A comparative analysis of blood and faecal-based laboratory methods in the diagnosis of extraintestinal microsporidia infection.

Diagnosis of extraintestinal microsporidiosis is always hampered due to non-specific symptoms and difficulty in diagnosis. This study aimed to compare the diagnostic utility of blood and faecal-based polymerase chain reaction (PCR) to detect microsporidiosis in immunocompromised patients. A total of 42 immunocompromised patients consisting of HIV-infected and chemotherapy-treated patients were enrolled. Paired faecal and blood samples were collected and subjected to PCR to detect Enterocytozoon bieneusi and Encephalitozoon spp. Faecal samples were microscopically screened for microsporidia spores. Overall, 42.9% (18/42) of patients were positive for microsporidiosis. Of this, 19.0% (8/42) and 4.8% (2/42) were positive by blood and stool PCR respectively. Meanwhile, 33.3% (14/42) of the faecal specimens were microscopically positive. Among the positive patients, 22.2% (4/18) had microsporidia confirmed by blood PCR and stool microscopy, suggestive of dissemination. Interestingly, the stool specimen in which microsporidia spores were detected via microscopy is not positive via PCR method. This highlights the limitation of the faecal-based detection method and the important use of blood samples for diagnosing extraintestinal microsporidiosis. Only E. bieneusi species were detected in all PCR-positive samples. This study highlights the diagnostic value of blood PCR in diagnosing extraintestinal microsporidiosis infections.

Study on intestinal parasitic infections and gut microbiota in cancer patients at a tertiary teaching hospital in Malaysia.

Intestinal parasitic infections (IPIs) can lead to significant morbidity and mortality in cancer patients. While they are unlikely to cause severe disease and are self-limiting in healthy individuals, cancer patients are especially susceptible to opportunistic parasitic infections. The gut microbiota plays a crucial role in various aspects of health, including immune regulation and metabolic processes. Parasites occupy the same environment as bacteria in the gut. Recent research suggests intestinal parasites can disrupt the normal balance of the gut microbiota. However, there is limited understanding of this co-infection dynamic among cancer patients in Malaysia. A study was conducted to determine the prevalence and relationship between intestinal parasites and gut microbiota composition in cancer patients. Stool samples from 134 cancer patients undergoing active treatment or newly diagnosed were collected and examined for the presence of intestinal parasites and gut microbiota composition. The study also involved 17 healthy individuals for comparison and control. Sequencing with 16S RNA at the V3-V4 region was used to determine the gut microbial composition between infected and non-infected cancer patients and healthy control subjects. The overall prevalence of IPIs among cancer patients was found to be 32.8%. Microsporidia spp. Accounted for the highest percentage at 20.1%, followed by Entamoeba spp. (3.7%), Cryptosporidium spp. (3.0%), Cyclospora spp. (2.2%), and Ascaris lumbricoides (0.8%). None of the health control subjects tested positive for intestinal parasites. The sequencing data analysis revealed that the gut microbiota diversity and composition were significantly different in cancer patients than in healthy controls (p < 0.001). A significant dissimilarity was observed in the bacterial composition between parasite-infected and non-infected patients based on Bray-Curtis (p = 0.041) and Jaccard (p = 0.021) measurements. Bacteria from the genus Enterococcus were enriched in the parasite-infected groups, while Faecalibacterium prausnitzii reduced compared to non-infected and control groups. Further analysis between different IPIs and non-infected individuals demonstrated a noteworthy variation in Entamoeba-infected (unweighted UniFrac: p = 0.008), Cryptosporidium-infected (Bray-Curtis: p = 0.034) and microsporidia-infected (unweighted: p = 0.026; weighted: p = 0.019; Jaccard: p = 0.031) samples. No significant dissimilarity was observed between Cyclospora-infected groups and non-infected groups. Specifically, patients infected with Cryptosporidium and Entamoeba showed increased obligate anaerobic bacteria. Clostridiales were enriched with Entamoeba infections, whereas those from Coriobacteriales decreased. Bacteroidales and Clostridium were found in higher abundance in the gut microbiota with Cryptosporidium infection, while Bacillales decreased. Additionally, bacteria from the genus Enterococcus were enriched in microsporidia-infected patients. In contrast, bacteria from the Clostridiales order, Faecalibacterium, Parabacteroides, Collinsella, Ruminococcus, and Sporosarcina decreased compared to the non-infected groups. These findings underscore the importance of understanding and managing the interactions between intestinal parasites and gut microbiota for improved outcomes in cancer patients.

Isolation and Identification of Nematode-Infecting Microsporidia.

Nematodes are naturally infected by the fungal-related pathogen microsporidia. These ubiquitous eukaryotic parasites are poorly understood, despite infecting most types of animals. Identifying novel species of microsporidia and studying them in an animal model can expedite our understanding of their infection biology and evolution. Nematodes present an excellent avenue for pursuing such work, as they are abundant in the environment and many species are easily culturable in the laboratory. The protocols presented here describe how to isolate bacterivorous nematodes from rotting substrates, screen them for microsporidia infection, and molecularly identify the nematode and microsporidia species. Additionally, we detail how to remove environmental contaminants and generate a spore preparation of microsporidia from infected samples. We also discuss potential pitfalls and provide suggestions on how to mitigate them. These protocols allow for the identification of novel microsporidia species, which can serve as an excellent starting point for genomic analysis, determination of host specificity, and infection characterization. © 2024 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Gathering samples Support Protocol 1: Generating 10× and 40× Escherichia coli OP50 and seeding NGM plates Basic Protocol 2: Microsporidia screening, testing for Caenorhabditis elegans susceptibility, and sample freezing Basic Protocol 3: DNA extraction, PCR amplification, and sequencing to identify nematode and microsporidia species Basic Protocol 4: Removal of contaminating microbes and preparation of microsporidia spores Support Protocol 2: Bleach-synchronizing nematodes.

A novel neurotropic microsporidium from the swamp guppy Micropoecilia picta from Grenada, West Indies.

A novel microsporidium was observed in wild swamp guppies Micropoecilia picta from Levera Pond within Levera National Park Grenada, West Indies. Initial observations indicated similarity with Pseudoloma neurophilia, an important pathogen in zebrafish Danio rerio. P. neurophilia exhibit broad host specifity, including members of the family Poecillidae, and both parasites infect the central nervous system. However, spore morphology and molecular phylogeny based on rDNA showed that the swamp guppy microsporidium (SGM) is distinct from P. neurophilia and related microsporidia (Microsporidium cerebralis and M. luceopercae). Spores of the SGM were smaller than others in the clade (3.6 µm long). Differences were also noted in histology; the SGM formed large aggregates of spores within neural tissues along with a high incidence of numerous smaller aggregates and single spores within the surface tissue along the ventricular spaces that extended submeninx, whereas P. neurophilia and M. cerebralis infect deep into the neuropile and cause associated lesions. Analysis of small subunit ribosomal DNA sequences showed that the SGM was <93% similar to these related microsporidia. Nevertheless, one of 2 commonly used PCR tests for P. neurophilia cross reacted with tissues infected with SGM. These data suggest that there could be other related microsporidia capable of infecting zebrafish and other laboratory fishes that are not being detected by these highly specific assays. Consequently, exclusive use of these PCR tests may not accurately diagnose other related microsporidia infecting animals in laboratory and ornamental fish facilities.

Staining blindly: an update on coloring techniques for fecal smears in parasitology: a scoping review.

Dye application for parasite highlighting in the Ova and Parasite exam is a common practice in parasitology diagnosis. Methods: A scoping review investigated how staining solutions interact with parasite structures. After screening 1334 papers, 35 met eligibility criteria. Results: Differentiating background from foreground in the fecal smear under light microscopy is the core of the research on this topic. Refractivity, unevenness of staining, size and temperature were explored to enhance staining protocols. Cryptosporidium spp. and Microsporidia were the main studied species. Conclusion: Studies on diagnostic efficacy outperform those that elucidate the physical-chemical interaction between dyes and parasites. An alternative approach involves technicians using computational tools to reduce subjectivity in fecal smear interpretation, deviating from conventional methods.

What is this article about? Coloring parasites during fecal exams has been widely used to find parasites in human feces. We searched for articles that could help us to answer the question: 'How do dyes give color to parasites?'. Then, we filtered the information from a total of 1334 articles to 35.What were the results? Cryptosporidium spp. and Microsporidia are microbes that can be seen only through a microscope. Researchers were interested in these two species in the last 40 years. Differentiating parasites from dirt on a glass slide is the main problem researchers are trying to solve. The way the light goes through parasites under a microscope, variation of staining, size and temperature of dyes have been explored to identify what gives better results in coloring protocols.What do the results of the study mean? Little is known about the chemical interaction between dyes and parasites. On the other hand, there are many studies on how good coloring methods are and comparing protocols. An alternative to the conventional approaches in staining parasites is the use of computational tools to reduce doubt in the exam interpretation by technicians.

[MICROSPORIDIUM KERATITIS: A CASE SERIES].

INTRODUCTION: Microsporidia is a phylum of intracellular parasites that secrete spores and stay in water sources. These parasites can cause infection in humans by invading the digestive system, the urinary system, the muscular system and the eye. Recently, the Israeli Ministry of Health announced that dozens of people in Israel were suspected of being infected with microsporidial keratitis after bathing in the waters of the Kinneret (Sea of Galilee). Here we present a brief overview of this microsporidial keratitis as well as three case presentations.

Diagnostic Utility of CDC DPDx for an Atypical Presentation of Infectious Crystalline Keratopathy-Like Infiltrate Secondary to Microsporidia.

PURPOSE: To report a case of atypical infectious crystalline keratopathy-like stromal infection secondary to microsporidia wherein diagnosis of the causative organism was aided by use of the Center for Disease Control (CDC) DPDx program. METHODS: We report the case of a 73-year-old woman who presented with atypical infectious crystalline keratopathy-like corneal infection without previous surgical history. RESULTS: The patient had previously been treated for recalcitrant corneal infection with topical antibiotics and steroids at an outside provider before referral. Further treatment with topical fortified antibiotics failed to improve the infection. Corneal biopsy was performed and sent to the CDC DPDx for diagnostic confirmation for presumptive microsporidia. The patient underwent therapeutic penetrating keratoplasty without recurrence of ocular infection. CONCLUSIONS: Utilization of the DPDx resource may help guide appropriate and timely diagnosis and management strategies in atypical presentations of infectious keratitis.

Molecular phylogeny of heritable symbionts and microbiota diversity analysis in phlebotominae sand flies and Culex nigripalpus from Colombia.

BACKGROUND: Secondary symbionts of insects include a range of bacteria and fungi that perform various functional roles on their hosts, such as fitness, tolerance to heat stress, susceptibility to insecticides and effects on reproduction. These endosymbionts could have the potential to shape microbial communites and high potential to develop strategies for mosquito-borne disease control. METHODOLOGY/PRINCIPAL FINDINGS: The relative frequency and molecular phylogeny of Wolbachia, Microsporidia and Cardinium were determined of phlebotomine sand flies and mosquitoes in two regions from Colombia. Illumina Miseq using the 16S rRNA gene as a biomarker was conducted to examine the microbiota. Different percentages of natural infection by Wolbachia, Cardinium, and Microsporidia in phlebotomines and mosquitoes were detected. Phylogenetic analysis of Wolbachia shows putative new strains of Lutzomyia gomezi (wLgom), Brumptomyia hamata (wBrham), and a putative new group associated with Culex nigripalpus (Cnig) from the Andean region, located in Supergroup A and Supergroup B, respectively. The sequences of Microsporidia were obtained of Pi. pia and Cx. nigripalpus, which are located on phylogeny in the IV clade (terrestrial origin). The Cardinium of Tr. triramula and Ps. shannoni were located in group C next to Culicoides sequences while Cardinium of Mi. cayennensis formed two putative new subgroups of Cardinium in group A. In total were obtained 550 bacterial amplicon sequence variants (ASVs) and 189 taxa to the genus level. The microbiota profiles of Sand flies and mosquitoes showed mainly at the phylum level to Proteobacteria (67.6%), Firmicutes (17.9%) and Actinobacteria (7.4%). High percentages of relative abundance for Wolbachia (30%-83%) in Lu. gomezi, Ev. dubitans, Mi. micropyga, Br. hamata, and Cx. nigripalpus were found. ASVs assigned as Microsporidia were found in greater abundance in Pi. pia (23%) and Cx. nigripalpus (11%). An important finding is the detection of Rickettsia in Pi. pia (58,8%) and Bartonella sp. in Cx. nigripalpus. CONCLUSIONS/SIGNIFICANCE: We found that Wolbachia infection significantly decreased the alpha diversity and negatively impacts the number of taxa on sand flies and Culex nigripalpus. The Principal Coordinate Analysis (PCoA) is consistent, which showed statistically significant differences (PERMANOVA, F = 2.4744; R2 = 0.18363; p-value = 0.007) between the microbiota of sand flies and mosquitoes depending on its origin, host and possibly for the abundance of some endosymbionts (Wolbachia, Rickettsia).

Case Report: First Report of Disseminated Trachipleistophora hominis Infection in an AIDS Patient from Thailand.

Microsporidial myositis caused by Trachipleistophora hominis is a life-threatening and emerging microsporidiosis among immunocompromised hosts. This article reports a case of disseminated microsporidiosis caused by T. hominis in southern Thailand. The patient had HIV and presented at the clinic with incapacitating muscle pain. She was diagnosed with disseminated microsporidiosis. Molecular identification revealed the sequence of 18S ribosomal RNA gene involving sequences sharing 99% nucleotide identity with T. hominis from an Australian patient. To our knowledge, this is the first study to report the detection of T. hominis microsporidia in an HIV patient in Thailand.

Fatal disseminated Anncaliia algerae myositis mimicking polymyositis in an immunocompromised patient.

We report the first New Zealand case of Anncaliia algerae myositis in a 55-year-old man with a history of psoriatic arthritis, treated with long-term immunosuppressive therapy. He resided in the city of Rotorua, which is famous for geothermal hot springs. A vastus lateralis muscle biopsy was performed to investigate the cause of an unexplained myositis. Light microscopy demonstrated a necrotizing myositis with scattered clusters of ovoid spores within the myocyte cytoplasm resembling microsporidia. DNA analysis by PCR and electron microscopy confirmed microsporidial myositis with features characteristic of A. algerae. Immunosuppressive drugs were stopped and the patient was treated with cholestyramine wash and albendazole. The patient deteriorated with involvement of bulbar and respiratory muscles requiring intensive care and ventilation. He died 3 weeks after diagnosis. Post-mortem examination of skeletal muscle from tongue and intercostal muscles also revealed numerous organisms confirming disseminated disease.

Pathological conditions of the sentinel bivalve, the little mussel Brachidontes rodriguezii, from contaminated intertidal sites in the Southwestern Atlantic coast.

A survey of pathological conditions affecting the natural beds of the dominant bivalve species of the intertidal rocky coasts of the Southern Atlantic Ocean, was performed. Samples of the little mussel (n = 992), Brachidontes rodriguezii, which is considered a sentinel species, were collected from seven sites that present different anthropogenic activity (low anthropogenic activity, harbor, and sewage waste) along the Argentinean coast, and processed by standard histological techniques. Our results showed for the first time in a B. rodriguezii population from Mar del Plata harbor a bacterium causing cellular lysis of the spermatogenic cells (6.5% of prevalence) and in a population from Villa Gesell, a site with low anthropogenic activity, one little mussel presented cytoplasmic vacuoles in the oocytes's cytoplasm similar to a microsporidian (0.2% of prevalence). A ciliated protozoan parasitizing the cytoplasm of the epithelial digestive tubules and larval stages of two different digenean parasites, was found infecting the little mussel from both contaminated and uncontaminated sites. Sporocysts of the family Bucephalidae invaded the gonad, causing severe gonadal damage including castration, and gymnophallid metacercariae located between the mantle and shell or embedded in the mantle tissues, occupied the gonadal space. In Punta Carballido, a site located next to a sewage outfall, the highest prevalence of infection was found, for the ciliated protozoan in the digestive tubules (5.1%) and for the digenean parasites (bucephalid sporocyst 24.4%, and gymnophallid metacercariae 50%). Moreover, we found a positive correlation between shell length and overall prevalence of parasites.

Molecular epidemiology of Microsporidia among HIV-positive and HIV-negative patients in the Limpopo province, South Africa.

INTRODUCTION: Human microsporidiosis represents an important and rapidly emerging opportunistic disease. The present study investigated the prevalence of microsporidia among HIV positive and HIV negative patients with or without diarrhoea in Vhembe and Mopani Districts in the Limpopo Province. METHODOLOGY: A total of 170 stool samples were collected from these patients and microsporidia species was detected using a Real-Time PCR targeting a conserved region of the small ribosomal subunit rRNA (SSU-rRNA) gene of Enterocytozoon bieneusi, Encephalitozoon intestinalis, Encephalitozoon hellem, and Encephalitozoon cuniculi. RESULTS: Fifty six (32.9%) were positive for microsporidia. The prevalence was higher in HIV negative patients (36.6%) while 24.1% of patients who were HIV positive had microsporidia. Microsporidia was more common among patients aged between 1 and 10 years (52.6%). However among the HIV positive patients, microsporidia prevalence was higher among those that were not taking antiretrovirals (ARVs) compared to those who were on ARVs, (36.6%) and (24.1%), respectively. Microsporidia was also noted to be significantly associated with diarrheal and stomach pains; p = 0.02 and p = 0.048, respectively. Furthermore, microsporidia infections was more prevalent among patients who had animals at home (p = 0.037). CONCLUSIONS: Study has shown a high prevalence of microsporidia among patients attending primary health centers in the Mopani District for the first time. Prevalence of microsporidia was higher among HIV negative and HIV positive patients who were not on ARV treatment. Keeping animals in the household appeared to be a risk of getting infected with microsporidia. Further studies are needed to determine the genetic characteristics of these organisms in the study population.

Two parasites in one host: spatiotemporal dynamics and co-occurrence of Microsporidia and Rickettsia in an amphipod host.

Biological interactions can greatly influence the abundance of species. This is also true for parasitic species that share the same host. Microsporidia and Rickettsia are widespread intracellular parasites in populations of Paracalliope fluviatilis, the most common freshwater amphipods in New Zealand. Although both parasites coexist in many populations, it is unclear whether they interact with each other. Here, we investigated spatial−temporal dynamics and co-occurrence of the two parasites, Microsporidia and Rickettsia in P. fluviatilis hosts, across one annual cycle and in three different locations. Prevalence of both Microsporidia and Rickettsia changed over time. However, while the prevalence of Rickettsia varied significantly between sampling times, that of Microsporidia did not change significantly and remained relatively low. The two parasites therefore followed different temporal patterns. Also, the prevalence of both parasites differed among locations, though the two species reached their highest prevalence in different locations. Lastly, there was no evidence for positive or negative associations between the two parasite species; the presence of one parasite in an individual host does not appear to influence the probability of infection by the other parasite. Their respective prevalence may follow different patterns among populations on a larger spatial scale due to environmental heterogeneity across locations.

The largest meta-analysis on the global prevalence of microsporidia in mammals, avian and water provides insights into the epidemic features of these ubiquitous pathogens.

BACKGROUND: Microsporidia are obligate intracellular parasites that can infect nearly all invertebrates and vertebrates, posing a threat to public health and causing large economic losses to animal industries such as those of honeybees, silkworms and shrimp. However, the global epidemiology of these pathogens is far from illuminated. METHODS: Publications on microsporidian infections were obtained from PubMed, Science Direct and Web of Science and filtered according to the Newcastle-Ottawa Quality Assessment Scale. Infection data about pathogens, hosts, geography and sampling dates were manually retrieved from the publications and screened for high quality. Prevalence rates and risk factors for different pathogens and hosts were analyzed by conducting a meta-analysis. The geographic distribution and seasonal prevalence of microsporidian infections were drawn and summarized according to sampling locations and date, respectively. RESULTS: Altogether, 287 out of 4129 publications up to 31 January 2020 were obtained and met the requirements, from which 385 epidemiological data records were retrieved and effective. The overall prevalence rates in humans, pigs, dogs, cats, cattle, sheep, nonhuman primates and fowl were 10.2% [2429/30,354; 95% confidence interval (CI) 9.2-11.2%], 39.3% (2709/5105; 95% CI 28.5-50.1%), 8.8% (228/2890; 95% CI 5.1-10.1%), 8.1% (112/1226; 95% CI 5.5-10.8%), 16.6% (2216/12,175; 95% CI 13.5-19.8%), 24.9% (1142/5967; 95% CI 18.6-31.1%), 18.5% (1388/7009; 95% CI 13.1-23.8%) and 7.8% (725/9243; 95% CI 6.4-9.2%), respectively. The higher prevalence in pigs suggests that routine detection of microsporidia in animals should be given more attention, considering their potential roles in zoonotic disease. The highest rate was detected in water, 58.5% (869/1351; 95% CI 41.6-75.5%), indicating that water is an important source of infections. Univariate regression analysis showed that CD4+ T cell counts and the living environment are significant risk factors for humans and nonhuman primates, respectively. Geographically, microsporidia have been widely found in 92 countries, among which Northern Europe and South Africa have the highest prevalence. In terms of seasonality, the most prevalent taxa, Enterocytozoon bieneusi and Encephalitozoon, display different prevalence trends, but no significant difference between seasons was observed. In addition to having a high prevalence, microsporidia are extremely divergent because 728 genotypes have been identified in 7 species. Although less investigated, microsporidia coinfections are more common with human immunodeficiency virus and Cryptosporidium than with other pathogens. CONCLUSIONS: This study provides the largest-scale meta-analysis to date on microsporidia prevalence in mammals, birds and water worldwide. The results suggest that microsporidia are highly divergent, widespread and prevalent in some animals and water and should be further investigated to better understand their epidemic features.

MICROSPORIDIA-ASSOCIATED GRANULOMATOUS DISEASE IN TWO AUSTRALIAN COLLECTIONS OF CAPTIVE INLAND BEARDED DRAGONS (POGONA VITTICEPS).

Microsporidia are obligate, intracellular fungi. In reptiles, they are most commonly reported in squamates. We report the first detection of microsporidiosis in inland bearded dragons (Pogona vitticeps) from Australia, and for the first time, mixed infections of microsporidium and adenovirus in asymptomatic inland bearded dragons. In one collection there were five individuals, one of which was lethargic, inappetent, and had lost weight. Two large ovarian granulomas were palpated (42 × 23 mm and 26 × 19 mm) and were surgically removed. This animal died shortly after surgery. Histological evaluation of these granulomas revealed granulomatous inflammation within or adjacent to ovarian tissue, containing numerous aggregates of microorganisms consistent with microsporidia. The organisms were confirmed as Encephalitozoon pogonae by polymerase chain reaction (PCR) and sequencing. Agamid adenovirus-1 was also detected. These two infectious agents were also detected by PCR in all the other bearded dragons in this collection (n = 5), all of which were asymptomatic. A single dragon from a second collection presented for a routine wellness examination after the sudden death of another dragon in the collection. This dragon had similar intracelomic masses to the dragon from the first collection. These were removed surgically, but the dragon died 5 wk later following 3 wk of treatment with 25 mg/kg fenbendazole PO q7 days. Necropsy samples were collected and the microsporidian Encephalitozoon pogonae was detected in oral-cloacal swabs, blood, and multiple tissues by PCR and sequencing. Agamid adenovirus-1 was not detected in this dragon.

Investigation of Intestinal Protozoon Prevalence in Immunocompromised Patients at a University Hospital

Objective: Immunocompromised patients are at a greater risk of developing intestinal parasite infections. In this study, we examined the presence of Enterocytozoon bieneusi, Encaphalitozoon intestinalis and other intestinal protozoa in stool samples of immunosuppressed patients. Methods: A total of 100 stool samples were obtained from patients receiving chemotherapy because of solid organ tumour with haematological malignancies and those receiving immunosuppressive treatment because of rheumatic diseases, organ transplant patients and patients receiving treatment for HIV-related infections. Stool samples were examined by using the native-lugol method in which the stool concentration, modified Kinyoun acid-fast and trichrome staining methods and parasite presence were analysed. The stool samples were also examined for the presence of Enterocytozoon bieneusi and Encephalitozoon intestinalis using an indirect fluorescent antibody method. Results: Intestinal parasites were detected in 12% of all patients. The distribution of intestinal parasites in patients were 7% Blastocystis spp., 2% Blastocystis spp. + Dientamoeba fragilis, 1% Blastocystis spp. + Entamoeba coli, 1% Blastocystis spp. + Giardia intestinalis and 1% G. intestinalis. Microsporidia spp. were detected in 4% of all patients by the IFAT method and in 8% of all patients by calcoflour staining method. Conclusion: In our study, the most prevalent parasite detected in the immunosuppressed patients was Blastocystis spp. The pathogenesis of Blastocystis spp. remains to be controversial, and their role in immunocompromised patients continues to remain unknown. Although these rates detected in our study are similar to the prevalence in the normal population, it is important to study these microorganisms in immunocompromised patients in terms of the associated decreasing morbidity and mortality rates.

Microsporidial Stromal Keratitis: Epidemiological Features, Slit-Lamp Biomicroscopic Characteristics, and Therapy.

PURPOSE: Microsporidial stromal keratitis is a rare form of infectious keratitis, with only 7 cases reported in the United States to date. This study was performed to evaluate risk factors, clinical features, and response to therapy. METHODS: A retrospective review of the medical records of all patients diagnosed with microsporidial stromal keratitis seen in the practices of the authors between 1999 and 2020 was performed. Diagnosis was determined by cytology or histopathology in corneal specimens. Risk factors, presence or absence of distinctive clinical features, and response to medical and surgical therapies were recorded. RESULTS: Nine patients-7M:2F, aged 7 to 99 years-with microsporidial stromal keratitis were identified. Exposures to recreational water and hymenopteran insect bites, both epidemiologically linked risk factors for systemic microsporidial infection, were identified in our patients. Presence of stromal edema with features of disciform keratitis and a distinctive granular keratitis were observed in 6 of 9 and 5 of 9 patients, respectively. Poor response to medical therapy was noted. Penetrating keratoplasty was effective in curing the infection. Final visual acuity was 20/40 or better in 6 of 9 patients. CONCLUSIONS: In patients with slowly progressive keratitis, history of exposure to recreational water or hymenopteran insects should be sought. In patients with corneal edema consistent with disciform keratitis, with evolution to a granular keratitis, microsporidia should be considered in the differential diagnosis. In cases of established microsporidial stromal keratitis, penetrating keratoplasty should be considered if prompt response to medical therapy is not noted.

The general architecture of black fly-parasite interactions: Parasitism in lotic systems at a continental scale.

We examined the general architecture of interactions between stream-dwelling larval black flies (Diptera: Simuliidae) and their common parasites in 1736 collections across North America. Mermithid nematodes (family Mermithidae), microsporidia (phylum Microsporidia), and the fungus Coelomycidium simulii Debaisieux (phylum Blastocladiomycota) infected larval black flies. We found similar continental distributions for these three parasite taxa across North America. At least one of these taxa was represented in 42.2% of all black fly collections. Species interactions in ecological networks typically imply that each link between species is equally important. By employing quantitative measures of host susceptibilities and parasite dependencies, we provide a more complete structure for host-parasite networks. The distribution of parasite dependencies and host susceptibilities were right-skewed, with low values indicating that most dependencies (parasites) and susceptibilities (hosts) were weak. Although regression analysis between host frequency and parasite incidence were highly significant, frequency analysis suggested that the distributions of parasites differ significantly among the four most common and closely related (same subgenus) species of hosts. A highly significant pattern of nestedness in our bipartite host-parasite network indicated that specialized parasites (i.e., those that interact with few host species) tend to occur as subsets of the most common hosts.

Prevalence of Microsporidiosis in Different Hosts in Turkey: A Meta-analysis.

OBJECTIVE: Microsporidia are opportunistic obligate intracellular pathogens which infect many vertebrate and invertebrate hosts. This study aimed at investigating all evidence about microsporidia infection in human and other vertebrate hosts in Turkey. METHODS: This study covered all prevalence studies, related to microsporidiosis in Turkey until April 2020, that were found in Web of Science, PubMed, Scopus, and ULAKBIM databases were considered in this meta-analysis. A total of 168 studies were identified in the systematic literature research. After the initial assessment, only 15 articles (12 humans and three other vertebrates) were included for meta-analysis. Data analysis was carried out using the Revman 5.3 (Review Manage 5.3) software. RESULTS: With the evaluation of these studies, it was found that the prevalence of microsporidia in humans (n=6.707) and other vertebrate hosts (n=506) was 13.4% and 15.2%, respectively. The risk ratio in the patient groups was 2.87 compared to the control group [95% confidence interval (CI): 1.20-6.87, I2=87%, p<0.00001]. There was no difference between genders and parasite prevalence (95% CI: 1.00-1.39, I2=18%, p=0.29). The prevalence of microsporidia was also found to be high in patients with diarrhea (95% CI: 1.09-1.58, I2=86%, p=0.0001) and in immunosuppressed individuals (95% CI: 1.86-3.70, I2=16%, p=0.31). CONCLUSION: Although there are few studies on the prevalence of these parasites, the results of this meta-analysis provides extensive information about the current situation in Turkey.

Microsporidia infection in patients with autoimmune diseases.

Purpose: Microsporidium is a spore-forming intracellular parasite that affects a wide range of hosts including humans. The tumor necrosis factor alpha (TNF-α) plays a key role in the immunity to infection with microsporidia. Recently, the TNF-α antagonists have proven successful in treating variable autoimmune diseases. In the current study, we aimed to investigate the impact of using TNF-α antagonists as a therapeutic regimen in the prevalence of infections with microsporidia. Materials and Methods: Diarrheal patients with distinct autoimmune diseases (n = 100) were assigned to the study. Patients taking anti-TNF-α medications (n = 60) were allocated to Group 1A and those undergoing non-TNF-α inhibitor treatment (n = 40) to Group 1B. Furthermore, patients with diarrhea without autoimmune disorders (n = 20) were allocated as controls. Stool specimens, 3 per patient, were collected and microscopically examined for microsporidia spores. A microsporidia-specific stool polymerase chain reaction was used to confirm the microscopic findings. Results: Microsporidia infection was identified in 28.3% (17/60), 10% (4/40), and in 5% (1/20) of patients in Group 1A, Group 1B, and in the control group, respectively. Overall, infection was significantly high in cases compared to the controls and in patients receiving TNF-α antagonists compared to patients not given TNF-α inhibitors (P < 0.05). Finally, infection was significantly higher in cases treated with TNF-α antagonists for ≥2 months compared to cases treated for <2 months of duration (P < 0.05). Conclusion: There was a significant increase in microsporidia infection in autoimmune disease patients undergoing treatment with TNF-α antagonists, and the duration of treatment is one of the risk factors. The study highlights the importance of microsporidia testing in immunocompromised patients, particularly those undergoing treatment with anti-TNF-α drugs and emphasises the need for awareness among clinicians regarding this opportunistic parasite.