Host-specific Cryptosporidium, Giardia and Enterocytozoon bieneusi in shelter dogs from central Europe

Cryptosporidium spp., Giardia intestinalis and microsporidia are unicellular opportunistic pathogens that can cause gastrointestinal infections in both animals and humans. Since companion animals may serve as a source of infection, the aim of the present screening study was to analyse the prevalence of these intestinal protists in fecal samples collected from dogs living in 10 animal shelters in central Europe (101 dogs from Poland and 86 from the Czech Republic), combined with molecular subtyping of the detected organisms in order to assess their genetic diversity. Genus-specific polymerase chain reactions were performed to detect DNA of the tested species and to conduct molecular subtyping in collected samples, followed by statistical evaluation of the data obtained (using χ2 or Fisher's tests). The observed prevalence was 15.5, 10.2, 1 and 1% for G. intestinalis, Enterocytozoon bieneusi, Cryptosporidium spp. and Encephalitozoon cuniculi, respectively. Molecular evaluation has revealed the predominance of dog-specific genotypes (Cryptosporidium canis XXe1 subtype; G. intestinalis assemblages C and D; E. cuniculi genotype II; E. bieneusi genotypes D and PtEbIX), suggesting that shelter dogs do not pose a high risk of human transmission. Interestingly, the percentage distribution of the detected pathogens differed between both countries and individual shelters, suggesting that the risk of infection may be associated with conditions typical of a given location.

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.

Microsporidia (Encephalitozoon cuniculi) in Patients with Degenerative Hip and Knee Disease, Czech Republic

Total joint arthroplasty is a commonly used surgical procedure in orthopedics. Revision surgeries are required in >10% of patients mainly because of prosthetic joint infection caused by bacteria or aseptic implant loosening caused by chronic inflammation. Encephalitozoon cuniculi is a microsporidium, an obligate intracellular parasite, capable of exploiting migrating proinflammatory immune cells for dissemination within the host. We used molecular detection methods to evaluate the incidence of E. cuniculi among patients who had total hip or knee arthroplasty revision. Out of 49 patients, E. cuniculi genotypes I, II, or III were confirmed in joint samples from 3 men and 2 women who had implant loosening. Understanding the risks associated with the presence of microsporidia in periprosthetic joint infections is essential for proper management of arthroplasty. Furthermore, E. cuniculi should be considered a potential contributing cause of joint inflammation and arthrosis.

The effect of host admixture on wild house mouse gut microbiota is weak when accounting for spatial autocorrelation

The question of how interactions between the gut microbiome and vertebrate hosts contribute to host adaptation and speciation is one of the major problems in current evolutionary research. Using bacteriome and mycobiome metabarcoding, we examined how these two components of the gut microbiota vary with the degree of host admixture in secondary contact between two house mouse subspecies (Mus musculus musculus and M. m. domesticus). We used a large data set collected at two replicates of the hybrid zone and model-based statistical analyses to ensure the robustness of our results. Assuming that the microbiota of wild hosts suffers from spatial autocorrelation, we directly compared the results of statistical models that were spatially naive with those that accounted for spatial autocorrelation. We showed that neglecting spatial autocorrelation can strongly affect the results and lead to misleading conclusions. The spatial analyses showed little difference between subspecies, both in microbiome composition and in individual bacterial lineages. Similarly, the degree of admixture had minimal effects on the gut bacteriome and mycobiome and was caused by changes in a few microbial lineages that correspond to the common symbionts of free-living house mice. In contrast to previous studies, these data do not support the hypothesis that the microbiota plays an important role in host reproductive isolation in this particular model system.

Dietary environmental factors shape the immune defense against Cryptosporidium infection

Cryptosporidium is a leading cause of diarrheal-related deaths in children, especially in resource-poor settings. It also targets the immunocompromised, chronically infecting people living with HIV and primary immunodeficiencies. There is no vaccine or effective treatment. Although it is known from human cases and animal models that CD4+ T cells play a role in curbing Cryptosporidium, the role of CD8+ T cells remains to be defined. Using a Cryptosporidium tyzzeri mouse model, we show that gut-resident CD8+ intraepithelial lymphocytes (IELs) confer resistance to parasite growth. CD8+ IELs express and depend on the ligand-dependent transcription factor aryl hydrocarbon receptor (AHR). AHR deficiency reduces CD8+ IELs, decreases their cytotoxicity, and worsens infection. Transfer of CD8+ IELs rescues severely immunodeficient mice from death following Cryptosporidium challenge. Finally, dietary supplementation of the AHR pro-ligand indole-3-carbinol in newborn mice promotes resistance to infection. Therefore, common dietary metabolites augment the host immune response to cryptosporidiosis, protecting against disease.

Cryptosporidium mortiferum n. sp. (Apicomplexa: Cryptosporidiidae), the species causing lethal cryptosporidiosis in Eurasian red squirrels (Sciurus vulgaris)

BACKGROUND

Cryptosporidium spp. are globally distributed parasites that infect epithelial cells in the microvillus border of the gastrointestinal tract of all classes of vertebrates. Cryptosporidium chipmunk genotype I is a common parasite in North American tree squirrels. It was introduced into Europe with eastern gray squirrels and poses an infection risk to native European squirrel species, for which infection is fatal. In this study, the biology and genetic variability of different isolates of chipmunk genotype I were investigated.

METHODS

The genetic diversity of Cryptosporidium chipmunk genotype I was analyzed by PCR/sequencing of the SSU rRNA, actin, HSP70, COWP, TRAP-C1 and gp60 genes. The biology of chipmunk genotype I, including oocyst size, localization of the life cycle stages and pathology, was examined by light and electron microscopy and histology. Infectivity to Eurasian red squirrels and eastern gray squirrels was verified experimentally.

RESULTS

Phylogenic analyses at studied genes revealed that chipmunk genotype I is genetically distinct from other Cryptosporidium spp. No detectable infection occurred in chickens and guinea pigs experimentally inoculated with chipmunk genotype I, while in laboratory mice, ferrets, gerbils, Eurasian red squirrels and eastern gray squirrels, oocyst shedding began between 4 and 11 days post infection. While infection in mice, gerbils, ferrets and eastern gray squirrels was asymptomatic or had mild clinical signs, Eurasian red squirrels developed severe cryptosporidiosis that resulted in host death. The rapid onset of clinical signs characterized by severe diarrhea, apathy, loss of appetite and subsequent death of the individual may explain the sporadic occurrence of this Cryptosporidium in field studies and its concurrent spread in the population of native European squirrels. Oocysts obtained from a naturally infected human, the original inoculum, were 5.64 × 5.37 μm and did not differ in size from oocysts obtained from experimentally infected hosts. Cryptosporidium chipmunk genotype I infection was localized exclusively in the cecum and anterior part of the colon.

CONCLUSIONS

Based on these differences in genetics, host specificity and pathogenicity, we propose the name Cryptosporidium mortiferum n. sp. for this parasite previously known as Cryptosporidium chipmunk genotype I.

Cryptosporidium equi n. sp. (Apicomplexa: Cryptosporidiidae): biological and genetic characterisations

The horse genotype is one of three common Cryptosporidium spp. in equine animals and has been identified in some human cases. The species status of Cryptosporidium horse genotype remains unclear due to the lack of extensive morphological, biological, and genetic data. In the present study, we have conducted biological and whole genome sequence analyses of an isolate of the genotype from hedgehogs and proposed to name it Cryptosporidium equi n. sp. to reflect its common occurrence in equine animals. Oocysts of C. equi measured 5.12 ± 0.36 μm × 4.46 ± 0.21 μm with a shape index of 1.15 ± 0.08 (n = 50). Cryptosporidium equi was infectious to 3-week-old four-toed hedgehogs (Atelerix albiventris) and mice, with a prepatent period of 2-9 days and a patent period of 30-40 days in hedgehogs. It was not infectious to rats and rabbits. Phylogenetic analyses of small subunit rRNA, 70 kDa heat shock protein, actin, 60 kDa glycoprotein and 100 other orthologous genes revealed that C. equi is genetically distinct from other known Cryptosporidium species and genotypes. The sequence identity between C. equi and Cryptosporidium parvum genomes is 97.9%. Compared with C. parvum, C. equi has lost two MEDLE genes and one insulinase-like protease gene and gained one SKSR gene. In addition, 60 genes have highly divergent sequences (sequence differences ≥ 5.0%), including those encoding mucin-like glycoproteins, insulinase-like peptidases, and MEDLE and SKSR proteins. The genetic uniqueness of C. equi supports its increasing host range and the naming of it as a valid Cryptosporidium species. This is the first known use of whole genome sequence data in delineating new Cryptosporidium species.

Follow-up investigation into Cryptosporidium prevalence and transmission in Western European dairy farms

Cryptosporidium parvum is an enteric parasite and a major contributor to acute enteritis in calves worldwide, causing an important economic burden for farmers. This parasite poses a major public health threat through transmission between livestock and humans. Our previous pilot study in Western Europe revealed a high prevalence of Cryptosporidium in calves of dairy farms. In the sequel study herein, 936 faecal samples were collected from the same 51 dairy farms across Belgium, France, and the Netherlands. Following DNA extraction, Cryptosporidium screening was carried out using nested-PCR amplification targeting the SSU rRNA gene. All positive samples were sequenced, and phylogenetic analyses were used to identify the Cryptosporidium spp. present. The 60 kDa glycoprotein (gp60) gene was also sequenced to determine the C. parvum subtypes present. Prevalence of Cryptosporidium ranged from 23.3% to 25%, across the three countries surveyed. The parasite was found in most of the farms sampled, with 90.2% testing positive. Cryptosporidium parvum, C. bovis, C. ryanae and C. andersoni were all identified, with the former being the most predominant, representing 71.4% of all infections. Cryptosporidium parvum was associated with pre-weaned calves, while other species were associated with older animals. Subtyping of gp60 gene revealed nine subtypes, eight of which have previously been reported to cause clinical disease in humans. Similarly to the first study, vertical transmission was not a major contributor to Cryptosporidium spread. Our study highlights the need for further investigation into cryptosporidiosis transmission, and future studies will require a One Health approach to reduce the impact of this disease.

Sympatric Recombination in Zoonotic Cryptosporidium Leads to Emergence of Populations with Modified Host Preference

Genetic recombination plays a critical role in the emergence of pathogens with phenotypes such as drug resistance, virulence, and host adaptation. Here, we tested the hypothesis that recombination between sympatric ancestral populations leads to the emergence of divergent variants of the zoonotic parasite Cryptosporidium parvum with modified host ranges. Comparative genomic analyses of 101 isolates have identified seven subpopulations isolated by distance. They appear to be descendants of two ancestral populations, IIa in northwestern Europe and IId from southwestern Asia. Sympatric recombination in areas with both ancestral subtypes and subsequent selective sweeps have led to the emergence of new subpopulations with mosaic genomes and modified host preference. Subtelomeric genes could be involved in the adaptive selection of subpopulations, while copy number variations of genes encoding invasion-associated proteins are potentially associated with modified host ranges. These observations reveal ancestral origins of zoonotic C. parvum and suggest that pathogen import through modern animal farming might promote the emergence of divergent subpopulations of C. parvum with modified host preference.

Horse-Specific Cryptosporidium Genotype in Human with Crohn's Disease and Arthritis

We identified an unusual subtype of a Cryptosporidium sp. horse genotype as the cause of cryptosporidiosis in a 13-year-old girl in Poland who was undergoing immunosuppressive treatment for juvenile rheumatoid arthritis and Crohn’s disease. The same subtype was identified in a horse the girl had ridden.

Encephalitozoon cuniculi and Extraintestinal Microsporidiosis in Bird Owners

We identified Encephalitozoon cuniculi genotype II parasites as a cause of extraintestinal microsporidiosis in 2 owners of birds also infected with E. cuniculi. Patients experienced long-lasting nonspecific symptoms; the disease course was more progressive in a patient with diabetes. Our findings suggest direct bird-to-human transmission of this pathogen.

High Occurrence of Zoonotic Subtypes of Cryptosporidiumparvum in Cypriot Dairy Farms

Cryptosporidium parvum is one of the major causes of neonatal calf diarrhoea resulting in reduced farm productivity and compromised animal welfare worldwide. Livestock act as a major reservoir of this parasite, which can be transmitted to humans directly and/or indirectly, posing a public health risk. Research reports on the prevalence of Cryptosporidium in ruminants from east Mediterranean countries, including Cyprus, are limited. This study is the first to explore the occurrence of Cryptosporidium spp. in cattle up to 24 months old on the island of Cyprus. A total of 242 faecal samples were collected from 10 dairy cattle farms in Cyprus, all of which were screened for Cryptosporidium spp. using nested-PCR amplification targeting the small subunit of the ribosomal RNA (18S rRNA) gene. The 60 kDa glycoprotein (gp60) gene was also sequenced for the samples identified as Cryptosporidium parvum-positive to determine the subtypes present. The occurrence of Cryptosporidium was 43.8% (106/242) with at least one positive isolate in each farm sampled. Cryptosporidium bovis, Cryptosporidium ryanae and C. parvum were the only species identified, while the prevalence per farm ranged from 20–64%. Amongst these, the latter was the predominant species, representing 51.8% of all positive samples, followed by C. bovis (21.7%) and C. ryanae (31.1%). Five C. parvum subtypes were identified, four of which are zoonotic—IIaA14G1R1, IIaA15G1R1, IIaA15G2R1 and IIaA18G2R1. IIaA14G1R1 was the most abundant, representing 48.2% of all C. parvum positive samples, and was also the most widespread. This is the first report of zoonotic subtypes of C. parvum circulating in Cyprus. These results highlight the need for further research into the parasite focusing on its diversity, prevalence, host range and transmission dynamics on the island.

A productive immunocompetent mouse model of cryptosporidiosis with long oocyst shedding duration for immunological studies

OBJECTIVES

Studies on the pathogenesis and immune responses of Cryptosporidium infection and development of drugs and vaccines use mostly immunocompromised mouse models. In this study, we establish an immunocompetent mouse model of cryptosporidiosis with high intensity and long duration of infection.

METHODS

We have obtained a Cryptosporidium tyzzeri isolate from laboratory mice, and infect adult C57BL/6J mice experimentally with the isolate for determinations of infectivity, infection patterns, pathological changes, and transcriptomic responses.

RESULTS

The isolate has an ID₅₀ of 5.2 oocysts, with oocyst shedding lasting at high levels for >2 months. The oocyst shedding is boosted by immunosuppression of animals and suppressed by paromomycin treatment. The isolate induces strong inflammatory and acquired immune responses, but down-regulates the expression of α-defensins in epithelium. Comparative genomics analysis has revealed significant sequence differences from other isolates in subtelomeric genes. The down-regulation of the expression of α-defensins may be responsible for the high-intensity and long-lasting infection in this animal model.

CONCLUSIONS

The immunocompetent mouse model of cryptosporidiosis developed has the advantages of high oocyst shedding intensity and long oocyst shedding duration. It provides an effective mechanism for the propagation of Cryptosporidium, evaluations of potential therapeutics, and studies of pathogen biology and immune responses.

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.

Cross-Border Investigations on the Prevalence and Transmission Dynamics of Cryptosporidium Species in Dairy Cattle Farms in Western Mainland Europe

Cryptosporidium is an apicomplexan parasitic protist, which infects a wide range of hosts, causing cryptosporidiosis disease. In farms, the incidence of this disease is high in animals such as cows, leading to extensive economic loss in the livestock industry. Infected cows may also act as a major reservoir of Cryptosporidium spp., in particular C. parvum, the most common cause of cryptosporidiosis in these animals. This poses a risk to the trading of livestock, to other farms via breeding centres, and to human health. This study is a part of a global project aimed at strategies to tackle cryptosporidiosis. To reach this target, it was essential to determine whether prevalence was dependent on the studied countries or if the issue was borderless. Indeed, C. parvum occurrence was assessed across dairy farms in certain regions of Belgium, France, and the Netherlands. At the same time, the animal-to-animal transmission of the circulating C. parvum subtypes was studied. To accomplish this, we analysed 1084 faecal samples, corresponding to 57 dairy farms from all three countries. To this end, 18S rRNA and gp60 genes fragments were amplified, followed by DNA sequencing, which was subsequently used for detection and subtyping C. parvum. Bioinformatic and phylogenetic methods were integrated to analyse and characterise the obtained DNA sequences. Our results show 25.7%, 24.9% and 20.8% prevalence of Cryptosporidium spp. in Belgium, France, and the Netherlands respectively. Overall, 93% of the farms were Cryptosporidium positive. The gp60 subtyping demonstrated a significant number of the C. parvum positives belonged to the IIa allelic family, which has been also identified in humans. Therefore, this study highlights how prevalent C. parvum is in dairy farms and further suggests cattle as a possible carrier of zoonotic C. parvum subtypes, which could pose a threat to human health.

Enterocytozoon Bieneusi Infects Children With Inflammatory Bowel Disease Undergoing Immunosuppressive Treatment

Objectives: Patients with inflammatory bowel disease (IBD) are susceptible to intestinal opportunistic infections due to both defective mucosal immunity and altered immune response resulting from immunosuppressive treatment. Microsporidia infecting the gastrointestinal tract and causing diarrhoea can potentially affect the course of IBD.

Methods: Stool samples (90 IBD children and 121 healthy age-matched controls) were screened for Encephalitozoon spp. and Enterocytozoon bieneusi by microscopy and polymerase chain reaction followed by sequencing.

Results:E. bieneusi genotype D was found in seven out of 90 (7.8%) IBD children. No children from the control group were infected, making the pathogen prevalence in the IBD group significant (P = 0.002). Furthermore, infection was confirmed only in patients receiving immunosuppressive treatment (P = 0.013).

Conclusions: Children with IBD are at risk of intestinal E. bieneusi infection, especially when receiving immunosuppressive treatment. Therefore, microsporidia should be considered as a significant infectious agent in this group of patients.

Cryptosporidium sciurinum n. sp. (Apicomplexa: Cryptosporidiidae) in Eurasian Red Squirrels (Sciurus vulgaris)

Cryptosporidium spp. are common protozoan pathogens in mammals. The diversity and biology of Cryptosporidium in tree squirrels are not well studied. A total of 258 Eurasian red squirrels (Sciurus vulgaris) from 25 and 15 locations in the Czech Republic and Slovakia, respectively, were examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, TRAP-C1, COWP, and gp60 loci. Out of 26 positive animals, only juveniles (9/12) were microscopically positive (18,000 to 72,000 OPG), and molecular analyses revealed the presence of Cryptosporidium sp. ferret genotype in all specimens. Oocysts obtained from naturally-infected squirrels measured 5.54-5.22 μm and were not infectious for laboratory mice (BALB/c and SCID), Mongolian gerbils, Guinea pigs, Southern multimammate mice, chickens, or budgerigars. None of naturally infected squirrels showed clinical signs of disease. The frequency of occurrence of the ferret genotype in squirrels did not vary statistically based on host age, gender or country of capture. Phylogenetic analysis of sequences from six loci revealed that Cryptosporidium sp. ferret genotype is genetically distinct from the currently accepted Cryptosporidium species. Morphological and biological data from this and previous studies support the establishment of Cryptosporidium sp. ferret genotype as a new species, Cryptosporidium sciurinum n. sp.

Cryptosporidium baileyi Pulmonary Infection in Immunocompetent Woman with Benign Neoplasm

Cryptosporidium baileyi, a bird-specific parasite, infects gastrointestinal, pulmonary, and urinary tracts of its host. We report on a C. baileyi infection associated with pulmonary hamartoma in an immunocompetent patient in Poland. Further work is needed to investigate the association between Cryptosporidium infections and tumors.

Raw Goat's Milk, Fresh and Soft Cheeses as a Potential Source of Encephalitozoon cuniculi

The aim of this work was to evaluate the effect of pasteurization and coagulation during goat cheese production on the infectivity of Encephalitozoon cuniculi spores for immunodeficient (SCID, CD4^-/-, and CD8^-/-) and immunocompetent (BALB/c and C57BL/6) mice. Goat milk and fecal samples were screened for the presence and quantity of microsporidial DNA using molecular methods. Experimentally produced cheese from E. cuniculi-enriched goat milk or goat cheese purchased from retail producers was fed with experimental mice susceptible to E. cuniculi infection. The mice were sacrificed in the presumed acute phase of infection and samples of their tissues were subject to molecular detection of specific E. cuniculi DNA. Specific DNA of E. cuniculi genotype II was detected in feces and milk of three out of 99 goats kept on 6 farms in the Czech Republic. Under experimental conditions, spores of E. cuniculi genotype II remained viable in artificially enriched fresh cheese and were able to cause infection in laboratory mice. E. cuniculi genotype I and II DNA were detected in eight of the nine goat cheeses purchased from various producers/breeders in the Czech Republic and these cheeses were able to develop infection in both immunodeficient and immunocompetent mice. The results of these experiments showed that spores of E. cuniculi genotype I and II are able to remain viable after cheese processing and thus fresh and soft cheeses should be considered a potential source of microsporidia.

Cryptosporidium myocastoris n. sp. (Apicomplexa: Cryptosporidiidae), the Species Adapted to the Nutria (Myocastor coypus)

Cryptosporidium spp., common parasites of vertebrates, remain poorly studied in wildlife. This study describes the novel Cryptosporidium species adapted to nutrias (Myocastor coypus). A total of 150 faecal samples of feral nutria were collected from locations in the Czech Republic and Slovakia and examined for Cryptosporidium spp. oocysts and specific DNA at the SSU, actin, HSP70, and gp60 loci. Molecular analyses revealed the presence of C. parvum (n = 1), C. ubiquitum subtype family XIId (n = 5) and Cryptosporidium myocastoris n. sp. XXIIa (n = 2), and XXIIb (n = 3). Only nutrias positive for C. myocastoris shed microscopically detectable oocysts, which measured 4.8–5.2 × 4.7–5.0 µm, and oocysts were infectious for experimentally infected nutrias with a prepatent period of 5–6 days, although not for mice, gerbils, or chickens. The infection was localised in jejunum and ileum without observable macroscopic changes. The microvilli adjacent to attached stages responded by elongating. Clinical signs were not observed in naturally or experimentally infected nutrias. Phylogenetic analyses at SSU, actin, and HSP70 loci demonstrated that C. myocastoris n. sp. is distinct from other valid Cryptosporidium species.

Intestinal parasites of dogs (Canis lupus familiaris) in Svalbard (Norway): low prevalence and limited transmission with wildlife

Domesticated dogs (Canis lupus familiaris Linnaeus, 1758) are widely kept on all continents and could share parasites with free-living animals. To understand the transmission of intestinal parasites between dogs kept on the four dog stations and wildlife in Svalbard, 170 faecal samples from dogs and 203 faecal samples from wildlife, including Arctic fox (Vulpes lagopus (Linnaeus, 1758); n = 62), Svalbard reindeer (Rangifer tarandus platyrhynchus (Vrolik, 1829); n = 106), sibling vole (Microtus levis Miller, 1908; n = 63), Pink-footed Goose (Anser brachyrhynchus Baillon, 1834; n = 30), Little Auk (Alle alle (Linnaeus, 1758); n = 49), and Black-legged Kittiwake (Rissa tridactyla (Linnaeus, 1758); n = 18), were individually screened for the presence of intestinal parasites using microscopy and PCR and nucleotide sequencing methods. Additionally, the results of the study were compared with previous studies performed in the same area. The roundworm Toxascaris leonina (Linstow, 1902) was found microscopically and by PCR in a dog (n = 1). The specific DNA of three species of parasitic protists was detected in dogs from different yards. Phylogenetic analyses revealed the presence of Cryptosporidium canis Fayer, Trout, Xiao, Morgan, Lal and Dubey, 2001 (n = 1), Encephalitozoon cuniculi Levaditi, Nicolau and Schoen, 1923 genotype II (n = 4), and dog-specific Enterocytozoon bieneusi Desportes, Le Charpentier, Galian, Bernard, Cochand-Priollet, Lavergne, Ravisse and Modigliani, 1985 genotypes (n = 12). This study showed overall a low prevalence of intestinal parasites in dogs in Svalbard and possible but minimal transmission with wildlife.

The course of infection of Encephalitozoon cuniculi genotype I in mice possess combination of features reported in genotypes II and III

Out of three genotypes of Encephalitozoon cuniculi (I-III) available for experimental studies, E. cuniculi genotype I remains the less characterized. This study describes for the first time individual phases of microsporidiosis caused by E. cuniculi genotype I and efficacy of albendazole treatment in immunocompetent BALB/c and C57Bl/6 mice and immunodeficient SCID, CD4^-/- and CD8^-/- mice using molecular detection and quantification methods. We demonstrate asymptomatic infection despite an intense dissemination of microsporidia into most organs within the first weeks post infection, followed by a chronic infection characterized by significant microsporidia persistence in immunocompetent, CD4^-/- and CD8^-/- mice and a lethal outcome for SCID mice. Albendazole application led to loss E. cuniculi genotype I infection in immunocompetent mouse strains, decreased spore burden by half in CD4^-/- and CD8^-/- mice, and prolongation of survival of SCID mice. These results showed Encephalitozoon cuniculi genotype I infection extend and albendazole sensitivity was comparable to E. cuniculi genotype II, but the infection onset speed and mortality rate was similar to E. cuniculi genotype III. These imply that differences in the course of infection and the response to treatment depend not only on immunological status of the host, but also on the genotype causing the infection.

Cryptosporidium ratti n. sp. (Apicomplexa: Cryptosporidiidae) and genetic diversity of Cryptosporidium spp. in brown rats (Rattus norvegicus) in the Czech Republic

The diversity and biology of Cryptosporidium that is specific for rats (Rattus spp.) are not well studied. We examined the occurrence and genetic diversity of Cryptosporidium spp. in wild brown rats (Rattus norvegicus) by microscopy and polymerase chain reaction (PCR)/sequencing targeting the small subunit rDNA (SSU), actin and HSP70 genes. Out of 343 faecal samples tested, none were positive by microscopy and 55 were positive by PCR. Sequence analysis of SSU gene revealed the presence of Cryptosporidium muris (n = 4), C. andersoni (n = 3), C. ryanae (n = 1), C. occultus (n = 3), Cryptosporidium rat genotype I (n = 23), Cryptosporidium rat genotype IV (n = 16) and novel Cryptosporidium rat genotype V (n = 5). Spherical oocysts of Cryptosporidium rat genotype I obtained from naturally-infected rats, measuring 4.4-5.4 μm × 4.3-5.1 μm, were infectious to the laboratory rats, but not to the BALB/c mice (Mus musculus) nor Mongolian gerbils (Meriones unguiculatus). The prepatent period was 3 days post infection and the patent period was longer than 30 days. Naturally- and experimentally-infected rats showed no clinical signs of disease. Percentage of nucleotide similarities at the SSU, actin, HSP70 loci between C. ratti n. sp. and the rat derived C. occultus and Cryptosporidium rat genotype II, III, IV, and V ranged from 91.0 to 98.1%. These genetic variations were similar or greater than that observed between closely related species, i.e. C. parvum and C. erinacei (93.2-99.5%). Our morphological, genetic and biological data support the establishment of Cryptosporidium rat genotype I as a new species, Cryptosporidium ratti n. sp.

Encephalitozoon cuniculi Genotype II Concentrates in Inflammation Foci

Background

Microsporidia of the genus Encephalitozoon are generally connected with severe infections with lethal outcome in immunodeficient hosts. In immunocompetent hosts, microsporidiosis typically establishes a balanced host–parasite relationship that produces minimal clinically overt disease. Although the alimentary tract represents one of the main primary target tissues, the mechanisms of reaching other tissues during systemic microsporidian infections remain unclear.

Methods

In the present study, we tested the relation between inflammation induction in immunocompetent and immunodeficient mice and the presence of spores of E. cuniculi genotype II in selected organs and in fecal specimens by using molecular and histology methods.

Results

We reported the positive connection between inflammation induction and the significant increase of E. cuniculi genotype II occurrence in inflammation foci in both immunocompetent BALB/c and immunodeficient severe combined immunodeficient (SCID) mice in the acute phase of infection and the re-activation of latent microsporidial infection following inflammation induction in immunocompetent mice.

Conclusion

The results imply possible involvement of immune cells serving as vehicles transporting E. cuniculi genotype II purposefully across the whole host body towards inflammation. With increasing number of records of infections, it is necessary to reconsider microsporidia as agents responsible for various pathologies. The elucidation of possible connection with pro-inflammatory immune responses represents an important challenge with consequences for human health and development of therapeutic strategies.

Population structure and geographical segregation of Cryptosporidium parvum IId subtypes in cattle in China

Background

Cryptosporidium parvum is a zoonotic pathogen worldwide. Extensive genetic diversity and complex population structures exist in C. parvum in different geographical regions and hosts. Unlike the IIa subtype family, which is responsible for most zoonotic C. parvum infections in industrialized countries, IId is identified as the dominant subtype family in farm animals, rodents and humans in China. Thus far, the population genetic characteristics of IId subtypes in calves in China are not clear.

Methods

In the present study, 46 C. parvum isolates from dairy and beef cattle in six provinces and regions in China were characterized using sequence analysis of eight genetic loci, including msc6-7, rpgr, msc6-5, dz-hrgp, chom3t, hsp70, mucin1 and gp60. They belonged to three IId subtypes in the gp60 gene, including IIdA20G1 (n = 17), IIdA19G1 (n = 24) and IIdA15G1 (n = 5). The data generated were analyzed for population genetic structures of C. parvum using DnaSP and LIAN and subpopulation structures using STRUCTURE, RAxML, Arlequin, GENALEX and Network.

Results

Seventeen multilocus genotypes were identified. The results of linkage disequilibrium analysis indicated the presence of an epidemic genetic structure in the C. parvum IId population. When isolates of various geographical areas were treated as individual subpopulations, maximum likelihood inference of phylogeny, pairwise genetic distance analysis, substructure analysis, principal components analysis and network analysis all provided evidence for geographical segregation of subpopulations in Heilongjiang, Hebei and Xinjiang. In contrast, isolates from Guangdong, Shanghai and Jiangsu were genetically similar to each other.

Conclusions

Data from the multilocus analysis have revealed a much higher genetic diversity of C. parvum than gp60 sequence analysis. Despite an epidemic population structure, there is an apparent geographical segregation in C. parvum subpopulations within China.

Subtyping Cryptosporidium ryanae: A Common Pathogen in Bovine Animals

Cryptosporidium ryanae is one of the most common species for cryptosporidiosis in cattle. However, little is known of the genetic characteristics of C. ryanae due to the lack of subtyping tools. In the present study, the 60-kDa glycoprotein (gp60) gene of C. ryanae was identified in whole genome sequence data and analyzed for sequence characteristics using bioinformatics tools. The protein it encodes had some of the typical characteristics of GP60 proteins, with a signal peptide, a furin cleavage site, and a glycosylphosphatidylinositol anchor at the C terminus of the protein, and numerous O-glycosylation sites. The gene sequence was used in the development of a subtyping tool, which was used in characterizing C. ryanae from 110 specimens from dairy cattle, 2 from beef cattle, 6 from yaks, and 4 from water buffaloes in China. Altogether, 17 subtypes from 8 subtype families were recognized, namely XXIa to XXIh. Possible host adaption was identified within this species, reflected by the unique occurrence of XXIa, XXIc, and XXIh in dairy cattle, yaks, and water buffaloes, respectively. Some geographical differences were detected in the distribution of subtype families in dairy cattle; specimens from southern China showed higher genetic diversity than from northern China, and the XXIa subtype family was only seen in dairy cattle in southern and eastern China. The gp60-based subtyping tool should be useful in molecular epidemiological studies of the transmission of C. ryanae.

Description of Cryptosporidium ornithophilus n. sp. (Apicomplexa: Cryptosporidiidae) in farmed ostriches

Background

Avian cryptosporidiosis is a common parasitic disease that is caused by five species, which are well characterised at the molecular and biological level, and more than 18 genotypes for which we have limited information. In this study, we determined the occurrence and molecular characteristics of Cryptosporidium spp. in farmed ostriches in the Czech Republic.

Methods

The occurrence and genetic identity of Cryptosporidium spp. were analysed by microscopy and PCR/sequencing of the small subunit rRNA, actin, HSP70 and gp60 genes. Cryptosporidium avian genotype II was examined from naturally and experimentally infected hosts and measured using differential interference contrast. The localisation of the life-cycle stages was studied by electron microscopy and histologically. Infectivity of Cryptosporidium avian genotype II for cockatiels (Nymphicus hollandicus (Kerr)), chickens (Gallus gallus f. domestica (L.)), geese (Anser anser f. domestica (L.)), SCID and BALB/c mice (Mus musculus L.) was verified.

Results

A total of 204 individual faecal samples were examined for Cryptosporidium spp. using differential staining and PCR/sequencing. Phylogenetic analysis of small subunit rRNA, actin, HSP70 and gp60 gene sequences showed the presence of Cryptosporidium avian genotype II (n = 7) and C. ubiquitum Fayer, Santín & Macarisin, 2010 IXa (n = 5). Only ostriches infected with Cryptosporidium avian genotype II shed oocysts that were detectable by microscopy. Oocysts were purified from a pooled sample of four birds, characterised morphometrically and used in experimental infections to determine biological characteristics. Oocysts of Cryptosporidium avian genotype II measure on average 6.13 × 5.15 μm, and are indistinguishable by size from C. baileyi Current, Upton & Haynes, 1986 and C. avium Holubová, Sak, Horčičková, Hlásková, Květoňová, Menchaca, McEvoy & Kváč, 2016. Cryptosporidium avian genotype II was experimentally infectious for geese, chickens and cockatiels, with a prepatent period of four, seven and eight days post-infection, respectively. The infection intensity ranged from 1000 to 16,000 oocysts per gram. None of the naturally or experimentally infected birds developed clinical signs in the present study.

Conclusions

The molecular and biological characteristics of Cryptosporidium avian genotype II, described here, support the establishment of a new species, Cryptosporidium ornithophilus n. sp.

A massive systematic infection of Encephalitozoon cuniculi genotype III in mice does not cause clinical signs

Encephalitozoon cuniculi genotype III disseminated intensively into most of the organs in all strains of mice, followed by a chronic infection with massive microsporidia persistence in immunodeficient mice and a partial decrease in C57Bl/6 mice. Treatment with 0.2 mg Albendazole/mouse/day temporarily reduces the number of affected organs in immunocompetent C57Bl/6 mice, but not in CD4^-/- and CD8^-/- mice. The application of medication temporarily decreased the spore burden at least by one order of magnitude in all groups. These results demonstrate that the E. cuniculi genotype III infection had a progressive course and surprisingly, Albendazole treatment had only a minimal effect. The E. cuniculi genotype III spore burden in individual organs reached up to 10⁸ or 10⁹ in immunocompetent or immunodeficient mice, respectively; however, these mice did not demonstrate any obvious clinical signs of microsporidiosis, and the immunodeficient mice survived longer. Our findings clearly show that the survival of mice does not correspond to spore burden, which provides new insight into latent microsporidiosis from an epidemiological point of view.

Encephalitozoon cuniculi Genotype III Evinces a Resistance to Albendazole Treatment in both Immunodeficient and Immunocompetent Mice

Of four genotypes of Encephalitozoon cuniculi, E. cuniculi genotype II is considered to represent a parasite that occurs in many host species in a latent asymptomatic form, whereas E. cuniculi genotype III seems to be more aggressive, and infections caused by this strain can lead to the death of even immunocompetent hosts. Although albendazole has been considered suitable for treatment of Encephalitozoon species, its failure in control of E. cuniculi genotype III infection has been reported. This study determined the effect of a 100× recommended daily dose of albendazole on an Encephalitozoon cuniculi genotype III course of infection in immunocompetent and immunodeficient mice and compared the results with those from experiments performed with a lower dose of albendazole and E. cuniculi genotype II. The administration of the regular dose of abendazole during the acute phase of infection reduced the number of affected organs in all strains of mice and absolute counts of spores in screened organs. However, the effect on genotype III was minor. Surprisingly, no substantial effect was recorded after the use of a 100× dose of albendazole, with larger reductions seen only in the number of affected organs and absolute counts of spores in all strains of mice, implying variations in albendazole resistance between these Encephalitozoon cuniculi genotypes. These results imply that differences in the course of infection and the response to treatment depend not only on the immunological status of the host but also on the genotype causing the infection. Understanding how microsporidia survive in hosts despite targeted antimicrosporidial treatment could significantly contribute to research related to human health.

Common occurrence of divergent Cryptosporidium species and Cryptosporidium parvum subtypes in farmed bamboo rats (Rhizomys sinensis)

BACKGROUND

Bamboo rats are widely farmed in southern China for meat, but their potential in transmitting pathogens to humans and other farm animals remains unclear.

METHODS

To understand the transmission of Cryptosporidium spp. in these animals, 709 fecal samples were collected in this study from Chinese bamboo rats (Rhizomys sinensis) on nine farms in Jiangxi, Guangxi and Hainan provinces, China. They were analyzed for Cryptosporidium spp. using PCR and sequence analyses of the small subunit rRNA gene. Cryptosporidium parvum, C. parvum-like and C. ubiquitum-like genotypes identified were subtyped by sequence analysis of the 60 kDa glycoprotein (gp60) gene.

RESULTS

Altogether, Cryptosporidium spp. were detected in 209 (29.5%) samples. The detection rate in samples from animals under two months of age (70.0%,105/150) was significantly higher than in samples from animals above 2 months (18.6%, 104/559; χ² = 150.27, df = 1, P < 0.0001). Four Cryptosporidium species/genotypes were identified: C. parvum (n = 78); C. occultus (n = 1); a new genotype that is genetically related to C. ubiquitum (n = 85); and another new genotype that is genetically related to C. parvum (n = 44). Among them, C. parvum (27,610 ± 71,911 oocysts/gram of feces) and the C. parvum-like genotype (38,679 ± 82,811 oocysts/gram of feces) had higher oocyst shedding intensity than the C. ubiquitum-like genotype (2470 ± 7017 oocysts/gram of feces) and the C. occultus (1012 oocysts/gram of feces). The C. parvum identified belonged to three subtypes in two rare subtype families, including IIpA9 (n = 43), IIpA6 (n = 6) and IIoA15G1 (n = 9), while the C. parvum-like and C. ubiquitum-like genotypes generated very divergent gp60 sequences.

CONCLUSIONS

Results of the present study suggest that bamboo rats on the study farms were infected with diverse Cryptosporidium species and divergent C. parvum subtypes, which probably had originated from their native habitats. As similar C. parvum subtypes have been recently detected in humans and farmed macaques, attentions should be paid to the potential role of these new farm animals in the transmission of zoonotic pathogens.

Update on Cryptosporidium spp.: highlights from the Seventh International Giardia and Cryptosporidium Conference

While cryptosporidiosis is recognized as being among the most common causes of human parasitic diarrhea in the world, there is currently limited knowledge on Cryptosporidium infection mechanisms, incomplete codification of diagnostic methods, and a need for additional therapeutic options. In response, the Seventh International Giardia and Cryptosporidium Conference (IGCC 2019) was hosted from 23 to 26 June 2019, at the Rouen Normandy University, France. This trusted event brought together an international delegation of researchers to synthesize recent advances and identify key research questions and knowledge gaps. The program of the interdisciplinary conference included all aspects of host-parasite relationships from basic research to applications to human and veterinary medicine, and environmental issues associated with waterborne parasites and their epidemiological consequences. In relation to Cryptosporidium and cryptosporidiosis, the primary research areas for which novel findings and the most impressive communications were presented and discussed included: Cryptosporidium in environmental waters, seafood, and fresh produce; Animal epidemiology; Human cryptosporidiosis and epidemiology; Genomes and genomic evolution encompassing: Comparative genomics of Cryptosporidium spp., Genomic insights into biology, Acquiring and utilizing genome sequences, Genetic manipulation; Host-parasite interaction (immunology, microbiome); and Diagnosis and treatment. High quality presentations discussed at the conference reflected decisive progress and identified new opportunities that will engage investigators and funding agencies to spur future research in a “one health” approach to improve basic knowledge and the clinical and public health management of zoonotic cryptosporidiosis.

Gastrointestinal parasites of arctic foxes (Vulpes lagopus) and sibling voles (Microtus levis) in Spitsbergen, Svalbard

The arctic fox (Vulpes lagopus), an apex predator with an omnipresent distribution in the Arctic, is a potential source of intestinal parasites that may endanger people and pet animals such as dogs, thus posing a health risk. Non-invasive methods, such as coprology, are often the only option when studying wildlife parasitic fauna. However, the detection and identification of parasites are significantly enhanced when used in combination with methods of molecular biology. Using both approaches, we identified unicellular and multicellular parasites in faeces of arctic foxes and carcasses of sibling voles (Microtus levis) in Svalbard, where molecular methods are used for the first time. Six new species were detected in the arctic fox in Svalbard, Eucoleus aerophilus, Uncinaria stenocephala, Toxocara canis, Trichuris vulpis, Eimeria spp., and Enterocytozoon bieneusi, the latter never found in the arctic fox species before. In addition, only one parasite was found in the sibling vole in Svalbard, the Cryptosporidium alticolis, which has never been detected in Svalbard before.

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

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

NMR metabolomics reveals effects of Cryptosporidium infections on host cell metabolome

Background

Cryptosporidium is an important gut microbe whose contributions towards infant and immunocompromise patient mortality rates are steadily increasing. Over the last decade, we have seen the development of various tools and methods for studying Cryptosporidium infection and its interactions with their hosts. One area that is sorely overlooked is the effect infection has on host metabolic processes.

Results

Using a ¹H nuclear magnetic resonance approach to metabolomics, we have explored the nature of the mouse gut metabolome as well as providing the first insight into the metabolome of an infected cell line. Statistical analysis and predictive modelling demonstrated new understandings of the effects of a Cryptosporidium infection, while verifying the presence of known metabolic changes. Of note is the potential contribution of host derived taurine to the diarrhoeal aspects of the disease previously attributed to a solely parasite-based alteration of the gut environment, in addition to other metabolites involved with host cell catabolism.

Conclusion

This approach will spearhead our understanding of the Cryptosporidium-host metabolic exchange and provide novel targets for tackling this deadly parasite.

Cryptosporidium proventriculi sp. n. (Apicomplexa: Cryptosporidiidae) in Psittaciformes birds

Cryptosporidiosis is a common parasitic infection in birds that is caused by more than 25 Cryptosporidium species and genotypes. Many of the genotypes that cause avian cryptosporidiosis are poorly characterized. The genetic and biological characteristics of avian genotype III are described here and these data support the establishment of a new species, Cryptosporidium proventriculi. Faecal samples from the orders Passeriformes and Psittaciformes were screened for the presence of Cryptosporidium by microscopy and sequencing, and infections were detected in 10 of 98 Passeriformes and in 27 of 402 Psittaciformes. Cryptosporidium baileyi was detected in both orders. Cryptosporidium galli and avian genotype I were found in Passeriformes, and C. avium and C. proventriculi were found in Psittaciformes. Cryptosporidium proventriculi was infectious for cockatiels under experimental conditions, with a prepatent period of six days post-infection (DPI), but not for budgerigars, chickens or SCID mice. Experimentally infected cockatiels shed oocysts more than 30 DPI, with an infection intensity ranging from 4,000 to 60,000 oocysts per gram (OPG). Naturally infected cockatiels shed oocysts with an infection intensity ranging from 2,000 to 30,000 OPG. Cryptosporidium proventriculi infects the proventriculus and ventriculus, and oocysts measure 7.4 × 5.8 μm. None of the birds infected C. proventriculi developed clinical signs.

The First Evidence of Cryptosporidium meleagridis Infection in a Colon Adenocarcinoma From an Immunocompetent Patient

Objectives: The potential linkage between Cryptosporidium spp. infection and colorectal human cancer was suggested by limited reports showing higher prevalence of C. parvum and C. hominis in patients with colon cancer. Here we conducted research concerning presence of Cryptosporidium spp. in malignant tissue collected from patients with colorectal cancer.

Methods: Cancerous colon tissue samples collected from 145 non-HIV infected patients with colorectal cancer were screened for Cryptosporidium spp. by immunofluorescence antibody test and genus-specific nested polymerase chain reaction followed by sequencing.

Results: Screened pathogen was found in cancerous tissue originating from immunocompetent man with colon adenocarcinoma. Genotyping revealed presence of Cryptosporidium meleagridis. The presence of Cryptosporidium life cycle stages (oocysts and endogenous stages) in colon carcinoma tissue was confirmed by genus-specific FITC-labeling.

Conclusions: Herein, we report on a C. meleagridis infection of a colon adenocarcinoma in an immunocompetent patient. This is the first report of C. meleagridis infection in the human colon and first evidence of active development of this species in cancer tissue.

Diversity of Cryptosporidium spp. in Apodemus spp. in Europe

The genetic diversity of Cryptosporidium spp. in Apodemus spp. (striped field mouse, yellow-necked mouse and wood mouse) from 16 European countries was examined by PCR/sequencing of isolates from 437 animals. Overall, 13.7% (60/437) of animals were positive for Cryptosporidium by PCR. Phylogenetic analysis of small-subunit rRNA, Cryptosporidium oocyst wall protein and actin gene sequences showed the presence of Cryptosporidium ditrichi (22/60), Cryptosporidium apodemi (13/60), Cryptosporidium apodemus genotype I (8/60), Cryptosporidium apodemus genotype II (9/60), Cryptosporidium parvum (2/60), Cryptosporidium microti (2/60), Cryptosporidium muris (2/60) and Cryptosporidium tyzzeri (2/60). At the gp60 locus, novel gp60 families XVIIa and XVIIIa were identified in Cryptosporidium apodemus genotype I and II, respectively, subtype IIaA16G1R1b was identified in C. parvum, and subtypes IXaA8 and IXcA6 in C. tyzzeri. Only animals infected with C. ditrichi, C. apodemi, and Cryptosporidium apodemus genotypes shed oocysts that were detectable by microscopy, with the infection intensity ranging from 2000 to 52,000 oocysts per gram of faeces. None of the faecal samples was diarrheic in the time of the sampling.

The opportunistic pathogen Encephalitozoon cuniculi in wild living Murinae and Arvicolinae in Central Europe

Encephalitozoon spp. is an obligate intracellular microsporidian parasite that infects a wide range of mammalian hosts, including humans. This study was conducted to determine the prevalence of Encephalitozoon spp. in wild living rodents from Poland, the Czech Republic and Slovakia. Faecal and spleen samples were collected from individuals of Apodemus agrarius, Apodemus flavicollis, Apodemus sylvaticus, and Myodes glareolus (n = 465) and used for DNA extraction. PCR, targeting the ITS region of the rRNA gene was performed. The overall prevalence of microsporidia was 15.1%. The occurrence of Encephalitozoon cuniculi in the abovementioned host species of rodents has been presented for the first time, with the highest infection rate recorded for A. flavicollis. Sequence analysis showed that the most frequent species was E. cuniculi genotype II (92.5%). E. cuniculi genotypes I (1.5%) and III (6.0%) were also identified.

Review of Cryptosporidium and Giardia in the eastern part of Europe, 2016

This paper reviews the current knowledge and understanding of Cryptosporidium spp. and Giardia spp. in humans, animals and the environment in 10 countries in the eastern part of Europe: Bosnia and Herzegovina, Croatia, Czech Republic, Estonia, Hungary, Latvia, Poland, Romania, Serbia and Slovenia. Methods: Published scientific papers and conference proceedings from the international and local literature, official national health service reports, national databases and doctoral theses in local languages were reviewed to provide an extensive overview on the epidemiology, diagnostics and research on these pathogens, as well as analyse knowledge gaps and areas for further research. Results: Cryptosporidium spp. and Giardia spp. were found to be common in eastern Europe, but the results from different countries are difficult to compare because of variations in reporting practices and detection methodologies used. Conclusion: Upgrading and making the diagnosis/detection procedures more uniform is recommended throughout the region. Public health authorities should actively work towards increasing reporting and standardising reporting practices as these prerequisites for the reported data to be valid and therefore necessary for appropriate control plans.

Prevalence and genotypic identification of Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi in pre-weaned dairy calves in Guangdong, China

Background

Cryptosporidium spp., Giardia duodenalis and Enterocytozoon bieneusi are common enteric pathogens in humans and animals. Data on the transmission of these pathogens are scarce from Guangdong, China, which has a subtropical monsoon climate and is the epicenter for many emerging infectious diseases. This study was conducted to better understand the prevalence and identity of the three pathogens in pre-weaned dairy calves in Guangdong.

Methods

The occurrence and genetic identity of three pathogens were analyzed by polymerase chain reaction. PCR-positive products were sequenced to determine the species and genotypes. A Chi-square test was used to compare the prevalence of pathogens among sampling dates, age groups, or clinical signs.

Results

The detection rates of Cryptosporidium spp., G. duodenalis and E. bieneusi were 24.0% (93/388), 74.2% (288/388) and 15.7% (61/388), respectively. Three Cryptosporidium species were detected, including C. bovis (n = 73), C. parvum (n = 12) and C. ryanae (n = 7); one animal had concurrence of C. bovis and C. parvum. C. parvum was the dominant species during the first two weeks of life, whereas C. bovis and C. ryanae were mostly seen at 3–9 weeks of age. Sequence analysis identified the C. parvum as subtype IIdA19G1. Assemblage E (n = 282), assemblage A (n = 1), and concurrence of A and E (n = 5) were identified among G. duodenalis-positive animals using multilocus genotyping (MLG). Altogether, 15, 10 and 17 subtypes of assemblage E were observed at the bg, gdh and tpi loci, respectively, forming 49 assemblage E MLGs. The highest detection rate of G. duodenalis was found in winter. Sequence analysis identified genotypes J (n = 57), D (n = 3) and one concurrence of J and D among E. bieneusi-positive animals. The detection rate of E. bieneusi was significantly higher in spring (38.0%; 41/108) than in summer (7.2%; 8/111) and winter (7.1%; 12/169).

Conclusions

These results indicate a common occurrence of C. parvum subtype IIdA19G1, G. duodenalis assemblage E, and E. bieneusi genotype J in pre-weaned dairy calves in Guangdong. More studies are needed to understand the unique genetic characteristics and zoonotic potential of the three enteric pathogens in the province.

Dual infection of urinary tract with Enterocytozoon bieneusi and Encephalitozoon cuniculi in HIV/AIDS patients

Microsporidia are emerging pathogens which cause an opportunistic infections in immunocompromised patients, especially those with AIDS. Intestinal microsporidiosis is the most recognized infection, whereas urinary tract infections caused by microsporidia are rarely paid attention to either due to their subclinical course or diagnostic difficulties. In this report dual microsporidial infection of urinary tract, caused by Enterocytozoon bieneusi and Encephalitozoon cuniculi was described in HIV/AIDS patients under cART therapy. Since microsporidiosis can cause severe complications or even death in immunosuppressed patients, our results suggest that microsporidial infection should be included in routine investigation of HIV-positive patients, even asymptomatic.

Symptomatic respiratory Encephalitozoon cuniculi infection in renal transplant recipients

OBJECTIVES

Encephalitozoon spp. and Enterocytozoon bieneusi are intracellular parasitic fungi from the phylum Microsporidia, which initially localize to the intestine. As opportunistic pathogens, Encephalitozoon spp. in particular can disseminate to the respiratory tract, among other locations. Patients on life-long immunosuppression are at higher risk of such infections, mostly symptomatic.

METHODS

Sputum samples and bronchial washings from 72 renal transplant recipients and 105 patients with various respiratory diseases were screened for Encephalitozoon spp. and E. bieneusi by microscopic examination and genus-specific nested PCR followed by genotyping.

RESULTS

A total of 8.3% (6/72) of immunosuppressed renal transplant recipients and 1.9% (2/105) of patients with various respiratory diseases, both immunocompetent and immunosuppressed, were positive for respiratory microsporidial infection. All six transplant recipients were Encephalitozoon cuniculi-positive by PCR/sequencing and five of them suffered from respiratory symptoms. The presence of microsporidial spores was also confirmed microscopically in three of the transplant recipients. Of the two immunocompetent patients with various respiratory diseases, one had an E. cuniculi infection, while the second had an E. bieneusi infection.

CONCLUSIONS

Life-long immunosuppression in renal transplant recipients increases the risk of respiratory infection by E. cuniculi. Microsporidia should be screened in respiratory samples of these patients, particularly when they have respiratory symptoms.

Evidence of transplacental transmission of Encephalitozoon cuniculi genotype II in murine model

Microsporidia are obligate intracellurar unicellular parasite of wide range of vertebrates. Although ingestion or inhalation of microsporidian spores is the main route of infection, assumed vertical transmission was described in some mammals. The present study was focused on proof of vertical transmission in mice under experimental conditions. Mice were infected with E. cuniculi genotype II intraperitoneally after mating, or perorally followed by mating in acute or chronic phase of infection. Fetuses were delivered by Caesarean section or mice were kept up to the parturition. Some of cubs were immediately after birth transferred to uninfected surrogate mothers. Group of cubs was immunosuppressed. All cubs were examined using polymerase chain reaction for the presence of Encephalitozoon after birth or in their age of 3 or 6 weeks, respectively. All fetuses delivered by Caesarean section, which were intraperitoneally or perorally infected were negative as well as all neonatal mice and youngsters tested in age of 6 weeks. Only immunosuppressed cubs and cubs of immunodeficient mice in age of 21 days were positive for Encephalitozoon cuniculi genotype II. Present results provided the evidence that transplacental transmission of Encephalitozoon cuniculi in mice occurs, but the mechanism of these transport is still unknown.

Host specificity and age-dependent resistance to Cryptosporidium avium infection in chickens, ducks and pheasants

Host- and age-specificity of Cryptosporidium avium were studied in 1-, 21- and 365-day-old chickens (Gallus gallus), domestic ducks (Anas platyrhynchos) and ring-necked pheasants (Phasianus colchicus) under experimental conditions. Cryptosporidium avium was not infectious for ring-necked pheasants, but it was infectious for ducks and chickens at all age categories. The course of infection in ducks did not differ among age categories, but 365-day-old chickens had less severe infections than 1- and 21-day-old chickens. The patent period in chickens and ducks was >30 DPI, but ducks started to shed oocysts of C. avium earlier (5-6 DPI) and at a lower intensity (accumulated value of infection intensity of 58,000-65,000 OPG) than chickens (9-11 DPI and accumulated value of infection intensity of 100,000-105,000 OPG). Experimentally infected birds showed no clinical signs of cryptosporidiosis.

The course of experimental giardiasis in Mongolian gerbil

Fifteen Mongolian gerbils were inoculated with 10 × 10⁶ viable trophozoites of Giardia intestinalis. Their faeces were examined daily by flotation method and the number of shed cysts was counted. Two animals (male and female) were euthanised at 4- to 5-day intervals (9, 14, 18 days post-infection (DPI)). The remaining nine gerbils were sacrificed and dissected at the end of the experiment (23 DPI). Their small intestinal tissues were processed for examination using histological sectioning and scanning electron microscopy and their complete blood count (CBC) was examined. The highest number of trophozoites at the total was observed in the duodenum in gerbils sacrificed on 14 DPI. Number of shed cysts was positively correlated with number of trophozoites rinsed from the intestine. Infected gerbils had lower body weight gain in comparison with control group and in three male gerbils; diarrhoea occurred during infection. Cyst shedding was negatively correlated with values of mean corpuscular haemoglobin concentration. Females showed another pattern in cyst shedding than males. This information needs to be taken into account while planning the experiments.