Search

Background: In rabbits, renal abscesses (pus-filled sores) are rare and diagnosis remains challenging. Therefore, in this study, we aimed to determine the clinical manifestation and diagnostic tests associated with renal abscess identification in rabbits. Case Description: A four-and-a-half-year-old castrated male Lionhead rabbit with a history of poor appetite and abdominal distension was admitted to the animal hospital. Blood analysis, radiography, ultrasonography, and computed tomography scans revealed a kidney abscess found within the renal parenchyma, with severe loss of the cortex and medulla, extending toward the capsule. Consequently, the rabbit underwent nephrectomy. The enlarged right kidney was surgically removed. Histopathological examination of the affected kidney showed severe necrosis and ischemic zones, atrophy of the renal tubules, and prominent heterophils with mixed inflammatory cell infiltrates. Immunohistochemistry and polymerase chain reaction confirmed Encephalitozoon cuniculi and Escherichia coli infections, respectively. Conclusion: This report provides novel insights into the diagnosis of renal abscesses in Lionhead rabbits. [ABSTRACT FROM AUTHOR]

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.

Encephalitozoon cuniculi is a microsporidian, domestic rabbits being the main host. The disease can be acute or subclinical, but treatment options are limited and usually with unrewarding results; therefore, diagnosis and prevention of encephalitozoonosis in rabbits are of the utmost importance. This study aims to obtain the first preliminary information of the prevalence of E. cuniculi in the north-western region of Romania. A total of 176 rabbits were clinically examined and 2 mL of blood was sampled from each. An enzyme-linked immunosorbent assay (ELISA) kit by Medicago (Medicago, Uppsala, Sweden) on the resulted blood serum was utilized. Statistical analysis of the results was conducted using the EpiInfo 2000 software (CDC, Atlanta, GA, USA). A total prevalence of 39.2% (69/176) was identified, with statistically significant differences in relation to the rabbits' clinical status, age, season of sampling, breeding system, body condition score and county of origin; the different family farms tested also had a statistically significant difference. This study gives the first preliminary information on this pathogen distribution on Romania's territory, but further studies need to be performed on larger regions to declare the prevalence in the country. [ABSTRACT FROM AUTHOR]

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.

We detected 24 Encephalitozoon cuniculi positive Ixodes ricinus ticks of 284 collected in the Czech Republic. Since the route of transmission of microsporidia is not fully understood, the presence of microsporidia in ticks raises the question of whether they may be involved in the transmission of these pathogens.

Encephalitozoon cuniculi is a microsporidian, domestic rabbits being the main host. The disease can be acute or subclinical, but treatment options are limited and usually with unrewarding results; therefore, diagnosis and prevention of encephalitozoonosis in rabbits are of the utmost importance. This study aims to obtain the first preliminary information of the prevalence of E. cuniculi in the north-western region of Romania. A total of 176 rabbits were clinically examined and 2 mL of blood was sampled from each. An enzyme-linked immunosorbent assay (ELISA) kit by Medicago (Medicago, Uppsala, Sweden) on the resulted blood serum was utilized. Statistical analysis of the results was conducted using the EpiInfo 2000 software (CDC, Atlanta, GA, USA). A total prevalence of 39.2% (69/176) was identified, with statistically significant differences in relation to the rabbits’ clinical status, age, season of sampling, breeding system, body condition score and county of origin; the different family farms tested also had a statistically significant difference. This study gives the first preliminary information on this pathogen distribution on Romania’s territory, but further studies need to be performed on larger regions to declare the prevalence in the country.

Simple Summary: Encephalitozoonosis is a disease caused by Encephalitozoon cuniculi. It is diagnosed primarily in rabbits, and is less frequently so in other animal species. E. cuniculi is classified as Microsporidia—fungi frequently found in the environment, that are resistant to numerous external factors. This pathogen is diagnosed primarily in rabbits, and is less frequently so in other animal species. The objective of the study was to analyze the prevalence of E. cuniculi infections in guinea pigs with different clinical disorders. The infected animals most frequently exhibited nervous and urinary system symptoms, as well as issues with vision organs, while several animals were recorded as having problems with the respiratory system and thyroid gland dysfunction. The study shows that encephalitozoonosis constitutes a significant problem in rodents kept as domestic animals, which in turn may be a source of infection for humans. Encephalitozoonosis is a disease caused by E. cuniculi. It is diagnosed primarily in rabbits but is less frequently so in other animal species. E. cuniculi is classified among Microsporidia—fungi frequently found in the environment, that are resistant to numerous external factors. Apart from rabbits, rodents form the next group of animals most exposed to infection with these pathogens. The objective of the study was to analyze the prevalence of E. cuniculi infection in guinea pigs with different clinical disorders. The study included 67 animals with E. cuniculi infection confirmed via real-time PCR. The infected animals most frequently exhibited nervous and urinary system symptoms, as well as issues with vision organs, while several animals were also recorded as having problems with the respiratory system and thyroid gland dysfunction. The study shows that encephalitozoonosis constitutes a significant problem in rodents kept as domestic animals, which in turn may be a source of infection for humans. [ABSTRACT FROM AUTHOR]

Simple Summary: Microsporidia are obligatory intracellular fungi that cause infection in a broad variety of eukaryotes. However, there are few epidemiological studies on microsporidia in red pandas in China. Therefore, we conducted an epidemiological survey of microsporidia in red pandas from six zoos in Sichuan Province, China. In 198 fecal samples, Enterocytozoon bieneusi was detected in 24 samples (12.1%), while Encephalitozoon spp. was detected in 8 fecal samples (4.0%). Further analysis revealed the presence of genotypes of E. bieneusi with zoonotic concerns. Interestingly, we also observed that the infection rate of microsporidia was higher in semi-free red pandas with more frequent contact with other animals or humans. This is the first report on the occurrence and genotypes of E. bieneusi and Encephalitozoon spp. in red pandas in Sichuan Province, China, contributing to our understanding of the worldwide distribution and genetic diversity of this pathogen. 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. [ABSTRACT FROM AUTHOR]

Simple Summary: It is well known that mammals can harbor various pathogens that can affect humans (known as zoonotic pathogens) including viruses, bacteria, fungi and parasites. Microsporidia are a group of pathogens related to fungi and parasites of several animals that can cause diarrhea or systemic infection in humans. Due to the limited knowledge about microsporidia infection in hedgehogs worldwide, this study aimed to analyze the presence and identity of microsporidia in a group of North African hedgehogs from the Canary Islands (Spain). Enterocytozoon bieneusi and Encephalitozoon cuniculi, two zoonotic species of microsporidia, were identified. These results suggest that microsporidia species with zoonotic risk circulate in the archipelago. Microsporidia are unicellular eukaryotic obligate intracellular parasites with a wide range of hosts reported worldwide; however, little is known about the epidemiological data on microsporidia infection in animals from the Canary Islands. Since data on microsporidia infection in hedgehog species are scarce, the aim of this study was to analyze the presence and identity of microsporidia in a group of North African hedgehogs (Atelerix algirus) using microscopic and molecular methods. From December 2020 to September 2021, a total of 36 fecal samples were collected from naturally deceased hedgehogs from Tenerife and Gran Canaria. All samples showed spore-compatible structures (100%; 36/36) under microscopic analysis, of which 61.1% (22/36) were amplified via the nested-polymerase chain reaction (PCR) targeting the partial sequence of the 16S rRNA gene, the internal transcribed spacer (ITS) region, and the partial sequence of the 5.8S rRNA gene. After Sanger sequencing and ITS analysis, Enterocytozoon bieneusi was detected in 47.2% (17/36) of the samples, identifying two novel genotypes (AAE1 and AAE2), followed by the detection of an undetermined species in 8.3% (3/36) and Encephalitozoon cuniculi genotype I in 5.6% (2/36) of the samples. This study constitutes the first report of microsporidia species in Atelerix algirus worldwide, highlighting the high prevalence of zoonotic species. [ABSTRACT FROM AUTHOR]

Microsporidia are obligate intracellular parasites related to fungi that cause severe infections in immunocompromised individuals. Encephalitozoon cuniculi is a microsporidian species capable of infecting mammals, including human and rodents. In response to microsporidian infection, innate immune system serves as the first line of defense and allows a partial clearance of the parasite via the innate immune cells, namely macrophages, neutrophils, dendritic cells, and Natural Killer cells. According to the literature, microsporidia bypass this response in vitro by modulating the response of macrophages. In order to study hostparasites interactions in vivo, we developed a model using the mouse ear pinna in combination with an intravital imaging approach. Fluorescent E. cuniculi spores were inoculated into the skin tissue to follow for the first time in real time in an in vivo model the recruitment dynamics of EGFP + phagocytic cells in response to the parasite. The results show that parasites induce an important inflammatory recruitment of phagocytes, with alterations of their motility properties (speed, displacement length, straightness). This cellular response persists in the injection zone, with spores detected inside the phagocytes up to 72 h post-infection. Immunostainings performed on ear tissue cryosections evoke the presence of developing infectious foci from 5 days post-infection, in favor of parasite proliferation in this tissue. Overall, the newly set up mice ear pinna model will increase our understanding of the immunobiology of microsporidia and in particular, to know how they can bypass and hijack the host immune system of an immunocompetent or immunosuppressed host. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is a microsporidial parasite that primarily infects domestic rabbits (Oryctolagus cuniculus). It is the causative agent of encephalitozoonosis, a disease with an internationally recognized seroprevalence among rabbits. This study determines the presence, clinical manifestation, and serological status of encephalitozoonosis in pet rabbits in Slovenia using various diagnostic procedures. From 2017 to 2021, 224 pet rabbit sera were collected and tested for encephalitozoonosis with the indirect immunofluorescence assay. Immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against E. cuniculi were confirmed in 160 (65.6%) cases. Most seropositive rabbits suffered from neurological clinical signs or signs of gastrointestinal disorders such as recurrent hypomotilities, chronic weight loss, cachexia, or anorexia, and fewer showed clinical signs related to the urinary system or phacoclastic uveitis. A quarter of the positively tested rabbits presented without clinical signs. Hematological and biochemical blood analysis confirmed that seropositive animals had elevated globulin and deviated albumin levels in comparison to the normal reference values of non-infected animals. Furthermore, rabbits with neurological clinical signs showed statistically significant higher levels of globulins and total protein. Sixty-eight whole-body radiographs and thirty-two abdominal ultrasound reports were analyzed, looking for changes in the shape or size of the urinary bladder, presence of urinary sludge or uroliths, and any abnormalities related to the kidneys (shape, size, or nephrolites). The results suggest that neurological defects in the urinary bladder caused by E. cuniculi lead to a distended urinary bladder and consequently dysuria, incontinence, urine scalding, and sludgy urine. [ABSTRACT FROM AUTHOR]

Obligately intracellular microsporidia regulate their host cell life cycles, including apoptosis, but this has not been evaluated in phagocytic host cells such as macrophages that can facilitate infection but also can be activated to kill microsporidia. We examined two biologically dissimilar human-infecting microsporidia species, Encephalitozoon cuniculi and Vittaforma corneae, for their effects on staurosporine-induced apoptosis in the human macrophage-differentiated cell line, THP1. Apoptosis was measured after exposure of THP-1 cells to live and dead mature organisms via direct fluorometric measurement of Caspase 3, colorimetric and fluorometric TUNEL assays, and mRNA gene expression profiles using Apoptosis RT2 Profiler PCR Array. Both species of microsporidia modulated the intrinsic apoptosis pathway. In particular, live E. cuniculi spores inhibited staurosporine-induced apoptosis as well as suppressed pro-apoptosis genes and upregulated anti-apoptosis genes more broadly than V. corneae. Exposure to dead spores induced an opposite effect. Vittaforma corneae, however, also induced inflammasome activation via Caspases 1 and 4. Of the 84 apoptosis-related genes assayed, 42 (i.e. 23 pro-apoptosis, nine anti-apoptosis, and 10 regulatory) genes were more affected including those encoding members of the Bcl2 family, caspases and their regulators, and members of the tumour necrosis factor (TNF)/TNF receptor R superfamily.

Microsporidia are obligate intracellular parasites related to fungi that cause severe infections in immunocompromised individuals. Encephalitozoon cuniculi is a microsporidian species capable of infecting mammals, including human and rodents. In response to microsporidian infection, innate immune system serves as the first line of defense and allows a partial clearance of the parasite via the innate immune cells, namely macrophages, neutrophils, dendritic cells, and Natural Killer cells. According to the literature, microsporidia bypass this response in vitro by modulating the response of macrophages. In order to study host-parasites interactions in vivo, we developed a model using the mouse ear pinna in combination with an intravital imaging approach. Fluorescent E. cuniculi spores were inoculated into the skin tissue to follow for the first time in real time in an in vivo model the recruitment dynamics of EGFP + phagocytic cells in response to the parasite. The results show that parasites induce an important inflammatory recruitment of phagocytes, with alterations of their motility properties (speed, displacement length, straightness). This cellular response persists in the injection zone, with spores detected inside the phagocytes up to 72 h post-infection. Immunostainings performed on ear tissue cryosections evoke the presence of developing infectious foci from 5 days post-infection, in favor of parasite proliferation in this tissue. Overall, the newly set up mice ear pinna model will increase our understanding of the immunobiology of microsporidia and in particular, to know how they can bypass and hijack the host immune system of an immunocompetent or immunosuppressed host.

Simple Summary: Microsporidia are a group of fungal-related pathogens widely distributed in the environment, with some species having a negative impact on animals and public health. The European rabbit (Oryctolagus cuniculus) is considered the natural host of Encephalitozoon cuniculi, a microsporidian pathogen of mammals, including humans. The infection caused by E. cuniculi, encephalitozoonosis, ranges from asymptomatic to severe lesions in rabbits, with clinical signs involving the central nervous system, kidney, and eye being the most common. The majority of reported cases have been in domestic rabbits, while cases in wild rabbits are uncommon. Due to the lack of data on microsporidia in the Canary Islands, the aim of this work was to analyze the prevalence and identity of microsporidia in fecal samples from rabbits in Tenerife. Enterocytozoon bieneusi and Encephalitozoon spp. are microsporidia with zoonotic potential that have been identified in humans, as well as in a large group of wild and domestic animals. Several wildlife species have been studied as reservoirs of zoonotic microsporidia in mainland Spain, including the European rabbit (Oryctolagus cuniculus). Due to a lack of data on microsporidia infection in wildlife on the Canary Islands, the aim of this work was to analyze the prevalence and identify the species of microsporidia in rabbits in Tenerife. Between 2015 and 2017, a total of 50 fecal samples were collected from rabbits in eight municipalities of Tenerife, Canary Islands, Spain. Seven of the fifty samples (14%) were amplified using nested polymerase chain reaction (PCR) targeting the partial sequence of the 16S rRNA gene, the internal transcribed spacer (ITS) region, and the partial sequence of the 5.8S rRNA gene. Sanger sequencing reveals the presence of Encephalitozoon cuniculi genotype I in two samples (4%), and undescribed microsporidia species in five samples (10%). This study constitutes the first molecular detection and genotyping of E. cuniculi in rabbits in Spain. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is a eukaryote, unicellular, spore-forming, obligate intracellular microorganism of the phylum Microsporidia, with domestic rabbits as its main host. Another important species in which this pathogen has been identified are humans, the infection being therefore called a "zoonosis". The transmission takes place via the horizontal route or the vertical route, and cell-mediated immunity plays the biggest role in the infected hosts' protection. Encephalitozoonosis can manifest itself as an acute infection, with neurological signs, renal signs, and ocular lesions, or as a chronic or subclinical infection, which is usually the case for asymptomatic carriers. The diagnostic techniques usually carried out are histological examination, serological tests, and molecular genetic techniques. The treatment of encephalitozoonosis is usually symptomatic, with unrewarding results, and prevention methods include periodical serological screening, prophylactic administration of fenbendazole, and maintenance of a clean environment. The purpose of this article is to review the current data regarding the pathogenesis, host immunity, clinical signs, diagnostic methods, treatment, and prevention methods of encephalitozoonosis in the domestic rabbit, as well as to analyze the prevalence of this disease in different countries of the world. [ABSTRACT FROM AUTHOR]

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 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. [ABSTRACT FROM AUTHOR]

Background: In rabbits, renal abscesses (pus-filled sores) are rare and diagnosis remains challenging. Therefore, in this study, we aimed to determine the clinical manifestation and diagnostic tests associated with renal abscess identification in rabbits., Case Description: A four-and-a-half-year-old castrated male Lionhead rabbit with a history of poor appetite and abdominal distension was admitted to the animal hospital. Blood analysis, radiography, ultrasonography, and computed tomography scans revealed a kidney abscess found within the renal parenchyma, with severe loss of the cortex and medulla, extending toward the capsule. Consequently, the rabbit underwent nephrectomy. The enlarged right kidney was surgically removed. Histopathological examination of the affected kidney showed severe necrosis and ischemic zones, atrophy of the renal tubules, and prominent heterophils with mixed inflammatory cell infiltrates. Immunohistochemistry and polymerase chain reaction confirmed Encephalitozoon cuniculi and Escherichia coli infections, respectively., Conclusion: This report provides novel insights into the diagnosis of renal abscesses in Lionhead rabbits., Competing Interests: All authors declare no potential conflicts of interest.

Objective:European hares (Lepus europaeus) are among the most important animals that are connected with humans in many countries and natural life. Hares are important for public health, since they carry many zoonotic diseases, such as Encephalitozoon cuniculi, Francisella tularensis and Toxoplasma gondii. The study aimed to determine the seroprevalence of Encephalitozoon cuniculi, Francisella tularensis and T. gondii and the potential zoonotic risk posed by hares that live in provinces of Turkey.Methods:Blood samples were collected from hares during the official hunting season. Serum samples were examined serologically by enzyme-linked immunosorbent assay for E. cuniculi, Sabin-Feldman dye test was used to examine T. gondii, while micro-agglutination test was used to examine F. tularensis.Results:Of the total of 42 hares examined, one (2.4%) was found positive for E. cuniculi, two (4.8%) were found positive for T. gondii and one (2.4%) was found positive for F. tularensis.Conclusion:Anti-T. gondii and anti-E. cuniculi antibodies were serologically detected in hares for the first time in Turkey. Furthermore, this is the first study reporting the seropositivity of F. tularensis infection in hares.

Encephalitozoonosis is a disease caused by E. cuniculi. It is diagnosed primarily in rabbits but is less frequently so in other animal species. E. cuniculi is classified among Microsporidia—fungi frequently found in the environment, that are resistant to numerous external factors. Apart from rabbits, rodents form the next group of animals most exposed to infection with these pathogens. The objective of the study was to analyze the prevalence of E. cuniculi infection in guinea pigs with different clinical disorders. The study included 67 animals with E. cuniculi infection confirmed via real-time PCR. The infected animals most frequently exhibited nervous and urinary system symptoms, as well as issues with vision organs, while several animals were also recorded as having problems with the respiratory system and thyroid gland dysfunction. The study shows that encephalitozoonosis constitutes a significant problem in rodents kept as domestic animals, which in turn may be a source of infection for humans.

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.

Microsporidia are unicellular eukaryotic obligate intracellular parasites with a wide range of hosts reported worldwide; however, little is known about the epidemiological data on microsporidia infection in animals from the Canary Islands. Since data on microsporidia infection in hedgehog species are scarce, the aim of this study was to analyze the presence and identity of microsporidia in a group of North African hedgehogs (Atelerix algirus) using microscopic and molecular methods. From December 2020 to September 2021, a total of 36 fecal samples were collected from naturally deceased hedgehogs from Tenerife and Gran Canaria. All samples showed spore-compatible structures (100%; 36/36) under microscopic analysis, of which 61.1% (22/36) were amplified via the nested-polymerase chain reaction (PCR) targeting the partial sequence of the 16S rRNA gene, the internal transcribed spacer (ITS) region, and the partial sequence of the 5.8S rRNA gene. After Sanger sequencing and ITS analysis, Enterocytozoon bieneusi was detected in 47.2% (17/36) of the samples, identifying two novel genotypes (AAE1 and AAE2), followed by the detection of an undetermined species in 8.3% (3/36) and Encephalitozoon cuniculi genotype I in 5.6% (2/36) of the samples. This study constitutes the first report of microsporidia species in Atelerix algirus worldwide, highlighting the high prevalence of zoonotic species.

Case series summary: Three domestic shorthair cats from California presented to veterinary ophthalmologists with immature cataracts. Other presenting clinical signs included corneal edema, anisocoria, anterior uveitis, elevated intraocular pressure, blepharospasm and/or lethargy. All patients were immunocompromised due to concurrent diseases and/or immunomodulatory drugs. Diagnostics included serial comprehensive ophthalmic examinations with tonometry, ocular ultrasound, electroretinogram and testing for other causes of feline uveitis. Testing for Encephalitozoon cuniculi included serology, histopathology and/or PCR of aqueous humor, lens material or paraffin-embedded whole eye. Treatments included antiparasitic medication, anti-inflammatory medication and supportive care in all three cases. Surgical treatment included enucleation (one case), bilateral phacoemulsification and unilateral intraocular lens placement (one case) and bilateral phacoemulsification with bilateral endolaser ciliary body ablation and bilateral intraocular lens implantation (one case). Both cats for which serologic testing for E cuniculi was performed were positive (1:64–1:4096). In all cats, diagnosis of intraocular E cuniculi was based on at least one of the following: lens histopathology or PCR of aqueous humor, lens material or paraffin-embedded ocular tissue. The clinical visual outcome was best in the patient undergoing phacoemulsification at the earliest stage of the cataract. Relevance and novel information: Encephalitozoon cuniculi should be considered as a differential cause of cataracts and uveitis in cats in California, the rest of the USA and likely worldwide. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi (E. cuniculi) is a microsporidian parasite commonly detected in rabbits and can infect humans and cause encephalitozoonosis. And Toxoplasma gondii is a prevalent parasite distributed worldwide and can infect almost all warm-blooded animals, including humans. The aim of the current study was to investigate the seroprevalence of E. cuniculi and Toxoplasma gondii, and risk factors of infection in pet rabbits reared in eastern coastal areas of China (Tianjin, Shandong, Jiangsu, Zhejiang, Shanghai and Fujian). Total 222 blood samples of pet rabbits were collected from local veterinary hospitals. The seropositivity rates of E. cuniculi were 16.22% (36/222) according to an Enzyme-linked immunosorbent assay (ELISA). Female pet rabbits was significantly higher than that in males (P=0.002), Zhejiang were markedly higher than those in Jiangsu and Shanghai (P=0.017, P=0.022), and cross-breed rabbits were dramatically higher than those in Chinchilla, New Zealand white, Rex (P=0.02, P=0.006, P=0.008). The seroprevalence of T. gondii was 13.06% (29/222) by the method of ELISA. The seroprevalence in Zhejiang was significantly higher than that in Shanghai (P=0.017). No difference in seroprevalence was detected with respect to the gender, age, species, health status, or season. These findings show that E. cuniculi and T. gondii are present and spread in pet rabbits. Therefore, pet rabbits should be considered as an important reservoir of encephalitozoonosis for humans and maybe important implication for public health in eastern coastal areas of China. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is a microsporidial parasite that primarily infects domestic rabbits (Oryctolagus cuniculus). It is the causative agent of encephalitozoonosis, a disease with an internationally recognized seroprevalence among rabbits. This study determines the presence, clinical manifestation, and serological status of encephalitozoonosis in pet rabbits in Slovenia using various diagnostic procedures. From 2017 to 2021, 224 pet rabbit sera were collected and tested for encephalitozoonosis with the indirect immunofluorescence assay. Immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against E. cuniculi were confirmed in 160 (65.6%) cases. Most seropositive rabbits suffered from neurological clinical signs or signs of gastrointestinal disorders such as recurrent hypomotilities, chronic weight loss, cachexia, or anorexia, and fewer showed clinical signs related to the urinary system or phacoclastic uveitis. A quarter of the positively tested rabbits presented without clinical signs. Hematological and biochemical blood analysis confirmed that seropositive animals had elevated globulin and deviated albumin levels in comparison to the normal reference values of non-infected animals. Furthermore, rabbits with neurological clinical signs showed statistically significant higher levels of globulins and total protein. Sixty-eight whole-body radiographs and thirty-two abdominal ultrasound reports were analyzed, looking for changes in the shape or size of the urinary bladder, presence of urinary sludge or uroliths, and any abnormalities related to the kidneys (shape, size, or nephrolites). The results suggest that neurological defects in the urinary bladder caused by E. cuniculi lead to a distended urinary bladder and consequently dysuria, incontinence, urine scalding, and sludgy urine.

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. [ABSTRACT FROM AUTHOR]

We detected 24 Encephalitozoon cuniculi positive Ixodes ricinus ticks of 284 collected in the Czech Republic. Since the route of transmission of microsporidia is not fully understood, the presence of microsporidia in ticks raises the question of whether they may be involved in the transmission of these pathogens.

Klára Brdíčková,1,2 Bohumil Sak,3 Nikola Holubová,3,4 Dana Květoňová,3 Lenka Hlásková,3 Marta Kicia,5 Żaneta Kopacz,5 Martin Kváč3,4 1Department of Clinical Microbiology, Bulovka Hospital, Prague, Czech Republic; 2Faculty of Science, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic; 3Institute of Parasitology, Biology Centre, Czech Academy of Science, České Budějovice, Czech Republic; 4Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic; 5Department of Biology and Medical Parasitology, Wroclaw Medical University, Wroclaw, PolandCorrespondence: Bohumil SakInstitute of Parasitology, Branišovská 31, České Budějovice 37005, Czech RepublicTel +420387775421Fax +420385310388Email casio@paru.cas.czBackground: 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

Abstract 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.

Encephalitozoon cuniculi is a eukaryote, unicellular, spore-forming, obligate intracellular microorganism of the phylum Microsporidia, with domestic rabbits as its main host. Another important species in which this pathogen has been identified are humans, the infection being therefore called a ”zoonosis”. The transmission takes place via the horizontal route or the vertical route, and cell-mediated immunity plays the biggest role in the infected hosts’ protection. Encephalitozoonosis can manifest itself as an acute infection, with neurological signs, renal signs, and ocular lesions, or as a chronic or subclinical infection, which is usually the case for asymptomatic carriers. The diagnostic techniques usually carried out are histological examination, serological tests, and molecular genetic techniques. The treatment of encephalitozoonosis is usually symptomatic, with unrewarding results, and prevention methods include periodical serological screening, prophylactic administration of fenbendazole, and maintenance of a clean environment. The purpose of this article is to review the current data regarding the pathogenesis, host immunity, clinical signs, diagnostic methods, treatment, and prevention methods of encephalitozoonosis in the domestic rabbit, as well as to analyze the prevalence of this disease in different countries of the world.

Enterocytozoon bieneusi and Encephalitozoon spp. are microsporidia with zoonotic potential that have been identified in humans, as well as in a large group of wild and domestic animals. Several wildlife species have been studied as reservoirs of zoonotic microsporidia in mainland Spain, including the European rabbit (Oryctolagus cuniculus). Due to a lack of data on microsporidia infection in wildlife on the Canary Islands, the aim of this work was to analyze the prevalence and identify the species of microsporidia in rabbits in Tenerife. Between 2015 and 2017, a total of 50 fecal samples were collected from rabbits in eight municipalities of Tenerife, Canary Islands, Spain. Seven of the fifty samples (14%) were amplified using nested polymerase chain reaction (PCR) targeting the partial sequence of the 16S rRNA gene, the internal transcribed spacer (ITS) region, and the partial sequence of the 5.8S rRNA gene. Sanger sequencing reveals the presence of Encephalitozoon cuniculi genotype I in two samples (4%), and undescribed microsporidia species in five samples (10%). This study constitutes the first molecular detection and genotyping of E. cuniculi in rabbits in Spain.

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.

Encephalitozoon cuniculi is a microsporidium belonging to the phylum Microspora. A few reports have described the clinical significance of E. cuniculi infection in young dogs. In American and Japanese household dog populations, the seroprevalence was found to be 21%, indicating its wide-spread existence. To evaluate the clinical significance of E. cuniculi in a cohort of young dogs with neurological signs, the presence of the organism and possible response to treatment were studied. Over a 1-year period, all young dogs (100) and/or if an EDTA-blood sample and/or urine sample tested positive by polymerase chain reaction (PCR). Sixteen dogs with various neurological signs were included in this study. Additional work-up included magnetic resonance imaging and cerebrospinal fluid analysis, but these revealed no abnormalities or indication of infection. All dogs were treated with fenbendazole for 10–30 days. Neurological signs disappeared completely in five dogs, 11 dogs continued to show neurological signs, and five dogs deteriorated and were euthanized, after which necropsy was performed in three. At necropsy no evidence of an E. cuniculi infection was found. We concluded that, although IgM titers and PCR indicated an E. cuniculi infection, it is most likely of limited clinical significance in young dogs.

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.

Encephalitozoon cuniculi was first recognized as the disease agent in rabbits in 1922. The genotype of E. cuniculi isolated from laboratory rabbits with the neurologic disease was described as genotype I. In the eye, this parasite causes damage to the lens, causing phacoclastic uveitis and cataracts. Intraocular infection often occurs in cases of transplacental transmission. There has been no report on the molecular diagnosis of the parasite in Turkey. The current study is the first report on the detection of E. cuniculi spores using the molecular method in Turkey. In our previous study, a rabbit breeding facility was determined seropositive for E. cuniculi infection monitored for five years in terms of clinical symptoms. An autopsy was performed for a definite diagnosis of the infection. Samples were stained according to the hematoxylin-eosin (H&E) staining after tissue processing procedure and histopathologic analysis was performed. In addition to, the samples for DNA extraction were also taken during the autopsy. ECUNF and ECUNR species-specific primer pairs were used for amplification and genotyping of E. cuniculi. The animals were observed no clinical symptoms except ocular lesion (n=9). Therefore, one of these rabbits was used in the autopsy to definite diagnosis and determination of the damage to the eye. As histopathological, the lesions in the eye were found in the initial or middle stage of progressive infection. The DNA sequence showed that E. cuniculi examined in the present study were genotype I. Possible cause of the visible white mass in the rabbit"s eye may be the parasite infection. Therefore, clinicians may consider E. cuniculi as one of the possible causes of ocular lesions in rabbits during daily inspection or ophthalmological examination.

Two 3 year-old, healthy, client-owned Lop rabbits presented with bilateral cataracts. After performing a physical examination, bloodwork, ocular ultrasonography and electroretinography, both animals were deemed good surgical candidates for phacoemulsification. Bilateral cataract surgery was performed and both rabbits regained vision in both eyes. Both animals developed post-operative ocular hypertension and one animal developed corneal ulcers immediately after surgery. Both surgical complications resolved with medical management. This case series describes phacoemulsification of bilateral cataracts in 2 companion rabbits and the use of an intraocular lens in 1 rabbit. Surgical treatment of cataracts can be considered as a treatment option whenever a healthy rabbit is visually impaired due to cataracts.

Background: Encephalitozoon cuniculi can affect a number of animals. Currently, there is limited clinical information on E. cuniculi in guinea pigs. Case description: A 3-year-old guinea pig with torticollis, dehydration, and hypothermia was brought to the clinic. After symptomatic treatment, the animal's status improved, and the animal returned home. Two computed tomography scans over a period of 23 days revealed oval hypodense lesions in the right temporal lobe, which enlarged over time. The animal was euthanized. A histopathological examination revealed focal granulomatous encephalitis, and PCR allowed the detection of E. cuniculi DNA in the brain tissue. It was found that the possible cause of the disease was E. cuniculi invasion. Conclusions: Based on this report, E. cuniculi should be considered a differential in guinea pigs with granulomatous encephalitis. [ABSTRACT FROM AUTHOR]

Objective: The aim of this study is to investigate the seroprevalence of Encephalitozoon cuniculi infection in rabbits in facilities with different care conditions in three different provinces. Methods: The sera samples of rabbits that have been hosted in open, semi-open and controlled areas which were obtained from three different enterprises with different environmental possibilities, hygienic situations, maintenance and feeding conditions were evaluated by using the ELISA kits. Results: Consequently, the seropositivity of the rabbits in open, semi-open and controlled shelters were found to be 70%, 40% and 80%, respectively. In this study, in the rabbit under the different care conditions, antibodies anti - E. cuniculi (63.3%) were found in all sera samples. Conclusion: In the context of the data obtained, it was seen that the animals taken into the facility may be infected from the beginning and an infected animal in the facility may have been a source of infection for the many others in the facility. It was also concluded that the septic and aseptic rules which are potentially accepted in the facilties are not enough in battling with the agent and that the zoonotic disease can be a risk for animal keepers and researchers. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is a microsporidian that infects rabbits resulting in a varied pathology of the nervous, renal, and ocular tissues. Serology based studies using different methods have been conducted indicating a high seroprevalence worldwide in pet rabbits. While qualitative results are not especially helpful in the diagnosis of this infection, quantitative titers can have increased predictive value. In the current study, results of enzyme-linked immunosorbent assay (ELISA) and immunofluorescence test methods were compared using banked samples from rabbits with confirmed infection and clinically normal rabbits. Pearson's analysis found good and significant correlation (R = 0.56, P = 0.0002). Bland Altman analysis demonstrated the methods were similar but not equivalent. The sensitivity ranged from 0.79 to 0.84 and the specificity was 1.00 for both assays. Anti- E. cuniculi IgM titers were also determined by ELISA to be an independent measure from IgG (R = 0.31, P = 0.06) with a sensitivity of 0.24 and specificity of 1.00. In total, these results confirm an agreement in the detection of IgG antibody by two different methods conducted at laboratories in the United States and Austria that are involved in research and clinical diagnostic testing of this agent. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is a unicellular, spore-forming, obligate intracellular eukaryote belonging to the phylum Microsporidia. It is known to infect mainly immunocompromised and immunocompetent mammals, including humans. The parasite–host relationship has been evaluated using both in vitro cell culturing and animal models. For example, Balb/c and C57BL/6 mouse strains have been used interchangeably, although the latter has been considered more susceptible due to the higher fungal load observed after infection. In the present study, we identified the characteristics of the immune response of C57BL/6 mice treated or not with the immunosuppressant cyclophosphamide (Cy) and challenged with E. cuniculi by intraperitoneal route. After 14 days of infection, serum was collected to analyze Th1, Th2, and Th17 cytokine levels. In addition, peritoneal washes were performed, and the spleen sample was collected for immune cell phenotyping, whereas liver, spleen, kidney, lung, intestine, and central nervous system (CNS) samples were collected for histopathological analysis. Although infected mice displayed a reduced absolute number of macrophages, they showed an M1 profile, an elevated number of CD4+T, CD8+T, B-1, and B-2 lymphocytes, with a predominance of Th1 inflammatory cytokines (interferon [IFN]-γ, tumor necrosis factor [TNF]-α, and interleukin [IL]-2) and Th17. Furthermore, Cy-Infected mice showed a reduced absolute number of macrophages with an M1 profile but a reduced number of CD4+T, CD8+T, B-1, and B-2 lymphocytes, with a predominance of Th1 inflammatory cytokines (IFN-γ, TNF-α, and IL-2) and Th2 (IL-4). This group displayed a higher fungal burden as well and developed more severe encephalitozoonosis, which was associated with a reduced number of T and B lymphocytes and a mixed profile of Th1 and Th2 cytokines. [Display omitted] • E. cuniculi infection determined clinical signs and inflammatory infiltrate in liver. • E. cuniculi infection reduced the macrophage population and Cy modified its profile. • Cy-Infected mice had reduced T and B lymphocytes. • Increased inflammatory cytokines in infected mice. • C57BL/6 mice showed a difference in macrophage population compared to Balb/c mice. [ABSTRACT FROM AUTHOR]

This study aimed to investigate pathology of oral E. cuniculi infection during pregnancy in pregnant mice and embryos. A total of 40 pregnant mice at first day of gestation were divided into two groups, first group were infected orally by E. cuniculi sores of 107 spores/ mice, second group left without any treatment. At 18th days of gestation all pregnant mice were euthanized. Gross pathology finding in pregnant mice of infected group included congestion of liver and lung, the embryos lesions consisted from enlargement of head and abdomen. Histological lesions in pregnant mice of infected group consisted of hepatic non-suppurative granulomatous lesions with E. cuniculi spores aggregation with lymphocytic infiltration, the lungs lesions consisted of infiltration of lymphocytes with E. cuniculi spores, kidney lesions composed from degenerative and necrotic changes in renal tubules, brain lesions consisted from lymphocytic infiltration with increase in number of glial cells, while intestine tissue sections showed hyperplasia of lymphatic tissue with present of parasitic vacuoles at tips of villi, the placenta exhibited E. cuniculi spores with hyperplasia of trophoblast in chorionic villi, while histological lesions in embryos showed lymphocytic infiltration around alveoli with hyperplasia of lymphatic tissue around bronchioles with absent the normal architecture of hepatic cords and vacuolation of hepatocytes with hyperplasia of lymphocytes in white pulp of spleen. This study provides insight into the pathology of E. cuniculi infection in pregnant mice and their embryos, also supports the hypothesis of intrauterine transmission of E. cuniculi infection to embryos during pregnancy period.

This study aimed to investigate pathology of oral E. cuniculi infection during pregnancy in pregnant mice and embryos. A total of 40 pregnant mice at first day of gestation were divided into two groups, first group were infected orally by E. cuniculi sores of 107 spores/ mice, second group left without any treatment. At 18th days of gestation all pregnant mice were euthanized. Gross pathology finding in pregnant mice of infected group included congestion of liver and lung, the embryos lesions consisted from enlargement of head and abdomen. Histological lesions in pregnant mice of infected group consisted of hepatic non-suppurative granulomatous lesions with E. cuniculi spores aggregation with lymphocytic infiltration, the lungs lesions consisted of infiltration of lymphocytes with E. cuniculi spores, kidney lesions composed from degenerative and necrotic changes in renal tubules, brain lesions consisted from lymphocytic infiltration with increase in number of glial cells, while intestine tissue sections showed hyperplasia of lymphatic tissue with present of parasitic vacuoles at tips of villi, the placenta exhibited E. cuniculi spores with hyperplasia of trophoblast in chorionic villi, while histological lesions in embryos showed lymphocytic infiltration around alveoli with hyperplasia of lymphatic tissue around bronchioles with absent the normal architecture of hepatic cords and vacuolation of hepatocytes with hyperplasia of lymphocytes in white pulp of spleen. This study provides insight into the pathology of E. cuniculi infection in pregnant mice and their embryos, also supports the hypothesis of intrauterine transmission of E. cuniculi infection to embryos during pregnancy period.

Eukaryotic pre-mRNA is processed by a large multiprotein complex to accurately cleave the 3' end, and to catalyse the addition of the poly(A) tail. Within this cleavage and polyadenylation specificity factor (CPSF) machinery, the CPSF73/CPSF3 endonuclease subunit directly contacts both CPSF100/CPSF2 and the scaffold protein Symplekin to form a subcomplex known as the core cleavage complex or mammalian cleavage factor. Here we have taken advantage of a stable CPSF73-CPSF100 minimal heterodimer from Encephalitozoon cuniculi to determine the solution structure formed by the first and second C-terminal domain (CTD1 and CTD2) of both proteins. We find a large number of contacts between both proteins in the complex, and notably in the region between CTD1 and CTD2. A similarity is also observed between CTD2 and the TATA-box binding protein (TBP) domains. Separately, we have determined the structure of the terminal CTD3 domain of CPSF73, which also belongs to the TBP domain family and is connected by a flexible linker to the rest of CPSF73. Biochemical assays demonstrate a key role for the CTD3 of CPSF73 in binding Symplekin, and structural models of the trimeric complex from other species allow for comparative analysis and support an overall conserved architecture.

Microsporidia are opportunistic pathogens that infect a wide range of invertebrates and vertebrates. To assess the potential role of dogs in the transmission of these zoonotic pathogens, a total of 282 fecal samples from dogs in the Central Anatolia Region of Turkey were analyzed by utilizing species specific polymerase chain reaction for the four most frequent human microsporidia. Two microsporidia species were recognized in 41 samples (14.5%). Encephalitozoon intestinalis was detected in 35 samples (12.4%) and it was the most common microsporidium. The second microsporidium, E. cuniculi, was identified in six (2.1%) of the samples. Sequence analysis of the intergenic spacer of the ribosomal ribonucleic acid (RNA) internal transcribed spacer (ITS) gene revealed the presence of three E. intestinalis haplotypes closely associated with each other. No polymorphic region was found among the ITS sequences of E. cuniculi isolates and they were characterized as genotype III. This study provides the first data on the zoonotic microsporidia species from dogs in Turkey. [ABSTRACT FROM AUTHOR]

Encephalitozoon cuniculi is an obligate macrophage parasite of vertebrates that commonly infects rodents, monkeys, dogs, birds, and humans. In the present study, we aimed to assess the phagocytosis and intracellular survival of E. cuniculi spores using untreated and lipopolysaccharide (LPS)-activated J774A.1 murine macrophages and assess the macrophage viability. The experimental groups comprised untreated spores, spores killed by heat treatment at 90 °C, and spores killed by treatment with 10% formalin. LPS-activated macrophages significantly increased the phagocytosis of spores and reduced their intracellular growth after 24 and 48 h (P < 0.01); however, after 72 h, we observed an increase in spore replication but no detectable microbicidal activity. These results indicate that LPS activation enhanced E. cuniculi phagocytosis between 24 and 48 h of treatment, but the effect was lost after 72 h, enabling parasitic growth. This study contributes to the understanding of the phagocytosis and survival of E. cuniculi in murine macrophages. [ABSTRACT FROM AUTHOR]