Most cited article - PubMed ID 21629721
Latent microsporidial infection in immunocompetent individuals - a longitudinal study
PURPOSE: Parasites of genus Encephalitozoon are well known pathogens of domestic animals however less attention was paid to its spread among wildlife that can play an important role of reservoir of infection. The aim of the study was to conduct molecular detection and genotype characterization of Encephalitozoon spp. in wild small mammals trapped in localities both near to and at a large distance from residential areas. METHODS: In total, 300 wild small mammals (274 Rodentia and 26 Eulipotyphla) were trapped in 41 localities of the Czech Republic and tested by nested PCR for Encephalitozoon spp. RESULTS: The DNA of Encephalitozoon spp. was proved in tissues (brain or liver) of 11% (32/300) of animals. There was a statistically significant difference (p < 0.001) in positivity among animal species with the most infected species Micromys minutus (50%, 4/8) and Myodes glareolus (17%, 9/53). There was also statistically significant difference (p < 0.001) between localities with the higher positivity (29%, 12/42) in localities near to residential areas, compared to localities with a large distance from residential areas (8%, 20/258). Sex and age of wild small mammals did not have effect on their positivity. Genotyping analysis revealed E. cuniculi genotype II in 22 samples and E. hellem genotype 1 A in one sample. CONCLUSION: This study brings new information on the molecular characterization of Encephalitozoon spp. isolated from wild small mammals trapped in two different areas (localities in near to residential areas and localities with a large distance from residential areas).
- Keywords
- Encephalitozoonosis, Genotyping, Urban area, Wildlife, Zoonosis,
- MeSH
- Animals, Wild * parasitology MeSH
- Encephalitozoon cuniculi genetics isolation & purification classification MeSH
- Encephalitozoon * genetics isolation & purification classification MeSH
- Encephalitozoonosis * veterinary epidemiology parasitology microbiology MeSH
- Genotype * MeSH
- Rodentia * parasitology MeSH
- Eulipotyphla parasitology MeSH
- Liver parasitology MeSH
- Brain parasitology MeSH
- Polymerase Chain Reaction MeSH
- Disease Reservoirs * parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
We retrospectively analyzed of 211 frozen cerebrospinal fluid samples from immunocompetent persons in the Czech Republic and detected 6 Encephalitozoon cuniculi-positive samples. Microsporidiosis is generally underestimated and patients are not usually tested for microsporidia, but latent infection in immunodeficient and immunocompetent patients can cause serious complications if not detected and treated.
- Keywords
- Czech Republic, Encephalitozoon cuniculi, PCR, cerebrospinal fluid, latent infection, parasites, qPCR, zoonoses,
- MeSH
- Adult MeSH
- Encephalitozoon cuniculi * isolation & purification genetics MeSH
- Encephalitozoonosis * cerebrospinal fluid microbiology epidemiology MeSH
- Immunocompetence MeSH
- Middle Aged MeSH
- Humans MeSH
- Retrospective Studies MeSH
- Aged MeSH
- Check Tag
- Adult MeSH
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic epidemiology MeSH
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.
- Keywords
- Czech Republic, Encephalitozoon cuniculi, PCR, arthroplasty, hip, implant loosening, knee, microsporidia, parasites, prosthetic joint infection, qPCR, zoonosis,
- MeSH
- Encephalitozoon cuniculi * genetics MeSH
- Encephalitozoonosis * epidemiology MeSH
- Humans MeSH
- Microsporidia * genetics MeSH
- Inflammation MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic epidemiology MeSH
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.
- Keywords
- Epidemiology, Infection, Latency, Mammals, Microsporidia, Recurrent infection, Transmission,
- MeSH
- Enterocytozoon * MeSH
- Feces microbiology MeSH
- Humans MeSH
- Microsporidia * genetics MeSH
- Persistent Infection MeSH
- Mammals MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
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.
- Keywords
- Encephalitozoon cuniculi, inflammation, targeted migration,
- Publication type
- Journal Article MeSH
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.
- Keywords
- Emerging infection, Host specificity, Protozoa, Transmission, Wildlife, Zoonosis,
- Publication type
- Journal Article MeSH
- Review MeSH
BACKGROUND: Infectious diseases represent the greatest threats to endangered species, and transmission from humans to wildlife under increased anthropogenic pressure has been always stated as a major risk of habituation. AIMS: To evaluate the impact of close contact with humans on the occurrence of potentially zoonotic protists in great apes, one hundred mountain gorillas (Gorilla beringei beringei) from seven groups habituated either for tourism or for research in Volcanoes National Park, Rwanda were screened for the presence of microsporidia, Cryptosporidium spp. and Giardia spp. using molecular diagnostics. RESULTS: The most frequently detected parasites were Enterocytozoon bieneusi found in 18 samples (including genotype EbpA, D, C, gorilla 2 and five novel genotypes gorilla 4-8) and Encephalitozoon cuniculi with genotype II being more prevalent (10 cases) compared to genotype I (1 case). Cryptosporidium muris (2 cases) and C. meleagridis (2 cases) were documented in great apes for the first time. Cryptosporidium sp. infections were identified only in research groups and occurrence of E. cuniculi in research groups was significantly higher in comparison to tourist groups. No difference in prevalence of E. bieneusi was observed between research and tourist groups. CONCLUSION: Although our data showed the presence and diversity of important opportunistic protists in Volcanoes gorillas, the source and the routes of the circulation remain unknown. Repeated individual sampling, broad sampling of other hosts sharing the habitat with gorillas and quantification of studied protists would be necessary to acquire more complex data.
- MeSH
- Cryptosporidium classification genetics isolation & purification MeSH
- Encephalitozoon classification genetics isolation & purification MeSH
- Encephalitozoonosis epidemiology microbiology MeSH
- Phylogeny MeSH
- Giardia classification genetics isolation & purification MeSH
- Giardiasis epidemiology parasitology MeSH
- Hominidae MeSH
- DNA, Intergenic genetics MeSH
- Cryptosporidiosis epidemiology parasitology MeSH
- Molecular Sequence Data MeSH
- Ape Diseases epidemiology microbiology parasitology MeSH
- Parks, Recreational MeSH
- Zoonoses epidemiology microbiology parasitology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Rwanda epidemiology MeSH
- Names of Substances
- DNA, Intergenic MeSH
From 2011 to 2012, the occurrence of Enterocytozoon bieneusi and Encephalitozoon spp. was surveyed at 29 randomly selected localities (both forest areas and enclosures) across four Central European countries: Austria, the Czech Republic, Poland, and the Slovak Republic. Isolates were genotyped by PCR amplification and characterization of the internal transcribed spacer (ITS) region using Enterocytozoon and Encephalitozoon-specific protocols. PCR revealed 16 mono-infections of Encephalitozoon cuniculi, 33 mono-infections of Enterocytozoon bieneusi and 5 concurrent infections of both Encephalitozoon cuniculi and Enterocytozoon bieneusi out of 460 faecal samples. Two genotypes (I and II) were revealed by sequence analysis of the ITS region of Encephalitozoon cuniculi. Eleven genotypes, five previously found in other hosts including domestic pigs (D, EbpA, EbpC, G and Henan-I) and six novel (WildBoar1-6), were identified in Enterocytozoon bieneusi. No other microsporidia infection was found in the examined faecal samples. Prevalence of microsporidia at the locality level ranged from 0 to 58.8 %; the prevalence was less than 25 % at more than 86 % of localities. Enterocytozoon bieneusi was detected as a predominant species infecting Eurasian wild boars (Sus scrofa). The present report is the most comprehensive survey of microsporidia infections in wild boars within the Czech Republic and selected Central European countries.
- MeSH
- Encephalitozoon cuniculi genetics isolation & purification MeSH
- Encephalitozoonosis epidemiology microbiology veterinary MeSH
- Enterocytozoon classification genetics isolation & purification MeSH
- Feces microbiology MeSH
- Genotype MeSH
- Microsporidiosis epidemiology microbiology veterinary MeSH
- Polymerase Chain Reaction MeSH
- Prevalence MeSH
- Sus scrofa microbiology MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Czech Republic epidemiology MeSH
- Poland epidemiology MeSH
- Austria epidemiology MeSH
- Slovakia epidemiology MeSH
BACKGROUND: Infectious diseases pose one of the greatest threats to endangered species, and a risk of gastrointestinal parasite transmission from humans to wildlife has always been considered as a major concern of tourism. Increased anthropogenic impact on primate populations may result in general changes in communities of their parasites, and also in a direct exchange of parasites between humans and primates. AIMS: To evaluate the impact of close contact with humans on the occurrence of potentially zoonotic protists in great apes, we conducted a long-term monitoring of microsporidia, Cryptosporidium and Giardia infections in western lowland gorillas at different stages of the habituation process, humans, and other wildlife in Dzanga-Sangha Protected Areas in the Central African Republic. RESULTS: We detected Encephalitozoon cuniculi genotypes I and II (7.5%), Enterocytozoon bieneusi genotype D and three novel genotypes (gorilla 1-3) (4.0%), Giardia intestinalis subgroup A II (2.0%) and Cryptosporidium bovis (0.5%) in gorillas, whereas in humans we found only G. intestinalis subgroup A II (2.1%). In other wild and domestic animals we recorded E. cuniculi genotypes I and II (2.1%), G. intestinalis assemblage E (0.5%) and C. muris TS03 (0.5%). CONCLUSION: Due to the non-specificity of E. cuniculi genotypes we conclude that detection of the exact source of E. cuniculi infection is problematic. As Giardia intestinalis was recorded primarily in gorilla groups with closer human contact, we suggest that human-gorilla transmission has occurred. We call attention to a potentially negative impact of habituation on selected pathogens which might occur as a result of the more frequent presence of humans in the vicinity of both gorillas under habituation and habituated gorillas, rather than as a consequence of the close contact with humans, which might be a more traditional assumption. We encourage to observe the sections concerning hygiene from the IUCN best practice guidelines for all sites where increased human-gorilla contact occurs.
- MeSH
- Time Factors MeSH
- Cryptosporidium classification genetics isolation & purification MeSH
- Encephalitozoon cuniculi genetics isolation & purification MeSH
- Enterocytozoon classification genetics isolation & purification MeSH
- Feces microbiology parasitology MeSH
- Phylogeny MeSH
- Genotype MeSH
- Giardia classification genetics isolation & purification MeSH
- Giardiasis parasitology veterinary MeSH
- Gorilla gorilla MeSH
- Habituation, Psychophysiologic MeSH
- Cryptosporidiosis parasitology veterinary MeSH
- Humans MeSH
- Microsporidia classification genetics isolation & purification MeSH
- Microsporidiosis microbiology veterinary MeSH
- Molecular Sequence Data MeSH
- Ape Diseases microbiology parasitology MeSH
- Sequence Analysis, DNA MeSH
- Social Environment MeSH
- Zoonoses microbiology parasitology MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Central African Republic MeSH
BACKGROUND: Microsporidia are obligate intracellular parasites causing severe infections with lethal outcome in immunocompromised hosts. However, these pathogens are more frequently reported as latent infections in immunocompetent individuals and raises questions about the potential risk of reactivation following induced immunosuppression. AIMS: To evaluate the possibility latent microsporidiosis, efficacy or albendazole, and reactivation, the authors monitored the course of E. cuniculi infection in immunocompetent BALB/c mice and immunodeficient SCID mice using molecular methods. METHODS: Mice were per orally infected with 10(7) spores of E. cuniculi. Selected groups were treated with albendazole, re-infected or chemically immunosuppressed by dexamethasone. The presence of microsporidia in the host's organs and feces were determined using PCR methods. Changes in numbers of lymphocytes in blood and in spleen after induction of immunosuppression were confirmed using flow cytometry analysis. RESULTS: Whereas E. cuniculi caused lethal microsporidiosis in SCID mice, the infection in BABL/c mice remained asymptomatic despite parasite dissemination into many organs during the acute infection phase. Albendazole treatment led to microsporidia elimination from organs in BALB/c mice. In SCID mice, however, only a temporary reduction in number of affected organs was observed and infection re-established post-treatment. Dexamethasone treatment resulted in a chronic microsporidia infection disseminating into most organs in BALB/c mice. Although the presence of E. cuniculi in organs of albendazole- treated mice was undetectable by PCR, it was striking that infection was reactivated by immunosuppression treatment. CONCLUSION: Our results demonstrated that microsporidia can successfully survive in organs of immunocompetent hosts and are able to reactivate from undetectable levels and spread within these hosts after induction of immunosuppression. These findings stress the danger of latent microsporidiosis as a life-threatening risk factor especially for individuals undergoing chemotherapy and in transplant recipients of organs originating from infected donors.
- MeSH
- Albendazole therapeutic use MeSH
- Chlorocebus aethiops MeSH
- Dexamethasone MeSH
- Encephalitozoon cuniculi * MeSH
- Encephalitozoonosis drug therapy immunology MeSH
- Feces microbiology MeSH
- Disease Models, Animal * MeSH
- Mice, Inbred BALB C MeSH
- Mice, SCID MeSH
- Mice MeSH
- Lymphocyte Count MeSH
- Polymerase Chain Reaction MeSH
- Flow Cytometry MeSH
- Vero Cells MeSH
- Viscera microbiology MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Albendazole MeSH
- Dexamethasone MeSH