Latent Microsporidial Infection in Immunocompetent Individuals – A Longitudinal Study

Microsporidia are a group of obligate intracellular parasitic fungi that have risen over the past two decades from obscure organisms to well recognized human pathogens. Out of 14 species reported to infect humans and causing more severe symptoms in immunocompromised individuals, microsporidia of the species Encephalitozoon and Enterocytozoon bieneusi are the most frequent causes of life-threatening chronic diarrhea and systemic disease in HIV patients and acute, self-limited diarrhea in immunocompetent persons. Although the diagnosis and clinical management of microsporidiosis cases have improved significantly recently, the epidemiology of human microsporidiosis is still unclear. To identify the occurrence of latent microsporidia infections in apparently healthy people, the authors tested sera, urine and stool originating from fifteen persons within a three month period. They found specific antibodies against microsporidia in sera originating from fourteen individuals, and using molecular tools, they detected microsporidial infection intermittently in all tested people. The presence of detectable amounts of microsporidial spores demonstrated that exposure to microsporidia is more common than previously believed and microsporidiosis is not linked to any clinical manifestations in healthy people. This finding should make the clinician more aware of the risk of this unapparent infection, its potential reactivation after immunosupression and consequences leading to life-threatening disease

Efekt Bisfenolu S a Bisfenolu A na morfometrické parametry štítné žlázy, změny hormonů a koncentrace jodu v moči potkanů Wistar

Bisphenol S (BPS) is the major substitute of the endocrine disruptor bisphenol A (BPA). Due to the presence of strong double bonds, BPS is more resistant to biodegradation and therefore more BPS remains in the environment. Numerous studies show that BPS disrupts the reproductive, nervous, and cardiovascular systems and could have an impact on thyroid hormones. The study aimed to analyze the effects of a 10-week exposition of BPS and BPA on lipid markers, morphometric parameters of the rat thyroid gland, the thyroid stimulating hormone (TSH) levels and the influence of BPS on urine iodine concentration. Male Wistar rats received BPS in sunflower oil daily by gavage. The control group (GI) received only the vehicle. The BPS experimental group two (GII) received 4 ug/kg/day, group three (GIII) received 50 ug/kg/day, and group four (GIV) received 100 mg BPS/kg/day. Group five (GV) received 100 mg BPA/kg/day. Groups four and five were made to compare the influence of high concentration between BPS and BPA. Results show the influence of BPS and BPA on body weight, triacylglycerols, cholesterol and total protein concentration. Morphometric changes in the size of thyroid gland follicles show a bigger influence of BPS than BPA. Results show also increasing in TSH concentrations in all groups with bisphenols up to physiology standards of Wistar rats (GI 3.14 ± 1.28 ng/ml, GII 5.12 ± 1.16 ng/ml, GIII 5.55 ± 2.39 ng/ml, GIV 5.56 ± 1.98 ng/ml, GV 4.47 ± 1.09 ng/ml) and influence of BPA and BPS on higher iodine concentrations in urine.Bisfenol S (BPS) je hlavní náhradou endokrinního disruptoru bisfenolu A (BPA). Díky přítomnosti silných dvojných vazeb je BPS odolnější vůči biologickému rozkladu, a proto zůstává více v prostředí. Četné studie ukazují, že BPS narušuje reprodukční, nervový a kardiovaskulární systém a může mít vliv na hormony štítné žlázy. Cílem studie bylo analyzovat účinky 10 týdenní expozice BPS a BPA na lipidové markery, morfometrické parametry štítné žlázy potkana, hladiny tyreoidálního stimulačního hormonu (TSH) a vliv BPS na koncentraci jódu v moči. Samci potkanů Wistar dostávali BPS ve slunečnicovém oleji denně jícnovou sondou. Kontrolní skupina (GI) obdržela pouze nosič. Experimentální skupina dvě (GII) dostávala 4 ug BPS/kg/den, skupina tři (GIII) dostávala 50 ug BPS/kg/den, skupina čtyři (GIV) dostávala 100 mg BPS/kg/den. Skupina pět (GV) dostávala 100 mg BPA/kg/den. Čtvrtá a pátá skupina byly vytvořeny pro porovnání vlivu vysoké koncentrace BPS a BPA. Výsledky ukazují vliv BPS a BPA na tělesnou hmotnost, triacylglyceroly, cholesterol a celkovou koncentraci bílkoviny. Morfometrické změny velikosti folikulů štítné žlázy vykazují větší vliv BPS než BPA. Výsledky také ukazují zvýšení koncentrací TSH ve všech skupinách s bisfenoly nad fyziologické standardy potkanů Wistar (GI 3,14 ± 1,28 ng/ml, GII 5,12 ± 1,16 ng/ml, GIII 5,55 ± 2 ,39 ng/ml, GIV 5,56 ± 1,98 ng/ml, GV 4,47 ± 1,09 ng/ml) a vliv BPA a BPS na zvýšené koncentrace jódu v moči

The First Evidence of Cryptosporidium meleagridis Infection in a Colon Adenocarcinoma From an Immunocompetent Patient

Objectives: The potential linkage between Cryptosporidium spp. infection and colorectal human cancer was suggested by limited reports showing higher prevalence of C. parvum and C. hominis in patients with colon cancer. Here we conducted research concerning presence of Cryptosporidium spp. in malignant tissue collected from patients with colorectal cancer.Methods: Cancerous colon tissue samples collected from 145 non-HIV infected patients with colorectal cancer were screened for Cryptosporidium spp. by immunofluorescence antibody test and genus-specific nested polymerase chain reaction followed by sequencing.Results: Screened pathogen was found in cancerous tissue originating from immunocompetent man with colon adenocarcinoma. Genotyping revealed presence of Cryptosporidium meleagridis. The presence of Cryptosporidium life cycle stages (oocysts and endogenous stages) in colon carcinoma tissue was confirmed by genus-specific FITC-labeling.Conclusions: Herein, we report on a C. meleagridis infection of a colon adenocarcinoma in an immunocompetent patient. This is the first report of C. meleagridis infection in the human colon and first evidence of active development of this species in cancer tissue

More than a rabbit's tale – Encephalitozoon spp. in wild mammals and birds

Within the microsporidian genus Encephalitozoon, three species, Encephalitozoon cuniculi, Encephalitozoon hellem and Encephalitozoon intestinalis have been described. Several orders of the Class Aves (Passeriformes, Psittaciformes, Apodiformes, Ciconiiformis, Gruiformes, Columbiformes, Suliformes, Podicipediformes, Anseriformes, Struthioniformes, Falconiformes) and of the Class Mammalia (Rodentia, Lagomorpha, Primates, Artyodactyla, Soricomorpha, Chiroptera, Carnivora) can become infected. Especially E. cuniculi has a very broad host range while E. hellem is mainly distributed amongst birds. E. intestinalis has so far been detected only sporadically in wild animals. Although genotyping allows the identification of strains with a certain host preference, recent studies have demonstrated that they have no strict host specificity. Accordingly, humans can become infected with any of the four strains of E. cuniculi as well as with E. hellem or E. intestinalis, the latter being the most common. Especially, but not exclusively, immunocompromised people are at risk. Environmental contamination with as well as direct transmission of Encephalitozoon is therefore highly relevant for public health. Moreover, endangered species might be threatened by the spread of pathogens into their habitats. In captivity, clinically overt and often fatal disease seems to occur frequently. In conclusion, Encephalitozoon appears to be common in wild warm-blooded animals and these hosts may present important reservoirs for environmental contamination and maintenance of the pathogens. Similar to domestic animals, asymptomatic infections seem to occur frequently but in captive wild animals severe disease has also been reported. Detailed investigations into the epidemiology and clinical relevance of these microsporidia will permit a full appraisal of their role as pathogens

Latent microsporidiosis caused by Encephalitozoon cuniculi in immunocompetent hosts: a murine model demonstrating the ineffectiveness of the immune system and treatment with albendazole.

BACKGROUND: Microsporidia are obligate intracellular parasites causing severe infections with lethal outcome in immunocompromised hosts. However, these pathogens are more frequently reported as latent infections in immunocompetent individuals and raises questions about the potential risk of reactivation following induced immunosuppression. AIMS: To evaluate the possibility latent microsporidiosis, efficacy or albendazole, and reactivation, the authors monitored the course of E. cuniculi infection in immunocompetent BALB/c mice and immunodeficient SCID mice using molecular methods. METHODS: Mice were per orally infected with 10(7) spores of E. cuniculi. Selected groups were treated with albendazole, re-infected or chemically immunosuppressed by dexamethasone. The presence of microsporidia in the host's organs and feces were determined using PCR methods. Changes in numbers of lymphocytes in blood and in spleen after induction of immunosuppression were confirmed using flow cytometry analysis. RESULTS: Whereas E. cuniculi caused lethal microsporidiosis in SCID mice, the infection in BABL/c mice remained asymptomatic despite parasite dissemination into many organs during the acute infection phase. Albendazole treatment led to microsporidia elimination from organs in BALB/c mice. In SCID mice, however, only a temporary reduction in number of affected organs was observed and infection re-established post-treatment. Dexamethasone treatment resulted in a chronic microsporidia infection disseminating into most organs in BALB/c mice. Although the presence of E. cuniculi in organs of albendazole- treated mice was undetectable by PCR, it was striking that infection was reactivated by immunosuppression treatment. CONCLUSION: Our results demonstrated that microsporidia can successfully survive in organs of immunocompetent hosts and are able to reactivate from undetectable levels and spread within these hosts after induction of immunosuppression. These findings stress the danger of latent microsporidiosis as a life-threatening risk factor especially for individuals undergoing chemotherapy and in transplant recipients of organs originating from infected donors

Intestinal parasites of dogs (Canis lupus familiaris) in Svalbard (Norway): Low prevalence and limited transmission with wildlife

The domesticated dogs (Canis lupus familiaris Linnaeus, 1758) are widely kept on all continents and could share the parasites with free-living animals. To understand the transmission of intestinal parasites between dogs kept on the four dog stations and wildlife in Svalbard, 170 faecal samples of dogs and 203 of wildlife included arctic fox (Vulpes lagopus Linnaeus, 1758, n=62); Svalbard reindeer (Rangifer tarandus platyrhynchus Vrolik, 1829, n=106); sibling vole (Microtus levis Miller, 1908, n=63); pink-footed goose (Anser brachyrhynchus Baillon, 1834, n=30); little auk (Alle alle Linnaeus, 1758, n=49) and black-legged kittiwake (Risa tridactyla Linnaeus, 1758, n=18) were individually screened for the presence of intestinal parasites using microscopy and PCR/sequencing methods. Additionally, the results of the study were compared with previous studies performed in the same area. Roundworm Toxascaris leonina Linstow, 1902 was found microscopically and by PCR in a dog (n=1). The specific DNA of three species of parasitic protists was detected in dogs from different yards. Phylogenetic analyses revealed the presence of Cryptosporidium canis Fayer, Trout, Xiao, Morgan, Lal and Dubey, 2001 (n=1), Encephalitozoon cuniculi Levaditi, Nicolau and Schoen, 1923 genotype II (n=4) and dog specific Enterocytozoon bieneusi Desportes, Le Charpentier, Galian, Bernard, Cochand-Priollet, Lavergne, Ravisse and Modigliani, 1985 genotypes (n=12). This study showed overall a low prevalence of intestinal parasites in dogs in Svalbard and possible but minimal transmission with wildlife.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

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

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