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1.
Mar Pollut Bull ; 160: 111691, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33181960

RESUMO

High-throughput sequencing of microbial assemblages has been proposed as an alternative methodology to the traditional ones used in marine monitoring and environmental assessment. Here, we evaluated pico- and nanoplankton diversity as ecological indicators in NW Mediterranean coastal waters by comparing their diversity in samples subjected to varying degrees of continental pressures. Using metabarcoding of the 16S and 18S rRNA genes, we explored whether alphadiversity indices, abundance of Operational Taxonomic Units and taxonomic groups (and their ratios) provide information on the ecological quality of coastal waters. Our results revealed that only eukaryotic diversity metrics and a limited number of prokaryotic and eukaryotic taxa displayed potential in assessing continental influences in our surveyed area, resulting thus in a restrained potential of microbial plankton diversity as an ecological indicator. Therefore, incorporating microbial plankton diversity in environmental assessment could not always result in a significant improvement of current marine monitoring strategies.


Assuntos
Biodiversidade , Plâncton , Eucariotos , Sequenciamento de Nucleotídeos em Larga Escala , RNA Ribossômico 18S/genética
2.
Water Sci Technol ; 82(6): 1205-1216, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33055410

RESUMO

In the present study, 24 green microalgae strains were isolated from selected aquatic sites of India. These were microscopically identified as Chlamydomonas sp., Scenedesmus sp., Chlorella sp., Dictyosphaerium sp. and Dunaliella sp. Nannochloropsis sp. (MCC 25), was used as a reference strain. Results showed that Dictyosphaerium sp. (MCC 10 and MCC 12) showed relatively higher nutritive content. The total soluble proteins in the reference strain was 21.4%, whereas it showed carbohydrate content of 17.2% and the lipids were 3.4% on a dry weight basis. Best performing strains were identified by biochemical characterization. Five genera were selected for molecular identification since they were the most representative based upon their area of isolation and their optimum content of total soluble proteins, carbohydrates and lipids. 18S rRNA sequencing authenticated their identification as Scenedesmus sp., Dictyosphaerium sp. and Chlorella sp. The sequences of these have been submitted in NCBI database with accession numbers as KT808247-KT808251. The correlation matrix showed positive correlation between carbohydrates and lipids, while negative correlation was seen between proteins and carbohydrates and between proteins and lipids. This study emphasizes the need for complete compositional analysis of the biomass for the possible applicability in the area of value addition.


Assuntos
Chlorella , Microalgas , Chlorella/genética , Genes de RNAr , Índia , Microalgas/genética , RNA Ribossômico 18S/genética , Análise de Sequência
3.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(4): 380-383, 2020 Aug 24.
Artigo em Chinês | MEDLINE | ID: mdl-32935512

RESUMO

OBJECTIVE: To investigate the genetic variation of Eurytrema pancreaticum isolated from goats in Huaihua City, Hunan Province. METHODS: The partial sequence of mitochondrial cytochrome I (pcox1) and ribosomal 18S rRNA genes were amplified using a PCR assay in E. pancreaticum isolates from goats in Huaihua City, Hunan Province, and the PCR amplification products were sequenced. Then, the gene sequences were subjected to genetic variation and phylogenetic analyses. RESULTS: The sequences of the pcox1 and 18S rRNA genes were 430 bp and 1 857 bp in length in 18 E. pancreaticum isolates from goats in Huaihua City, Hunan Province, and there were 14 and 35 variation sites in pcox1 and 18S rRNA gene sequences, with intra-species genetic variations of 0 to 1.4% and 0 to 0.8%, respectively. The sequences of pcox1 and 18S rRNA genes had 99.0% to 99.8% and 99.5% to 99.8% homologies with those from E. pancreaticum Chinese strain recorded in the GenBank database. Consistent phylogenetic analysis results were found based on pcox1 and 18S rRNA genes. The 18 E. pancreaticum isolates from goats in Huaihua City were clustered into a clade with the known E. pancreaticum isolates registered in GenBank, and the clade with these 18 E. pancreaticum isolates was close to the clades with Eurytrema species and far from the clades with other trematodes. CONCLUSIONS: The E. pancreaticum isolates from goats have a low genetic variation in Huaihua City, Hunan Province. Mitochondrial pcox1 and ribosomal 18S rRNA genes may serve as molecular markers for the studies on the genetic variation in goat-derived E. pancreaticum.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons , Variação Genética , Cabras , RNA Ribossômico 18S , Trematódeos , Animais , Complexo IV da Cadeia de Transporte de Elétrons/genética , Cabras/parasitologia , Filogenia , RNA Ribossômico 18S/genética , Homologia de Sequência do Ácido Nucleico , Trematódeos/classificação , Trematódeos/genética , Trematódeos/isolamento & purificação
4.
Protist ; 171(4): 125751, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32890795

RESUMO

With highly specialized morphology and unexplored functional capacities, ciliates from extreme habitats are drawing increasing attention. During a microbial investigation of a solar saltern pond (salinity 240‰) on Mallorca, Spain, a previously unknown scuticociliate, Platynematum rossellomorai n. sp. was isolated, cultured and studied using a tripartite approach consisting of a morphological description, a molecular analysis and an ecophysiological characterization. The ciliate has distinct morphological characteristics and its main diagnostic features include a large anteriorly positioned oral area (occupying almost half of the body length), two caudal cilia and a small number of somatic kineties. However, due to the most important generic feature of Cinetochilidae, the consistency of the arrangement of the adoral membranes, the ciliate is classified as a new member of the genus Platynematum. Its 18S rRNA gene sequence shows a sequence similarity of 91.0% to the closest deposited relative, Platynematum salinarum, and a phylogenetic analysis reveals a close relationship to other members of the family Cinetochilidae Perty, 1852. Growth experiments identify the ciliate as a borderline halophile, with a tolerance range between 180 and 280‰ salinity. The ciliate apparently accumulates the compatible solutes glycine betaine and ectoine to counterbalance osmotic stress, however, other osmoregulatory mechanisms are not excluded.


Assuntos
Oligoimenóforos/classificação , Filogenia , Tanques/parasitologia , DNA de Protozoário/genética , Oligoimenóforos/citologia , Oligoimenóforos/genética , RNA Ribossômico 18S/genética , Espanha , Especificidade da Espécie
5.
Korean J Parasitol ; 58(4): 403-411, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32871634

RESUMO

Adult ascarid worms from the field mice, Apodemus agrarius, were observed with a light and scanning electron microscope, and molecularly analized with 18S rRNA gene. In the scanning electron microscope, 3 prominent labia were present in the anterior end of male and female worms, but the interlabia and gubernaculum were absent. Scanning electron micrographs showed cervical alae as vestigial organs that looked like a slightly uplifted superficial sewing stitch. Total 6 pairs of post-cloacal papillae were observed on the tail of the male worms. The tail of female worms was blunt and conical shape with a spine-like structure, mucron. The eggs were sub-globular, coated with the albuminous layer and 73 by 82 µm in average size. The superficial pits of T. apodemi egg (mean 8.6×6.7 µm) are obviously bigger than those of Toxocara spp. The partial sequence of 18S rRNA showed the sequence homology of Toxocara canis (99.6%), Toxocara cati (99.4%), Toxascaris leonina (99.4%), and Toxocara vitulorum (99.2%). Conclusively, it was confirmed that ascarid nematodes, Toxocara apodemi, recovered from striped field mice in Korea are taxonomically conspecific relationship with genus Toxocara and genetic divergence from other Toxocara species.


Assuntos
Murinae/parasitologia , Toxocara/genética , Toxocara/ultraestrutura , Animais , Feminino , Humanos , Masculino , Microscopia Eletrônica de Varredura , RNA de Helmintos/genética , RNA Ribossômico 18S/genética , República da Coreia , Toxocara/classificação , Toxocara/isolamento & purificação
6.
Nucleic Acids Res ; 48(18): 10441-10455, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32941651

RESUMO

Comprehensive genome-wide analysis has revealed the presence of translational elements in the 3' untranslated regions (UTRs) of human transcripts. However, the mechanisms by which translation is initiated in 3' UTRs and the physiological function of their products remain unclear. This study showed that eIF4G drives the translation of various downstream open reading frames (dORFs) in 3' UTRs. The 3' UTR of GCH1, which encodes GTP cyclohydrolase 1, contains an internal ribosome entry site (IRES) that initiates the translation of dORFs. An in vitro reconstituted translation system showed that the IRES in the 3' UTR of GCH1 required eIF4G and conventional translation initiation factors, except eIF4E, for AUG-initiated translation of dORFs. The 3' UTR of GCH1-mediated translation was resistant to the mTOR inhibitor Torin 1, which inhibits cap-dependent initiation by increasing eIF4E-unbound eIF4G. eIF4G was also required for the activity of various elements, including polyU and poliovirus type 2, a short element thought to recruit ribosomes by base-pairing with 18S rRNA. These findings indicate that eIF4G mediates translation initiation of various ORFs in mammalian cells, suggesting that the 3' UTRs of mRNAs may encode various products.


Assuntos
Fator de Iniciação 4G em Eucariotos/genética , GTP Cicloidrolase/genética , Fases de Leitura Aberta/genética , Serina-Treonina Quinases TOR/genética , Regiões 3' não Traduzidas/genética , Fator de Iniciação 4E em Eucariotos/genética , Humanos , Naftiridinas/farmacologia , Poliovirus/genética , Biossíntese de Proteínas/genética , Capuzes de RNA/genética , RNA Mensageiro/genética , RNA Ribossômico 18S/genética , Ribossomos/genética , Serina-Treonina Quinases TOR/antagonistas & inibidores
7.
Rev Bras Parasitol Vet ; 29(3): e012420, 2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32756775

RESUMO

Piroplasm species were analyzed by molecular tools in total 31 blood samples from positive dogs, previously checked by stained slides, stored until DNA extraction between 2016 to 2018 in the laboratory Clinical Analyzes in Niterói, Rio de Janeiro. The piroplasms were identified by PCR, targeting the 18S rRNA gene and sequencing. From the total number of samples only 24 (77.4%) were positive and show adequate nucleotide sequences for interpretation with identity between 93%-100% with Babesia vogeli in compared to the sequences isolated of infected dogs from other states in Brazil deposited on GenBank. Most of dogs infected with B. vogeli had anemia (62.5%) and thrombocytopenia (95.8%). The findings of this study are compatible with previous reports in the literature and highlight B. vogeli as the most incriminated species in canine piroplasmosis in Brazil, and thrombocytopenia the hematological alteration most frequently identified in this infection. It is important to note that this is the first study involving the molecular characterization of piroplasms in the metropolitan region of Rio de Janeiro, based on PCR followed by sequencing.


Assuntos
Babesia , Babesiose , Sangue , Doenças do Cão , Manejo de Espécimes , Animais , Babesia/genética , Babesiose/sangue , Sangue/parasitologia , Análise Química do Sangue , Brasil , Doenças do Cão/sangue , Doenças do Cão/parasitologia , Cães , RNA Ribossômico 18S/genética , Manejo de Espécimes/veterinária
8.
Protist ; 171(4): 125752, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32814281

RESUMO

The genus Psilotricha was established by Stein in 1859, with P. acuminata as the type species within the family Oxytrichidae. This species lacked a full description until it was re-discovered in 2001, showing that its morphological and morphogenetic characters confirmed the inclusion in the family Oxytrichidae. Since then, the genus Psilotricha has had a convoluted taxonomy despite the morphological evidence available. In this paper, we describe a new Psilotricha species, Psilotricha silvicola n. sp., from woodland soils in Southern England (United Kingdom). The morphology was investigated in live and protargol-impregnated specimens. Our findings show that P. silvicola n. sp. shares morphological characteristics with P. acuminata, including the distinctive cell shape and the long and sparse cirri. Phylogenetic analysis of the 18S rRNA gene places this new species within the family Oxytrichidae, nested apart from the family Psilotrichidae (which includes the genera Urospinula, Psilotrichides and Hemiholosticha), in a clade containing species of the family Oxytrichidae. Furthermore, the morphology of another Psilotricha species, P. viridis, found in a freshwater pond in the same woodland area, is also here described, bringing additional insight into the taxonomy of the genus. Our findings provide further evidence for inclusion of the genus Psilotricha within the oxytrichids.


Assuntos
Cilióforos/classificação , Solo/parasitologia , Cilióforos/citologia , Cilióforos/genética , DNA de Protozoário/genética , Florestas , Água Doce , Filogenia , RNA Ribossômico 18S/genética , Especificidade da Espécie , Reino Unido
9.
Parasitol Res ; 119(11): 3729-3737, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32779020

RESUMO

A new Eimeria species is described from a common bronzewing pigeon (Phaps chalcoptera) (Latham, 1790) in Western Australia. Sporulated oocysts of Eimeria chalcoptereae n. sp. (n = 30) are subspheroidal, 22-25 × 21-24 (23.5 × 22.6) µm; length/width (L/W) ratio 1.0-1.1 (1.04) µm. Wall bi-layered, 1.0-1.4 (1.2) µm thick, outer layer smooth, c.2/3 of total thickness. Micropyle barely discernible. Oocyst residuum is absent, but 2 to 3 small polar granules are present. Sporocysts (n = 30) ellipsoidal, 13-14 × 7-8 (13.5 × 7.2) µm; L/W ratio 1.8-2.0 (1.88). Stieda body present, flattened to half-moon-shaped, 0.5 × 2.0 µm; sub-Stieda present, rounded to trapezoidal, 1.5 × 2.5 µm; para-Stieda body absent; sporocyst residuum present, usually as an irregular body consisting of numerous small granules that appear to be membrane-bound. Sporozoites vermiform, with a robust refractile body and centrally located nucleus. Isolated Eimeria oocysts were analysed at the 18S and 28S ribosomal RNA and the mitochondrial cytochrome oxidase (COI) loci. Analyses revealed that Eimeria chalcoptereae n. sp. shared the highest number of molecular features with an Eimeria sp. previously identified from a domestic pigeon in Australia (KT305927-29), with similarities at these three loci of 98.53%, 97.32% and 94.93%, respectively. According to morphological and molecular analysis, the isolated coccidian parasite is a new species of Eimeria named Eimeria chalcoptereae n. sp. after its host, the common bronzewing pigeon (Phaps chalcoptera) (Columbiformes: Columbidae) (Latham, 1790).


Assuntos
Doenças das Aves/parasitologia , Coccidiose/veterinária , Columbidae/parasitologia , Eimeria/citologia , Eimeria/genética , Animais , Coccidiose/parasitologia , DNA de Protozoário/genética , Eimeria/classificação , Eimeria/crescimento & desenvolvimento , Complexo IV da Cadeia de Transporte de Elétrons/genética , Oocistos/citologia , Filogenia , Proteínas de Protozoários/genética , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Esporozoítos/citologia , Austrália Ocidental
10.
Exp Parasitol ; 218: 107967, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32858044

RESUMO

Reported incidence rates of cryptosporidiosis in Ireland are consistently among the highest in Europe. Despite the national prevalence of this enteric parasite and the compulsory nature of incidence surveillance and reporting, in-depth analyses seeking to genotype clinical isolates of Cryptosporidium on an intra-species level are rarely undertaken in Ireland. This molecular epidemiology study of 163 clinical Cryptosporidium isolates was conducted in Southern Ireland, from 2015 to 2018, in order to ascertain population subtype heterogeneity. Analysis was conducted via real-time PCR amplification and gp60 gene sequencing, which successfully determined the subtype designation of 149 of the 163 (91.4%) tested isolates. Overall, 12 C. parvum and five C. hominis subtypes were identified, with the incidence of the regionally predominant C. parvum species found to primarily occur during springtime months, while C. hominis incidence was largely confined to late summer and autumnal months. Additionally, one C. parvum and four C. hominis subtypes were newly reported by this study, having not been previously identified in clinical or livestock infection in Ireland. Overall, these data give insight into the diversification of the Cryptosporidium population and emergent subtypes, while also allowing comparisons to be made with clinical epidemiological profiles reported previously in Ireland and elsewhere.


Assuntos
Criptosporidiose/parasitologia , Cryptosporidium/classificação , Zoonoses/parasitologia , Animais , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Cryptosporidium/isolamento & purificação , Cryptosporidium parvum/classificação , Cryptosporidium parvum/genética , Cryptosporidium parvum/isolamento & purificação , DNA de Protozoário/isolamento & purificação , Fezes/parasitologia , Gastroenterite/parasitologia , Glicoproteínas/química , Glicoproteínas/genética , Humanos , Incidência , Irlanda/epidemiologia , Estudos Longitudinais , Prevalência , Proteínas de Protozoários/química , Proteínas de Protozoários/genética , RNA Ribossômico 18S/genética , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Estações do Ano , Alinhamento de Sequência
11.
Protist ; 171(4): 125755, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32858402

RESUMO

The systematics of Hypotricha is one of the most puzzling problems in ciliate biology, having spanned numerous conflicting hypotheses with unstable relationships at various levels in molecular trees, for which the constant addition of newly discovered species has only increased the confusion. The hypotrichs comprise a remarkable morphologically diversified group of ciliates, and the phylogenetic potential of morphological traits is generally recognized. However, such characters were rarely used in phylogenetic reconstructions, and congruence with molecular data never assessed from simultaneous analyses. To properly reconciliate morphological and molecular information, maximum-likelihood and parsimony analyses of 79 morphological characters and 18S rDNA sequences were performed for 130 ingroup terminals, broadly sampled to represent the known hypotrich diversity. As result, well-supported and relatively stable clades were recovered, based on which the redefined Hypotricha comprises at least six higher taxa: The "arcuseriids", Holostichida, Parabirojimida, and the "amphisiellids", plus the two large clades Kentrurostylida nov. tax. (Hispidotergida nov. tax. and Simplicitergida nov. tax.) and Diatirostomata nov. tax. ("bistichellids", "kahliellids", Gonostomatida and Dorsomarginalia [Postoralida nov. tax. and Uroleptida]). Each taxon was circumscribed by synapomorphies, of which most were homoplastic, as the natural history of hypotrichs is portrayed by an outstanding quantity of convergences and reversions.


Assuntos
Cilióforos/classificação , Filogenia , Cilióforos/citologia , Cilióforos/genética , RNA Ribossômico 18S/genética , Especificidade da Espécie
12.
Parasitol Res ; 119(10): 3347-3357, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32833051

RESUMO

A total of 57 tissue samples of domestic pigs (Sus scrofa) were collected from the meat outlets of five north Indian states and examined for sarcocystosis by histological and molecular methods. The genomic DNA extracted from five representative positive isolates was subjected to PCR amplification of the partial 18S rRNA gene followed by cloning and sequencing. Sequence analysis of the newly generated Indian isolates recorded 96.9-100.0% identity with published sequences of Sarcocystis suihominis. Two new haplotypes that have not been previously described manifested 99.5-100.0% nucleotide homology within themselves. In the phylogenetic analysis, Indian isolates of S. suihominis grouped together with S. suihominis originating from Italy, and they collectively formed a sister clade with Sarcocystis miescheriana within a clade containing various Sarcocystis spp. of ruminants having felids as final hosts. At the same time, this clade separated from a sister clade containing Sarcocystis spp. of bovid or cervid ruminants using canids as known or surmised definitive host. The current study established the phylogenetic relationship of Indian isolates of S. suihominis with various Sarcocystis spp. as well as with other taxa of Sarcocystidae family based on 18S rRNA gene for the first time.


Assuntos
Sarcocystis/classificação , Sarcocystis/genética , Sarcocistose/veterinária , Sus scrofa/parasitologia , Doenças dos Suínos/parasitologia , Animais , Haplótipos , Índia/epidemiologia , Filogenia , RNA Ribossômico 18S/genética , Sarcocystis/isolamento & purificação , Sarcocistose/epidemiologia , Sarcocistose/parasitologia , Suínos , Doenças dos Suínos/epidemiologia
13.
Parasitol Res ; 119(10): 3549-3553, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32783071

RESUMO

From a longitudinal survey conducted on 30 Danish mink farms in 2016, 11.0% of faecal samples (456/4140) were positive for Cystoisospora laidlawi oocysts by microscopy, with 60% (189/315) of mink being positive at least once during the study period. Morphological analysis of sporulated oocysts identified Cystoisospora oocysts measuring 34.3 × 29.5 µm with an oocyst length/width (L/W) ratio of 1.2. The morphological features of the oocysts were identical to Isospora laidlawi previously morphological identified in farmed mink from Denmark and elsewhere. Phylogenetic analysis of 18S rDNA sequences (1221 bp) from three positive mink indicated that Cystoisospora from mink shared the highest genetic similarity to C. canis from a Canadian dog (99.6%). The phylogenetic analysis placed Cystoisospora from mink in a clade with other Cystoisospora isolates.


Assuntos
Isospora/isolamento & purificação , Isosporíase/veterinária , Vison/parasitologia , Infecções Protozoárias em Animais/parasitologia , Animais , DNA de Protozoário/genética , Dinamarca/epidemiologia , Fazendas , Fezes/parasitologia , Isospora/classificação , Isospora/citologia , Isospora/genética , Isosporíase/parasitologia , Oocistos/classificação , Oocistos/citologia , Oocistos/genética , Oocistos/isolamento & purificação , Filogenia , RNA Ribossômico 18S/genética
14.
Parasitol Res ; 119(9): 2955-2963, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32647992

RESUMO

Equine piroplasmosis (EP) is an infectious, tick-borne disease caused by the hemoprotozoan parasites, Theileria equi, Babesia caballi, and a recently reported new species, T. haneyi. Infections by these apicomplexan parasites limit performance and cause economic losses for the horse industry. Equine piroplasmosis is widespread in the northern regions of Nigeria, where an increasing portion of the animal population is composed of horses. This disease has remained epidemiologically challenging, especially as the movement of horses increases across Nigeria. In this study, blood samples from 300 horses were collected in three states of northwestern Nigeria. The presence of piroplasms was screened by nested PCR targeting 18S rDNA and positive samples were analyzed using species-specific-nested PCR-targeting genes including ema1 (T. equi), rap1 (B. caballi), and a gene coding a protein of unknown function (T. haneyi). Species-specific-nPCR results demonstrated that the prevalence of T. equi was 13.0% (39/300), B. caballi was 3.3% (10/300) and T. haneyi was 2.7% (8/300). Mixed infections with T. equi and B. caballi was 2.7% (8/300) while T. equi, B. caballi, and T. haneyi multiple infection prevalence was 0.6% (2/300). We used 18S rDNA sequences to determine close relationships between T. equi by phylogenetic analysis and demonstrated that among 57 sequences of Theileria parasites, 28 samples belonged to clade A (49%), 13 samples were found to be clade C (22%), and 16 were clade D (28%). These results demonstrate the genetic diversity of T. equi circulating in horses from Nigeria.


Assuntos
Babesiose/diagnóstico , Doenças dos Cavalos/diagnóstico , Cavalos/parasitologia , Reação em Cadeia da Polimerase/veterinária , Theileriose/diagnóstico , Animais , Babesia/genética , Babesia/isolamento & purificação , Babesiose/epidemiologia , Babesiose/parasitologia , Bovinos , Doenças dos Cavalos/parasitologia , Nigéria/epidemiologia , Filogenia , RNA Ribossômico 18S/genética , Theileria/genética , Theileria/isolamento & purificação , Theileriose/epidemiologia , Theileriose/parasitologia , Doenças Transmitidas por Carrapatos/epidemiologia
15.
Rev Bras Parasitol Vet ; 29(3): e005120, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32638835

RESUMO

Siganids are the most important marine fish distributed along the African coast. Therefore, the current study aimed to investigate parasite fauna infects one of the most important mariculture fish species in the Red Sea, the Rabbit fish Siganus rivulatus. One acanthocephalan species has been isolated from the posterior region of fish intestine, belonging to the Neoechinorhynchidae family, and named as Neoechinorhynchus macrospinosus Amin & Nahhas, 1994 based on its morphological and morphometric features. In order to determine the accurate taxonomic position of this acanthocephalan species, molecular phylogenetic analysis was carried out based on the partial sequences of 18S rDNA gene region. The obtained data revealed that this species was associated with a close identity ˃71% for other species belonging to the Neoechinorhynchidae family. In addition, the recovered species deeply embedded in the Neoechinorhynchus genus, closely related to the previously described Neoechinorhynchus sp., N. mexicoensis, and N. golvani with identity percent of 95.14, 93.59, 93.59%, respectively. Therefore, the present study provide a better understanding about the taxonomic status of N. macrospinosus based on 18S rDNA that can be useful for achieving a proper assessment of biodiversity.


Assuntos
Acantocéfalos , Doenças dos Peixes , Helmintíase Animal , Filogenia , Acantocéfalos/anatomia & histologia , Acantocéfalos/classificação , Acantocéfalos/genética , Animais , DNA de Helmintos/genética , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , RNA Ribossômico 18S/genética
16.
Aquat Toxicol ; 226: 105556, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32652413

RESUMO

Ribosomal (r)DNA is a highly dynamic, conserved, multigene family whose sequence homogeneity is thought to be maintained by intra- and interchromosomal recombination, which are capable of changing rDNA copy number. It is generally not known how environmental stress such as sublethal exposure to environmentally relevant concentrations of metals impacts rDNA copy number. To determine how chronic metal exposure affects rDNA, we measured copy number of the 18S rRNA gene in 355 copper and nickel-exposed samples and 132 metal-free samples derived from 325 mutation accumulation (MA) lines of two genetically distinct Daphnia pulex lineages. The MA lines were sampled at four time points over 100+ generations of clonal propagation. The copy number of rDNA was also measured in 15 individuals sampled from a metal-free non-MA control population established from the same progenitor as one of the MA lineages. We found that mean rDNA copy number fluctuated across lines exposed to metals with a tendency to decrease over time. In contrast, mean rDNA copy number in the metal-free control lines and the non-MA population remained stable over time. It is generally accepted that extreme rDNA loss results in the loss of organism fitness. Thus, fluctuations in rDNA copy number, including losses, could affect the long-term viability of natural populations of Daphnia in metal-contaminated habitats.


Assuntos
Variações do Número de Cópias de DNA/efeitos dos fármacos , DNA Ribossômico/genética , Daphnia/efeitos dos fármacos , Metais Pesados/toxicidade , Acúmulo de Mutações , Poluentes Químicos da Água/toxicidade , Animais , Cobre/toxicidade , Daphnia/genética , Níquel/toxicidade , RNA Ribossômico 18S/genética , Reprodução/efeitos dos fármacos , Reprodução/genética
17.
Am J Trop Med Hyg ; 103(2): 778-784, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32602431

RESUMO

The ultrasensitive Alere Plasmodium falciparum Malaria Ag histidine-rich protein 2 rapid diagnostic test (Alere uRDT, Suwon City, South Korea) is a new diagnostic tool which is more expensive than other malaria rapid diagnostic tests (RDTs) routinely used in Ugandan clinics. The manufacturer recommends testing samples within 2 days and scoring results after 20 minutes, which may be impractical in high-volume resource-poor clinics. We compared testing by the Alere Ag rapid diagnostic test (uRDT), CareStart RDT, microscopy, and an ultrasensitive I8S rRNA quantitative reverse transcription polymerase chain reaction (qRT-PCR) using survey and clinical samples. For the Alere uRDT, we used survey blood samples stored at 4°C for 44 days and for some clinical samples deliberately scored results beyond 20 minutes. The Alere uRDT and qRT-PCR identified asymptomatic parasitemia cases in 56% and 72%, respectively, of survey samples originally scored as negative by the CareStart RDT. Using qRT-PCR as a gold standard, the Alere uRDT was superior to the CareStart RDT in estimating asymptomatic parasite prevalence in a cross-sectional survey (P = 0.007) and in detection of clinically significant malaria; both RDTs were comparable in detecting asymptomatic parasitemia in the clinic (P = 0.599). Scoring Alere uRDT results at 20 minutes produced valid results confirmed by the CareStart RDT, but there was a consistent background; scoring the Alere uRDT beyond 20 minutes produced false-positive results. The Alere uRDT outperformed the CareStart RDT (ACCESSBIO, Somerset, NJ) in a field survey in estimating malaria prevalence and in the clinic for symptomatic malarial illness. It produced reliable results using samples stored at 4°C for 44 days, but test results read beyond 20 minutes were invalid.


Assuntos
Antígenos de Protozoários/imunologia , Malária Falciparum/diagnóstico , Parasitemia/diagnóstico , Plasmodium falciparum/imunologia , Proteínas de Protozoários/imunologia , Adolescente , Adulto , Infecções Assintomáticas , Criança , Pré-Escolar , Reações Falso-Positivas , Feminino , Humanos , Lactente , Masculino , Microscopia , Plasmodium falciparum/genética , Plasmodium falciparum/isolamento & purificação , RNA Ribossômico 18S/genética , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fatores de Tempo , Uganda
18.
Parasitol Res ; 119(8): 2597-2608, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32607707

RESUMO

Trichodinid ciliates were isolated from calanoid copepods and were characterized by morphological and molecular techniques. The trichodinids found in this study were morphologically similar to Trichodina acuta, but morphometric differences were observed between our specimens and T. acuta. The T. acuta specimens, isolated from fish in several geographical locations around the world, were slightly larger than specimens in our population. In fact, our morphological and morphometric data are more similar to Trichodina diaptomi populations, also found on copepods. Moreover, our phylogenetic analyses revealed that the 18S rRNA gene sequence from our samples emerged in a clade with two T. acuta sequences, infesting fish hosts in China. These three sequences showed 100% identity. Our data, along with a taxonomic review, suggest that the species T. diaptomi, described recently, is actually a synonym of T. acuta and that this species may be related to fish and copepod hosts. In conclusion, we highlight the urgent need to better investigate the polymorphism and host specificity within the Mobilida, as this data may represent important characters to better understand the evolution into this order.


Assuntos
Copépodes/parasitologia , Oligoimenóforos/classificação , Animais , DNA de Protozoário/genética , Peixes/parasitologia , Especificidade de Hospedeiro , Oligoimenóforos/citologia , Oligoimenóforos/genética , Filogenia , RNA Ribossômico 18S/genética , Análise de Sequência de DNA
19.
Parasitol Res ; 119(10): 3315-3326, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32699938

RESUMO

Haemogregarina species are apicomplexan blood parasites infecting vertebrates such as fish, lizards, and turtles. Due to the high morphological similarity of the erythrocytic stages infecting host species, it has always been a challenge to identify the true diversity of these parasites. Therefore, taxonomic studies are presently based on the combination of morphological and molecular data. In Tunisia, two species of Haemogregarina have been reported within the freshwater turtle Mauremys leprosa (Geoemydidae) for more than 40 years. Since M. leprosa occurs in the same aquatic environments as Emys orbicularis (Emydidae) in Tunisia, our objectives were to assess parasite diversity and specificity on the basis of both morphological and molecular approaches. The turtles were surveyed and sampled across six aquatic areas of Tunisia. Among the 39 specimens of M. leprosa and seven of E. orbicularis that were trapped and investigated, the presence of haemogregarines was detected in the blood of turtles only at sites where leeches were observed. Three 18S variants were identified, which corresponded to three distinct Haemogregarina species, among which one was identified as Haemogregarina stepanowi. The two other species that were detected are likely new to science. Because we show the occurrence of more than one blood parasite species within a single host specimen, our study provides the first report of coinfection with molecularly distinct Haemogregarina spp.


Assuntos
Coccidiose/veterinária , Coinfecção/veterinária , Eucoccidiida/genética , Água Doce/parasitologia , Tartarugas/parasitologia , Animais , Coccidiose/parasitologia , Coinfecção/parasitologia , Eucoccidiida/classificação , Eucoccidiida/isolamento & purificação , Variação Genética , Sanguessugas/parasitologia , RNA Ribossômico 18S/genética , Tunísia/epidemiologia , Tartarugas/classificação
20.
Int J Syst Evol Microbiol ; 70(4): 2405-2419, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32559827

RESUMO

The morphology of two new scuticociliates, Uronema apomarinum sp. nov. and Homalogastra parasetosa sp. nov., isolated from a mangrove wetland in Shenzhen, PR China, was studied using live observation and the protargol impregnation method. Uronema apomarinum is characterized by a body size of about 20-35×10-15 µm in vivo, a partly two-rowed membranelle 1, and 12 or 13 somatic kineties. Homalogastra parasetosa is distinguished by a membranelle 1 comprising two longitudinal rows of basal bodies. Three Homalogastra setosa populations are suggested as subjective synonyms of the new species. Improved diagnoses of the genus Homalogastra Kahl, 1926 and its type species Homalogastra setosa Kahl, 1926 are provided. Results of phylogenetic analyses based on 18S rRNA gene and ITS1-5.8S-ITS2 region sequences indicate that U. apomarinum is most closely related to U. marinum, while the closest relative of H. parasetosa is H. setosa.


Assuntos
Oligoimenóforos/classificação , Filogenia , China , DNA Espaçador Ribossômico/genética , Oligoimenóforos/isolamento & purificação , RNA Ribossômico 18S/genética , Análise de Sequência de DNA , Proteínas de Prata , Áreas Alagadas
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