Search Results (14)

Microsporidiosis is a zoonotic disease that derives from disparate sources. Most of the microsporidial agents are host-specific but some are capable of interspecies transmission, causing disease in various animals including humans. Human microsporidiosis may be caused by 17 species, with Encephalitozoon cuniculi, E. intestinalis and E. hellem mostly being responsible for human infections worldwide. Wildlife and migratory waterfowl can serve as reservoirs of these human-infectious agents and play a significant role in disseminating these pathogens into the environment. The aim of the study was to detect E. cuniculi, E. intestinalis and E. hellem in wild, migratory greater white-fronted geese (Anser albifrons) and other Anatidae members in feacal samples obtained in north-western Poland, using a molecular method. We collected 189 fecal droppings from Anatidae species (75 samples from greater white-fronted geese and 114 from other Anser spp.) during autumn migration. New species specific primers for PCR amplification were used to amplify a fragment of the small subunit ribosomal (SSU) rRNA of E. cuniculi, E. intestinalis and E. hellem. All fecal droppings were negative for E. intestinalis and E. hellem whereas E cuniculi was detected in 6 of 189 fecal samples (3.2%; 95% CI: 1.3–6.3%). In total, 1 of 75 tested fecal samples of greater white-fronted geese was positive (1.3%; 95% CI: 0.08–5.7%) while 5 of 114 (4.4%; 95% CI: 1.6–9.1%) tested fecal samples without exact species affiliation (only Anser sp.) were also positive. The phylogenetic analysis placed the sequences obtained from the birds’ droppings in the clade E. cuniculi from various rodents, wild carnivores and humans. Our results provide the first description of the occurrence and genotyping of the microsporidian E. cuniculi in greater white-fronted geese and in other members of the Anserinae Subfamily. Our findings support the results of other authors that E. cuniculi may originate from diverse sources, including common waterfowl. Our results are important in a One Health context, as wild migrating waterfowl may disseminate this zoonotic agent in remote regions through their migratory behaviour. These species should be considered significant sources of zoonotic pathogens, potentially hazardous to domestic and farmed animals as well as humans. Full article

The aim of this paper is to study the presence and temporal variation/distribution of microsporidian species (Enterocytozoon bieneusi and Encephalitozoon spp.) in chickens from different farms in Bombali district (Sierra Leone). Fresh faecal samples were collected from twenty chickens in April 2019, while twelve were collected in Summer 2022. Six faecal samples gave positive results microscopically (spores of Encephalitozoon spp. were observed in five samples, and E. bieneusi in one). Five samples from 2019 were found to be positive by molecular methods: two E. intestinalis and E. hellem, and one E. bieneusi; meanwhile, ten samples from 2022 were positive for spores of the genus Encephalitozoon, specifically from eight chicken. Full article

Although the etiological relevance of the detection of microsporidia in human stool samples remains uncertain, the immunological status of patients has been posited as an important determinant of potential clinical impact of these parasites. To further assess the interplay between the epidemiology of microsporidia and immunological markers, we conducted a study utilizing real-time PCR targeting Enterocytozoon bieneusi, Encephalitozoon cuniculi, Encephalitozoon hellem, and Encephalitozoon intestinalis, combined in a single fluorescence channel. The study involved a cohort of 595 clinically and immunologically well-characterized Ghanaian HIV patients, alongside 82 HIV-negative control individuals from Ghana. While microsporidial DNA was absent in HIV-negative controls, among people living with HIV, its prevalence was inversely correlated with CD4+ lymphocyte counts: 6.0% in those with >500 cells/µL, 9.5% in those with 200–499 cells/µL, 13.8% in those with 50–199 cells/µL, and 27.5% in those with <50 cells/µL, respectively. Correspondingly, microsporidia were more frequently detected in HIV patients who were not receiving antiretroviral therapy. There were no associations with clinical symptoms including gastroenteritis with the exception of a non-significant trend towards weight loss. HLA-DR+CD38+ on CD4+ T lymphocytes, a marker of immune activation, as well as Ki67, a marker of cell proliferation, were increased on CD4+ T lymphocytes in HIV patients with microsporidia, suggesting an immune response may be triggered. In conclusion, our assessment indicates a higher prevalence of microsporidia in the stool of Ghanaian HIV patients, which varies with their immunological status. However, given the lack of clear associations with clinical symptoms, the detection of microsporidia in the stool of HIV patients needs to be cautiously interpreted in clinical settings. Full article

Encephalitozoon cuniculi and Encephalitozoon hellem are fungus-related, obligate intracellular pathogens belonging to the microsporidia. Both microorganisms occur in mammals, birds and even humans, thus revealing a zoonotic potential. Knowledge of their relevance in wild rabbits is very limited so far. Thus, the aim of the present study was to investigate the occurrence of E. cuniculi and E. hellem in wild rabbit populations in southern Germany (Bavaria). Therefore, blood and organ samples (brain/kidney) of 158 wild rabbits were investigated by immunofluorescence and PCR-based assays. Antibodies to E. cuniculi were detected in 24 of the 158 (15.2%) wild rabbits, while DNA of E. cuniculi was found in 7 (4.4%) and DNA of E. hellem was found in 3 (1.9%). Sequencing identified E. cuniculi genotype 1. This study provides the first E. cuniculi genotype determination in free-living wild rabbits worldwide and the first evidence of E. hellem in rabbits worldwide. Wild rabbits should, therefore, be regarded as a reservoir for both pathogens and, on the basis of molecular evidence from kidney tissue and presumed urine excretion, also as a source of infection for E. cuniculi for animals and humans. Full article

When the zoonotic parasite of rodents that can cause human neuroangiostrongyliasis, i.e., Angiostrongylus cantonensis, is found in its natural definitive hosts, it is usually reported in isolation, as if the rat lungworm were the only component of its parasite community. In this study, we report the coinfections found in rats naturally infected by A. cantonensis in urban populations of Rattus norvegicus and Rattus rattus in Valencia, Spain. In addition to the rat lungworms, which were found in 14 of the 125 rats studied (a prevalence of 11.20%), 18 other parasite species (intestinal and tissular protists, microsporidia and helminths) were found, some of them with high burdens. Fourteen of these nineteen species found are potential zoonotic parasites, namely Blastocystis, Giardia duodenalis, Cryptosporidium spp., Enterocytozoon bieneusi, Encephalitozoon hellem, Toxoplasma gondii, Brachylaima spp., Hydatigera taeniaeformis s.l. larvae, Hymenolepis nana, Hymenolepis diminuta, Angiostrongylus cantonensis, Calodium hepaticum, Gongylonema neoplasticum and Moniliformis moniliformis. The total predominance of coinfected rats as well as their high parasite loads seem to indicate a trend towards parasite tolerance. Full article

Humans can potentially be exposed to Enterocytozoon bieneusi and Encephalitozoon spp. from topsoils when playing or spending time in recreational areas. Two hundred and seventy-seven topsoil samples were collected across Alcalá de Henares (Spain) in July 2017: one hundred and fifty-five urban, sixty industrial and twelve from a public garden. Simultaneous detection was performed using a SYBR Green real-time PCR following the appropriate extraction of DNA with Fast-Prep for Soil^®. The organic matter content (OM), pH, electrical conductivity (EC) and soil texture (percentages of sand, clay and silt) were also determined. E. bieneusi was detected in nine (five urban, four industrial); meanwhile, Encephalitozoon spp. was detected in 22 topsoil samples (sixteen urban, six industrial; ten E. intestinalis, nine E. intestinalis/E. hellem and three E. cuniculi). The presence of E. bieneusi was associated with urban soils that presented lower EC (0.50 vs. 0.71 dS/m; p-value = 0.0110), as this factor may provide a richer environment for the survival of spores. The presence of microsporidian spores was higher in those topsoils with a higher OM content for E. bieneusi (6.96% vs. 4.98%; p-value = 0.0342) and E. intestinalis/E. hellem in one of the four quadrants into which the urban area was divided (5.54% vs. 3.12%; p-value = 0.0007). E. intestinalis is present in industrial topsoils with significantly lower contents of sand (14.5% vs. 21.74; p-value = 0.00003) but higher contents of silt (78.5% vs. 64.9%; p-value = 0.0229), which might be attributed to the differences in the capacity of topsoils to retain moisture, depending on their texture. Moreover, the provision of enough oxygen might play a role in the higher presence of E. intestinalis/E. hellem in urban topsoils with lower contents of clay (11% vs. 19%; p-value = 0.0200). A better understanding of these potential associations is critical in selecting appropriate decontamination techniques and strategies to prevent and minimise human exposure. Full article

Microsporidia are widely spread obligate intracellular fungal pathogens from vertebrate and invertebrate organisms, mainly transmitted by contaminated food and water. This study aims to detect the presence of major human-pathogenic microsporidia, i.e., Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi, in the gastrointestinal tract of commercially harvested marine fish from Mediterranean coast of the Comunidad Valenciana, Eastern Spain. A total of 251 fish, 138 farmed fish and 113 wild fish from commercial fishing were tested by SYBR Green real-time PCR, enabling the simultaneous detection of the four targeted species. E. intestinalis/hellem was found in 1.45% of farmed fish and 7.96% of wild fish, while Enterocytozoonidae was detected in 2.90% and 18.58% of farmed and wild fish, respectively. E. cuniculi was not detected in any of the analyzed specimens. To the authors’ knowledge, this is the first report of E. intestinalis/hellem in fish, particularly in marine fish. Although the role of fish in these species’ epidemiology remains unknown, this finding points out a potential public health risk linked to fish consumption. Further studies are necessary to characterize these microsporidia in fish hosts better and to elucidate their epidemiological role. Full article

Bats may carry various viruses and bacteria which can be harmful to humans, but little is known about their role as a parasitic source with zoonotic potential. The aim of this study was to test wild bats for the presence of selected parasites: Toxoplasma gondii, Neospora caninum and microsporidia Encephalitozoon spp. In total, brain and small intestine tissues of 100 bats (52 Myotis myotis, 43 Nyctalus noctula and 5 Vespertilio murinus) were used for the DNA isolation and PCR detection of the abovementioned agents. Toxoplasma gondii DNA was detected by real-time PCR in 1% of bats (in one male of M. myotis), while all bats were negative for N. caninum DNA. Encephalitozoon spp. DNA was detected by nested PCR in 25% of bats, including three species (twenty-two M. myotis, two N. noctula and one V. murinus). Positive samples were sequenced and showed homology with the genotypes Encephalitozoon cuniculi II and Encephalitozoon hellem 2C. This is the first study on wild vespertilionid bats from Central Europe and worldwide, with a relatively high positivity of Encephalitozoon spp. detected in bats. Full article

Enterocytozoon bieneusi and Encephalitozoon spp. are microsporidian pathogens with zoonotic potential that pose significant public health concerns. To ascertain the occurrence and genotypes of E. bieneusi and Encephalitozoon spp., we used nested PCR to amplify the internal transcribed spacer (ITS) gene and DNA sequencing to analyze 198 fecal samples from red pandas from 6 zoos in China. The total rate of microsporidial infection was 15.7% (31/198), with 12.1% (24/198), 1.0% (2/198), 2.0% (4/198) and 1.0% (2/198) for infection rate of E. bieneusi, Encephalitozoon cuniculi, Encephalitozoon intestinalis and Encephalitozoon hellem, respectively. One red panda was detected positive for a mixed infection (E. bieneusi and E. intestinalis). Red pandas living in semi-free conditions are more likely to be infected with microsporidia (χ² = 6.212, df = 1, p < 0.05). Three known (SC02, D, and PL2) and one novel (SCR1) genotypes of E. bieneusi were found. Three genotypes of E. bieneusi (SC02, D, SCR1) were grouped into group 1 with public health importance, while genotype PL2 formed a separate clade associated with group 2. These findings suggest that red pandas may serve as a host reservoir for zoonotic microsporidia, potentially allowing transmission from red pandas to humans and other animals. Full article

Background: Microsporidia are a group of pathogens that infect all kinds of animals, such as humans, silkworms, honeybees, and shrimp; they, therefore, pose a severe threat to public health and the economy. There are over 1500 species of microsporidia that have been reported, among which Encephalitozoon hellem and Nosema bombycis are the representative zoonotic and insect-infecting species, respectively. Investigating their cell infection patterns is of great significance for understanding their infection mechanisms. Methods: Specific probes were designed for the ribosomal RNA sequences of microsporidia. Fluorescence in situ hybridization (FISH) was used to trace the proliferation cycle of the pathogens in different cells. Results: Here, two rRNA large subunit gene (LSUrRNA) probes specifically labeling N. bombycis were obtained. The life cycle of N. bombycis in silkworm cells and E. hellem in three kinds of host cells was graphically drawn. N. bombycis meronts were first observed at 30 hours post-infection (hpi), and they began merogony. Sporonts were observed at 42 hpi, and the first entire proliferation cycle was completed at 48 hpi. The proliferation cycle of E. hellem in RK13 and HEK293 epithelial cells was almost the same, completing the first life cycle after 24 hpi, but it was significantly delayed to 32 hpi in RAW264.7. Conclusions: Specific FISH probes were established for labeling microsporidia in multiple host cells. The proliferation characteristics of representative zoonotic and insect-infecting microsporidian species were clarified. This study provides an experimental pattern for future analyses of microsporidian infection mechanisms. Full article

Background: Microsporidia are a group of obligated intracellular fungus pathogens. Monocytes and the derivative macrophages are among the most important players in host immunity. The invasion of microsporidia may significantly affect the monocytes maturation and extravasation processes. Methods: We utilized a previously established microsporidia infection murine model to investigate the influences of microsporidia Encephalitozoon hellem (E. hellem) infection on monocyte maturation, releasing into the circulation and extravasation to the inflammation site. Flow cytometry and qPCR analysis were used to compare the monocytes and derivative macrophages isolated from bone marrow, peripheral blood and tissues of E. hellem-infected and control mice. Results: The results showed that the pro-inflammatory group of CD11b⁺Ly-6C⁺ monocytes are promoted in E. hellem-infected mice. Interestingly, the percentage of Ly-6C⁺ monocytes from E. hellem-infected mice are significantly lower in peripheral blood while significantly higher in the inflamed small intestine, together with up-regulated ratio of F4/80 macrophage in small intestine as well. Conclusions: Our findings demonstrated that E. hellem infection leads to promoted monocytes maturation in bone marrow, up-regulation of extravasation from peripheral blood to inflammation site and maturation into macrophages. Our study is the first systematic analysis of monocytes maturation and trafficking during microsporidia infection, and will provide better understanding of the pathogen–host interactions. Full article

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

Background: Encephalitozoon hellem (E. hellem) belongs to a group of opportunistic pathogens called microsporidia. Microsporidia infection symptoms vary and include diarrhea, ocular disorders and systemic inflammations. Traditionally, immunodeficient animals were used to study microsporidia infection. To overcome the difficulties in maintenance and operation using immunodeficient mice, and to better mimic natural occurring microsporidia infection, this study aims to develop a pharmacologically immunosuppressed murine model of E. hellem infection. Methods: Wild-type C57BL/6 mice were immunosuppressed with dexamethasone (Dex) and then E. hellem spores were inoculated into the mice intraperitoneally. Control groups were the Dex-immunosuppressed but noninoculated mice, and the Dex-immunosuppressed then lipopolysaccharide (LPS)-treated mice. Mice body weights were monitored and all animals were sacrificed at the 15th day after inoculation. Tissue fragments and immune cells were collected and processed. Results: Histopathological analysis demonstrated that E. hellem inoculation resulted in a disseminated nonlethal infection. Interestingly, E. hellem infection desensitized the innate immunity of the host, as shown by cytokine expressions and dendritic cell maturation. We also found that E. hellem infection greatly altered the composition of host gut microbiota. Conclusions: Dex-immunosuppressed mice provide a useful tool for study microsporidiosis and the interactions between microsporidia and host immunity. Full article

Microsporidia are obligate intracellular protist-like fungal pathogens that infect a broad range of animal species, including humans. This study aimed to assess the presence of zoonotic microsporidia (Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi) in organ meats of European wild rabbit (Oryctolagus cuniculus) and Iberian hare (Lepus granatensis) consumed by humans in Spain. Between July 2015 and December 2018, kidney samples from 383 wild rabbits and kidney and brain tissues from 79 Iberian hares in southern Spain were tested by species-specific PCR for the detection of microsporidia DNA. Enterocytozoon bieneusi infection was confirmed in three wild rabbits (0.8%; 95% CI: 0.0–1.7%) but not in hares (0.0%; 95% CI: 0.0–4.6%), whereas E. intestinalis DNA was found in one wild rabbit (0.3%; 95% CI: 0.0–0.8%) and three Iberian hares (3.8%; 95% CI: 0.0–8.0%). Neither E. hellem nor E. cuniculi infection were detected in the 462 (0.0%; 95% CI: 0.0–0.8%) lagomorphs analyzed. The absence of E. hellem and E. cuniculi infection suggests a low risk of zoonotic foodborne transmission from these wild lagomorph species in southern Spain. To the authors’ knowledge, this is the first report of E. intestinalis infection in wild rabbits and Iberian hares. The presence of E. bieneusi and E. intestinalis in organ meats from wild lagomorphs can be of public health concern. Additional studies are required to determine the real prevalence of these parasites in European wild rabbit and Iberian hare. Full article