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1.
Med Mycol ; 62(7)2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38816207

ABSTRACT

Candida auris represents one of the most urgent threats to public health, although its ecology remains largely unknown. Because amphibians and reptiles may present favorable conditions for C. auris colonization, cloacal and blood samples (n = 68), from several snake species, were cultured and molecularly screened for C. auris using molecular amplification of glycosylphosphatidylinositol protein-encoding genes and ribosomal internal transcribed spacer sequencing. Candida auris was isolated from the cloacal swab of one Egyptian cobra (Naja haje legionis) and molecularly identified in its cloaca and blood. The isolation of C. auris from wild animals is herein reported for the first time, thus suggesting the role that these animals could play as reservoirs of this emerging pathogen. The occurrence of C. auris in blood requires further investigation, although the presence of cationic antimicrobial peptides in the plasma of reptiles could play a role in reducing the vitality of the fungus.


Candida auris represents one of the most urgent threats to public health. In this study, we reported for the first time the isolation of C. auris from snake thus suggesting the role of these animals as reservoirs of this emerging pathogen.


Subject(s)
Candida , Candidiasis , DNA, Ribosomal Spacer , Disease Reservoirs , Animals , Candida/genetics , Candida/classification , Candida/isolation & purification , Candida/drug effects , Disease Reservoirs/microbiology , Candidiasis/microbiology , Candidiasis/veterinary , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/chemistry , Cloaca/microbiology , Sequence Analysis, DNA , DNA, Fungal/genetics , Blood/microbiology , Snakes/microbiology , Elapidae , Egypt , Phylogeny
2.
Mycopathologia ; 189(3): 43, 2024 May 06.
Article in English | MEDLINE | ID: mdl-38709328

ABSTRACT

During an epidemiological survey, a potential novel species within the basidiomycetous yeast genus Trichosporon was observed. The clinical strain was obtained from a urine sample taken from a Brazilian kidney transplant recipient. The strain was molecularly identified using the intergenic spacer (IGS1) ribosomal DNA locus and a subsequent phylogenetic analysis showed that multiple strains that were previously reported by other studies shared an identical IGS1-genotype most closely related to that of Trichosporon inkin. However, none of these studies provided an in-depth characterization of the involved strains to describe it as a new taxon. Here, we present the novel clinically relevant yeast for which we propose the name Trichosporon austroamericanum sp. nov. (holotype CBS H-24937). T. austroamericanum can be distinguished from other siblings in the genus Trichosporon using morphological, physiological, and phylogenetic characters.


Subject(s)
DNA, Fungal , DNA, Ribosomal Spacer , Phylogeny , Sequence Analysis, DNA , Transplant Recipients , Trichosporon , Trichosporonosis , Trichosporon/classification , Trichosporon/genetics , Trichosporon/isolation & purification , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Fungal/genetics , Humans , Brazil , Trichosporonosis/microbiology , Cluster Analysis , Mycological Typing Techniques , Kidney Transplantation , Microscopy , Genotype
3.
Med Mycol ; 61(5)2023 May 01.
Article in English | MEDLINE | ID: mdl-37070928

ABSTRACT

This study looked for correlations between molecular identification, clinical manifestation, and morphology for Trichophyton interdigitale and Trichophyton mentagrophytes. For this purpose, a total of 110 isolates were obtained from Czech patients with various clinical manifestations of dermatophytosis. Phenotypic characters were analyzed, and the strains were characterized using multilocus sequence typing. Among the 12 measured/scored phenotypic features, statistically significant differences were found only in growth rates at 37 °C and in the production of spiral hyphae, but none of these features is diagnostic. Correlations were found between T. interdigitale and higher age of patients and between clinical manifestations such as tinea pedis or onychomychosis. The MLST approach showed that internal transcribed spacer (ITS) genotyping of T. mentagrophytes isolates has limited practical benefits because of extensive gene flow between sublineages. Based on our results and previous studies, there are few taxonomic arguments for preserving both species names. The species show a lack of monophyly and unique morphology. On the other hand, some genotypes are associated with predominant clinical manifestations and sources of infections, which keep those names alive. This practice is questionable because the use of both names confuses identification, leading to difficulty in comparing epidemiological studies. The current identification method using ITS genotyping is ambiguous for some isolates and is not user-friendly. Additionally, identification tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry fail to distinguish these species. To avoid further confusion and to simplify identification in practice, we recommend using the name T. mentagrophytes for the entire complex. When clear differentiation of populations corresponding to T. interdigitale and Trichophyton indotineae is possible based on molecular data, we recommend optionally using a variety rank: T. mentagrophytes var. interdigitale and T. mentagrophytes var. indotineae.


Species in the T. mentagrophytes complex lack support from usual taxonomic methods and simple identification tools are missing or inaccurate. To avoid recurring confusions, we propose naming the entire complex as T. mentagrophytes and optionally use rank variety to classify the observed variability.


Subject(s)
Tinea , Animals , Phylogeny , Tinea/diagnosis , Tinea/veterinary , Multilocus Sequence Typing/veterinary , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/chemistry , Sequence Analysis, DNA/veterinary , DNA, Fungal/genetics , DNA, Fungal/chemistry , Trichophyton , Phenotype
4.
Mycopathologia ; 188(6): 957-971, 2023 Dec.
Article in English | MEDLINE | ID: mdl-37728680

ABSTRACT

The majority of Candida species are known as non-pathogenic yeasts and rarely involved in human diseases. However, recently case reports of human infections caused by non-albicans Candida species have increased, mostly in immunocompromised hosts. Our study aimed to describe and characterize as thoroughly as possible, a new species of the Metschnikowia clade, named here Candida massiliensis (PMML0037), isolated from a clinical sample of human sputum. We targeted four discriminant genetic regions: "Internal Transcribed Spacers" of rRNA, D1/D2 domains (28S large subunit rRNA) and part of the genes encoding Translation Elongation Factor 1-α and ß-tubulin2. The genetic data were compared to morphological characters, from scanning electron microscopy (TM 4000 Plus, SU5000), physiological, including the results of oxidation and assimilation tests of different carbon sources by the Biolog system, and chemical mapping by Energy-Dispersive X-ray Spectroscopy. Lastly, the in vitro antifungal susceptibility profile was performed using the E-test™ exponential gradient method. The multilocus analysis supported the genetic position of Candida massiliensis (PMML0037) as a new species of the Metschnikowia clade, and the phenotypic analysis highlighted its unique morphological and chemical profile when compared to the other Candida/Metschnikowia species included in the study.


Subject(s)
Candida , Metschnikowia , Humans , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/chemistry , Phylogeny , DNA, Fungal/genetics , DNA, Fungal/chemistry , Yeasts/genetics , RNA, Ribosomal/genetics , Metschnikowia/genetics , RNA, Ribosomal, 28S , Sequence Analysis, DNA , Mycological Typing Techniques
5.
Mol Biol (Mosk) ; 57(3): 411-426, 2023.
Article in Russian | MEDLINE | ID: mdl-37326045

ABSTRACT

The genes coding for the rRNAs seem evolutionary conserved on the first glance, but astonish one with their variability in the structure and a variety of functions on closer examination. The non-coding parts of rDNA contain regulatory elements, protein binding sites, pseudogenes, repetitive sequences, and microRNA genes. Ribosomal intergenic spacers are not only in charge with the nucleolus morphology and functioning, namely, the rRNA expression and ribosome biogenesis, but also control nuclear chromatin formation thus mediating cell differentiation. The alterations in the expression of these non-coding regions of rDNA in response to environmental stimuli underlie the keen sense of a cell to various types of stressors. Malfunctioning of this process may result in a wide range of pathologies from oncology to neurodegenerative disease and mental illness. Here, we observe to-date materials on the structure and transcription of the ribosomal intergenic spacer in humans and its role in rRNA expression, in-born disease development, and cancer.


Subject(s)
Neurodegenerative Diseases , Humans , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , RNA, Ribosomal/genetics , RNA, Ribosomal/chemistry , Repetitive Sequences, Nucleic Acid
6.
Nature ; 534(7605): 133-7, 2016 06 02.
Article in English | MEDLINE | ID: mdl-27251291

ABSTRACT

Ribosome biogenesis is a highly complex process in eukaryotes, involving temporally and spatially regulated ribosomal protein (r-protein) binding and ribosomal RNA remodelling events in the nucleolus, nucleoplasm and cytoplasm. Hundreds of assembly factors, organized into sequential functional groups, facilitate and guide the maturation process into productive assembly branches in and across different cellular compartments. However, the precise mechanisms by which these assembly factors function are largely unknown. Here we use cryo-electron microscopy to characterize the structures of yeast nucleoplasmic pre-60S particles affinity-purified using the epitope-tagged assembly factor Nog2. Our data pinpoint the locations and determine the structures of over 20 assembly factors, which are enriched in two areas: an arc region extending from the central protuberance to the polypeptide tunnel exit, and the domain including the internal transcribed spacer 2 (ITS2) that separates 5.8S and 25S ribosomal RNAs. In particular, two regulatory GTPases, Nog2 and Nog1, act as hub proteins to interact with multiple, distant assembly factors and functional ribosomal RNA elements, manifesting their critical roles in structural remodelling checkpoints and nuclear export. Moreover, our snapshots of compositionally and structurally different pre-60S intermediates provide essential mechanistic details for three major remodelling events before nuclear export: rotation of the 5S ribonucleoprotein, construction of the active centre and ITS2 removal. The rich structural information in our structures provides a framework to dissect molecular roles of diverse assembly factors in eukaryotic ribosome assembly.


Subject(s)
Cryoelectron Microscopy , Ribosomal Proteins/metabolism , Ribosomal Proteins/ultrastructure , Ribosome Subunits, Large, Eukaryotic/chemistry , Ribosome Subunits, Large, Eukaryotic/ultrastructure , Saccharomyces cerevisiae/chemistry , Saccharomyces cerevisiae/ultrastructure , Active Transport, Cell Nucleus , Base Sequence , Catalytic Domain , Cell Nucleus/chemistry , Cell Nucleus/metabolism , Cell Nucleus/ultrastructure , Cytoplasm/metabolism , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , DNA, Ribosomal Spacer/metabolism , DNA, Ribosomal Spacer/ultrastructure , GTP Phosphohydrolases/chemistry , GTP Phosphohydrolases/metabolism , GTP Phosphohydrolases/ultrastructure , GTP-Binding Proteins/chemistry , GTP-Binding Proteins/metabolism , GTP-Binding Proteins/ultrastructure , Models, Molecular , Molecular Sequence Data , Nuclear Proteins/chemistry , Nuclear Proteins/metabolism , Nuclear Proteins/ultrastructure , Protein Binding , RNA, Fungal/genetics , RNA, Fungal/metabolism , RNA, Fungal/ultrastructure , RNA, Ribosomal/genetics , RNA, Ribosomal/metabolism , RNA, Ribosomal/ultrastructure , Ribonucleoproteins/chemistry , Ribonucleoproteins/metabolism , Ribonucleoproteins/ultrastructure , Ribosomal Proteins/chemistry , Ribosomal Proteins/isolation & purification , Ribosome Subunits, Large, Eukaryotic/metabolism , Rotation , Saccharomyces cerevisiae/cytology , Saccharomyces cerevisiae/metabolism , Saccharomyces cerevisiae Proteins/chemistry , Saccharomyces cerevisiae Proteins/isolation & purification , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae Proteins/ultrastructure
7.
ScientificWorldJournal ; 2022: 2122619, 2022.
Article in English | MEDLINE | ID: mdl-35774411

ABSTRACT

Anisakis nematodes infecting Indian mackerel (Rastrelliger kanagurta) were initially discovered in Thailand in our preliminary investigation. Nevertheless, the species of Anisakis collected has not been determined nor has its genetic variation been researched. Thus, this study aimed to molecularly identify the species of Anisakis specimens using the internal transcribed spacer (ITS) region of ribosomal DNA sequences. In addition, the intraspecific genetic variation was also determined using mitochondrial cytochrome oxidase subunit II (COII) gene sequences. The phylogenetic relationships of the ITS region classified all samples into Anisakis typica; however, the genetic variation between them could not be distinguished. By contrast, the phylogenetic tree analysis of the COII region identified all samples as A. typica, with 17 different haplotypes by 66 polymorphic sites and five of the substitutions resulted in amino acid change. Additionally, the distribution pattern of the COII region can be separated into two groups between South America and Asian countries. All our haplotypes belong to Asian countries. Compared with the two genetic markers used in this investigation, COII appears to be a better candidate for studying genetic variation sensitive to environmental changes and intermediate or definitive host behavioral changes.


Subject(s)
Anisakiasis , Anisakis , Perciformes , Animals , Anisakis/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Genetic Variation/genetics , Perciformes/genetics , Phylogeny , Thailand
8.
Biochem Biophys Res Commun ; 534: 233-239, 2021 01 01.
Article in English | MEDLINE | ID: mdl-33276952

ABSTRACT

Many early studies of ribosomal RNA gene (rDNA) suggested that rDNA tandem repeats within species are homogeneous. However, increasing number of reports have found intra-individual rDNA polymorphism across a range of taxa. Here, we reported a high level of intra-individual polymorphism of 18S-ITS1-5.8S rDNA in the genome of Cynoglossus melampetalus (Pleuronectiformes: Cynoglossidae), indicating a non-concerted evolution manner. Sequence alignments found two distinct types of 18S and 5.8S (Type A and B) and five types of ITS1 sequence (Type A - E) coexisted in the genome differing in length, GC content, secondary structure stability and minimum free energy. Based on the unique features of pseudogene and comparison of the conserved 18S rDNA sequence and 5.8S secondary structure of 22 flatfishes revealed that Type B sequences of 18S, 5.8S and their linked ITS1 were putative pseudogenes. So far, detection of rRNA pseudogenes from the multiple rDNA copies has been an intricate puzzle. Our results, as a result, provide a new ideal for rRNA pseudogene identification.


Subject(s)
DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal/chemistry , Flatfishes/genetics , Pseudogenes , RNA, Ribosomal, 18S/genetics , RNA, Ribosomal, 5.8S/genetics , Animals , Nucleic Acid Conformation , Polymorphism, Genetic , Sequence Alignment , Sequence Analysis, DNA
9.
Epidemiol Infect ; 148: e49, 2020 02 14.
Article in English | MEDLINE | ID: mdl-32054545

ABSTRACT

A new fast-growing mycobacterium, designated strain QGD101T, was isolated from the sputum of an 84-year-old man suspected of tuberculosis in Wuhan Medical Treatment Center, Hubei, China. This strain was a gram-staining-negative, aerobic, non-spore-forming and catalase-positive bacterium, which was further identified as the NTM by PNB and TCH tests. The moxifloxacin and levofloxacin exhibited strong suppressing function against QGD101T with MIC values of 0.06 and 0.125 µg/ml after drug susceptibility testing of six main antimicrobial agents on mycobacteria. Based on the sequence analysis of 16S rRNA, rpoB, hsp65 and 16S-23S rRNA internal transcribed spacer, the strain QGD101T could not be identified to a species level. Mycobacterium moriokaense ATCC43059T that shared the highest 16S rRNA gene sequence similarity (98%) with strain QGD101T was actually different in genomes average nucleotide identity (78.74%). In addition, the major cellular fatty acids of QGD101T were determined as C18:1ω9c, C16:0 and C18:2ω6c. The DNA G + C content was 64.9% measured by high performance liquid chromatography. Therefore, the phenotypic and genotypic characterisation of this strain led us to the conclusion that it represents a novel species of mycobacteria, for which the name Mycobacterium hubeiense sp. nov. (type strain QGD101T = CCTCCAA 2017003T = KCTC39927T) was proposed. Thus, the results of this study are very significant for the clinical diagnosis of tuberculosis and future personalised medicine.


Subject(s)
Mycobacterium Infections, Nontuberculous/microbiology , Mycobacterium/classification , Mycobacterium/isolation & purification , Sputum/microbiology , Aged, 80 and over , Antitubercular Agents/pharmacology , Bacterial Proteins/genetics , Base Composition , Chaperonin 60/genetics , China , Cluster Analysis , Cytosol/chemistry , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , DNA-Directed RNA Polymerases/genetics , Fatty Acids/analysis , Humans , Levofloxacin/pharmacology , Male , Microbial Sensitivity Tests , Moxifloxacin/pharmacology , Mycobacterium/genetics , Mycobacterium/physiology , Phylogeny , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA
10.
Avian Pathol ; 49(1): 47-55, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31486682

ABSTRACT

Outbreaks of avian trichomonosis are being reported worldwide; meanwhile, the genetic and virulence variations are under investigation. In this study, the occurrence and genetic variability of oral or faecal trichomonads among various avian species were investigated. Samples obtained from either the oropharyngeal cavity, crop/oesophagus, droppings/cloaca, or conjunctival swabs of avian species were inspected for flagellates. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples was performed to investigate the genetic diversity of the isolates. Investigation of 737 birds revealed an infection rate of 15.7% in the upper gastrointestinal tract, 7.3% in the faecal samples, and 0.7% involvement of the conjunctiva. Phylogenetic analysis of partial ITS1-5.8s rRNA-ITS2 sequences from selected samples, identified genotypes A and B of Trichomonas gallinae and genogroups A-C and E of Tetratrichomonas gallinarum. A novel ITS genotype of intestinal trichomonads was also detected in hooded crow (Corvus cornix) and common mynah (Acridotheres tristis). In the present study, in addition to Columbiformes and Falconiformes, trichomonads were detected in Passeriformes and Galliformes with the involvement of organs other than the gastrointestinal tract. Genotype A T. gallinae was detected in domestic pigeons (Columba livia domestica), a laughing dove (Spilopelia senegalensis), a common kestrel (Falco tinnunculus), a budgerigar (Melopsittacus undulates), and a canary (Serinus canaria). Distinct genotype B was detected in a common mynah and a budgerigar. Genogroups A-C of T. gallinarum were also demonstrated in Galliformes and Anseriformes. Furthermore, two novel trichomonad ITS genotypes were detected in hooded crows and a common mynah warranting detailed multi-locus molecular analysis.RESEARCH HIGHLIGHTSITS diversity of trichomonads was shown in various avian species.Diversity of the parasites' target organ and clinical manifestations was demonstrated.Two novel ITS genotype trichomonads from common mynah and hooded crow were identified.


Subject(s)
Bird Diseases/parasitology , Protozoan Infections, Animal/parasitology , Trichomonadida/genetics , Animals , Anseriformes/parasitology , Bird Diseases/epidemiology , Canaries/parasitology , Columbiformes/parasitology , Crows/parasitology , DNA, Protozoan/chemistry , DNA, Protozoan/isolation & purification , DNA, Ribosomal Spacer/chemistry , Falconiformes/parasitology , Galliformes/parasitology , Genotype , Humans , Iran/epidemiology , Melopsittacus/parasitology , Multilocus Sequence Typing/veterinary , Passeriformes/parasitology , Phylogeny , Prevalence , Protozoan Infections, Animal/epidemiology , Psittaciformes/parasitology , RNA, Ribosomal, 5.8S/genetics , Starlings/parasitology , Trichomonadida/classification , Trichomonas/genetics
11.
Exp Parasitol ; 209: 107814, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31816280

ABSTRACT

Giardia duodenalis is one of the most important intestinal parasites globally, especially in children, and in Cuba is the leading cause of chronic paediatric diarrhoea in this population. G. duodenalis is composed of eight genetic groups (or assemblages), two of which (A and B) are apparently zoonotic, occurring in both humans and other animals. However, consensus on the most appropriate genotyping scheme for optimal characterization of G. duodenalis isolates is lacking. In this article we present the results of three descriptive observational studies conducted in Havana, Cuba between 2010 and 2013, with the aim of comparing the results from molecular (PCR) approaches targeting different genes in order to assign with confidence 224 isolates of G. duodenalis to the correct assemblages. In each sub-study, following DNA isolation by the phenol/chloroform/isoamyl alcohol extraction method, PCR targeting the triose phosphate isomerase (tpi) gene was used for molecular characterization, as well as one additional PCR-method targeting another gene or pair of genes. DNA amplification was obtained in 87%, 83%, and 80% in the three sub-studies. Although excellent agreement (kappa index = 1) was recorded between results from some pairs of genes, for other combinations only moderate or substantial agreement was achieved. These results highlight the importance of interpretation of genotyping data, especially when single genetic markers are used. From the results of our studies, PCR targeting a combination of the tpi gene and the intergenic spacer region of rDNA may be a useful approach for the molecular characterization of G. duodenalis isolates.


Subject(s)
Genotyping Techniques/standards , Giardia lamblia/classification , Giardiasis/parasitology , Polymerase Chain Reaction/methods , Animals , Child , Child, Preschool , Cuba , DNA, Protozoan/chemistry , DNA, Protozoan/isolation & purification , DNA, Ribosomal Spacer/chemistry , Feces/parasitology , Giardia lamblia/genetics , Giardia lamblia/isolation & purification , Glutamate Dehydrogenase/genetics , Humans , Polymorphism, Restriction Fragment Length , Triose-Phosphate Isomerase/genetics
12.
Nucleic Acids Res ; 46(13): 6712-6725, 2018 07 27.
Article in English | MEDLINE | ID: mdl-29788454

ABSTRACT

Despite the key role of the human ribosome in protein biosynthesis, little is known about the extent of sequence variation in ribosomal DNA (rDNA) or its pre-rRNA and rRNA products. We recovered ribosomal DNA segments from a single human chromosome 21 using transformation-associated recombination (TAR) cloning in yeast. Accurate long-read sequencing of 13 isolates covering ∼0.82 Mb of the chromosome 21 rDNA complement revealed substantial variation among tandem repeat rDNA copies, several palindromic structures and potential errors in the previous reference sequence. These clones revealed 101 variant positions in the 45S transcription unit and 235 in the intergenic spacer sequence. Approximately 60% of the 45S variants were confirmed in independent whole-genome or RNA-seq data, with 47 of these further observed in mature 18S/28S rRNA sequences. TAR cloning and long-read sequencing enabled the accurate reconstruction of multiple rDNA units and a new, high-quality 44 838 bp rDNA reference sequence, which we have annotated with variants detected from chromosome 21 of a single individual. The large number of variants observed reveal heterogeneity in human rDNA, opening up the possibility of corresponding variations in ribosome dynamics.


Subject(s)
Chromosomes, Human, Pair 21 , DNA, Ribosomal/chemistry , Genes, rRNA , Genetic Variation , Animals , Cell Line , Cloning, Molecular , DNA, Ribosomal/isolation & purification , DNA, Ribosomal Spacer/chemistry , Humans , Mice , Nucleic Acid Conformation , Nucleolus Organizer Region/chemistry , RNA, Ribosomal/chemistry , RNA, Ribosomal/metabolism , Sequence Analysis, DNA
13.
Proc Natl Acad Sci U S A ; 114(7): 1726-1731, 2017 02 14.
Article in English | MEDLINE | ID: mdl-28137844

ABSTRACT

The movement of nuclear DNA from one vascular plant species to another in the absence of fertilization is thought to be rare. Here, nonnative rRNA gene [ribosomal DNA (rDNA)] copies were identified in a set of 16 diploid barley (Hordeum) species; their origin was traceable via their internal transcribed spacer (ITS) sequence to five distinct Panicoideae genera, a lineage that split from the Pooideae about 60 Mya. Phylogenetic, cytogenetic, and genomic analyses implied that the nonnative sequences were acquired between 1 and 5 Mya after a series of multiple events, with the result that some current Hordeum sp. individuals harbor up to five different panicoid rDNA units in addition to the native Hordeum rDNA copies. There was no evidence that any of the nonnative rDNA units were transcribed; some showed indications of having been silenced via pseudogenization. A single copy of a Panicum sp. rDNA unit present in H. bogdanii had been interrupted by a native transposable element and was surrounded by about 70 kbp of mostly noncoding sequence of panicoid origin. The data suggest that horizontal gene transfer between vascular plants is not a rare event, that it is not necessarily restricted to one or a few genes only, and that it can be selectively neutral.


Subject(s)
Cell Nucleus/genetics , DNA, Ribosomal/genetics , Gene Transfer, Horizontal , Phylogeny , Poaceae/genetics , DNA, Plant/chemistry , DNA, Plant/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Diploidy , Evolution, Molecular , Genes, Plant/genetics , Hordeum/classification , Hordeum/genetics , Poaceae/classification , Sequence Analysis, DNA
14.
Int J Mol Sci ; 21(17)2020 Sep 03.
Article in English | MEDLINE | ID: mdl-32899108

ABSTRACT

The crucial function of the internal transcribed spacer 2 (ITS2) region in ribosome biogenesis depends on its secondary and tertiary structures. Despite rapidly evolving, ITS2 is under evolutionary constraints to maintain the specific secondary structures that provide functionality. A link between function, structure and evolution could contribute an understanding to each other and recently has created a growing point of sequence-structure phylogeny of ITS2. Here we briefly review the current knowledge of ITS2 processing in ribosome biogenesis, focusing on the conservative characteristics of ITS2 secondary structure, including structure form, structural motifs, cleavage sites, and base-pair interactions. We then review the phylogenetic implications and applications of this structure information, including structure-guiding sequence alignment, base-pair mutation model, and species distinguishing. We give the rationale for why incorporating structure information into tree construction could improve reliability and accuracy, and some perspectives of bioinformatics coding that allow for a meaningful evolutionary character to be extracted. In sum, this review of the integration of function, structure and evolution of ITS2 will expand the traditional sequence-based ITS2 phylogeny and thus contributes to the tree of life. The generality of ITS2 characteristics may also inspire phylogenetic use of other similar structural regions.


Subject(s)
DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Evolution, Molecular , Genetic Speciation , Phylogeny , Animals , DNA, Ribosomal Spacer/metabolism , Humans
15.
J Clin Microbiol ; 57(9)2019 09.
Article in English | MEDLINE | ID: mdl-31189587

ABSTRACT

The Trichophyton rubrum species complex comprises commonly encountered dermatophytic fungi with a worldwide distribution. The members of the complex usually have distinct phenotypes in culture and cause different clinical symptoms, despite high genome similarity. In order to better delimit the species within the complex, molecular, phenotypic, and physiological characteristics were combined to reestablish a natural species concept. Three groups, T. rubrum, T. soudanense, and T. violaceum, could be distinguished based on the sequence of the internal transcribed spacer (ITS) ribosomal DNA barcode gene. On average, strains within each group were similar by colony appearance, microscopy, and physiology, but strains between groups showed significant differences. Trichophyton rubrum strains had higher keratinase activity, whereas T. violaceum strains tended to be more lipophilic; however, none of the phenotypic features were diagnostic. The results of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and amplified fragment length polymorphism (AFLP) were partially consistent with the ITS data but failed to distinguish the species unambiguously. Despite their close similarity, T. violaceum, T. soudanense, and T. rubrum can be regarded as independent species with distinct geographical distributions and clinical predilections. Trichophyton soudanense is pheno- and genotypically intermediate between T. rubrum and T. violaceum For routine diagnostics, ITS sequencing is recommended.


Subject(s)
Trichophyton/classification , Amplified Fragment Length Polymorphism Analysis , Cluster Analysis , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Humans , Microbiological Techniques , Microscopy , Phylogeny , Sequence Analysis, DNA , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tinea/microbiology , Trichophyton/genetics , Trichophyton/isolation & purification , Trichophyton/physiology
16.
J Clin Microbiol ; 57(2)2019 02.
Article in English | MEDLINE | ID: mdl-30487306

ABSTRACT

The fungal order Onygenales includes many pathogens of humans and animals, and recent studies have shown some onygenalean fungi to be significant emerging pathogens of reptiles. Although many of these fungi have similar morphological features in histologic tissue sections, recent molecular analyses have revealed a genetically complex and diverse group of reptile pathogens comprising several genera, most notably Nannizziopsis, Ophidiomyces, and Paranannizziopsis Infections by members of these genera have been previously reported in a variety of reptile species, including crocodilians, lizards, snakes, and tuataras, with negative impacts on conservation efforts for some reptiles. Despite the well-documented pathogenicity of these fungi in all other extant reptile lineages, infection has not yet been reported in aquatic turtles. In this study, we report the isolation of an onygenalean fungus associated with shell lesions in freshwater aquatic turtles. The morphologic and genetic characteristics of multiple isolates (n = 21) are described and illustrated. Based on these features and results of a multigene phylogenetic analysis, a new genus and species, Emydomyces testavorans, are proposed for these fungi isolated from turtle shell lesions.


Subject(s)
Animal Shells/microbiology , Mycoses/veterinary , Onygenales/classification , Onygenales/isolation & purification , Phylogeny , Turtles/microbiology , Actins/genetics , Animals , Antifungal Agents/pharmacology , Cluster Analysis , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Fresh Water , Genes, rRNA , Histocytochemistry , Microbial Sensitivity Tests , Microbiological Techniques , Microscopy , Mycoses/microbiology , Onygenales/cytology , Onygenales/genetics , RNA, Fungal/genetics , RNA, Ribosomal, 18S/genetics , RNA, Ribosomal, 28S/genetics , Sequence Analysis, DNA
17.
J Clin Microbiol ; 57(2)2019 02.
Article in English | MEDLINE | ID: mdl-30463892

ABSTRACT

A total of 133 clinical Trichosporon isolates were collected in the National China Hospital Invasive Fungal Surveillance Net (CHIF-NET) program in 2009 to 2016. Accurate identification was performed by sequencing of the intergenic spacer 1 (IGS1) region. Among these isolates, Trichosporon asahii (108 isolates [81.2%]) was the leading species, followed by Trichosporon dermatis (7 isolates [5.3%]), Trichosporon asteroides (5 isolates [3.8%]), Trichosporon inkin (5 isolates [3.8%]), Trichosporon dohaense (3 isolates [2.3%]), and 1 isolate (0.7%) each of Trichosporon faecale, Trichosporon jirovecii, Trichosporon mucoides, Trichosporon coremiiforme, and Trichosporon montevideense Both the Vitek mass spectrometry (MS) (bioMérieux, Marcy l'Etoile, France) and Bruker Biotyper MS (Bruker Daltonics GmbH, Germany) platforms gave high levels (>97.5%) of correct identification when the species were present in the database. The geometric mean (GM) of amphotericin B MICs for T. asahii was 2-fold higher than that for non-asahii Trichosporon High fluconazole MICs (≥8 µg/ml) were observed for 25% of T. asahii isolates (27/108 isolates) and 16% of non-asahii Trichosporon (4/25 isolates) isolates. Itraconazole MICs were ≤0.5 µg/ml for 89.5% of the isolates. Voriconazole was the most potent antifungal agent in vitro, with a GM of 0.09 µg/ml. Genotyping of the isolates using IGS1 sequence alignment revealed that genotype 1 was most common (41.7%), followed by genotype 4 (31.5%), genotype 3 (23.1%), genotype 5 (0.9%), genotype 6 (0.9%), and genotype 7 (1.8%). Our data on species distribution, genotypes, and antifungal susceptibilities may contribute to a better understanding of the epidemiology of invasive Trichosporon infections throughout China.


Subject(s)
Antifungal Agents/pharmacology , Genotype , Invasive Fungal Infections/epidemiology , Trichosporon/isolation & purification , Trichosporonosis/epidemiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , China/epidemiology , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Female , Genotyping Techniques , Humans , Infant , Infant, Newborn , Invasive Fungal Infections/microbiology , Male , Microbiological Techniques , Middle Aged , Prospective Studies , Sequence Analysis, DNA , Trichosporon/classification , Trichosporon/drug effects , Trichosporon/genetics , Trichosporonosis/microbiology , Young Adult
18.
Histochem Cell Biol ; 152(4): 271-280, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31346697

ABSTRACT

In human cells, the intergenic spacers (IGS), which separate ribosomal genes, are complex approximately 30 kb-long loci. Recent studies indicate that all, or almost all, parts of IGS may be transcribed, and that at least some of them are involved in the regulation of the ribosomal DNA (rDNA) transcription, maintenance of the nucleolar architecture, and response of the cell nucleus to stress. However, since each cell contains hundreds not quite identical copies of IGS, the structure and functions of this locus remain poorly understood, and the dynamics of its products has not been specially studied. In this work, we used quantitative PCR to measure the expression levels of various rDNA regions at different times after inhibition of the transcription by Actinomycin D applied in high doses. This approach allowed us to measure real or extrapolated half-life times of some IGS loci. Our study reveals characteristic dynamic patterns suggestive of various pathways of RNA utilization and decay.


Subject(s)
DNA, Ribosomal Spacer/metabolism , RNA/biosynthesis , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , HeLa Cells , Humans , RNA/analysis , RNA/genetics , RNA/isolation & purification
19.
Mol Phylogenet Evol ; 139: 106531, 2019 10.
Article in English | MEDLINE | ID: mdl-31185298

ABSTRACT

Semi-aquatic freshwater earthworms in the genus Glyphidrilus from Southeast Asia are characterized by both an extreme morphological crypsis among divergent phylogenetic lineages and a high morphological variability within the same phylogenetic lineages. The present study provides a new taxonomic framework for this problematic genus in SE Asia by integrating DNA sequence and morphological data. When single-locus and multilocus multispecies coalescent-based (MSC) species delimitation methods were applied to DNA sequence data, they usually yielded highly incongruent results compared to morphology-based species identifications. This suggested the presence of several cryptic species and high levels of intraspecific morphological variation. Applying reciprocal monophyly to the cytochrome c oxidase subunit 1 (COI) gene tree allowed us to propose the existence of 33 monophyletic species. Yet, often substantially more molecular operational taxonomic units (MOTUs) were obtained when species delimitation was based on COI and 16S rRNA sequences. In contrast, the ITS1 and ITS2 sequences suggested fewer MOTUs and did not recover most of the monophyletic species from the Mekong basin. However, several of these latter taxa were better supported when MSC species delimitation methods were applied to the combined mtDNA and ITS datasets. The ITS2 secondary structure retrieved one unnamed Mekong basin species that was not uncovered by the other methods when applied to ITS2 sequences. In conclusion, based on an integrative taxonomic workflow, 26 Glyphidrilus candidate species were retained and two remained to be confirmed. As such, this study provides evidence to suggest nine species new to science and to synonymize 12 nominal morphospecies. It also illustrates that the uncritical use of COI as a universal DNA barcode may overestimate species diversity because COI may be unable to distinguish between divergent conspecific lineages and different candidate species.


Subject(s)
Aquatic Organisms/classification , Oligochaeta/anatomy & histology , Oligochaeta/classification , Animals , Aquatic Organisms/genetics , Asia, Southeastern , Base Sequence , Bayes Theorem , DNA Barcoding, Taxonomic , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Nucleic Acid Conformation , Oligochaeta/genetics , Phylogeny , Polymorphism, Genetic , Species Specificity
20.
Microb Pathog ; 129: 168-175, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30742949

ABSTRACT

In this present study, for the first time, we evaluated the cystic fibrosis (CF) patients for the Scedosporium species and their antifungal susceptibility against eight antifungal agents. During one-year period, 90 Sputum samples were collected from Iranian CF patients. All samples were evaluated by direct microscopic examination, culture onto four different media including Malt extract agar, Inhibitory mold agar, Brain Heart Infusion and Scedo-Select III. The mold isolated fungi were identified by PCR-Sequencing of ITS and ß-tubulin genes. In-vitro antifungal susceptibility was performed according to the Clinical & Laboratory Standards Institute (CLSI) M38-A2 guidelines. Out of 90 CF patients, 47 (52.2%) were male. The age of the patients ranged from 1 to 34 years (median of 15.84 ±â€¯7.41 years). Overall, 3 (3.3%) cases were positive for Scedosporium spp. of which two isolates were characterized as Scedosporium boydii and one isolate as S. ellipsoideum. Among Aspergillus genus, A. flavus (29.4%) was the most prevalent species followed by A. tubingensis (24.7%), A. niger (17.0%) and A. fumigatus (14.5%). The minimum effective concentration ranges of micafungin, anidulafungin, and caspofungin were 0.008-0.031 µg/mL, 0.0625-0.25 µg/mL, and 0.0625-0.25 µg/mL, respectively. All isolates of Scedosporium species showed high minimum inhibitory concentration to the triazoles tested, except voriconazole. Our results showed that A. flavus and Scedosporium species are the most prevalent molds isolated from CF patient populations in Iran. Our findings have also showed that Scedo-Select III can be used as a reliable culture media for isolation of Scedosporium spp. in clinical samples.


Subject(s)
Cystic Fibrosis/complications , Lung Diseases, Fungal/epidemiology , Lung Diseases, Fungal/microbiology , Scedosporium/isolation & purification , Adolescent , Adult , Antifungal Agents/pharmacology , Child , Child, Preschool , Cluster Analysis , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Female , Humans , Infant , Iran/epidemiology , Male , Microbial Sensitivity Tests , Microbiological Techniques , Microscopy , Phylogeny , Prevalence , Prospective Studies , Scedosporium/classification , Scedosporium/genetics , Sequence Analysis, DNA , Tubulin/genetics , Young Adult
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