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1.
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.  相似文献   

2.
Microsporidia are opportunistic pathogens in nature infecting all animal phyla. There is a potential risk of microsporidian spores transmission from urban rooks inhabiting some metropolitan cities to people through casual interactions. The aim of this study was to identify microsporidia species in the droppings of rooks in Wroclaw, Poland. A total of 15 collective sets of droppings were examined using nested‐PCR method. Amplification of ITS rRNA gene revealed the presence of Enterocytozoon bieneusi D, Peru 6, and Encephalitozoon hellem 1A genotypes. This study indicates that excreta of urban rooks can be an important source of human infection with these pathogens.  相似文献   

3.
We developed nested PCR protocols and performed a multiyear survey on the prevalence of several protozoan parasites in wild northern bobwhite (Colinus virginianus) and scaled quail (Callipepla squamata) in the Rolling Plains ecoregion of Texas and Oklahoma (i.e. fecal pellets, bird intestines and blood smears collected between 2010 and 2013). Coccidia, cryptosporidia, and microsporidia were detected in 46.2%, 11.7%, and 44.0% of the samples (n = 687), whereas histomona and hematozoa were undetected. Coccidia consisted of one major and two minor Eimeria species. Cryptosporidia were represented by a major unknown Cryptosporidium species and Cryptosporidium baileyi. Detected microsporidia species were highly diverse, in which only 11% were native avian parasites including Encephalitozoon hellem and Encephalitozoon cuniculi, whereas 33% were closely related to species from insects (e.g. Antonospora, Liebermannia, and Sporanauta). This survey suggests that coccidia infections are a significant risk factor in the health of wild quail while cryptosporidia and microsporidia may be much less significant than coccidiosis. In addition, the presence of E. hellem and E. cuniculi (known to cause opportunistic infections in humans) suggests that wild quail could serve as a reservoir for human microsporidian pathogens, and individuals with compromised or weakened immunity should probably take precautions while directly handling wild quail.  相似文献   

4.
Samples of intestinal content from thirty fattened pigs of six farms slaughtered at an abattoir in North-Western Germany, and faecal samples of four pigs kept as laboratory animals at the Federal Institute for Risk Assessment (BfR, Berlin, Germany) were investigated for the occurrence of microsporidia by light microscopy, PCR and sequencing. A modified Webers trichrome staining and the immunohistochemistry (the Avidin-Biotin-Peroxidase-Complex technique with a polyclonal anti-Encephalitozoon cuniculi-serum and monoclonal antibodies against Encephalitozoon intestinalis and Enterocytozoon bieneusi) was used as a screening method for the light microscopical detection of these pathogenic eukaryotes. By this light microscopically methods microsporidia suspected organisms were found in all samples (100%). By the use of PCR, microsporidia were identified in fourteen samples (41.2%). The prevalence of microsporidia infections among the farms diversifies from 0 to 80% as considered by PCR. E. bieneusi was the most prevalent species and was identified in twelve fattened pigs (40%) from five of the six tested farms (83.3%) and in two of the four laboratory animals (50%). Three of the E. bieneusi species belonged to the genotype O, one to the genotype E, and one to the genotype F. Two isolates were identified as novel genotypes and two samples showed a mixed infection of different genotypes. In three faecal samples of the pigs from two farms E. cuniculi genotype III was identified. One sample contained both microsporidia species. To our knowledge, this is the first time that the genotype III of E. cuniculi was identified in swine.  相似文献   

5.
The term microsporidia is used to describe several species of opportunistic protozoan parasites. Encephalitozoon intestinalis and Enterocytozoon bieneusi have been found in stools of more than 40% of AIDS patients with diarrhea. Diagnosis of infection with these small protozoans has been difficult, and until recently their occurrence has not been well documented. Formalin is widely used to preserve clinical specimens, but due to the nature of the fixation process, subsequent analysis, especially analysis by the PCR, is difficult. This study evaluated methods used to prepare formalin-fixed fecal specimens for PCR amplification of microsporidial DNA. Two methods were devised to allow PCR detection and subsequent identification of microsporidia in formalin-fixed fecal specimens to the species level. One method involved immunomagnetic separation to concentrate microsporidial spores from fecal specimens. In the second method Chelex resin (Bio-Rad, Hercules, Calif.) was used to remove inhibitory substances, followed by a DNA concentration step. Both methods resulted in reproducible, confirmed detection of microsporidia in formalinized fecal specimens and subsequent species determination by PCR sequencing. The detection sensitivity was two in vitro culture-derived spores (Encephalitozoon intestinalis) for the direct PCR. The reproducible detection sensitivity for DNA amplification from formalin-fixed fecal samples was 200 spores for either the Chelex method or the immunomagnetic bead separation method. Thus, we developed two methods for rapid, inexpensive detection of microsporidial spores in formalin-fixed fecal specimens.  相似文献   

6.
Research pertaining to the two closely‐related microsporidian genera Nosema and Vairimorpha is hindered by inconsistencies in species differentiation within and between the two clades. One proposal to better delimit these genera is to restructure the Nosema around a “True Nosema” clade, consisting of species that share a characteristic reversed ribosomal DNA operon arrangement and small subunit (SSU) ribosomal DNA sequences similar to that of the Nosema type species, N. bombycis. Using this framework, we assess two distinct microsporidia recovered from the forest insect Bruce spanworm (Operophtera bruceata) by sequencing their SSU and internal transcribed spacer regions. Phylogenetic analyses place one of our isolates within the proposed True Nosema clade close to N. furnacalis and place the other in the broader Nosema/Vairimorpha clade close to N. thomsoni. We found that 25% of Bruce spanworm cadavers collected over the four‐year study period were infected with microsporidia, but no infections were detected in cadavers of the Bruce spanworm's invasive congener, the winter moth (O. brumata), collected over the same period. We comment on these findings as they relate to the population dynamics of the Bruce spanworm‐winter moth system in this region, and more broadly, on the value of ribosomal DNA operon arrangement in Nosema systematics.  相似文献   

7.
Microsporidia are known opportunistic microorganisms and usually transmitted via the fecal–oral route. However, there is no information about human‐infecting microsporidia in wildlife in Iran. This study aimed to investigate and analyze human‐infecting microsporidia isolated from raccoons in north of Iran. Totally, 30 fecal samples were collected; then, DNA extraction was performed and specific fragments of the SSU rRNA gene of Enterocytozoon bieneusi and Encephalitozoon species were amplified. After amplification and sequencing the ITS, the results were compared to the GenBank database. Phylogenetic trees and network analysis were employed to explore probable relationships. E. bieneusi was the only detected microsporidia among samples. Genotyping showed the genotypes D, E, and RA in 15/18 (83.33%), 1/18 (5.55%), and 2/18 (11.11%) of samples, respectively. Novel genotypes RA1 and RA2 grouped together and apart from other genotypes. E. bieneusi genotypes D and E clustered with the genotypes previously reported from animals, humans, and environmental samples. Network analysis revealed six distinct sequence types among raccoon's isolates. This study demonstrated that E. bieneusi genotype D was the most prevalent microsporidia among raccoons. It seems that wildlife may play a role in dispersion of microsporidia spores.  相似文献   

8.
Human-associated microsporidia were frequently observed in fecal samples of 331 feral pigeons in Amsterdam, The Netherlands, obtained during high- and low-breeding periods. Thirty-six of 331 samples (11%) contained the human pathogens Enterocytozoon bieneusi (n = 18), Encephalitozoon hellem (n = 11), Encephalitozoon cuniculi (n = 6), and Encephalitozoon intestinalis (n = 1); 5 samples contained other microsporidia. Pigeon feces can be an important source of human microsporidian infection.  相似文献   

9.
The FTA technology was applied for sampling, archiving, and molecular analysis of the DNA isolated from stool samples to diagnose and identify microsporidia, the intracellular opportunistic parasites which induce malabsortion syndrome in immunosuppressed humans, particularly in patients with AIDS. Microsporidia DNA was successfully amplified in 6 of 50 stool samples of HIV-positive patients of the S. P. Botkin Memorial Infectious Disease Hospital (St. Petersburg) applied to FTA cards (FTA-Cars, Whatman Inc. Florham Park, NJ, USA). Amplicons (the fragments of rDNA) were directly sequenced, and microsporidia species--Encephalitozoon intestinalis, E. cuniculi, E. hellem, and Enterocytozoon bieneusi--were identified in Genbank by NCBI BLAST program. The FTA method of DNA immobilization is especially promising for epidemiological and field population studies which involve genotyping of microsporidia species and isolates.  相似文献   

10.
DNA barcoding aims to develop an efficient tool for species identification based on short and standardized DNA sequences. In this study, the DNA barcode paradigm was tested among the genera of the tribe Sisyrinchieae (Iridoideae). Sisyrinchium, with more than 77% of the species richness in the tribe, is a taxonomically complex genus. A total of 185 samples belonging to 98 species of Sisyrinchium, Olsynium, Orthrosanthus and Solenomelus were tested using matK, trnHpsbA and internal transcribed spacer (ITS). Candidate DNA barcodes were analysed either as single markers or in combination. Detection of a barcoding gap, similarity‐based methods and tree‐based analyses were used to assess the discrimination efficiency of DNA barcodes. The levels of species identification obtained from plastid barcodes were low and ranged from 17.35% to 20.41% for matK and 5.11% to 7.14% for trnH‐psbA. The ITS provided better results with 30.61–38.78% of species identified. The analyses of the combined data sets did not result in a significant improvement in the discrimination rate. Among the tree‐based methods, the best taxonomic resolution was obtained with Bayesian inference, particularly when the three data sets were combined. The study illustrates the difficulties for DNA barcoding to identify species in evolutionary complex lineages. Plastid markers are not recommended for barcoding Sisyrinchium due to the low discrimination power observed. ITS gave better results and may be used as a starting point for species identification.  相似文献   

11.
Biological invasions are regarded as threats to global biodiversity. Among invasive aliens, a number of plant species belonging to the genera Myriophyllum, Ludwigia and Cabomba, and to the Hydrocharitaceae family pose a particular ecological threat to water bodies. Therefore, one would try to prevent them from entering a country. However, many related species are commercially traded, and distinguishing invasive from non‐invasive species based on morphology alone is often difficult for plants in a vegetative stage. In this regard, DNA barcoding could become a good alternative. In this study, 242 samples belonging to 26 species from 10 genera of aquatic plants were assessed using the chloroplast loci trnHpsbA, matK and rbcL. Despite testing a large number of primer sets and several PCR protocols, the matK locus could not be amplified or sequenced reliably and therefore was left out of the analysis. Using the other two loci, eight invasive species could be distinguished from their respective related species, a ninth one failed to produce sequences of sufficient quality. Based on the criteria of universal application, high sequence divergence and level of species discrimination, the trnH‐psbA noncoding spacer was the best performing barcode in the aquatic plant species studied. Thus, DNA barcoding may be helpful with enforcing a ban on trade of such invasive species, such as is already in place in the Netherlands. This will become even more so once DNA barcoding would be turned into machinery routinely operable by a nonspecialist in botany and molecular genetics.  相似文献   

12.
As a common feature of eukaryotic proteins, tandem amino acid repeat has been studied extensively in both animal and plant proteins. Here, a comparative analysis focusing on the proteins having tandem repeats was conducted in eight microsporidia, including four mammal‐infecting microsporidia (Encephalitozoon cuniculi, Encephalitozoon intestinalis, Encephalitozoon hellem and Encephalitozoon bieneusi) and four insect‐infecting microsporidia (Nosema apis, Nosema ceranae, Vavraia culicis and Nosema bombycis). We found that the proteins with tandem repeats were abundant in these species. The quantity of these proteins in insect‐infecting microsporidia was larger than that of mammal‐infecting microsporidia. Additionally, the hydrophilic residues were overrepresented in the tandem repeats of these eight microsporidian proteins and the amino acids residues in these tandem repeat sequences tend to be encoded by GC‐rich codons. The tandem repeat position within proteins of insect‐infecting microsporidia was randomly distributed, whereas the tandem repeats within proteins of mammal‐infecting microsporidia rarely tend to be present in the N terminal regions, when compared with those present in the C terminal and middle regions. Finally, a hypothetical protein EOB14572 possessing four tandem repeats was successfully characterized as a novel endospore wall protein, which colocalized with polar tube of N. bombycis. Our study provided useful insight for the study of the proteins with tandem repeats in N. bombycis, but also further enriched the spore wall components of this obligate unicellular eukaryotic parasite.  相似文献   

13.
ABSTRACT. Phylogenetic analysis of the small subunit ribosomal DNA of a broad range of representative microsporidia including five species from humans ( Enterocytozoon bieneusi, Nosema corneum, Septata intestinalis, Encephalitozoon hellem and Encephalitozoon cuniculi ), reveals that human microsporidia are polyphyletic in origin. Septata intestinalis and E. hellem are very similar to the mammalian parasite E. cuniculi . Based on the results of our phylogenetic analysis, we suggest that S. intestinalis be designated Encephalitozoon intestinalis . Furthermore, analysis of our data indicates that N. corneum is much more closely related to the insect parasite Endoreticulatus schubergi than it is to other Nosema species. This finding is supported by recent studies which have shown a similarity between E. schubergi and N. corneum based on the origin and development of the parasitophorous vacuole. Thus these opportunistic microsporidian parasites can originate from hosts closely or distantly related to humans. Finally, the phylogeny based on small subunit ribosomal DNA sequences is highly inconsistent with traditional classifications based on morphological characters. Many of the important morphological characters (diplokaryon, sporophorous vesicle, and meiosis) appear to have multiple origins.  相似文献   

14.
Several recent studies suggest local adaptation in multiple taxa across Hawaii's steep environmental gradients. Restoration efforts in devastated tropical island ecosystems may be deficient if we lack an understanding of the interactions and dependencies in communities that occur along these gradients. Endangered Hawaiian tree snails are part of a snail–epiphyte–plant system where they graze fungi and other microbes on the leaf surface, a process difficult to observe using conventional techniques. Tree snails have undergone catastrophic decline due to introduced predators, removal by shell collectors, and human‐influenced habitat degradation. Prior to this study, little was known about the relationship among tree‐snails, their host plants, and the epiphytic microbes on which they feed. In this study, we identified scale‐dependent selection of substrates in Achatinella sowerbyana and Achatinella lila across the species’ ranges. We assessed: (1) within‐plant diet selection using high‐throughput DNA sequencing (micro‐scale); (2) among‐plant selection of tree host species (small‐scale); (3) and the influence of climate on this system (macro‐scale). Selection of substrates occurred at two scales: fungal communities in fecal samples differed in composition from those available on leaf surfaces; and at all sites, snail occurrence on Metrosideros polymorpha, a foundational forest plant, was significantly higher than expected based on availability. Habitat restoration efforts should focus on out‐planting of M. polymorpha, the preferred snail host tree, in degraded habitat. Fungal differences across sites suggest relocation efforts to predator‐free enclosures may be hindered by microbial shifts associated with geographic distance or differing environments.  相似文献   

15.
Microsporidiosis is an emerging and opportunistic infection associated with wide range of clinical syndromes in humans. Confirmation of the presence of microsporidia in different samples is laborious, costly and often difficult. The present study was designed to evaluate the utility of the Co-agglutination test (Co-A test) for detection of urinary, fecal and circulating microsporidial antigens in experimentally infected mice. One hundred and twenty male Swiss albino mice were divided into non infected control and infected experimental groups which were further subdivided into two equal subgroups; immunosuppressed and immunocompetent. Microsporidial spores were isolated from human stools and identified to be Encephalitozoon intestinalis by the molecular methods. They were used to infect each subgroup of mice, then their urine, stools and sera were collected at the 1st, 3rd, 5th, 7th and 9th days post-infection (PI). Co-A test, using prepared hyperimmune serum, was used to detect antigens in all samples collected. The cross reactivity of microsporidial hyperimmune sera with antigens of Cyclospora cyatenensis and Cryptosporidium parvum was investigated by Co-A test. The results showed that Co-A test was effective in detecting microsporidial antigen in stool of immunosuppressed infected mice from the 1st day PI, and in urine and serum from the 3rd day PI till the end of the study. In the immunocompetent subgroup, Co-A test detected microsporidial antigens in stool, serum and urine of mice from the 1st day, 3rd day and the 5th day PI, respectively till the end of the study, without cross reactivity with C. cyatenensis or C. parvum in both subgroups. Co-A test proved to be simple and suitable tool for detecting microsporidial antigen in different specimens and did not need sophisticated equipment. It is very practical under field or rural conditions and in poorly equipped clinical laboratories.  相似文献   

16.
DNA barcoding is an efficient method to identify specimens and to detect undescribed/cryptic species. Sanger sequencing of individual specimens is the standard approach in generating large‐scale DNA barcode libraries and identifying unknowns. However, the Sanger sequencing technology is, in some respects, inferior to next‐generation sequencers, which are capable of producing millions of sequence reads simultaneously. Additionally, direct Sanger sequencing of DNA barcode amplicons, as practiced in most DNA barcoding procedures, is hampered by the need for relatively high‐target amplicon yield, coamplification of nuclear mitochondrial pseudogenes, confusion with sequences from intracellular endosymbiotic bacteria (e.g. Wolbachia) and instances of intraindividual variability (i.e. heteroplasmy). Any of these situations can lead to failed Sanger sequencing attempts or ambiguity of the generated DNA barcodes. Here, we demonstrate the potential application of next‐generation sequencing platforms for parallel acquisition of DNA barcode sequences from hundreds of specimens simultaneously. To facilitate retrieval of sequences obtained from individual specimens, we tag individual specimens during PCR amplification using unique 10‐mer oligonucleotides attached to DNA barcoding PCR primers. We employ 454 pyrosequencing to recover full‐length DNA barcodes of 190 specimens using 12.5% capacity of a 454 sequencing run (i.e. two lanes of a 16 lane run). We obtained an average of 143 sequence reads for each individual specimen. The sequences produced are full‐length DNA barcodes for all but one of the included specimens. In a subset of samples, we also detected Wolbachia, nontarget species, and heteroplasmic sequences. Next‐generation sequencing is of great value because of its protocol simplicity, greatly reduced cost per barcode read, faster throughout and added information content.  相似文献   

17.
Die‐back disease caused by Phomopsis (Diaporthe) azadirachtae is the devastating disease of Azadirachta indica. Accurate identification of P. azadirachtae is always problematic due to morphological plasticity and delayed appearance of conidia. A species‐specific PCR‐based assay was developed for rapid and reliable identification of P. azadirachtae by designing a species‐specific primer‐targeting ITS region of P. azadirachtae isolates. The assay was validated with DNA isolated from different Phomopsis species and other fungal isolates. The PCR assay amplified 313‐bp product from all the isolates of P. azadirachtae and not from any other Phomopsis species or any genera indicating its specificity. The assay successfully detected the pathogen DNA in naturally and artificially infected neem seeds and twigs indicating its applicability in seed quarantine and seed health testing. The sensitivity of the assay was 100 fg when genomic DNA of all isolates was analysed. The PCR‐based assay was 92% effective in comparison with seed plating technique in detecting the pathogen. This is the first report on the development of species‐specific PCR assay for identification and detection of P. azadirachtae. Thus, PCR‐based assay developed is very specific, rapid, confirmatory and sensitive tool for detection of pathogen P. azadirachtae at early stages.  相似文献   

18.
Electron microscopy of leaf samples displaying streak symptoms from enset (Ensete ventricosum), a banana‐like plant widely cultivated in Ethiopia, showed the presence of bacilliform shaped virions as known for badnaviruses. DNA extracts subjected to rolling circle amplification (RCA), polymerase chain reaction (PCR) and cloning and sequence analysis revealed that the virus has a circular double‐stranded DNA genome of 7,163 nucleotides encoding predicted proteins of 21.5 kDa, 14.5 kDa and 202.5 kDa, a genome organization known for badnaviruses. The virus is phylogenetically most closely related to Sugarcane bacilliform Guadeloupe D virus with a nucleotide sequence identity of 77.2% at the conserved RT/RNase‐H region and 73.6% for the whole genome. Following the current species demarcation criteria, the virus should be considered as an isolate of a new species in the genus Badnavirus for which the name Enset leaf streak virus (ELSV) is suggested. Leaf samples from enset and banana were screened using virus‐specific primers, and ELSV was detected in six of 40 enset but not found in any of 61 banana samples. On the other hand, Banana streak OL virus (BSOLV) was detected from the majority (60%) of symptomatic banana samples but not from enset samples. This paper reports the first full‐genome sequence of a putative new badnavirus species infecting plants in the genus Ensete. In addition, this is the first report of the occurrence of BSOLV in Ethiopia.  相似文献   

19.
The worldwide decline and local extinctions of bumblebees have raised a need for fast and accurate tools for species identification. Morphological characters are often not sufficient, and molecular methods have been increasingly used for reliable identification of bumblebee species. Molecular methods often require high‐quality DNA which makes them less suitable for analysis of low‐quality or older samples. We modified the PCR–RFLP protocol for an efficient and cost‐effective identification of four bumblebee species in the subgenus Bombus s. str. (B. lucorum, B. terrestris, B. magnus and B. cryptarum). We used a short partial mitochondrial COI fragment (446 bp) and three diagnostic restriction enzymes (Hinf I, Hinc II and Hae III) to identify species from degraded DNA material. This approach allowed us to efficiently determine the correct species from all degraded DNA samples, while only a subset of samples 64.6% (31 of 48) resulted in successful amplification of a longer COI fragment (1064 bp) using the previously described method. This protocol can be applied for conservation and management of bumblebees within this subgenus and is especially useful for fast species identification from degraded samples.  相似文献   

20.
The use of nondestructive methods for obtaining DNA from amphibians (e.g. buccal swabs) allows genetic studies to be performed without affecting the survival of the studied individuals. In this study, we compared two methods of nondestructive DNA sampling, buccal swabs and interdigital membrane or toe‐clipping, in several amphibian species of different size: Rhinella spinulosa, Ratacamensis, six species of the genus Telmatobius and Pleurodema thaul. We evaluated the integrity of the DNA extracted by sequencing fragments of mitochondrial and nuclear genes and by generating amplified fragment length polymorphisms markers (AFLPs). In all cases, we obtained an adequate amount of DNA (mean range 55–298 ng/μL). We obtained identical DNA sequences from buccal swab and interdigital membrane/toe‐clip for all individuals. The differences in the coding of AFLP markers between the tissues were similar to those reported for replicas of the same type of sample in similar analyses in other species of amphibians. In conclusion, the use of buccal swabs is a trustworthy and inexpensive method to obtain DNA for mitochondrial and nuclear sequencing and AFLP analyses. Given the types of markers evaluated, buccal swabs may be used for phylogenetic, phylogeographic and population genetic studies, even in small amphibians (<33 mm).  相似文献   

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