Generation of a Microsporidia Species Attribute Database and Analysis of the Extensive Ecological and Phenotypic Diversity of Microsporidia

Microsporidia are a large group of parasites that cause death and disease in humans and many agriculturally important animal species. To fully understand the diverse properties of these parasites, we curated species reports from the last 160 years.

Comprehensive survey of microsporidia reveals extensive ecological and phenotypic diversity

Microsporidia are a large group of fungal-related obligate intracellular parasites. Though many microsporidia species have been identified over the past 160 years, there is a lacking depiction of the full diversity of this phylum. To systematically describe the characteristics of these parasites, we created a database of 1,428 species and their attributes, including the hosts they infect and spore characteristics. We find that microsporidia have been reported to infect 15 metazoan and four protozoan phyla, with smaller phyla being underrepresented. Most species are only reported to infect a single host, but those that are generalists are also more likely to infect a broader set of host tissues. Strikingly, polar tubes are 3-fold longer in species that infect tissues besides the intestine, suggesting that polar tube length is a determinant of tissue specificity. Phylogenetic analysis revealed four clades which each contain microsporidia infecting hosts from all major habitats. Although related species are more likely to infect similar hosts, we observe examples of changes in host specificity and convergent evolution. Taken together, our results show that microsporidia display vast diversity in their morphology and the hosts they infect, illustrating the flexibility of these parasites to evolve new traits.

Microscopic and Molecular Description of the Microsporidian Parasite,Heterosporis sp., Infecting Lizardfish, Saurida undosquamis in the Persian Gulf

Background: The lizardfish is an economically important fish in the Persian Gulf with high rates of parasitic infections. Microsporidia species, as opportunistic parasites, cause several disorders, which in turn result in economic problems. Objectives: The main objective was to evaluate Heterosporis sp. infection in Persian Gulf lizardfish using the small subunit ribosomal RNA phylogenetics to describe and classification of the unknown microsporidia species as well as morphological characteristics. Methods: The abdominal cavities of fifty specimens of lizardfish, Saurida undosquamis, were examined using morphological and molecular techniques. Some irregular whitish cyst-like were fixed for histopathological and transmission electron observations. The small subunit ribosomal genomic DNA was studied and a 1,279 bp genomic sequence was amplified and investigated for molecular analysis. Results: Twenty-two (out of fifty) specimens were infected with irregular whitish microsporidian cysts. Light and electron microscopic findings revealed round cysts containing large numbers of monomorphic and ovoid spores with a posterior vacuole. Polar tube coiled between six and eight-times, in one row. The large xenoma (hypertrophied parasitizing host cells) was encapsulated by a host-derived thick connective tissue in pathological samples. The phylogenetic analysis showed that despite some morphological similarity of the Persian Gulf microsporidia sp. to Glugea spp., the most closely related species with minimum genetic distance to Heterosporis anguillarum isolated is Japanese eels (Anguillajaponica). Conclusions: This is the first phylogenetic report of microsporidian infections in mesenteric tissues of lizardfish S. undosquamis in Iran including morphological and molecular markers, to introduce novel species

Pneumocystis jirovecii and microsporidia: An unusual coinfection in HIV patients?

Pneumocystis jirovecii and microsporidia species are recognized as opportunistic infectious pathogens in AIDS patients. Coinfection of both in one patient has been rarely reported. The aim of the present study was to investigate the coinfection of P. jirovecii and microsporidia in different tissues from AIDS deceased patients. Post mortem histological finding of P. jirovecii and microsporidia was demonstrated by means of the Grocott's methenamine silver and Brown Brenn staining, respectively. Molecular technique was used for identification and characterization of both fungi. Out of the 514 autopsied cases P. jirovecii and microsporidia species were identified in 53 (10.3%) and 62 (12.1%) cases respectively. A total of five cases (0.97%) coinfected with Pneumocystis and microsporidia were recovered from all analyzed autopsies. Coinfection of Pneumocystis and microsporidia is very challenging and raises interesting issues about host-parasite relationship. The early diagnosis of both pathogens must be crucial to establish correct and early treatments, improve the patient's evolution, reducing the risk of death.

Evaluation of the Effectiveness of Selected Treatments of Nosema Spp. Infection by the Hemocytometric Method and Duplex Pcr

Recent years have witnessed an increase in the mortality of honey bees in many regions of the world. The observed decrease in the bee population results from a combination of factors, and microsporidian parasites Nosema apis and N. ceranae are among the main contributors. Those parasites cause a microsporidian infection that shortens the lifespan of bees and reduces the productivity of bee colonies. The aim of this study was to evaluate the effectiveness of Nozevit, Api Herb and ApiX (acetylsalicylic acid + Artemisia absinthium L. extract) in the control of infections caused by Nosema spp. in a field experiment. Two groups of worker bees were evaluated - hive bees and forager bees returning to the hive. The effect of the analyzed therapies on the number of spores and the microsporidia species were analyzed by the hemocytometric method and duplex PCR. A statistical analysis revealed that the applied treatments had reduced the number of spores by 31.15% on average. In hive bees, Nosema spp. infection was most effectively reduced by Nozevit (67.85%) and ApiX (63.36%). Coinfections (N. ceranae and N. apis) were affirmed in all bee samples before treatments. However, after the treatments, single infection of N. apis and N. ceranae were detected. The tested treatments were more effective in the control of N. apis than N. ceranae.

COMPARISON OF METHODS FOR DETECTION OF MICROSPORIDIA SPECIES OF THE GENUS NOSEMA IN HONEY BEES (APIS MELLIFERA)

Two microsporidia species of the Nosema genus cause nosemosis in the adult honeybee: N. apis and N. ceranae. For diagnostic purposes and the determination of infection level various microscopic and molecular biological methods are used. Th e aim of this research was to compare the reliability of the traditional microscopic assessment and two PCR techniques: simplex- and duplex-PCR. Honey bee samples were taken from 150 colonies. Microscopic examination, performed according to the recommendations of the OIE, revealed Nosema spores in 68.67% samples analysed, whilst with the simplex-PCR method all samples (100.0%) proved positive. On the other hand, duplex-PCR method used for the identifi cation of Nosema species resulted in 84.0% positive samples, all of which were N. ceranae. Our recommendation of the simplex-PCR method for the monitoring of honey bees in fi eld conditions is based on its higher reliability than the microscopic assessment in the detection of low-level infections, as well as its potential for the detection of vegetative Nosema sp. stages; thus the early detection and timely prevention of Nosema infection would be possible. Nosema species identifi cation is simplest and most cost-eff ective if performed with the duplex-PCR analysis. However, the simplex-PCR is more reliable, thus, it is suggested that samples that were negative when assessed with microscopy and duplex-PCR analysis undergo simplex-PCR.