberian lynxes from Spain. Overall, E. bieneusi was detected in 3.2% (8/251) of the animals examined. None of the samples tested were positive for Encephalitozoon spp. Four known (D, EbfelA, PigEBITS7, and Type IV) and a novel (named as LynxSpEb1) E. bieneusi genotypes were identified. All the genotypes found belonged to the zoonotic Group 1 of E. bieneusi. This study provides the first genotyping data of E. bieneusi in Iberian lynx in Spain. Our result indicate that the Iberian lynx does not seem to play a relevant role in the epidemiology of Encephalitozoon spp., and that this endangered felid is likely acting as spillover host rather than a true reservoir of E. bieneusi. Additional studies should be conducted to assess the impact of this parasite in the health status of the endangered Iberian lynx.

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.

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.

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 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.

Prevalence and Novel Genotypes Identification of Enterocytozoon bieneusi in Dairy Cattle in Yunnan Province, China

Simple Summary

We first report the prevalence of Enterocytozoon bieneusi in Holstein Cows and dairy buffalo in Yunnan province of China, with a percentage of positivity of 0.59% (5/841). Two novel zoonotic potential genotypes of E. bieneusi were found. We analyzed the different influencing factors (region, season, variety, breeding mode, gender, age), but the differences were not statistically significant.

Abstract

Enterocytozoon bieneusi is a fungus-like protist parasite that can cause diarrhea and enteric diseases. The infection of E. bieneusi has been reported in many host species, including cattle and humans. However, information on prevalence and genotype distribution of E. bieneusi in dairy cattle in Yunnan province in China is still absent. In this study, 490 Holstein Cows and 351 dairy buffalo fecal samples were collected from three regions in Yunnan province, China. By using nest-PCR that targets the internal transcribed spacer (ITS), we found that the prevalence of E. bieneusi was 0.59% (5/841). DNA sequence analysis showed that five E. bieneusi genotypes were identified in this study, including two novel genotypes, YNDCEB-90 and YNDCEB-174, and three known genotypes (I, J, BEB4). Phylogenetic analysis revealed that two novel genotypes, YNDCEB-90 and YNDCEB-174, were clustered into Group 1, representing the zoonotic potential. The remaining genotypes I, J, and BEB4, which are the most frequent genotypes of E. bieneusi infection in cattle and lead to E. bieneusi infection in humans, belonged to Group 2. Although the lower prevalence of E. bieneusi was detected in dairy cattle in Yunnan province, it indicates that dairy cattle should be considered to be one of the potential hosts for transmitting E. bieneusi to humans. These findings are important for the development of effective prevention strategies for microsporidiosis.

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.

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.

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.