Molecular identification of Enterocytozoon bieneusi, Cryptosporidium, and Giardia in Brazilian captive birds

The global epidemiology of Microsporidia infection in birds: A systematic review and meta-analysis

This study aimed to assess the global status and genetic diversity of Microsporidia infection in different birds. An online search was conducted in international databases from 1 January 1990 to 30 June 2022. A total of 34 articles (including 37 datasets) were included for the final meta-analysis. The pooled global prevalence of Microsporidia infection in birds was 14.6% (95% CI: 11.6-18.1). The highest prevalence of Microsporidia was found in wild waterfowl which was 54.5% (28.1-78.6). In terms of detection methods, the pooled prevalence was estimated to be 21.2% (95% CI: 12.1-34.4) and 13.4% (95% CI: 10.3-17.3) for using microscopic and molecular detection methods, respectively. Enterocytozoon bieneusi was the most common pathogen (24/31; 77.42% of the studies) according to PCR-based methods, and genotype D was the highest reported genotype (nine studies). In conclusion, designing strategies for the control and prevention of Microsporidia infection in birds should be recommended.

Genetic diversity of Cryptosporidium spp., Encephalitozoon spp. and Enterocytozoon bieneusi in feral and captive pigeons in Central Europe

Cryptosporidium spp., Enterocytozoon bieneusi and Encephalitozoon spp. are the most common protistan parasites of vertebrates. The results show that pigeon populations in Central Europe are parasitised by different species of Cryptosporidium and genotypes of microsporidia of the genera Enterocytozoon and Encephalitozoon. A total of 634 and 306 faecal samples of captive and feral pigeons (Columba livia f. domestica) from 44 locations in the Czech Republic, Slovakia and Poland were analysed for the presence of parasites by microscopy and PCR/sequence analysis of small subunit ribosomal RNA (18S rDNA), 60 kDa glycoprotein (gp60) and internal transcribed spacer (ITS) of SSU rDNA. Phylogenetic analyses revealed the presence of C. meleagridis, C. baileyi, C. parvum, C. andersoni, C. muris, C. galli and C. ornithophilus, E. hellem genotype 1A and 2B, E. cuniculi genotype I and II and E. bieneusi genotype Peru 6, CHN-F1, D, Peru 8, Type IV, ZY37, E, CHN4, SCF2 and WR4. Captive pigeons were significantly more frequently parasitised with screened parasite than feral pigeons. Cryptosporidium meleagridis IIIa and a new subtype IIIl have been described, the oocysts of which are not infectious to immunodeficient mice, whereas chickens are susceptible. This investigation demonstrates that pigeons can be hosts to numerous species, genotypes and subtypes of the studied parasites. Consequently, they represent a potential source of infection for both livestock and humans.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

Exploring genetic variability of Giardia duodenalis and Enterocytozoon bieneusi in raw vegetables and fruits: implications for food safety and public health in Mozambique

Giardia duodenalis and Enterocytozoon bieneusi are etiological agents of enteric diseases characterized by diarrhea that can progress to chronicity in humans, especially in children and in immunocompromised patients. This study aims to assess the genetic pattern of G. duodenalis and E. bieneusi detected in vegetables and fruits commercialized in Maputo markets, Mozambique and determine their public health importance. Eight study points were sampled: a farmer zone, a wholesale, four retail markets, and two supermarkets in Maputo city, where eight types of horticultural products were purchased. Using nested-PCR methods, 2.8% (9/321) and 1.3% (4/321) of samples monitored were positive for G. duodenalis and E. bieneusi, respectively. Based on the analysis of the β-giardin and ITS rRNA sequences of G. duodenalis and E. bieneusi detected, respectively, four different sequences of G. duodenalis (three novel sequences: BgMZ1, BgMZ2, and BgMZ3, and one known sequence) all from assemblage B and three genotypes of E. bieneusi (two novel sequences: EbMZ4 and EbMZ5, and one known sequence: KIN-1) from group 1. These microorganisms were found and characterized for the first time in horticultural products in Maputo markets. All identified G. duodenalis and E. bieneusi display high genetic similarity within their β-giardin and ITS rRNA sequences, respectively, having been clustered into assemblages and genotypes with high zoonotic transmission potential. Our study may represent a relevant step in the understanding of these intestinal pathogens in association with fresh vegetables and fruits for human consumption, for a better and broader "One Health" approach.

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

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

Molecular detection and prevalence of human-pathologic Enterocytozoon bieneusi among pet birds in Mosul, Iraq

Enterocytozoon bieneusi has been classified as an emerging infectious organism (microsporidium) due to the global increase in the number of cases infecting both humans and animals. The goal of this study was to use the polymerase chain reaction method to determine the prevalence and risk factors associated with E. bieneusi infection among pet birds in Mosul, Iraq. Faecal samples from a total of six hundred and twenty-eight pet birds belonging to fifteen (15) different species were analyzed by targeting the internal transcribed spacer (ITS) of the rRNA gene. Of the total number of pet birds sampled, 203 tested positive for the parasite, representing 32.32% (95% CI = 28.75-36.06) of the sampled population. There was a significant difference (p < 0.01) in the prevalence of E. bieneusi infection among the different species of pet birds, with the highest prevalence recorded among Eurasian bullfinches (Pyrrhula pyrrhula) (64.06%; 95% CI = 55.48-72.02), budgerigars (Melopsittacus undulatus) (48.72%; 95% CI = 40.93-56.55), Fischer's lovebirds (Agapornis fischeri) (25.00%; 95% CI = 13.45-40.05), and macaws parrots (Ara ararauna) (25.00%; 95% CI = 1.25-75.77). The order, source, and health status of pet birds were significantly (p < 0.05) associated with the prevalence of E. bieneusi infection among pet birds in Mosul, Iraq. In conclusion, the level of prevalence of E. bieneusi among pet birds may increase the risk of infection for owners of pet birds in Iraq.

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

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

Survey on the Presence of Bacterial and Parasitic Zoonotic Agents in the Feces of Wild Birds

Wild avifauna may act as fecal source of bacterial and parasitic pathogens for other birds and mammals. Most of these pathogens have a relevant impact on human and livestock health which may cause severe disease and economic loss. In the present study, the fecal samples collected from 121 wild birds belonging to 15 species of the genera Anas, Tadorna, Fulica, Arddea, Larus, Falco, Athene, Accipiter, and Columba were submitted to bacteriological and molecular analyses to detect Brucella spp., Coxiella burnetii, Mycobacterium spp., Salmonella spp., Cryptosporidium spp., Giardia spp., and microsporidia. Four (3.3%) animals were positive for one pathogen: one Anas penelope for C. burnetii, one Larus michahellis for S. enterica serovar Coeln, and two Columba livia for Encephalitozoon hellem. Although the prevalence rates found in the present survey were quite low, the obtained results confirm that wild birds would be the a potential fecal source of bacterial and parasitic zoonotic pathogens which sometimes can also represent a severe threat for farm animals.

Multilocus Genotyping of Giardia duodenalis in Mostly Asymptomatic Indigenous People from the Tapirapé Tribe, Brazilian Amazon

Little information is available on the occurrence and genetic variability of the diarrhoea-causing enteric protozoan parasite Giardia duodenalis in indigenous communities in Brazil. This cross-sectional epidemiological survey describes the frequency, genotypes, and risk associations for this pathogen in Tapirapé people (Brazilian Amazon) at four sampling campaigns during 2008–2009. Microscopy was used as a screening test, and molecular (PCR and Sanger sequencing) assays targeting the small subunit ribosomal RNA, the glutamate dehydrogenase, the beta-giardin, and the triosephosphate isomerase genes as confirmatory/genotyping methods. Associations between G. duodenalis and sociodemographic and clinical variables were investigated using Chi-squared test and univariable/multivariable logistic regression models. Overall, 574 individuals belonging to six tribes participated in the study, with G. duodenalis prevalence rates varying from 13.5–21.7%. The infection was positively linked to younger age and tribe. Infected children <15 years old reported more frequent gastrointestinal symptoms compared to adults. Assemblage B accounted for three out of four G. duodenalis infections and showed a high genetic diversity. No association between assemblage and age or occurrence of diarrhoea was demonstrated. These data indicate that the most likely source of infection was anthropic and that different pathways (e.g., drinking water) may be involved in the transmission of the parasite.

Molecular Identification of Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis in Captive Pet Birds in Henan Province, Central China

Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis are common enteric pathogens that are capable of infecting humans and animals. Total of 1,005 fecal samples from captive pet birds were collected from seven locations in Henan Province, China. The results demonstrated that 9.9% (99/1,005) of the captive birds were infected with one of these three pathogens. Enterocytozoon bieneusi was the most prevalent species among the birds (45/1,005, 4.5%) followed by G. duodenalis (33/1,005, 3.3%) and Cryptosporidium spp. (21/1,005, 2.1%). Five Cryptosporidium species were identified, namely, C. baileyi (10), C. galli (5), C. meleagridis (4), C. andersoni (1), and C. parvum (1). Two known E. bieneusi genotypes were identified: Peru 6 (44) was identified in pigeons (34) and European turtle doves (10); whereas, the genotype PtEb I (1) was only identified in a pigeon. Only G. duodenalis assemblage E (33) was identified in some pet birds. To the best of our knowledge, this study is the first to undertake the molecular identification of G. duodenalis in birds in China. The identification of potentially zoonotic species/genotypes of the pathogens suggests that exposure to the excreta of these birds, either directly or via food and water, may pose a threat to human health.

Epidemiology of Giardia duodenalis assemblages in Brazil: there is still a long way to go

Giardia duodenalis infection is distributed worldwide and can achieve prevalence around 60%, especially in developing countries. This protozoan is divided into eight assemblages, in which A and B have high zoonotic potential, whereas C to H are host-specific. This scenario is changing as molecular studies progress, highlighting that knowledge on host-specificity still has a long way to go. Understanding the players involved in transmission routes enables rational designs of control strategies. Considering the high prevalence of giardiasis, this review aims to gather together the data on available studies on the distribution of G. duodenalis assemblages in Brazil until September 2020.

Occurrence of Cryptosporidium and Giardia in wild birds from Qinghai Lake on the Qinghai-Tibetan Plateau, China

Cryptosporidium and Giardia are important intestinal zoonotic pathogens that can infect various hosts and cause diarrhoeal diseases. There are few reports of the epidemiological prevalence and molecular characterization of Cryptosporidium and Giardia in wild birds around Qinghai Lake and in the surrounding areas on the Qinghai-Tibetan Plateau, Northwest China. Therefore, the aim of this study was to determine the Cryptosporidium spp. and Giardia duodenalis genotypes and their epidemiological prevalence in wild birds by PCR amplification. To our knowledge, this is the first report of a variety of Cryptosporidium spp. and G. duodenalis infections in wild birds from that area, with overall prevalence rates of 8.98% (61/679) and 3.39% (23/679), respectively. Furthermore, PCR sequencing confirmed the presence of Cryptosporidium baileyi (n = 3), Cryptosporidium parvum (n = 58), and G. duodenalis assemblage B (n = 19) and E (n = 4) in wild birds from the areas around Qinghai Lake. The results of the present study demonstrated the wide distribution of Cryptosporidium and Giardia among wild birds, which has potential public health significance. Moreover, the study findings also provided useful molecular epidemiological data for monitoring and investigating the two parasitic protozoa in wild animals and surrounding environments.

Enterocytozoon bieneusi of animals-With an 'Australian twist'

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

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).

Ecological and public health significance of Enterocytozoon bieneusi

Enterocytozoon bieneusi, a fungus-like protist parasite, causes symptomatic and asymptomatic intestinal infections in terrestrial animals and is also abundant in the environment. This parasite has been isolated from a variety of host types including humans, livestock, companion animals, birds, and wildlife, as well as the natural and urban environments including drinking source water, coastal water, recreational water, wastewater, vegetables in retail markets, and raw milk on farms. E. bieneusi exhibits high genetic diversity among host species and environmental sources and at least 500 genotypes have been identified thus far. Since its discovery in AIDS patients in 1985, scientists across the world have worked to demonstrate the natural history and public health potential of this pathogen. Here we review molecular typing studies on E. bieneusi and summarize relevant data to identify the potential sources of human and nonhuman infections and environmental contamination. This review also discusses the possible transmission routes of E. bieneusi and the associated risk factors, and advocates the importance of the One Health approach to tackle E. bieneusi infections.

Epidemiological investigation and genotypes of Enterocytozoon bieneusi in 11 captive Rhesus macaque populations

Enterocytozoon bieneusi is an obligate intracellular parasite and the most common pathogen of microsporidiosis in humans and animals. In this study, a total of 198 fecal samples were collected from 11 captive populations of Rhesus macaque in Chinese zoos, to investigate the prevalence and analyze the zoonotic potential of E. bieneusi by genotype of the Internal Transcribed Spacer (ITS) gene on the rRNA of E. bieneusi via nested PCR. Results showed that the average infection rate of E. bieneusi in the 11 populations was 13.6%, and the highest infection rate was 56.5% in the population of Xinjiang Tianshan Zoo. Seven genotypes were identified including 2 known genotypes (D and CM1) and 5 novel genotypes (Mul1, Mul2, Mul3, Mul4 and Mul5). Phylogenetic analysis revealed that the novel genotypes Mul2, Mul3, Mul4 and Mul5 belonged to Group 1 showed the zoonotic potential．These findings extend the distribution of E. bieneusi genotypes and provide baseline data for controlling E. bieneusi infection.

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The overall prevalence of E. bieneusi was 13.6%（27/198) based on PCR analysis of the ITS region of the ribosomal RNA gene.

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Seven genotypes of Enterocytozoon bieneusi were identified.

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One zoonotic genotypes (D) and five novel genotypes (Mul1-5) were identified.

First detection of Enterocytozoon bieneusi in whooper swans (Cygnus cygnus) in China

Background

Enterocytozoon bieneusi is a parasite that infects humans and a wide range of other animals. The large migratory waterfowl, the whooper swan (Cygnus cygnus), travels through many cities during its migration and can spread parasites. Despite receiving increasing attention worldwide, there have been no reports of E. bieneusi infection occurring in C. cygnus. Therefore, this study aims to assess the prevalence and genetic characteristics of E. bieneusi in C. cygnus in Sanmenxia, China.

Methods

Altogether, 467 fresh fecal samples were collected in the Swan Wetland Park in Sanmenxia, China. Genomic DNA was extracted from fresh fecal samples (n = 467) and E. bieneusi was identified by nested PCR amplification of the internal transcribed spacer (ITS) region. ITS-positive sequences were aligned and phylogenetically analyzed to determine the genotypes of E. bieneusi.

Results

The overall prevalence of E. bieneusi in C. cygnus was 7.49% (35/467). Sequencing of the 35 positive samples revealed eight known genotypes (EbpA, EbpC, Henan-III, Henan-IV, BEB6, CD9, Peru6 and PtEb IX) and three novel genotypes (CSW1, CSW2 and CSW3). The phylogenetic tree constructed from the ITS sequences showed that seven genotypes (Peru6, EbpA, EbpC, Henan-III, CSW3, Henan-IV and CSW1) clustered within the zoonotic Group 1 while the remaining novel genotype CSW2 clustered within Group 5.

Conclusions

To our knowledge, this is the first report of E. bieneusi in C. cygnus. Of public health significance, our results suggest that migratory C. cygnus might play an important role in the water-borne transmission of E. bieneusi. Effective strategies will be necessary to control E. bieneusi infection in C. cygnus, other animals and humans.

First Detection of Cryptosporidium spp. in Migratory Whooper Swans (Cygnus cygnus) in China

Cryptosporidium is an important protozoan parasite that can cause gastrointestinal diseases in humans and that also causes respiratory and gastrointestinal diseases in birds. In this study, we investigated the occurrence of Cryptosporidium species in migratory whooper swans in China. Fecal samples (n = 467) from whooper swans were collected from Sanmenxia Swan Lake National Urban Wetland Park, China. The samples were analyzed for Cryptosporidium species and genotypes with PCR along a sequence analysis of the small subunit rRNA. Cryptosporidium was detected in eight of the 467 (1.7%) samples. The analysis of the small subunit rRNA sequence data revealed two zoonotic species (Cryptosporidium parvum and Cryptosporidium andersoni) and one genotype (Cryptosporidium goose genotype II). These are the first data on the positive rate of Cryptosporidium spp. in whooper swans in China, and they suggest that whooper swans can harbor the zoonotic species C. parvum and C. andersoni in China.

Prevalence and genetic characterization of Enterocytozoon bieneusi and Giardia duodenalis in Tibetan pigs in Tibet, China

Enterocytozoon bieneusi and Giardia duodenalis are important opportunistic enteric zoonotic pathogens that cause diarrhoea and intestinal diseases in animals and humans. China is the largest producer of pigs, but whether Tibetan pigs, a unique pig breed in Tibet, are infected with E. bieneusi and G. duodenalis is unknown. Therefore, we conducted a molecular epidemiological survey to determine the prevalence of E. bieneusi and G. duodenalis in Tibetan pigs in Tibet, China, and identified the genotypes of these causative agents. A total of 345 faecal specimens were collected from Tibetan pigs from three Tibet counties (Milin, Cuona and Gongbujiangda), examined by nested PCR and sequenced utilizing genetic markers in the ribosomal internal transcribed spacer (ITS) region of the rRNA and glutamate dehydrogenase (gdh) gene for E. bieneusi and G. duodenalis, respectively. Moreover, using multilocus sequence typing, the subtypes of E. bieneusi were identified based on four loci (MS1, MS3, MS4 and MS7). A total of 41 (11.88%) faecal samples from Tibetan pigs were E. bieneusi-positive, and 2 (0.58%) were G. duodenalis-positive. The multivariate logistic regression analysis showed that age was considered a risk factor for Tibetan pig infection of E. bieneusi. Two novel (GB11, GB31) and four known E. bieneusi genotypes (EbpC, EbpD, PigEBITS5 and CHS12) were identified and were all classified as zoonotic group 1 according to the phylogenetic analysis. Two MLGs (MLGI and MLGII) were further identified in the E. bieneusi EbpC genotype by multilocus sequence typing analysis. In addition, two G. duodenalis assemblages (D and E) were found in the present study. To our knowledge, the current study is the first to detect the prevalence and perform genetic characterization of G. duodenalis in Tibetan pigs in Tibet, China. The results could provide essential data for controlling E. bieneusi and G. duodenalis infections in Tibetan pigs that are in contact with other animals and humans, as Tibetan pigs could be a potential source for human infection by these pathogens.

New genotypes and molecular characterization of Enterocytozoon bieneusi in pet birds in Southwestern China

Enterocytozoon bieneusi, a unicellular enteric microsporidian parasite, can infect humans and a wide range of animals throughout the world. Although E. bieneusi has been identified in many animals, there is no information regarding the genotypes of E. bieneusi in pet birds in China. Birds are important sources of emerging infectious diseases that affect humans, and immunosuppressed individuals can be exposed to potential zoonotic agents shed by birds. The aim of the present study was to determine the prevalence and genotypic diversity of E. bieneusi in pet birds, as well as assessed its zoonotic potential. A total of 387 fecal samples were collected from Psittaciformes (n = 295), Passeriformes (n = 67), and Galliformes (n = 16) from four pet markets in Sichuan province, Southwestern China. The overall prevalence of E. bieneusi in pet birds was 25.1% based on nested polymerase chain reaction analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA (rRNA) gene (Psittaciformes, 21.7%; Passeriformes, 37.3%; Galliformes, 50.0%). Eight genotypes of E. bieneusi were identified, including five known genotypes (D, SC02, BEB6, CHB1, and MJ5) and three novel genotypes (SCB-I, SCB-II, and SCB-III). In phylogenetic analysis, genotypes D and SC02 and one novel genotype SCB-II were clustered within group 1, genotype BEB6 was classified within group 2, and the remaining genotypes (CHB1, MJ5, SCB-I, and SCB-III) clustered with group 10. To the best of our knowledge, this is the first report of E. bieneusi infection in pet birds in China. Genotypes D, SC02, and BEB6 that have been previously identified in humans, were found in pet birds in this study, suggesting that these pet birds can be a potential source of human microsporidiosis in China.

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This is the first to report the prevalence of E. bieneusi in pet birds in China.

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The overall prevalence of E. bieneusi was 25.1% (97/387) based on PCR analysis of the ITS region of the ribosomal RNA gene.

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Five known genotypes (D, SC02, BEB6, CHB1, and MJ5) and three novel genotypes (SCB-I, SCB-II, and SCB-III) were identified.

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This study will enrich the epidemiological data of E. bieneusi infection 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.

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.

Enterocytozoon bieneusi is the most prevalent opportunistic microsporidian species causing diarrhea in humans and animals worldwide. Due to frequent occurrence of chronic or life-threatening diarrhea mainly in HIV/AIDS patients and others patients such as elderly people, transplant recipients and cancer patients, epidemiological studies of E. bieneusi focus on this susceptible population. Asymptomatic carriers of E. bieneusi are often neglected, and their role in the transmission of this microorganism is not paid enough attention. The prevalence of E. bieneusi is also actually related to the geographical locations, the populations and the socioeconomic conditions. The infectious diseases usually disproportionately affect poor populations. In China, although total economy has developed rapidly, there is the regional imbalance in economic development and some minority areas remain poor. Thus, we carried out a molecular epidemiology survey of E. bieneusi among 289 Yao people with and without diarrhea from a poverty-stricken ethnic township. We identified E. bieneusi in 8.30% (24/289) of people, with the majority (83.33%, 20/24) of positive individuals having no diarrhea. Meanwhile, zoonotic genotype Peru6 was found to be dominant in infected people. Our study emphasizes the importance and significance in epidemiological surveys of E. bieneusi in non-diarrheal people and assessment of risk factors for 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.

Occurrence of zoonotic Enterocytozoon bieneusi in cats in Brazil

Enterocytozoon bieneusi is an opportunistic intestinal pathogen that infects humans and a wide variety of animals worldwide. Our aim in this study was to investigate the occurrence of E. bieneusi in a domestic cat population in Campo Grande, Mato Grosso do Sul, Brazil. Sixty fecal samples from diarrheic cats were subjected to polymerase chain reaction (PCR) and the amplicons were sequenced for identification. E. bieneusi was detected in two samples (3.3%), both identified as genotype D. This genotype has already been reported in animals and humans and is considered a zoonotic genotype. Our findings represent the first report of E. bieneusi in domestic cats in Brazil, reinforcing the importance of identifying this agent as a source of infection in animals and humans.

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.

Giardia duodenalis in primates: Classification and host specificity based on phylogenetic analysis of sequence data

Giardia duodenalis colonizes the gastrointestinal tract of a wide range of hosts, including humans and other primates. It is grouped into eight different Assemblages and, beyond that, into a number of sub-Assemblages, defined ad hoc on the basis of genetic differences; these various groups are often considered to be associated with a specific restricted host range. The aim of this study was to use publicly available genotyping data to investigate the relatedness of human and non-human primate (NHP) Giardia isolates in order to evaluate the usefulness of current taxonomic classification and to assess whether there is potential for zoonotic transmission between humans and NHP. Our final data set consisted of sequence data from 165 isolates, 111 from NHP and 54 from humans. Assemblages were well defined, but sub-Assemblages across Assemblage B were not resolved. Although sub-Assemblages AI and AII were resolved, the terms were not found to capture any useful molecular or host/deme properties. In the phylogenetic tree, NHP isolates were scattered among human isolates across Assemblages A and B, and were even found in Assemblage E. We conclude that there does not appear to be significant molecular distinction between human and NHP Giardia isolates across these four molecular markers. Thus, on the basis of these markers, we cannot exclude a risk for zoonotic and anthropozoonotic transmission of Assemblages A and B isolates, irrespective of sub-Assemblage classification. We further evaluated the relative merit of the four genes used in genotyping studies. The tpi, gdh and bg genes gave relatively congruent tree topologies, but the SSU gene did not resolve Assemblages according to the current classification. Future genotyping efforts should aim for multilocus or whole-genome approaches and, in particular, use of the SSU gene as the sole marker should be avoided when possible.

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

BACKGROUND

Giardia duodenalis and Enterocytozoon bieneusi are widespread pathogens that can infect humans and various animal species. Thus far, there are only a few reports of G. duodenalis and E. bieneusi infections in ruminant wildlife. Thus, the objective of this study was to examine the prevalence of G. duodenalis and E. bieneusi in forest musk deer in Sichuan, China, as well as identifying their genotypes.

RESULTS

In total, we collected 223 faecal samples from musk deer at the Sichuan Institute of Musk Deer Breeding in Dujiangyan (n = 80) and the Maerkang Breeding Institute (n = 143). Five (2.24%) faecal samples were positive for G. duodenalis; three belonged to assemblage E, and two belonged to assemblage A based on the sequence analysis of the β-giardin (bg) gene. One sample each was found to be positive based on the glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) gene, respectively. Thirty-eight (17.04%) faecal samples were found to be E. bieneusi-positive based on the internal transcribed spacer (ITS) sequence, and only SC03 genotype was identified, which belonged to the zoonotic group 1 according to the phylogenic analysis. The infection rates were significantly different among the different geographical areas and age groups but had no apparent association with gender or clinical symptoms.

CONCLUSIONS

To our knowledge, this was the first molecular characterisation of G. duodenalis and E. bieneusi in musk deer. Identification of the zoonotic genotypes indicated a potential public health threat, and our study suggested that the forest musk deer is an important carrier of these parasites.

Molecular characterization of Cryptosporidium spp. in poultry from Brazil

Cryptosporidiosis is an important zoonotic disease caused by Cryptosporidium. Infections in birds are mainly caused by C. meleagridis, C. baileyi, and C. galli. C. meleagridis is the third most common cause of cryptosporidiosis in humans and the only Cryptosporidium species known to infect both birds and mammals. One hundred and fifty-five fecal specimens from different poultry species (chicken, turkey, ostrich, helmeted guinea fowl, quail, pheasant, and emu) were collected at local markets in the state of Minas Gerais, Brazil. Twenty-three (14.8%) birds (20 chickens, 2 quails, and 1 turkey) were found Cryptosporidium-positive. This constitutes the first report of Cryptosporidium in turkeys from Brazil. Nucleotide sequence analysis identified C. meleagridis in chickens (15), a turkey (1), and a quail (1), C. baileyi in chickens (4) and a quail (1), and a mixed infection C. meleagridis/C. baileyi in a chicken (1). This is the first report of C. meleagridis in turkeys and quails from Brazil. Using the gp60 gene, three subtype families were identified, IIIa, IIIb and IIIg. Within subtype family IIIg, four subtypes were identified in chickens, two novel (IIIgA25G3R1 and IIIgA21G3R1) and two previously reported (IIIgA22G3R1 and IIIgA24G2R1). Within subtype family IIIb two subtypes were identified, IIIbA24G1R1 in a chicken and IIIbA23G1R1 in a quail. A novel subtype in the family IIIa was identified (IIIaA22G3R1) in a turkey. The finding of C. meleagridis subtypes previously identified in humans (IIIgA22G3R1, IIIbA24G1R1 and IIIbA23G1R1) indicates that they can be potentially zoonotic. Further subtyping studies that clarify genetic diversity of C. meleagridis are required to better understand host specificity, source of infection, and transmission dynamics of C. meleagridis.

Detection and molecular characterization of Cryptosporidium spp. in captive canaries (Serinus canaria) using different diagnostic methods

This study used several diagnostic methods to examine the occurrence of and molecularly characterize Cryptosporidium spp. in captive canaries (Serinus canaria) in southern and southeastern Brazil. A total of 498 fecal samples were purified by centrifugal-flotation using Sheather's solution. Cryptosporidium spp. diagnosis was performed using three diagnostic methods: malachite green negative staining, nested PCR targeting the 18S rRNA gene, followed by sequencing the amplified fragments, and duplex real-time PCR targeting the 18S rRNA specific to detect Cryptosporidium galli and Cryptosporidium avian genotype III. The overall positivity for Cryptosporidium spp. (total samples positive in at least one protocol) from the microscopic analysis, nested PCR and duplex real-time PCR protocol results was 13.3% (66/498). The positivity rates were 2.0% (10/498) and 4.6% (23/498) for Cryptosporidium spp. by microscopy and nested PCR, respectively. Sequencing of 20 samples amplified by nested PCR identified C. galli (3.0%; 15/498), Cryptosporidium avian genotype I (0.8%; 4/498) and Cryptosporidium avium (0.2%; 1/498). Duplex real-time PCR revealed a positivity of 7.8% (39/498) for C. galli and 2.4% (12/498) for avian genotype III. Malachite green negative staining differed significantly from nested PCR in detecting Cryptosporidium spp. Duplex real-time PCR was more sensitive than nested PCR/sequencing for detecting gastric Cryptosporidium in canaries.

First detection and genetic characterisation of Enterocytozoon bieneusi in wild deer in Melbourne's water catchments in Australia

BACKGROUND

Enterocytozoon bieneusi is reported to be a common microsporidian of humans and animals in various countries. However, E. bieneusi has yet to be recorded in animals in Australia. Here, we undertook the first molecular epidemiological investigation of E. bieneusi in three species of deer (Cervus elaphus, Dama dama and Rusa unicolor) that live in the catchment areas that supply the city of Melbourne with drinking water.

METHODS

Genomic DNA was extracted from a total of 610 individual faecal samples from wild deer, including sambar deer (Rusa unicolor) (n = 516), red deer (Cervus elaphus) (n = 77) and fallow deer (Dama dama) (n = 17) from nine catchment areas, and then tested using a nested PCR-based sequencing approach employing internal transcribed spacer (ITS) of nuclear ribosomal DNA as the genetic marker.

RESULTS

Enterocytozoon bieneusi was detected in 25 of all 610 (4.1%) samples exclusively in samples from sambar deer. The analysis of ITS sequence data revealed three known (D, J and Type IV) and two new (MWC_d1 and MWC_d2) genotypes of E. bieneusi. Although the significance of the latter two new genotypes is presently unknown, phylogenetic analysis of ITS sequence data sets showed that they cluster with genotypes D and Type IV, which have been recorded previously in humans. These findings suggest that sambar deer in the water catchments harbour zoonotic genotypes of E. bieneusi.

CONCLUSIONS

Further insight into the epidemiology of E. bieneusi in wildlife, water and the environment in Australia will be important to have an informed position on the public health significance of microsporidiosis caused by this microbe.

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.