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1.
JMIR Res Protoc ; 12: e45684, 2023 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-37171840

RESUMO

BACKGROUND: Effective dissemination of research to health and social care practitioners enhances clinical practice and evidence-based care. Social media use has potential to facilitate dissemination to busy practitioners. OBJECTIVE: This is a protocol for a systematic review that will quantitatively synthesize evidence of the effectiveness of social media, compared with no social media, for dissemination of research evidence to health and social care practitioners. Social media platforms, formats, and sharing mechanisms used for effective dissemination of research evidence will also be identified and compared. METHODS: Electronic database searches (MEDLINE, PsycINFO, CINAHL, ERIC, LISTA, and OpenGrey) will be conducted from January 1, 2010, to January 10, 2023, for studies published in English. Randomized, nonrandomized, pre-post study designs or case studies evaluating the effect of social media on dissemination of research evidence to postregistration health and social care practitioners will be included. Studies that do not involve social media or dissemination or those that evaluate dissemination of nonresearch information (eg, multisource educational materials) to students or members of the public only, or without quantitative data on outcomes of interest, will be excluded. Screening will be carried out by 2 independent reviewers. Data extraction and quality assessment, using either the Cochrane tool for assessing risk of bias or the Newcastle-Ottawa Scale, will be completed by 2 independent reviewers. Outcomes of interest will be reported in 4 domains (reach, engagement, dissemination, and impact). Data synthesis will include quantitative comparisons using narrative text, tables, and figures. A meta-analysis of standardized pooled effects will be undertaken, and subgroup analyses will be applied, if appropriate. RESULTS: Searches and screening will be completed by the end of May 2023. Data extraction and analyses will be completed by the end of July 2023, after which findings will be synthesized and reported by the end of October 2023. CONCLUSIONS: This systematic review will summarize the evidence for the effectiveness of social media for the dissemination of research evidence to health and social care practitioners. The limitations of the evidence may include multiple outcomes or methodological heterogeneity that limit meta-analyses, potential risk of bias in included studies, and potential publication bias. The limitations of the study design may include potential insensitivity of the electronic database search strategy. The findings from this review will inform the dissemination practice of health and care research. TRIAL REGISTRATION: PROSPERO CRD42022378793; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=378793. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/45684.

2.
J Gerontol Nurs ; 49(2): 36-42, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36719658

RESUMO

The devastating effects of coronavirus disease 2019 (COVID-19) highlight the critical need for effective infection prevention and control (IPC) practices in nursing homes. Nursing management and infection preventionists should be cognizant of the most common reasons underlying federal IPC citations during the pandemic. Analysis of IPC citation data from the first 7 months of the public health emergency identified that adherence to personal protective equipment (PPE) and mask use, appropriate transmission-based precautions, and hand hygiene were the most common reasons for COVID-19-related F880 citations, including those that placed a person at immediate risk for serious injury or death. More specific staff practices and other factors leading to a citation are also highlighted. Although nursing homes may have limited control over factors such as PPE supply and staffing resources, nursing management and infection preventionists can use these results to help ensure that operational mechanisms, staff training, and adherence monitoring efforts effectively address the areas most associated with COVID-19 IPC noncompliance. [Journal of Gerontological Nursing, 49(2), 36-42.].


Assuntos
COVID-19 , Humanos , COVID-19/prevenção & controle , Pandemias/prevenção & controle , Casas de Saúde , Instituições de Cuidados Especializados de Enfermagem , Controle de Infecções/métodos
3.
BMJ ; 376: o134, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-35082137

RESUMO

The studyMcCarthy M, Bates C, Elson N, Hunt S, Milne-Skillman, Forrester-Jones R. 'Love makes me feel good inside and my heart is fixed': What adults with intellectual disabilities have to say about love and relationships. J Appl Res Intellect Disabil 2021;00:1-11.To read the full NIHR Alert, go to: https://evidence.nihr.ac.uk/alert/romantic-relationships-adults-with-learning-disabilities/.


Assuntos
Corte/psicologia , Deficiências da Aprendizagem/psicologia , Amor , Apoio Social , Adulto , Feminino , Humanos , Deficiências da Aprendizagem/reabilitação , Masculino
4.
IMA Fungus ; 11: 20, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33062585

RESUMO

We formed the Collection of Zoosporic Eufungi at the University of Michigan (CZEUM) in 2018 as a cryopreserved fungal collection consolidating the University of Maine Culture Collection (UMCC, or JEL), the University of Alabama Chytrid Culture Collection (UACCC), and additional zoosporic eufungal accessions. The CZEUM is established as a community resource containing 1045 cryopreserved cultures of Chytridiomycota, Monoblepharidomycota, and Blastocladiomycota, with 52 cultures being ex-type strains. We molecularly characterized 431 cultures by amplifying the majority of the rDNA operon in a single reaction, yielding an average fragment length of 4739 bp. We sequenced multiplexed samples with an Oxford Nanopore Technology MinION device and software, and demonstrate the method is accurate by producing sequences identical to published Sanger sequences. With these data, we generated a phylogeny of 882 zoosporic eufungi strains to produce the most comprehensive phylogeny of these taxa to date. The CZEUM is thus largely characterized by molecular data, which can guide instructors and researchers on future studies of these organisms. Cultures from the CZEUM can be purchased through an online portal.

5.
Fungal Biol ; 123(2): 109-116, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30709516

RESUMO

This study reconstructs early stages of Rozella allomycis endoparasitic infection of its host, Allomyces macrogynus. Young thalli of A. macrogynus were inoculated with suspensions of R. allomycis zoospores and allowed to develop for 120 h. Infected thalli at intervals were fixed for electron microscopy and observed. Zoospores were attracted to host thalli, encysted on their surfaces, and penetrated their walls with an infection tube. The parasite cyst discharged its protoplast through an infection tube, which invaginated the host plasma membrane. The host plasma membrane then surrounded the parasite protoplast and formed a compartment confining it inside host cytoplasm. The earliest host-parasite interface within host cytoplasm consisted of two membranes, the outer layer the host plasma membrane and the inner layer the parasite plasma membrane. At first a wide space separated the two membranes and no material was observed within this space. Later, as the endoparasite thallus expanded within the compartment, the two membranes became closely appressed. As the endoparasite thallus continued to enlarge, the interface developed into three membrane layers. Thus, host plasma membrane surrounded the parasite protoplast initially without the parasite having to pierce the host plasma membrane for entry. Significantly, host-derived membrane was at the interface throughout development.


Assuntos
Allomyces/ultraestrutura , Fungos/ultraestrutura , Interações Hospedeiro-Parasita/fisiologia , Microscopia Eletrônica/métodos , Esporos Fúngicos/ultraestrutura , Membrana Celular/ultraestrutura
6.
IMA Fungus ; 10: 4, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-32647613

RESUMO

Aphelids are parasitoids of various algae and diatoms, and in a recent classification are contained in family Aphelidiaceae, phylum Aphelidiomycota, kingdom Fungi. Family Aphelidiaceae (the only family in the phylum) is composed of four genera: Aphelidium, Paraphelidium, Amoeboaphelidium, and Pseudaphelidium. All species are known morphologically, and most have been illustrated. Few have been examined ultrastructurally, and even fewer have been sequenced for molecular comparisons. Recent studies in molecular phylogenetics have revealed an abundance of related environmental sequences that indicate unrealized biodiversity within the group. Herein, we briefly summarize the history of aphelids and acknowledge the controversy of placement of the group with related organisms. With light microscopic images and transmission electron micrographs, we illustrate typical life cycle stages for aphelids, provide updated descriptions and taxonomy for all described species, and provide a key to the species.

7.
J Eukaryot Microbiol ; 66(1): 4-119, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30257078

RESUMO

This revision of the classification of eukaryotes follows that of Adl et al., 2012 [J. Euk. Microbiol. 59(5)] and retains an emphasis on protists. Changes since have improved the resolution of many nodes in phylogenetic analyses. For some clades even families are being clearly resolved. As we had predicted, environmental sampling in the intervening years has massively increased the genetic information at hand. Consequently, we have discovered novel clades, exciting new genera and uncovered a massive species level diversity beyond the morphological species descriptions. Several clades known from environmental samples only have now found their home. Sampling soils, deeper marine waters and the deep sea will continue to fill us with surprises. The main changes in this revision are the confirmation that eukaryotes form at least two domains, the loss of monophyly in the Excavata, robust support for the Haptista and Cryptista. We provide suggested primer sets for DNA sequences from environmental samples that are effective for each clade. We have provided a guide to trophic functional guilds in an appendix, to facilitate the interpretation of environmental samples, and a standardized taxonomic guide for East Asian users.


Assuntos
Biodiversidade , Eucariotos/classificação , Filogenia , Terminologia como Assunto
8.
J Eukaryot Microbiol ; 66(3): 404-412, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30099810

RESUMO

Zoospores of the oomycete Saprolegnia ferax release adhesive material from K-bodies at the onset of attachment to substrates. To understand more fully how K-bodies function in adhesion, enzyme activity was investigated cytochemically in secondary zoospores. Presence of catalase, a marker enzyme for microbodies, was explored in the diaminobenzidine (DAB) reaction. Although pH 9.2 DAB-staining characteristic of catalase activity was detected in the granular matrix regions of K-bodies, reaction controls indicated that the reaction was due to oxidative enzyme activity other than catalase. Because polyphenol oxidase (PPO) is another metal-containing enzyme capable of oxidizing DAB, activity of this enzyme was tested with a more specific substrate, dihydroxyphenylalanine (DOPA). In the DOPA procedure, reaction product was exclusively localized within K-bodies, indicating the presence of PPO. Results with three methods of reaction controls (elimination of substrate, addition of a PPO enzyme inhibitor, and heat-inactivation of enzymes) all supported the presence of PPO in K-bodies. This study highlights potential roles for K-body PPO in stabilization of adhesion bodies by: cross-linking matrix phenolic proteins or glycoproteins as K-bodies discharge adhesives onto substrates, or polymerizing phenolics protective against microbial attacks of the adhesion pad.


Assuntos
Catecol Oxidase/metabolismo , Saprolegnia/metabolismo , Microcorpos/metabolismo
9.
Fungal Biol ; 122(12): 1171-1183, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30449355

RESUMO

The purpose of our research is to investigate the morphology, zoospore ultrastructure, and molecular phylogenetic placement of a chytrid from Australia. From a survey of chytrid fungi in New South Wales, Australia, we isolated strain PL AUS 026 and putatively identified it as Polyphlyctis unispina. Light microscopic evaluation determined strain PL AUS 026 to be similar to two other strains of P. unispina characterized in the literature but to have a more complex thallus than that of the type. Molecular phylogenetic analyses placed our strain as sister of or basal to Chytridiaceae, Chytridiales. Ultrastructural analysis of the zoospore of strain PL AUS 026 revealed unique features. On the basis of our analyses we designate strain PL AUS 026 as a new species, Polyphlyctis willoughbyi. This research extends our concept of Chytridiaceae systematics and ultrastructural variation in the Chytridiales zoospore.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/citologia , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/citologia , Quitridiomicetos/genética , Quitridiomicetos/ultraestrutura , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Microscopia , Microscopia Eletrônica de Transmissão , New South Wales , RNA Fúngico/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Esporos Fúngicos/genética , Esporos Fúngicos/ultraestrutura
10.
Mycologia ; 110(5): 811-821, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30274555

RESUMO

Food webs in temporary forest ponds are driven by decomposition of terrestrial inputs. Chytrid fungi are important components of the fungal community, degrading leaf litter in streams reliant on terrestrial inputs and in lake ecosystems where they may stabilize the food web. However, little is known about chytrid fungi in temporary forest ponds. We inventoried the chytrid diversity present in two temporary forest ponds via light microscopy of baited samples and ion semiconductor (Ion Torrent) sequencing of environmental DNA. We quantified trends of chytrid alpha and beta diversity as a function of spatial and temporal factors. A total of 59 chytrid taxa were detected throughout the study. Beta diversity exhibited variation across the sampled months for both the entire fungal community as well as for chytrids alone. Shifts in community composition were also apparent, although diversity metrics and composition patterns did not meet adjusted P values. The results of this study highlight the diversity of chytrid fungi in temporary forest ponds and the need for further studies on the spatial and temporal dynamics of chytrid species.


Assuntos
Biodiversidade , Quitridiomicetos/classificação , Quitridiomicetos/isolamento & purificação , Lagoas/microbiologia , Quitridiomicetos/citologia , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Florestas , Genes de RNAr , Microscopia , RNA Fúngico/genética , RNA Ribossômico 28S/genética , Análise de Sequência de DNA
11.
Fungal Biol ; 122(11): 1041-1049, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30342620

RESUMO

While surveying chytrid diversity in lakes and streams, we found on cellulosic bait a chytrid that had both monocentric and polycentric thallus forms. We brought this chytrid into axenic culture from three sites in eastern North America, studied its thallus development and zoospore ultrastructure, and compared its 28S rDNA sequence with those of other members of the Chytridiomycota. Thallus morphology matched that described for the rare chytrid, Cladochytrium polystomum Zopf. Sporangia were spherical and produced numerous long discharge tubes. After discharge, zoospores remained in spherical clusters at the tips of the inoperculate openings of discharge tubes. After 10-30 min zoospores either swam away or encysted in place. Zoospore ultrastructural features included a cell coat, flagellar plug, and paracrystalline inclusion, features typical of members of the Chytridiales. However, the flagellar apparatus structure and organellar organization differed from that of zoospores previously described. Based on its molecular phylogeny and its zoospore ultrastructural features, we classify C. polystomum as a member of the Chytridiaceae in the Chytridiales. Because its thallus development and its ribosomal DNA sequences diverged decidedly from those of Cladochytrium tenue Nowak, the type species of Cladochytrium, we erected Zopfochytrium as a new genus for this chytrid.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/isolamento & purificação , Esporos Fúngicos/ultraestrutura , Quitridiomicetos/genética , Quitridiomicetos/ultraestrutura , Lagos/microbiologia , Microscopia Eletrônica de Transmissão , Filogenia , Rios/microbiologia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
12.
Fungal Biol ; 122(11): 1109-1123, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30342626

RESUMO

The purpose of our research is to investigate morphology, zoospore ultrastructure, and molecular placement of six strains in the Asterophlyctis (Chytridiales) lineage. In previous molecular analyses strain JEL 186, putatively Asterophlyctis sarcoptoides, placed as basal in family Chytriomycetaceae. Recent sampling for chytrids resulted in isolation of five strains (WJD 209, MP 058, JEL 524, JEL 857, and JEL 885) molecularly related to strain JEL 186. Our morphological evaluations reveal that strains JEL 186 and WJD 209 are members of Asterophlyctis. Strain WJD 209 is considered representative of the type, A. sarcoptoides, and strain JEL 186 a new species, Asterophlyctis michiganensis. The four strains MP 058, JEL 524, JEL 857, and JEL 885 are distinct from Asterophlyctis, and we consider them as members of a new genus, Wheelerophlyctis, composed of two species, Wheelerophlyctis interior and Wheelerophlyctis interiexterior. Asterophlyctis and Wheelerophlyctis are sister taxa and we demarcate that lineage as Asterophlyctaceae. The two genera also have similar zoospore ultrastructure, which is unique among strains in Chytridiales. In consideration of their molecular position and zoospore ultrastructure, we hypothesize that Asterophlyctis and Wheelerophlyctis represent a bridge between Chytriomycetaceae and Chytridiaceae. This research expands our concepts of systematics and zoospore ultrastructural variation in Chytridiales.


Assuntos
Quitridiomicetos/crescimento & desenvolvimento , Quitridiomicetos/isolamento & purificação , Esporos Fúngicos/ultraestrutura , Quitridiomicetos/classificação , Quitridiomicetos/genética , DNA Fúngico/genética , DNA Ribossômico/genética , Água Doce/microbiologia , Microscopia Eletrônica de Transmissão , Filogenia , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação
13.
IMA Fungus ; 9: 383-399, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30622888

RESUMO

Rozella is a genus of endoparasites of a broad range of hosts. Most species are known by their morphology and host specificity, while only three have been examined ultrastructurally and had portions of their genome sequenced. Determined in molecular phylogenies to be the earliest diverging lineage in kingdom Fungi, Rozella currently nests among an abundance of environmental sequences in phylum Cryptomycota, superphylum Opisthosporidia. Here we briefly summarize a history of Rozella, provide descriptions of all species, and include a key to the species of Rozella.

14.
J Eukaryot Microbiol ; 65(2): 180-190, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28749611

RESUMO

Increasing numbers of sequences of basal fungi from environmental DNA studies are being deposited in public databases. Many of these sequences remain unclassified below the phylum level because sequence information from identified species is sparse. Lack of basic biological knowledge due to a dearth of identified species is extreme in Cryptomycota, a new phylum widespread in the environment and phylogenetically basal within the fungal lineage. Consequently, we are attempting to fill gaps in the knowledge of Rozella, the best-known genus in this lineage. Rozella is a genus of unwalled, holocarpic, endobiotic parasites of hosts including Chytridiomycota, Blastocladiomycota, Oomycota, Basidiomycota, and a green alga, with most species descriptions based on morphology and host specificity. We found a Rozella parasitizing a Pythium host that was a saprobe on spruce pollen bait placed with an aquatic sample. We characterized the parasite with light microscopy, TEM of its zoospores and sporangia, and its 18S/28S rDNA. Comparison with other Rozella species indicates that the new isolate differs morphologically, ultrastructurally, and genetically from Rozella species for which we have data. Features of the zoospore also differ from those of previously studied species. Herein we describe the Rozella as a new species, R. multimorpha.


Assuntos
Fungos/classificação , Fungos/genética , Fungos/ultraestrutura , Filogenia , DNA Fúngico/genética , DNA Ribossômico/genética , Microscopia Eletrônica de Transmissão , Pythium/microbiologia , Análise de Sequência de DNA
15.
Fungal Biol ; 121(6-7): 561-572, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28606351

RESUMO

Rozella allomycis is an obligate endoparasite of the water mold Allomyces and a member of a clade (= Opisthosporidia) sister to the traditional Fungi. Gaining insights into Rozella's development as a phylogenetically pivotal endoparasite can aid our understanding of structural adaptations and evolution of the Opisthosporidia clade, especially within the context of genomic information. The purpose of this study is to characterize the interface between R. allomycis and Allomyces anomalus. Electron microscopy of developing plasmodia of R. allomycis in host hyphae shows that the interface consists of three-membrane layers, interpreted as the parasite's plasma membrane (inner one layer) and a host cisterna (outer two layers). As sporangial and resting spore plasmodia develop, host mitochondria typically cluster at the surface of the parasite and eventually align parallel to the three-membrane layered interface. The parasite's mitochondria have only a few cristae and the mitochondrial matrix is sparse, clearly distinguishing parasite mitochondria from those of the host. Consistent with the expected organellar topology if the parasite plasmodia phagocytize host cytoplasm, phagocytic vacuoles are at first bounded by three-membrane layers with host-type mitochondria lining the inner membrane. Thus, Rozella's nutrition, at least in part, is phagotrophic in contrast to osmotrophic nutrition of traditional fungi.


Assuntos
Fungos/ultraestrutura , Interações Hospedeiro-Parasita , Microscopia Eletrônica , Organelas/ultraestrutura
16.
J Eukaryot Microbiol ; 64(5): 655-667, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28187245

RESUMO

Aphelids are a diverse group of intracellular parasitoids of algae and diatoms, and are sister to true fungi. Included in four genera, the 14 described species utilize phagocytosis as their mode of nutrition, and the life cycles of these taxa are remarkably similar. However, their putative specificity of host, morphological and ultrastructural features, and genetic divergence have been considered in taxon delineation. Here, we examine the host specificity, morphology, ultrastructure, and molecular 18S gene sequence of a new species in Aphelida, Aphelidium desmodesmi sp. nov. This taxon is in a well-supported clade with two other species of Aphelidium, and this lineage is sister to Amoeboaphelidium and Paraphelidium. Of interest, the mitochondrial structure of Aph. desmodesmi is more like that of Paraphelidium than that of Aphelidium aff. melosirae, the only other species of Aphelidium to have been examined ultrastructurally. This research examines and expands our understanding of host range, morphological diversity, and genetic divergence of the aphelids.


Assuntos
Eucariotos/classificação , Análise de Sequência de DNA/métodos , DNA Ribossômico/genética , Eucariotos/genética , Eucariotos/ultraestrutura , Especificidade de Hospedeiro , Microscopia Eletrônica de Transmissão , Filogenia , RNA Ribossômico 18S/genética
17.
Fungal Biol ; 121(1): 1-10, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28007212

RESUMO

Rozella is a genus of unwalled endoparasites of a variety of hosts including Oomycota (Stramenopiles), Blastocladiomycota and Chytridiomycota (Fungi), and one green alga (Coleochaete, Chlorophyceae). It currently includes more than 20 formally described species, and no new species of Rozella have been described since 1987. We discovered a new Rozella species parasitizing Rhizoclosmatium globosum (Chytridiales, Chytridiomycota) and investigated its morphology, ultrastructure, and phylogenetic position. Herein named as Rozella rhizoclosmatii sp. nov., the organism induces hypertrophy of the host. Its zoospore is ultrastructurally similar to that of Rozella allomycis, although it has a unique zoospore ultrastructural feature, a lattice of perpendicular rods about the nucleus. The 18S rDNA molecular sequence of R. rhizoclosmatii is similar to that of the previously sequenced 'Rozella ex Rhizoclosmatium'. This is the first study to inclusively characterize a new species of Rozella with morphological, ultrastructural and molecular data. As this is only the second Rozella species to be examined ultrastructurally, and because it is parasitic on a member of Chytridiomycota and not Blastocladiomycota, this research supports the conservative nature of zoospore ultrastructure to help define the genus.


Assuntos
Fungos/classificação , Fungos/isolamento & purificação , Filogenia , Esporos Fúngicos/ultraestrutura , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fungos/genética , Fungos/ultraestrutura , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
18.
Mycologia ; 108(4): 731-43, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27582565

RESUMO

Only a few chytrid fungi have been reported as parasites of dinoflagellates. Among these reports, chytrids are periodically observed growing on the dinoflagellate, Peridinium gatunense, in Lake Kinneret (Sea of Galilee), Israel. Because of the distinctive roles of parasitic chytrid fungi in decreasing phytoplankton populations and in transforming inedible algae into chytrid biomass which zooplankton grazers can eat, characterizing dinoflagellate parasites contributes to our understanding of the sustainability of this important water resource. An undescribed chytrid parasite of P. gatunense from Lake Kinneret has recently been brought into pure culture (KLL_TL-060613), facilitating exploration of its infection process. To evaluate the ability of this chytrid to affect host populations, we determined the effect of: (1) temperature and light (or dark) on prevalence of infection and (2) host growth phase and parasite:host ratio on percentage of infection. The greatest amplification in host infection occurred in cultures grown in the dark at 25 C. The percentage of host cells infected increased as the availability of host cells compared to parasite cells increased. These results demonstrate that environmental factors influence the chytrid's potential to affect Peridinium gatunense populations. Because this chytrid had not been described taxonomically, we characterized its thallus morphology, development, zoospore ultrastructure and phylogenetic relationships. Zoospore ultrastructure was compatible with the Group II type zoospore characteristic of the family Chytridiaceae in the Chytridiales. Consistent with this observation, phylogenetic analyses of nuc 28S rDNA D1-D3 domains (28S) placed the chytrid in a clade among described taxa in the Chytridiaceae. Because thallus morphology was distinct from these other taxa, as well as other described parasites of dinoflagellates, this chytrid is described as a new genus and species, Dinochytrium kinnereticum.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/isolamento & purificação , Dinoflagellida/microbiologia , Quitridiomicetos/genética , Quitridiomicetos/fisiologia , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Interações Hospedeiro-Parasita , Israel , Luz , Microscopia , Filogenia , RNA Ribossômico 28S/genética , Análise de Sequência de DNA , Temperatura
19.
Mycologia ; 108(4): 744-52, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27582566

RESUMO

Zoospore ultrastructural characters combined with molecular phylogenetic hypotheses have been used to revise the taxonomy of zoosporic true fungi. An example is the reclassification of Rhizophlyctis rosea-like fungal strains into four new families and three new genera within the order Rhizophlyctidales. One genus was Borealophlyctis, which included a Canadian isolate, DAOMC 229843. A recent survey of chytrid diversity in Alabama (USA) yielded additional strains (WJD 170, WJD 171) in the Borealophlyctis lineage. With light and transmission-electron microscopy we examined strains DAOMC 229843, WJD 170 and WJD 171. We also analyzed partial nuc 28S rDNA D1-D3 domains (28S) and nuc rDNA region encompassing the internal transcribed spacers 1 and 2 and 5.8S (ITS) sequences to determine the phylogenetic placement of the strains within Rhizophlyctidales. Based on molecular divergence and morphological differences from the type Borealophlyctis paxensis, we recognize DAOMC 229843, WJD 170 and WJD 171 as representatives of the new species Borealophlyctis nickersoniae.


Assuntos
Quitridiomicetos/classificação , Quitridiomicetos/isolamento & purificação , Alabama , Canadá , Quitridiomicetos/citologia , Quitridiomicetos/genética , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Microscopia , Dados de Sequência Molecular , Filogenia , RNA Ribossômico 28S/genética , RNA Ribossômico 5,8S/genética , Análise de Sequência de DNA
20.
Fungal Biol ; 120(3): 324-37, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26895861

RESUMO

Successful algal cultivation for biofuel production is one path in the transition to a renewable energy economy. The green alga Scenedesmus dimorphus is a candidate for biofuel production, but is subject to parasitism and subsequent population crash when cultivated in open ponds. From an open pond cultivating S. dimorphus for biofuel production in New Mexico, USA, an amoeboid parasite was isolated, designated as isolate FD61, and its rDNA operon sequenced. A BLAST search for nuc 18S rDNA (18S) sequence similarity identified the parasite as Paraphysoderma sedebokerense (Blastocladiomycota). Here, we examine the ultrastructure of P. sedebokerense and compare it with that of a sister taxon, Physoderma maydis. The parasite has thin-walled vegetative sporangia and thick-walled resting sporangia. Our observations indicate that amoeboid swarmers are produced in the vegetative phase, while either amoeboid swarmers or zoospores are the product of meiosis in resting sporangia. Meiosis is confirmed by the presence of synaptonemal complexes in resting sporangia nuclei. Notably, P. sedebokerense has a Golgi apparatus with stacked cisternae, a feature reported for P. maydis, but which is absent in all other examined taxa in Blastocladiomycota. This report furthers our knowledge of the life cycle of P. sedebokerense.


Assuntos
Blastocladiomycota/ultraestrutura , Clorófitas/microbiologia , Blastocladiomycota/classificação , Blastocladiomycota/genética , Blastocladiomycota/isolamento & purificação , Análise por Conglomerados , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Dados de Sequência Molecular , Organelas/ultraestrutura , Filogenia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
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