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.

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.

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.

European ground squirrels Spermophilus citellus (Linnaeus) do not share identical Cryptosporidium spp. with North American ground squirrels.

Cryptosporidium Tyzzer, 1910 is one of the most common protistan parasites of vertebrates. The results of this study provide the first data on Cryptosporidium diversity in the European ground squirrel Spermophilus citellus (Linnaeus). A total of 128 faecal samples of European ground squirrels from 39 localities in the Czech Republic were analysed for the presence of Cryptosporidium spp. by microscopy and PCR/sequence analysis of small subunit ribosomal RNA (SSU) and the actin gene. While the microscopical examination did not reveal the presence of any Cryptosporidium oocysts, eight samples from six localities were PCR-positive. Phylogenetic analyses revealed the presence of five different Cryptosporidium spp. isolates. Four isolates, designated as Cryptosporidium sp. isolate Sc01-04, detected in wild populations and never recorded before, clustered closely to Cryptosporidium genotypes that have previously been found in North American ground squirrels' species. Cryptosporidium sciurinum Prediger, Jezková, Holubová, Sak, Konecný, Rost, McEvoy, Rajský et Kvác, 2021 was found in an animal sanctuary. Because C. sciurinum had previously been detected in Eurasian red squirrels Sciurus vulgaris Linnaeus at the same facility, it can be concluded that this Cryptosporidium was transmitted from tree squirrels to ground squirrels within the animal sanctuary. The results indicate that populations of European and North American ground squirrels are parasitised by different Cryptosporidium spp. At the same time, this is the first description of the occurrence of C. sciurinum in ground squirrels.

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.

Calicophoron daubneyi (Dinnik, 1962) (Digenea) in beef and dairy cattle in the Czech Republic: prevalence and drug efficacy.

A total of 1,724 beef and 2,941 dairy cattle older than one year from 66 beef and 67 dairy farms in the Czech Republic were examined for the presence of rumen and liver fluke eggs in 2019-2022. Out of 227 positive animals, all were positive for paramphistome and five for fasciolid eggs. Molecular analysis of the ITS2 rDNA revealed the presence of Calicophoron daubneyi (Dinnik, 1962) and Fasciola hepatica Linnaeus, 1758. Faecal egg count (FEC) showed low infection intensity (12 EPG) in animals infected with F. hepatica and high variability in C. daubneyi infections (2-589 EPG). Efficacy of oxyclozanide, albendazole, ivermectin, and closantel against C. daubneyi infection was evaluated at eight beef cattle herds. Faecal samples were collected from all positive animals at 0 and 21days post-treatment. Based on FEC, albendazole, ivermectin and closantel reduced the number of C. daubneyi eggs shed by 0-9.9%, with no effect on the number of infected animals. The use of oxyclozanide on two beef farms showed 100% efficacy against C. daubneyi and F. hepatica. Follow-up examination 5-6 months after drug application showed reinfection of most animals with C. daubneyi, but the FEC was significantly lower. The finding of four dairy cows infected with C. daubneyi housed in a stable without pasture suggests the possibility of the infection being introduced through roughage.

Comparison of the Concentration of Encephalitozoon cuniculi Genotypes I and III in Inflammatory Foci Under Experimental Conditions.

Background: Microsporidia of the genus Encephalitozoon are usually associated with severe infections in immunodeficient hosts while, in immunocompetent ones, microsporidiosis produces minimal clinically apparent disease. Despite their microscopic size, microsporidia are capable of causing systemic infection within a few days. However, the mechanisms by which microsporidia reach target tissues during acute infection remain unclear. Out of four genotypes of Encephalitozoon cuniculi, only three are available for experimental studies, with E. cuniculi genotype II being the best characterized. Methods: In the present study, we tested the association between inflammation induction in immunocompetent and immunodeficient mice and the presence of spores of E. cuniculi genotypes I and III in selected organs using molecular methods and compared the results with previously published data on E. cuniculi genotype II. Results: We reported the positive connection between inflammation induction and the significant increase of E. cuniculi genotypes I and III occurrence in inflammatory foci in both immunocompetent BALB/c and immunodeficient severe combined immunodeficient (SCID) mice in the acute phase of infection. The induction of inflammation resulted in increased concentration of E. cuniculi of both genotypes in the site of inflammation, as previously reported for E. cuniculi genotype II. Moreover, our study extended the spectrum of differences among E. cuniculi genotypes by the variations in dispersal rate within host bodies after experimentally induced inflammation. Conclusion: The results imply possible involvement of immune cells serving as vehicles transporting E. cuniculi towards inflammation foci. The elucidation of possible connection with pro-inflammatory immune responses represents an important challenge with implications for human health and the development of therapeutic strategies.

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.

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.

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.

Sparse Evidence for Giardia intestinalis, Cryptosporidium spp. and Microsporidia Infections in Humans, Domesticated Animals and Wild Nonhuman Primates Sharing a Farm-Forest Mosaic Landscape in Western Uganda.

Zoonotic pathogen transmission is considered a leading threat to the survival of non-human primates and public health in shared landscapes. Giardia spp., Cryptosporidium spp. and Microsporidia are unicellular parasites spread by the fecal-oral route by environmentally resistant stages and can infect humans, livestock, and wildlife including non-human primates. Using immunoassay diagnostic kits and amplification/sequencing of the region of the triosephosphate isomerase, small ribosomal subunit rRNA and the internal transcribed spacer genes, we investigated Giardia, Cryptosporidium, and microsporidia infections, respectively, among humans, domesticated animals (livestock, poultry, and dogs), and wild nonhuman primates (eastern chimpanzees and black and white colobus monkeys) in Bulindi, Uganda, an area of remarkably high human-animal contact and spatial overlap. We analyzed 137 fecal samples and revealed the presence of G. intestinalis assemblage B in two human isolates, G. intestinalis assemblage E in one cow isolate, and Encephalitozoon cuniculi genotype II in two humans and one goat isolate. None of the chimpanzee and colobus monkey samples were positive for any of the screened parasites. Regular distribution of antiparasitic treatment in both humans and domestic animals in Bulindi could have reduced the occurrence of the screened parasites and decreased potential circulation of these pathogens among host species.

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.

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.

Occurrence and genetic diversity of Cryptosporidium spp. in wild foxes, wolves, jackals, and bears in central Europe.

Parasites of the genus Cryptosporidium Tyzzer, 1910 are one of the most common protistan parasites of vertebrates. Faecal samples from 179 red foxes (Vulpes vulpes [Linnaeus]), 100 grey wolves (Canis lupus Linnaeus), 11 golden jackals (Canis aureus Linnaeus), and 63 brown bears (Ursus arctos Linnaeus) were collected in the Czech Republic, Poland and Slovakia. Samples were examined for the presence of Cryptosporidium spp. using microscopy and PCR/sequence analysis. Phylogenetic analysis based on the small subunit ribosomal RNA (SSU), actin and 60-kDa glycoprotein (gp60) genes using the maximum likelihood method revealed the presence of Cryptosporidium tyzzeri Ren, Zhao, Zhang, Ning, Jian et al., 2012 (n = 1) and C. andersoni Lindsay, Upton, Owens, Morgan, Mead et Blackburn, 2000 (n = 2) in red foxes, C. canis Fayer, Trout, Xiao, Morgan, Lai et Dubey, 2001 (n = 2) and C. ubiquitum Fayer, Santín et Macarisin, 2010 (n = 2) in grey wolves, and C. galli Pavlásek, 1999 in brown bears (n = 1) and red foxes (n = 1). Subtyping of isolates of C. ubiquitum and C. tyzzeri based on sequence analysis of gp60 showed that they belong to the XIId and IXa families, respectively. The presence of specific DNA of C. tyzzeri, C. andersoni and C. galli, which primarily infect the prey of carnivores, is probably the result of their passage through the gastrointestinal tract of the carnivores. Finding C. ubiquitum XIId in wolves may mean broadening the host spectrum of this subtype, but it remains possible this is the result of infected prey passing through the wolf - in this case deer, which is a common host of this parasite. The dog genotype of C. canis was reported for the first time in wolves.

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.