Encephalitozoon cuniculi Microsporidia in Cerebrospinal Fluid from Immunocompetent Patients, Czech Republic

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.

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.

Renal pathology in wild European rabbits

BACKGROUND

There is a relative paucity of data examining the prevalence of renal pathology in wild rabbits.

METHODS

Sixty-two wild rabbits that had been shot for population control in Cambridgeshire, UK, underwent postmortem examination, including macroscopic and microscopic renal assessment.

RESULTS

The majority (82%) of the animals had macroscopically and microscopically normal kidneys. One animal (1.6%) had severe perirenal abscessation. Pasteurella spp. was isolated from this lesion. Ten rabbits (16%) had microscopic renal pathology comprising minimal to mild renal inflammation or fibrosis. No Encephalitozoon cuniculi organisms were detected histologically.

LIMITATIONS

The sample population was composed of shot rabbits, so the probability of detecting moribund individuals was reduced. Extrapolation of these data to the wider UK wild rabbit population may be limited as rabbits were shot at two sites within a 3 km radius of each other.

CONCLUSION

Renal pathology is rare in the population examined.

A multidisciplinary review about Encephalitozoon cuniculi in a One Health perspective

Encephalitozoon cuniculi is a microsporidian parasite mostly associated with its natural host, the rabbit (Oryctolagus cuniculus). However, other animals can be infected, like other mammals, birds, and even humans. Although it usually causes subclinical infection, it can also lead to encephalitozoonosis, a clinical disease characterized by neurological, ocular, and/or renal signs that can be even fatal, especially in immunocompromised individuals. Therefore, this multidisciplinary review contributes with updated information about the E. cuniculi, deepening in its molecular and genetic characterization, its mechanisms of infection and transmission, and its prevalence among different species and geographic locations, in a One Health perspective. Recent information about the diagnostic and therapeutic approach in the main host species and the prophylaxis and infection control measures currently suggested are also discussed.

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.

Encephalitozoon cuniculi infection in farmed rabbits in Egypt

BACKGROUND

Encephalitozoon cuniculi is an important microsporidian parasite with zoonotic potential. The present study highlights the impact of encephalitozoonosis on rabbit health in Egypt. Three rabbit farms in Giza, with a total of 16,400 rabbits were investigated due to occurrence of rabbits displaying clinical signs consistent with encephalitozoonosis.

RESULTS

Clinical signs observed during a 4 months observation period in 2018 included vestibular disease, paresis, limb paralysis, cataracts, phacoclastic uveitis, frequent urination, marked decrease in body weight and in some pregnant females, also repeated abortions. The total morbidity rates in adult and young rabbits were 76.7% and 81.5%, respectively. The highest mortality rate was recorded in offspring (12.3%), followed by dams (5.6%), and the lowest recorded mortality rate was in males (0.04%). Post-mortem findings included enteritis, pale enlarged kidneys, congested leptomeninges, focal brain necrosis, and endometrial congestion. Histopathological examination revealed nonsuppurative meningoencephalitis and glial nodules with central necrosis in the brain, vacuolation and necrosis of renal tubular epithelium, and corneal ulceration and ruptured lens capsule with fragmentation of lenticular fibres. E. cuniculi were observed in the brain, retinal ganglion cells, kidneys, and liver. Transmission electron microscopy examination revealed the presence of different developmental stages of E. cuniculi in the brain and kidney. Presence of E. cuniculi was confirmed by conventional polymerase chain reaction using a universal 16S gene for Encephalitozoon spp. followed by sequencing and sequence analysis.

CONCLUSIONS

The presence of E. cuniculi in rabbits was confirmed at three farms in Egypt. Nervous signs and ocular lesions were the most predominant findings in these farms.

Detection of Encephalitozoon spp. from human diarrheal stool and farm soil samples in Korea

Microsporidia are eukaryotic organisms that cause zoonosis and are major opportunistic pathogens in HIV-positive patients. However, there is increasing evidence that these organisms can also cause gastrointestinal and ocular infections in immunocompetent individuals. In Korea, there have been no reports on human infections with microsporidia to date. In the present study, we used real-time PCR and nucleotide sequencing to detect Encephalitozoon intestinalis infection in seven of 139 human diarrheal stool specimens (5%) and Encephalitozoon hellem in three of 34 farm soil samples (8.8%). Genotype analysis of the E. hellem isolates based on the internal transcribed spacer 1 and polar tube protein genes showed that all isolates were genotype 1B. To our knowledge, this is the first report on human E. intestinalis infection in Korea and the first report revealing farm soil samples as a source of E. hellem infection. Because microsporidia are an important public health issue, further large-scale epidemiological studies are warranted.

Prevalence of antibodies to Encephalitozoon cuniculi in European hares (Lepus europaeus)

INTRODUCTION AND OBJECTIVES

Encephalitozoon cuniculi is an obligate intracellular parasite infecting especially domestic rabbits; however, spontaneous infections have been documented in other mammalian species such as dogs, cats, rabbits, horses, cows and sheep all over the world. Encephalitozoonosis is a chronic and latent disease leading to renal failure, encephalitis, disorders of brain and urinary tract, and may lead to death. There are limited reports on encephalitozoonosis in wildlife, which is why the aim of this study was to detect the prevalence of antibodies to E. cuniculi in European hares.

MATERIALS AND METHODS

Samples of blood sera from 701 wild hares from the Czech Republic (n = 245), the Slovak Republic (n = 211) and Austria (n = 245) were examined by indirect immunofluorescence antibody test (IFAT); samples with titer ≥ 40 were marked as positive.

RESULTS

The total seroprevalence of E. cuniculi antibodies was 1.42% with titres in the range 40-640. Antibodies to E. cuniculi were detected in 2.9% (7/245), 0.8% (2/245) and 0.47% (1/211) hares from the Czech Republic, Austria and the Slovak Republic, respectively.

CONCLUSIONS

This is the first detection of antibodies to E. cuniculi in hares from Europe showing that hares could be exposed to E. cuniculi infection, however with a low rate.

First report of Enterocytozoon bieneusi and Encephalitozoon intestinalis infection of wild mice in Slovakia

Increased risk of zoonotic transmission of the potential human pathogenic species Enterocytozoon bieneusi, Encephalitozoon intestinalis and Encephalitozoon cuniculi was detected in wild immunocompetent mice (Mus musculus musculus; n=280). Analysis was conducted with the use of PMP1/PMP2 primers and SYBR Green RT-PCR. Using Real Time PCR and comparing the sequences with sequences in the GenBank, E. bieneusi was detected in 3 samples (1.07 %), E. cuniculi in 1 sample (0.35 %) and E. intestinalis in 1 sample (0.35 %). The results of this report document the low host specificity of detected microsporidia species, and imply the importance of synanthropic rodents as a potential source of human microsporidial infection.

Diversity of microsporidia, Cryptosporidium and Giardia in mountain gorillas (Gorilla beringei beringei) in Volcanoes National Park, Rwanda

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.

Evaluation of spore wall protein 1 as an alternative antigen for the diagnosis of Encephalitozoon cuniculi infection of farmed foxes using an enzyme-linked immunosorbent assay

The sequence encoding SWP1 was cloned from the genome of Encephalitozoon cuniculi. Recombinant SWP1 (rSWP1) was expressed in Escherichia coli and used to detect E. cuniculi infections in farmed foxes and dogs with an indirect enzyme-linked immunosorbent assay (ELISA) in the present study. The sera of foxes infected with E. cuniculi could be distinguished from the sera of foxes infected with Toxoplasma gondii, Neospora caninum, and Cryptosporidium parvum using the ELISA. In total, 198 fox samples collected in Liaoning were used to determine the prevalence of antibodies against this disease. The results showed that 16.7% of the fox serum samples were positive according to the ELISA using rSWP1, which agreed with the ELISA results based on recombinant PTP2 (rPTP2). The sensitivity and specificity of the ELISA based on rSWP1 suggest that this could be an alternative method for the diagnosis of E. cuniculi infections in foxes. In addition, 298 dog samples collected in Beijing, Shanghai, and Hunan were also detected in this study, of which six dog samples (2%) were positive according to the ELISA using rSWP1. To the best of our knowledge, this is the first study to demonstrate the serological prevalence of E. cuniculi infections in dogs and foxes in China.

[Prevalence of Encephalitozoon intestinalis and Enterocytozoon bieneusi in HIV positive patients to Maracaibo, Venezuela]

Microsporidioses are considered emerging and opportunistic infections in immunocompromised individuals worldwide. The purpose of this study was to identify the species of intestinal microsporidia in patients with HIV-AIDS from the Servicio Autónomo Hospital Universitario de Maracaibo, Venezuela (SAHUM). Fecal samples were collected from 50 patients with confirmed diagnosis of HIV, during the years 2007 and 2008; the CD4 values were obtained from 42 patients. The samples were analyzed by separate PCRs to identify Encephalitozoon intestinalis and Enterocytozoon bieneusi. Microsporidia species showed a 36% prevalence: ten patients had Encephalitozoon intestinalis, four Enterocytozoon bieneusi and four both species. An inverse and statistically significant relationship between the CD4 count and the presence of microsporidia in the fecal sample was also found. It is remarkable the high prevalence of microsporidia species observed in the HIV patients studied, with a predominance of E. intestinalis.

Occurrence of microsporidia as emerging pathogens in Slovak Roma children and their impact on public health

INTRODUCTION AND OBJECTIVE

Microsporidia are identified as ubiquitous organisms of almost every animal group and are now recognized as emerging opportunistic pathogens of human. The risk factors include immunodeficiency, lack of sanitation, and exposure to contaminated water and infected animals. In Slovakia, the places with an increased risk of infection due to the presence of risk factors and routes of transmission are represented by Roma settlements. Therefore, the aim of this work was to study the occurrence of Encephalitozoon spp. and E. bieneusi in children living in Roma settlements.

MATERIALS AND METHODS

Stool samples were examined of 72 clinically healthy children coming from a group of the non-integrated Roma minority for the presence of microsporidia Encephalitozoon spp. and E. bieneusi. Microsporidian spores were detected by standard Rylux D, staining and by PCR and DNA sequencing.

RESULTS

Of the total number of 72 stool smears examined, 22 were positive, which represented 30.6%. By the Real Time PCR, E. bieneusi was detected in 3 samples (4.2 %) and E. cuniculi in 19 samples (26.4 %). By comparing the sequences with sequences in the GenBank, E. cuniculi genotype I (Accession No. AJ005581.1) and E. bieneusi genotype A (Accession No. AF101197.1).

CONCLUSIONS

Microsporidia, as newly emerging pathogens of humans and animals, are characterised by the production of spores which are environmentally resistant. Diseases caused by them have a cosmopolitan occurrence. Although E. bieneusi and E. cuniculi belong to the most frequently diagnosed species of microsporidia in humans, in Slovakia, this is the first confirmed evidence of E. bieneusi genotype A, as well as E. cuniculi genotype I in humans by the molecular method.

[Microsporidia in pediatric patients with leukemia or limphoma]

INTRODUCTION

Microsporidia are intracellular micro-organisms, characterized by mature spores with chitin walls and by one extrusive polar tube through which they pour their sporoplasm to the host cells. In immunocompromised patients, Enterocytozoon bieneusi and Encephalitozoon intestinalis produce diarrhea and systemic dissemination. In Mexico there is not information about microsporidia in children with cancer.

OBJECTIVE

The aim of this pilot study was to investigate the presence of microsporidia species in pediatric patients with leukemia or lymphoma.

MATERIAL AND METHODS

We obtained fecal samples from thirteen patients. The samples were processed to detect microsporidia by both modified Ziehl-Neelsen and clacofluor white stains, DNA was isolated to amplify rRNA specific sequences, to identify E. bieneusi, E. intestinalis, E. cuniculi and E. hellem by DNA polymerase chain reaction (PCR). Other parasites and pathogenic bacteria were also tested.

RESULTS

Based on morphologic traits 7/13 samples were found positives to microsporidia and 6/10 by PCR. Was identified E. bieneusi in three patients with leukemia and one with lymphoma, another two children with leukemia were infected with E. intestinalis. Almost all children were high-risk patients and in phase of re-induction, consolidation or with many chemotherapy treatments. All the patients with microspiridia did not present diarrhea at the moment of the sampling; however, in two children with diarrhea it was found Cyclospora cayetanensis. Also we obtained feces from five patients' mothers and microsporidia spores were identified by stain in all of them and by PCR it was diagnosed the species in three of them.

CONCLUSION

It was demonstrated that the feces of patients with leukemia or lymphoma had microsporidia, therefore is necessary to know the prevalence of these microorganisms and to analyze their impact in evolution of cancer patients.

The occurrence of microsporidial infections and toxoplasmosis in Slovak women

AIM OF THE STUDY

To determine the prevalence of antibodies to intracellular pathogens (Toxoplasma gondii, Encephalitozoon cuniculi, and Encephalitozoon intestinalis) in sera of Slovak women.

MATERIAL AND METHODS

Enzyme-linked immunosorbent assay (ELISA) was used for the detection of specific IgG antibodies to Toxoplasma gondii, Encephalitozoon cuniculi, and Encephalitozoon intestinalis in 118 sera samples from Slovak women with different diagnoses.

RESULTS

Women were divided into three groups based on the age. In group 1 (n = 26, age > 51), nine women tested positive for T. gondii, two for E. cuniculi, and one for E. intestinalis. The respective numbers in group 2 (n = 53, age range 36-50) were 18, three, and seven, and in group 3 (n = 39, age range 20-35) 13, two, and four. In an attempt to find the relationship between the clinical diagnosis and the prevalence of the three pathogens, we divided the study subjects into four groups based on the condition (diseases of the nervous, respiratory, and immune systems and pregnancy). A statistically significant relationship between the diagnosis and the prevalence of a pathogen was found (p < 0.001). In women with diseases of the respiratory system, antibodies against Toxoplasma gondii were most often detected, while infection with E. intestinalis was most commonly associated with nervous system diseases and the highest seroprevalence of E. cuniculi was found in women diagnosed with immune system disorders.

CONCLUSIONS

In our study, the seroprevalence rates of the three infections in pregnant women were similar, showing no significant difference. Women with diseases of the respiratory system were most often seropositive for T. gondii. Our result is consistent with the known fact that in humans, toxoplasmosis may affect various organs of the body, causing diverse clinical signs. However, the respiratory system is commonly involved and pneumonia may result. The most common finding is a mild, flu-like illness that lasts a few days. The women with different types of immunodeficiency disorders had the highest seropositivity rates for E. cuniculi and the second most common infection in this group was toxoplasmosis. Both of these parasites are opportunistic and can cause serious problems in immunocompromised individuals (HIV-positives, organ transplant recipients, chemotherapy patients). The women diagnosed with the nervous system disorders were most commonly infected with E. intestinalis. The relationship between the disease and this pathogen is not clear, but E. intestinalis is responsible for various pathologies; it causes mainly disseminated infections and damage to the digestive tract. E. intestinalis is a parasite very close to E. cuniculi affecting either the nervous system or the respiratory tract depending on the type of host.

Spore-forming microsporidian encephalitozoon: current understanding of infection and prevention in Japan

Microsporidia are spore-forming obligate intracellular parasites. They are known to cause opportunistic infections in humans through zoonotic, waterborne and foodborne transmission routes. This article reviews the present knowledge regarding microsporidian Encephalitozoon cuniculi infections in animals living in the human environment in Japan and discusses the basic measures required for the effective disinfection of Encephalitozoon. The article also discusses seroepidemiologic data from healthy people in order to shed light on the mechanisms of protective immunity and to identify potential strategies for preventive medicine.

Study on the prevalence of Toxoplasma gondii and Neospora caninum and molecular evidence of Encephalitozoon cuniculi and Encephalitozoon (Septata) intestinalis infections in red foxes (Vulpes vulpes) in rural Ireland

Thoracic fluid (pleural fluid and clotted blood) from 206 foxes were examined for antibodies to Toxoplasma gondii and 220 thoracic fluid samples were tested for Neospora caninum antibodies using indirect immunofluorescent antibody tests (IFAT). A total of 115 (56%) and six (3%) foxes had antibodies to T. gondii and N. caninum, respectively. The brains from 148 foxes were examined for histological lesions and pathological changes suggestive of parasitic encephalitis were observed in 33 (22%). Two thirds of these foxes had antibodies to T. gondii and one fox had antibodies to both T. gondii and N. caninum. PCR assays carried out on DNA extracted from the 33 brains with histological lesions were negative for N. caninum but one of the brains was positive for T. gondii. Microsporidian DNA was also amplified from the brains of two of these foxes. Sequencing these amplicons revealed 100% homology with Encephalitozoon (Septata) intestinalis in one fox and Encephalitozoon cuniculi in the second fox. This is the first report of Encephalitozoon infections in wildlife in Ireland.

Seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, GA, USA

In the current study, we determined the seroprevalence of Toxoplasma gondii, Sarcocystis neurona, and Encephalitozoon cuniculi in three species of lemurs from St. Catherines Island, Georgia. Serum samples were tested from 52 ring-tailed lemurs (Lemur catta), six blue-eyed black lemurs (Eulemur macaco flavifrons), and four black and white ruffed lemurs (Varecia variegata variegata) using an agglutination assay. Three ring-tailed lemurs (5.8%) were positive for T. gondii (titer of 1:50); one ring-tailed lemur (1.9%) and one black and white ruffed lemur (25%) were positive for S. neurona (titers of 1:1000); and one ring-tailed lemur (1.9%) was positive for E. cuniculi (titer of 1:400). All blue-eyed black lemurs were negative for antibodies to T. gondii, S. neurona, and E. cuniculi. This is the first detection of antibodies to T. gondii in ring-tailed lemurs and antibodies to S. neurona and E. cuniculi in any species of prosimian.

Microsporidian species known to infect humans are present in aquatic birds: implications for transmission via water?

Human microsporidiosis, a serious disease of immunocompetent and immunosuppressed people, can be due to zoonotic and environmental transmission of microsporidian spores. A survey utilizing conventional and molecular techniques for examining feces from 570 free-ranging, captive, and livestock birds demonstrated that 21 animals shed microsporidian spores of species known to infect humans, including Encephalitozoon hellem (20 birds; 3.5%) and Encephalitozoon intestinalis (1 bird; 0.2%). Of 11 avian species that shed E. hellem and E. intestinalis, 8 were aquatic birds (i.e., common waterfowl). The prevalence of microsporidian infections in waterfowl (8.6%) was significantly higher than the prevalence of microsporidian infections in other birds (1.1%) (P < 0.03); waterfowl fecal droppings contained significantly more spores (mean, 3.6 x 10(5) spores/g) than nonaquatic bird droppings contained (mean, 4.4 x 10(4) spores/g) (P < 0.003); and the presence of microsporidian spores of species known to infect humans in fecal samples was statistically associated with the aquatic status of the avian host (P < 0.001). We demonstrated that a single visit of a waterfowl flock can introduce into the surface water approximately 9.1 x 10(8) microsporidian spores of species known to infect humans. Our findings demonstrate that waterborne microsporidian spores of species that infect people can originate from common waterfowl, which usually occur in large numbers and have unlimited access to surface waters, including waters used for production of drinking water.

First report on Encephalitozoon intestinalis infection of swine in Europe

Encephalitozoon intestinalis infection of sows is reported from a pig farm in Slovakia. Spores were detected by direct microscopic visualisation in the faeces of 25 out of 27 sows (92.6%). This finding was also supported serologically by the presence of specific anti-E. intestinalis antibodies and by a species-specific polymerase chain reaction (PCR). This is the first report on E. intestinalis infection of swine in Europe.

Prevalence of antibodies to Encephalitozoon cuniculi in horses from Brazil

Encephalitozoon cuniculi has been associated with natural cases of abortion and stillbirth in horses. However, little is known about the prevalence of this parasite in horses. We examined sera from 559 horses from Brazil for antibodies to E. cuniculi using the indirect immunofluorescent antibody (IFA) test and the direct agglutination test (DAT). We found that 79 (14.1%) were positive in the IFA test and 70 (12.5%) were positive in the DAT. Compared to the IFA as the "gold standard" the sensitivity of the DAG was 94.0% and the specificity was 96.1%. Our study indicates that horses in Brazil are frequently exposed to E. cuniculi.

Seroprevalence of antibodies to Encephalitozoon cuniculi in domestic rabbits in the United Kingdom

Serum samples from 97 clinically healthy domestic rabbits were tested for antibodies to Encephalitozoon cuniculi by an indirect elisa technique. Fifty (52 per cent) of them were seropositive. The samples were taken as part of a routine health screen or before general anaesthesia at 22 veterinary practices in England, Scotland and Wales, and the veterinary surgeons were asked to complete a questionnaire to provide information concerning the animal's husbandry, diet, vaccination, health status and any preventive medicine routines. None of these factors was found to be associated with the serological status of the rabbits.

PCR detection of Neospora caninum, Toxoplasma gondii and Encephalitozoon cuniculi in brains of wild carnivores

Neospora caninum, Toxoplasma gondii and Encephalitozoon cuniculi are important pathogens with affinity to the central nervous system of many animals. 240 brains of wild carnivores were examined by PCR-based diagnosis. The presence of N. caninum DNA was confirmed in 4.61% (7/152) red foxes (Vulpes vulpes). DNA of T. gondii was found in 4.92% (3/61) martens (Martes sp.) and in 1.32% (2/152) red foxes. DNA of E. cuniculi was determined in 3.28% (2/61) martens and in one examined European otter (Lutra lutra). There were no co-infections found. These results provide the first evidence of E. cuniculi in the European otter, the first report of N. caninum in foxes in the Czech Republic and confirm the presence of T. gondii in wild carnivores in the Czech Republic.

Analysis of four human microsporidian isolates by MALDI-TOF mass spectrometry

Spores of four species of microsporidia isolated from humans were analyzed by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) and specific biomarkers were found for each. The microsporidia analyzed included three species, Encephalitozoon cuniculi, Encephalitozoon hellem, and Encephalitozoon intestinalis and the fourth organism is the recently described Brachiola algerae. Whole spores, spore shells, and soluble fractions were applied directly to the MALDI target without further purification steps. MALDI-TOF MS analysis of both whole spores and soluble fractions of the four isolates revealed a group of unique, characteristic, and reproducible spectral markers in the mass range of 2,000-8,000 Da. Statistical analysis of the averaged centroided masses uncovered two distinct sets of unique peptides or biomarkers, one originated from whole spores and the other from soluble fractions, that can differentiate the four microsporidian species studied. MALDI-TOF MS analysis of whole organisms is a rapid, sensitive, and specific option to characterize microsporidian isolates and has the potential for several applications in parasitology.

Survey for Encephalitozoon cuniculi in arctic foxes (Alopex lagopus) in Greenland

Wild arctic foxes (Alopex lagopus) from Greenland were tested for antibodies to Encephalitozoon cuniculi with an enzyme-linked immunosorbent assay and a carbon immunoassay. Of 230 tested foxes none was seropositive. This finding contrasts with observations from other arctic areas and absence of rodents in the diet of these arctic foxes is the most likely explanation for absence of E. cuniculi.

Serological investigation of canine encephalitozoonosis in Norway

Encephalitozoon cuniculi, a microsporidian parasite of vertebrates, is considered a health risk to AIDS patients and other immunocompromised human beings. In most hosts, infection with the parasite runs a subclinical course. In some carnivore species, however, clinical disease affecting whole litters arises from intrauterine transmission of the parasite. In both blue foxes ( Alopex lagpus) and dogs ( Canis familiaris), outbreaks of encephalitozoonosis can be severe. Canine encephalitooonosis has been reported from various parts of the world, including South Africa and the United States. In Norway, there have been large outbreaks of the disease in blue fox farms, affecting also mink, but there have been no reports of encephalitozoonosis in dogs. Infection in dogs would represent a zoonotic problem, due to the close social relationship between dog and man. The purpose of the present study was to investigate the possible occurrence of E. cuniculi infection in Norwegian dogs by serological methods. In the study, 1,104 canine serum samples, originally submitted for biochemical analysis by veterinary practitioners throughout Norway, were screened by enzyme-linked immunosorbent assay for antibodies to E. cuniculi. Samples from 237 of the dogs were tested also by the indirect fluorescent antibody test. All samples were concluded as negative. The results indicate that the likelihood of occurrence of E. cuniculi infection in Norwegian dogs is small.

Fox encephalitozoonosis: isolation of the agent from an outbreak in farmed blue foxes (Alopex lagopus) in Finland and some hitherto unreported pathologic lesions

The farmed blue fox (Alopex lagopus) is particularly susceptible to congenital infections of the microsporidian species Encephalitozoon cuniculi. This report is based on an outbreak of the disease in Finland with high mortality. Five pups (four males and one female) with prolonged disease were examined. The pups had moderate pathological alterations in the kidneys and mild lesions were found in the brains, hearts, salivary and prostatic glands. Diagnosis of E. cuniculi infection was made from serological tests (ELISA, CIA, IFAT), and by in vitro isolation of the parasite from the brain of all five pups investigated. The identity was confirmed by molecular means as E. cuniculi strain II ('mouse strain'). Novel histopathological lesions not described as yet in fox encephalitozoonosis are presented. These include cerebral infarction and necrotizing inflammation of the renal pelvis. The sources and mechanisms of spreading of E. cuniculi to blue foxes are discussed.

An indirect ELISA for detection of Encephalitozoon cuniculi infection in farmed blue foxes (Alopex lagopus)

Infection with the intracellular microsporidium Encephalitozoon cuniculi can cause serious disease, encephalitozoonosis, in the blue fox (Alopex lagopus). The disease diagnosis is based on clinical signs and pathological findings, and detection of E. cuniculi or circulating antibodies directed against the parasite. Indirect immunofluorescence (IFAT) and carbon immunoassay (CIA) are the most commonly used serological methods for diagnosis in this species. In the present study, an indirect ELISA (enzyme linked immunosorbent assay) was established and evaluated against IFAT by testing of 205 field samples from blue foxes. There was high agreement between the results of the ELISA and CIA (kappa=0.99), and the ELISA and IFAT (kappa=0.958). There was no significant statistical difference between the tests (p>0.05). It was concluded that the ELISA could be used to identify seropositive farmed blue foxes. The advantage of the ELISA lies in the potential of screening large numbers of animals with the goal of eradicating E. cuniculi infection in the farms.

Genetic homology among thirteen Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus-infected patients with intestinal microsporidiosis

The ribosomal DNA internal transcribed spacer sequences of 13 unrelated Encephalitozoon intestinalis isolates obtained from human immunodeficiency virus (HIV)-infected patients with intestinal microsporidiosis were analyzed by gene amplification and DNA sequencing. Among these isolates, we found only one genetic lineage which suggests that E. intestinalis may have a clonal distribution in HIV-infected patients.

The first finding of antibodies to Encephalitozoon cuniculi in cows in Slovakia

The presence of antibodies against Encephalitozoon cuniculi in cows was observed by the method of indirect immunofluorescence (IFAT). The animals reacting at the titre 1:64 and more were considered positive. Of the total number of 55 sera examined, 20 were positive at the titre 1:64, from which four were positive at the titre 1:256 also. Our results indicate that it is very important to carry out screening examinations in large-scale breeding of cattle due to the persistent high percentage of bovine abortions and disorders in the reproductive cycle of unknown etiology.

Prevalence of intestinal encephalitozoonosis in Mexico

Infections with Encephalitozoon (phylum Microspora) protozoa in immunodeficient patients have emerged worldwide. The prevalence of infections due to Encephalitozoon species in nonclinical populations remains unclear. We conducted a cross-sectional survey of two rural highland villages in Mexico by using monoclonal antibody 3B6 to Encephalitozoon in immunofluorescence to assess the prevalence of Encephalitozoon spores in human stools. We found that 20 (7.84%) of the 255 subjects were positive and that 15 (21.4%) of the 70 households had at least one member who was positive. These results suggest that Encephalitozoon species, most likely Encephalitozoon intestinalis, may be commonly present in community settings.

Microsporidia (Encephalitozoon cuniculi) in wild rabbits in Australia

OBJECTIVE

To determine the prevalence of infection with Encephalitozoon cuniculi in wild rabbit populations in Western Australia, and to isolate the organism from seropositive rabbits.

DESIGN

Serological screening of wild and clinically affected domestic rabbit populations.

SAMPLE POPULATION

Eighty-one wild rabbits from south-western Western Australia and 29 laboratory rabbits.

PROCEDURE

Indirect immunofluorescence antibody technique and in-vitro amplification of parasite isolates in fibroblast cultures.

RESULTS

Of the 81 wild rabbits and 29 laboratory rabbits, 20 and 22 respectively, had antibodies to E cuniculi. E cuniculi from the urine of one seropositive laboratory rabbit and from brain and kidney tissues of eight and five seropositive laboratory and wild rabbits respectively were isolated in fibroblast cultures.

CONCLUSION

E cuniculi infection has been shown for the first time to be prevalent in wild rabbits in Australia. Techniques have been developed for the isolation and culture of the causative agent. Comparative studies can now be undertaken to determine risk factors for clinical disease in domestic rabbits and the relationship among E cuniculi isolates from wild and domestic rabbits.

[Encephalitozoon cuniculi--clinical and epidemiologic significance. Results of a preliminary serologic study in humans]

Recently attention in human medicine has been drawn to encephalitozoonoses. Increased liability to develop the infection is found in particular in people with an impaired immunobiological condition. Evidence of this are more numerous infections in AIDS patients. However, the impact of encephalitozoonoses cannot be ruled out in other groups of patients. This calls however for specific aimed investigations. The authors examined 98 sera of employees of a slaughterhouse for encephalitozoonosis. Five sera (5.1%) were positive. Sera of 92 forestry workers, 22 dog breeders and 150 blood donors were negative. In future it will be necessary to focus attention on seropositive subjects in conjunction with the possible transmission of the disease from animals to man.

Intestinal microsporidiosis

Intestinal microsporidiosis is caused by the protozoan parasites Enterocytozoon bieneusi and Encephalitozoon intestinalis. The disease has been described within the past decade and is found predominantly in acquired immunodeficiency syndrome (AIDS) patients in association with diarrhea. There have been rare reports of infections in immunocompetent patients. Both species of microsporidia invade and multiply within the enterocytes of the small intestine; Encephalitozoon intestinalis also causes a disseminated infection. Electron microscopy has been the mainstay of diagnosis, but improved noninvasive methods of detecting spores in feces are in development. The biology and pathogenicity of the parasites and the pathology and treatment of the disease are poorly understood.

Prevalence of microsporidiosis due to Enterocytozoon bieneusi and Encephalitozoon (Septata) intestinalis among patients with AIDS-related diarrhea: determination by polymerase chain reaction to the microsporidian small-subunit rRNA gene

Microsporidia are emerging as opportunistic pathogens in patients with AIDS. Enterocytozoon bieneusi and Encephalitozoon (Septata) intestinalis have been implicated in enteric infections in AIDS patients with chronic diarrhea, a wasting syndrome, and malabsorption. We used the polymerase chain reaction (PCR) and primers that amplify the conserved regions of the small-subunit rRNA (SSU-rRNA) gene of E. bieneusi and E. intestinalis in tissue specimens from HIV-infected patients with and without diarrhea to examine the association between microsporidia and diarrhea in patients with AIDS. Tissue specimens were obtained from 68 patients with AIDS and diarrhea (mean CD4 lymphocyte count, 21/mm3) and 43 AIDS patients without diarrhea (mean CD4 lymphocyte count, 60/mm3). By means of PCR with use of the SSU-rRNA primers specific for E. bieneusi and E. intestinalis, we found that 44% of patients with diarrhea were infected with microsporidia, whereas only 2.3% of the patients without diarrhea were infected with microsporidia (P < .001). There was a clear association between the presence of microsporidia and diarrhea. In addition, the SSU-rRNA primers proved to be sensitive and specific when used in this clinical setting.

Retrospective study of diseases in a captive Lemming Colony

Fifty-four ill or nonproductive lemmings (Dicrostonyx spp.) were evaluated for signs, lesions and causes of disease for 5 yr in a domestic colony. Parasitic granulomas caused by Encephalitozoon cuniculi were the most common finding and were seen in 22 lemmings. The disease was characterized by circling and torticollis with granulomas in many tissues, especially the central nervous system. Suppurative otitis occurred in 12 lemmings and was associated with Klebsiella pneumonia infection; circling was the common sign. Hepatic microabscesses were present in seven lemmings but a cause was not identified. Five lemmings had neoplasms and 14 had either suppurative processes, aspermia, or ovarian cysts.

Prevalence of Encephalitozoon cuniculi antibodies in terrestrial mammals in Iceland, 1986 to 1989

Antibodies to Encephalitozoon cuniculi were found in wild arctic foxes (Alopex lagopus), feral mink (Mustela vison), wood mice (Apodemus sylvaticus) and house mice (Mus musculus) in Iceland. Animals with antibodies were found throughout the country. No lesions attributable to encephalitozoonosis were found in adult animals necropsied. However, one arctic fox cub with a neurological disorder had pathological and serological evidence of encephalitozoonosis.

Rabbit encephalitozoonosis in Kenya

Encephalitozoon cuniculi infection was diagnosed in a laboratory rabbit breeding colony at Muguga, Kenya. This is the first report of the disease in rabbits in Kenya. Post-mortem examination showed gross renal lesions and the presence of the parasite in histological sections of the cerebrum and cerebellum. On Gram stain, spores were observed in the kidney sections.