Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Parasitol Res ; 121(10): 2917-2926, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35941324

RESUMO

There is considerable confusion concerning the relationships among species of Sarcocystis found in donkeys and horses. Here, we describe a Sarcocystis species in Chinese donkeys (Equus asinus). Sarcocysts were found in 12 of 32 (37.5%) adult donkeys. By light microscopy, they were divided into two types, thin-walled and thick-walled. The thin-walled were macroscopic (up to 320 µm wide) and had short club-like protrusions (up to 2.7 µm long); the thick-walled were microscopic (up to 135 µm wide) and had villar protrusions (up to 5.4 µm long). Ultrastructures of the two types exhibited similar morphological characteristics, including bundled microtubules in the core of the villar protrusions penetrating diagonally into the ground substance, similar to wall type 11c. Three genetic markers, 18S rDNA, 28S rDNA, and mitochondrial cox1, obtained from the two morphotypes were sequenced and analyzed. The sequences of the three loci in the two morphotypes presented high intraspecific similarities of 97.2-99.5%, 97.8-99.6% and 99.0 - 99.9%, respectively. The most similar sequences in GenBank to the newly obtained 18S rDNA, 28S rDNA and cox1 sequences were those of Sarcocystis spp. in horses, with similarities of 90.0 - 97.5%, 94.7 - 95.1%, and 82.6 - 84.5%, respectively. Phylogenetic analysis using the three genetic markers indicated that the Sarcocystis sp. in donkeys formed an individual clade most closely related to a clade encompassing Sarcocystis spp. in horses. Further studies are needed for taxonomic identification of sarcocysts in donkeys because the Sarcocystis species in donkeys and horses are not successfully cross transmissible despite morphological similarities.


Assuntos
Sarcocystis , Sarcocistose , Animais , DNA Ribossômico/genética , Equidae , Marcadores Genéticos , Cavalos , Filogenia , RNA Ribossômico 18S/genética , Sarcocistose/epidemiologia , Sarcocistose/veterinária
2.
J Nematol ; 532021.
Artigo em Inglês | MEDLINE | ID: mdl-34079955

RESUMO

A new species of entomopathogenic nematodes, Steinernema sandneri n. sp., was recovered by baiting from Poland. Its morphological traits indicate that the new species is a member of the feltiae-kraussei group. A body length of 843 (708-965) µm, a more anterior position of excretory pore (56 µm), and the lower D% value (40 vs > 46) discriminate this species from most of the other group members. The first-generation males of S. sandneri n. sp. can be distinguished from the other clade members by a 60 µm long spicule, a relatively long gubernaculum (GS% = 79), and the position of the excretory pore (80 µm). Phylogenetic analysis of the ITS rDNA, D2D3 of 28 S rDNA, and cox1 sequences confirmed that S. sandneri n. sp. is a new species of the feltiae-kraussei group, closely related to S. kraussei and S. silvaticum.

3.
Syst Biol ; 65(6): 1024-1040, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27288478

RESUMO

The proliferation of DNA data is revolutionizing all fields of systematic research. DNA barcode sequences, now available for millions of specimens and several hundred thousand species, are increasingly used in algorithmic species delimitations. This is complicated by occasional incongruences between species and gene genealogies, as indicated by situations where conspecific individuals do not form a monophyletic cluster in a gene tree. In two previous reviews, non-monophyly has been reported as being common in mitochondrial DNA gene trees. We developed a novel web service "Monophylizer" to detect non-monophyly in phylogenetic trees and used it to ascertain the incidence of species non-monophyly in COI (a.k.a. cox1) barcode sequence data from 4977 species and 41,583 specimens of European Lepidoptera, the largest data set of DNA barcodes analyzed from this regard. Particular attention was paid to accurate species identification to ensure data integrity. We investigated the effects of tree-building method, sampling effort, and other methodological issues, all of which can influence estimates of non-monophyly. We found a 12% incidence of non-monophyly, a value significantly lower than that observed in previous studies. Neighbor joining (NJ) and maximum likelihood (ML) methods yielded almost equal numbers of non-monophyletic species, but 24.1% of these cases of non-monophyly were only found by one of these methods. Non-monophyletic species tend to show either low genetic distances to their nearest neighbors or exceptionally high levels of intraspecific variability. Cases of polyphyly in COI trees arising as a result of deep intraspecific divergence are negligible, as the detected cases reflected misidentifications or methodological errors. Taking into consideration variation in sampling effort, we estimate that the true incidence of non-monophyly is ∼23%, but with operational factors still being included. Within the operational factors, we separately assessed the frequency of taxonomic limitations (presence of overlooked cryptic and oversplit species) and identification uncertainties. We observed that operational factors are potentially present in more than half (58.6%) of the detected cases of non-monophyly. Furthermore, we observed that in about 20% of non-monophyletic species and entangled species, the lineages involved are either allopatric or parapatric-conditions where species delimitation is inherently subjective and particularly dependent on the species concept that has been adopted. These observations suggest that species-level non-monophyly in COI gene trees is less common than previously supposed, with many cases reflecting misidentifications, the subjectivity of species delimitation or other operational factors.


Assuntos
Classificação/métodos , Lepidópteros/classificação , Lepidópteros/genética , Filogenia , Animais , Viés , Código de Barras de DNA Taxonômico , DNA Mitocondrial , Genes Mitocondriais
4.
Korean J Parasitol ; 54(2): 181-5, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27180576

RESUMO

Human sparganosis is a zoonotic disease caused by infection with larval forms (procercoid/plerocercoid) of Spirometra spp. The purpose of this study was to identify Spirometra spp. of infected snakes using a multiplex PCR assay and phylogenetic analysis of mitochondrial DNA sequence data from the spargana of terrestrial snakes obtained from Korea and China. A total of 283 snakes were obtained that included 4 species of Colubridae comprising Rhabdophis tigrinus tigrinus (n=150), Dinodon rufozonatum rufozonatum (n=64), Elaphe davidi (n=2), and Elaphe schrenkii (n=7), and 1 species of Viperidae, Agkistrodon saxatilis (n=60). The snakes were collected from the provinces of Chungbuk, Chungnam, and Gyeongbuk in Korea (n=161), and from China (n=122). The overall infection rate with spargana was 83% (235/283). The highest was recorded for D. rufozonatum rufozonatum (100%), followed by A. saxatilis (85%) and R. tigrinus tigrinus (80%), with a negative result for E. davidi (0%) and E. schrenkii (0%). The sequence identities between the spargana from snakes (n=50) and Spirometra erinaceieuropaei (KJ599680) or S. decipiens (KJ599679) control specimens were 90.8% and 99.2%, respectively. Pairwise genetic distances between spargana (n=50) and S. decipiens ranged from 0.0080 to 0.0107, while those between spargana and S. erinaceieuropaei ranged from 0.1070 to 0.1096. In this study, all of the 904 spargana analyzed were identified as S. decipiens either by a multiplex PCR assay (n=854) or mitochondrial cox1 sequence analysis (n=50).


Assuntos
Infecções por Cestoides/veterinária , Colubridae/parasitologia , Ciclo-Oxigenase 1/genética , DNA Mitocondrial/genética , Spirometra/classificação , Spirometra/genética , Viperidae/parasitologia , Animais , Sequência de Bases , Infecções por Cestoides/parasitologia , China , DNA de Helmintos/genética , Reação em Cadeia da Polimerase Multiplex , Filogenia , República da Coreia , Análise de Sequência de DNA , Spirometra/isolamento & purificação
5.
Korean J Parasitol ; 54(6): 743-750, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28095659

RESUMO

Mus musculus (Rodentia: Muridae) has generally been infected with a rodent hookworm Nippostrongylus brasiliensis. In this report, we present morphological and molecular identification of N. brasiliensis by light and scanning electron microscopy and PCR amplification of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene and the protein sequences encoded by cox1 gene, respectively. Despite the use of N. brasiliensis in many biochemistry studies from India, their taxonomic identification was not fully understood, especially at the species level, and no molecular data is available in GenBank from India. Sequence analysis of cox1 gene in this study revealed that the present specimen showed close identity with the same species available in GenBank, confirming that the species is N. brasiliensis. This study represents the first record of molecular identification of N. brasiliensis from India and the protein structure to better understand the comparative phylogenetic characteristics.


Assuntos
Nippostrongylus/classificação , Nippostrongylus/isolamento & purificação , Doenças dos Roedores/parasitologia , Infecções por Strongylida/veterinária , Estruturas Animais/anatomia & histologia , Animais , Análise por Conglomerados , DNA de Helmintos/química , DNA de Helmintos/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Índia , Masculino , Camundongos , Microscopia , Nippostrongylus/anatomia & histologia , Nippostrongylus/genética , Filogenia , Análise de Sequência de DNA , Infecções por Strongylida/parasitologia
6.
Exp Parasitol ; 142: 38-42, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24726960

RESUMO

Traditional classification of Demodex mites by hosts and phenotypic characteristics is defective because of environmental influences. In this study, we proposed molecular identification of four phenotypes of two human Demodex species based on mitochondrial cox1 fragments for the first time. Mites collected from sufferers' facial skin were classified into four phenotypes: phenotype A-C with finger-like terminus, and phenotype D with cone-like terminus. The results of molecular data showed that cox1 sequences were all 429 bp. Divergences, genetic distances and transition/transversion ratios among the three phenotypes with finger-like terminus were 0.0-3.0%, 0.000-0.031, and 6/3-5/0, respectively, in line with intraspecific differences. However, those measures between the phenotype with cone-like terminus and phenotypes with finger-like terminus were 19.6-20.5%, 0.256-0.271, and 0.58 (31/53)-0.66 (35/53), respectively, reaching interspecific level. Phylogenetic trees also showed that the three phenotypes with finger-like terminus clustered as one clade, and the phenotype with cone-like terminus formed another one. Therefore, we conclude that mitochondrial cox1 sequence is a good marker for identification of two human Demodex species. Molecular data indicate no subspecies differentiation. Terminus is an effective character for species identification. Mites with finger-like terminus are Demodex folliculorum, and those with cone-like terminus are Demodex brevis.


Assuntos
Ácaros/classificação , Animais , China , Complexo IV da Cadeia de Transporte de Elétrons/genética , Humanos , Ácaros/anatomia & histologia , Ácaros/genética , Mitocôndrias/enzimologia , Fenótipo , Filogenia
7.
Ticks Tick Borne Dis ; 15(1): 102282, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37989015

RESUMO

Canine babesiosis is an important protozoan tick-borne disease associated with anemia and thrombocytopenia and caused by several different Babesia spp. Babesia negevi was first reported to infect dogs in the Middle East in 2020. This study describes the presentation, clinical signs, parasitemia levels quantified by molecular techniques, laboratory findings and treatment of dogs infected with B. negevi following the first description of this species. Clinical findings in the infected dogs, a 3-year old female and two 8-week old male and female pups, included extreme lethargy and pale mucous membranes, anemia and thrombocytopenia found in all three animals. Fever was present in the older female and icterus in the female pup. Babesia parasites resembling B. negevi were detected by microscopy of blood smears from the dogs. PCR of blood targeting the 18S rRNA and cox1 genes confirmed that babesiosis was caused by B. negevi and PCR targeting the Borrelia flagellin gene indicated co-infection with Borrelia persica in two dogs. Treatment of the dogs with imidocarb dipropionate resulted in clinical improvement and initial decrease in the B. negevi parasite load as detected by quantitative PCR in two dogs, however the female pup continued to deteriorate and died. The parasite load in the 3-year old female decreased from 43,451 parasites/µl blood pre-imidocarb dipropionate treatment to 803 parasites/µl within two weeks. In the surviving pup, it decreased from 3,293,538 parasites/µl pre-treatment to 20,092 parasites/µl after two weeks. Babesia negevi DNA was still recovered from blood samples by PCR despite repeated treatment with imidocarb dipropionate one-month post-treatment in the surviving pup and up to seven months post-treatment in the 3-year old female. Only treatment with atovaquone and azithromycin for ten days eliminated B. negevi in both dogs as confirmed by negative PCR two weeks later. In conclusion, treatment with imidocarb dipropionate was helpful for recovery from clinical disease but did not facilitate parasite elimination, and it is therefore recommended to treat canine B. negevi infection with the combination of atovaquone and azithromycin.


Assuntos
Anemia , Antiprotozoários , Babesia , Babesiose , Doenças do Cão , Trombocitopenia , Cães , Animais , Masculino , Feminino , Babesiose/parasitologia , Atovaquona/uso terapêutico , Antiprotozoários/uso terapêutico , Azitromicina/uso terapêutico , Babesia/genética , Anemia/tratamento farmacológico , Doenças do Cão/parasitologia
8.
Parasit Vectors ; 16(1): 50, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36732867

RESUMO

BACKGROUND: Limited data are currently available on protozoan parasites of the genus Sarcocystis that infect their avian hosts within the order Anseriformes (waterfowl). To date, no Sarcocystis species has been recorded in ducks in China. METHODS: Leg muscles were sampled from 26 domestic ducks (Anas platyrhynchos) in China in 2021. Morphological characteristics of sarcocysts detected in the muscle tissue were described using light microscopy (LM) and transmission electron microscopy (TEM). Genomic DNA was extracted from single sarcocysts obtained from different ducks, and three genetic markers, 18S ribosomal DNA (18S rDNA), 28S ribosomal DNA (28S rDNA) and mitochondrial (mt) cytochrome oxidase subunit 1 (cox1), were amplified and cloned for sequence analyses. RESULTS: Sarcocysts were observed by LM in only three of the 28 samples (10.7%). These sarcocysts had a thick cyst wall with numerous brush-like villar protrusions (vps) of 3.8-4.3 µm in length (n = 30) on the cyst surface. TEM observation showed that the sarcocysts had lanceolated vps. Each vps narrowed in the stalk and contained a bundle of microtubules that extended into the ground substance. Comparisons of the new sequences with those deposited in GenBank showed that the most similar sequences were those of Sarcocystis halieti in the great cormorant Phalacrocorax carbo and European starling Sturnus vulgaris, and Sarcocystis calchasi in the domestic pigeon (Columba livia) at the 18S rDNA (99.1% identity); Sarcocystis wenzeli from the domestic chicken Gallus gallus at the 28S rDNA (95.9-96.0% identity); and Sarcocystis speeri from the opossum at the mtcox1 (98.2% identity). The new 18S rDNA, 28S rDNA and mitochondrial cox1 sequences shared up to 99.0%, 95.6% and 97.7% identity, respectively, with those of Sarcocystis spp. obtained from Anseriformes avian hosts. Phylogenetic analysis inferred from the sequences of the three genetic markers placed the organism within a group of Sarcocystis spp. obtained from avian or carnivorous intermediate hosts and avian, marsupial or carnivorous definitive hosts. Based on the morphological observation and molecular analyses, the organism found in the Chinese domestic ducks was regarded as a new species and named Sarcocystis platyrhynchosi n. sp. CONCLUSIONS: Based on morphology and sequence analyses, the microcysts diagnosed in the domestic ducks examined in this study were named as a new species. This is the first record of Sarcocystis spp. from waterfowl in China. Sarcocysts of similar morphology occur frequently in different Anseriformes birds, and the relationships among these species need to be further clarified in future studies using more molecular markers.


Assuntos
Anseriformes , Sarcocystidae , Sarcocystis , Sarcocistose , Animais , Sarcocystis/genética , Patos , Sarcocistose/epidemiologia , Sarcocistose/veterinária , Sarcocistose/parasitologia , Sarcocystidae/genética , Columbidae , Filogenia , Marcadores Genéticos , RNA Ribossômico 18S/genética , DNA Ribossômico/genética , Microscopia Eletrônica de Transmissão , Galinhas , China/epidemiologia
9.
Korean J Parasitol ; 50(2): 137-41, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22711925

RESUMO

From 2006 to 2010, hospitals in Hanoi treated 10 human patients for dirofilariasis. The worms were collected from parasitic places, and identification of the species was completed by morphology and molecular methods. Ten parasites were recovered either from the conjunctiva (n=9) or subcutaneous tissue (n=1). The parasites were 4.0-12.5 cm in length and 0.5-0.6 mm in width. Morphological observations suggested all parasites as Dirofilaria repens. Three of the 10 parasites (1 from subcutaneous tissue and 2 from eyes) were used for molecular confirmation of the species identification. A portion of the mitochondrial cox1 (461 bp) was amplified and sequenced. Nucleotide and amino acid homologies were 95% and 99-100%, respectively, when compared with D. repens (Italian origin, GenBank AJ271614; DQ358814). This is the first report of eye dirofilariasis and the second report of subcutaneous tissue dirofilariasis due to D. repens in Vietnam.


Assuntos
Dirofilaria repens/isolamento & purificação , Dirofilariose/diagnóstico , Dirofilariose/patologia , Olho/parasitologia , Tela Subcutânea/parasitologia , Adulto , Idoso , Animais , Ciclo-Oxigenase 1/genética , Dirofilaria repens/anatomia & histologia , Dirofilaria repens/genética , Dirofilariose/parasitologia , Oftalmopatias/parasitologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Diagnóstico Molecular/métodos , Parasitologia/métodos , Filogenia , Reação em Cadeia da Polimerase , Análise de Sequência de DNA , Homologia de Sequência , Dermatopatias/parasitologia , Vietnã
10.
Mol Ecol Resour ; 22(8): 2967-2980, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35757869

RESUMO

DNA barcoding and metabarcoding have been increasingly used in species delimitation and species diversity assessment, respectively, and the molecular markers used in animals are mainly derived from mitochondrial DNA. It is well known that the phenomenon of multiple mitochondrial haplotypes within the same specimen (hereafter referred to as "mitotype diversity") may have a negative impact on the proper assessment of biodiversity by metabarcoding. However, few studies have focused on the incidence of this phenomenon and its effects on metabarcoding results using different sample preparation strategies, such as mock community construction using pooled high-throughput sequencing (HTS) data, DNA-pooling and Tissue-pooling. In this study, we investigated mitotype diversity and its influence on metabarcoding based on 398 specimens from 66 species of Insecta and 82 specimens from 16 species of Arachnida by HTS of the mitochondrial cox1 gene fragment. The results revealed that mitotype diversity was common in the studied taxa and significantly increased the number of operational taxonomic units (OTUs) using the three sample preparation strategies. The results also showed that the bioinformatics pipeline based on authentic amplicon sequence variants was more reliable than the pipeline based on OTUs. Regarding the sample preparation strategies of DNA-pooling and Tissue-pooling commonly used in metabarcoding, our results revealed that their results of metabarcoding were quite similar, and the Tissue-pooling strategy was therefore preferred because of its simplicity. Our study calls for additional attention to the interference of mitotype diversity on the results of DNA metabarcoding in biodiversity assessment.


Assuntos
Aracnídeos , Código de Barras de DNA Taxonômico , Animais , Biodiversidade , Código de Barras de DNA Taxonômico/métodos , DNA Mitocondrial/genética , Insetos/genética
11.
Parasitol Int ; 91: 102643, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35961578

RESUMO

Reports of zoonotic infections caused by the filarial nematode Onchocerca japonica have recently increased in Japan. A 69-year-old woman living in Sosa City, Chiba Prefecture, Kanto Region, Honshu, developed a painful nodule at the metacarpophalangeal joint of the index finger of her right hand. The causative agent was identified as a female O. japonica based on the histopathological characteristics (i.e., cuticle with transverse triangular ridges but without inner striae) of the biopsy specimens of the nodule. The species identification was corroborated by cox1 gene sequencing of the worm tissues isolated from paraffin-embedded sections of the specimens. Subsequent to the excision of the nodule, followed by anthelmintic treatment, the patient remained asymptomatic. Human infection with O. japonica has not previously been reported in Kanto Region, Eastern Honshu. The present case is likely linked to the recent expansion of the geographic range of the Japanese wild boar into this area.


Assuntos
Filarioidea , Oncocercose , Doenças dos Suínos , Idoso , Animais , Feminino , Humanos , Japão , Onchocerca/genética , Oncocercose/diagnóstico , Sus scrofa , Suínos , Zoonoses/diagnóstico
12.
Vet Parasitol ; 299: 109583, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34583143

RESUMO

Cercopithifilaria bainae is a filarioid nematode of dogs shown to use Rhipicephalus sanguineus sensu lato (s.l.), the brown dog tick, as the vector. Previously in the United States, C. bainae infections have been reported in a dog from Florida, and in dogs and ticks in Oklahoma, but data are lacking from other areas of the country. Here, we tested brown dog ticks from across the United States for C. bainae DNA to assess the geographic distribution of where this novel parasite may be cycling in ticks and dogs. Archival brown dog ticks were available for testing through the national tick survey Show Us Your Ticks. Ticks were morphologically identified, dissected, and tested by PCR to detect filarioid mitochondrial DNA. A total of 1400 brown dog ticks were tested from 321 separate animals from 23 states, with 5.7 % (80/1400) of the ticks testing positive for C. bainae DNA. At least one positive tick was detected in submissions from 9 states in addition to Florida and Oklahoma. Cercopithifilaria bainae DNA was detected in larval, nymphal, and adult stages of brown dog ticks and only in ticks removed from dogs. Of all dogs with brown dog ticks collected from them, 17.6 % (55/312) were infested with at least one tick that harbored C. bainae DNA. Findings from this study demonstrate a wider geographic range of C. bainae than previously known, and that dogs are commonly infested with brown dog ticks with molecular evidence of C. bainae infection.


Assuntos
Doenças do Cão , Filarioidea , Rhipicephalus sanguineus , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Cães , Larva , Ninfa , Estados Unidos/epidemiologia
13.
Int J Parasitol ; 50(14): 1133-1144, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32866491

RESUMO

Infection by the small liver fluke, Opisthorchis viverrini, causes serious public health problems, including cholangiocarcinoma, in Thailand and southeastern Asian countries. Previous studies have reported that O. viverrini represents a species complex with varying levels of genetic differentiation in Thailand and Lao PDR. In this study, we re-examined population genetic structure and genetic diversity of O. viverrini using extensive samples of the parasite collected over 15 years from 12 geographical localities in Thailand and eight localities in Lao PDR. Parasite life-cycle stages of 721 individuals of O. viverrini (91 cercariae, 230 metacercariae and 400 adult worms) were genotyped using 12 microsatellite loci. Metacercariae exhibited genetic diversity comparable with that of experimentally raised adults: metacercariae can therefore be used to represent O. viverrini populations without the need for laboratory definitive hosts. Data obtained from larval as well as adult worms identified two distinct genetic clusters of O. viverrini. Sequences of a portion of the mitochondrial cox1 gene strongly supported the existence of these two clusters. One, the widespread cluster, was found at all sampled sites. The second cluster occurred only in Phang Khon District, Sakon Nakhon Province (SPk), within the Songkram River wetland in Thailand. A striking feature of our data relates to the temporal dynamics of the SPk cluster, which was largely replaced by representatives of the widespread cluster over time. If the SPk cluster is excluded, no marked genetic differences were seen among O. viverrini populations from Thailand and Lao PDR. The underlying causes of the observed population structure and population dynamics of O. viverrini are not known.


Assuntos
DNA Mitocondrial/genética , Geografia , Repetições de Microssatélites , Opistorquíase , Opisthorchis , Animais , Opistorquíase/parasitologia , Opisthorchis/genética , Tailândia
14.
Harmful Algae ; 88: 101657, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31582152

RESUMO

Marine dinoflagellates of the genus Dinophysis are well known for producing diarrhetic shellfish poisoning (DSP) toxins and/or pectenotoxins which have a significant impact on public health as well as on marine aquaculture. Out of more than 80 Dinophysis species recorded so far, D. cf. acuminata is the most commonly observed in coastal areas worldwide. Due to their highly similar morphological features, however, an accurate discrimination of the various D. cf. acuminata species such as D. acuminata, D. ovum, and D. sacculus under light microscopy has proven to be a difficult task to accomplish. Hence, these species have thus far been referred to as the "Dinophysis acuminata complex". Recent studies showed a discrimination between local strains of D. acuminata and D. ovum from Galician, northwestern Spain, using the mitochondrial cox1 gene as a genetic marker in addition to commonly used morphological features such as size and contour of the large hypothecal plates, shape of the small cells formed as part of their polymorphic life-cycle, development of the left sulcal list and ribs, and length of the right sulcal list. In the present study, attempts were made to discriminate between D. acuminata and D. ovum following single-cell isolation of 54 "D. acuminata complex" collected from Korean coastal waters, based on the abovementioned traits. Morphological data showed that all the traits analyzed overlapped between the two species. The mitochondrial cox1 (cytochrome c oxidase subunit I) gene sequences of every isolate were also determined, but a genetic distinction between D. acuminata and D. ovum could not be confirmed, suggesting that the cox1 gene is not a suitable genetic marker for discrimination between the two species. The results of this study suggest that the morphological variations observed within the "D. acuminata complex" may have been caused by several factors (e.g. different geographical locations, seasonal changes, and different environmental conditions), and that D. acuminata and D. ovum may be the same species.


Assuntos
Dinoflagellida , Toxinas Marinhas , Intoxicação por Frutos do Mar , Humanos , Espanha
15.
Acta Trop ; 190: 45-51, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30278154

RESUMO

Cystic echinococcosis (CE) and alveolar echinococcosis (AE) are highly co-endemic in Sichuan, a part of Qinghai-Tibet Plateau where is a typical Tibetan nomadic community living area. In order to better understand the Echinococcus spp. of human being infected origins in this area, 140 lesions were collected from echinococcosis patients who were received operations during the period of 2014-2016 in different geographic districts in this region. Partial DNA sequences of the mitochondrial cox1 gene were analyzed. The genetic characterization of the isolates from 3 different places including Ganzi, Aba and Liangshan were assessed. Of all the 140 samples, the great majority was identified as Echinococcus granulosus sensu stricto (n = 108). Echinococcus multilocularis was confirmed to be another important pathogen of the human infections (n = 31). Additionally, one Echinococcus canadensis (G6/7) isolate from Ganzi was confirmed. Comparing the clinical diagnosis with the sequencing results, 6.4% (9/140) of the cases were misdiagnosed between AE and CE, and another 8.6% (12/140) were unclassified to sub-type in echinococcosis. Higher rates of misdiagnosis and unclassified diagnosis were found in AE cases (12.9%, 4/31 and 16.1%, 5/31 respectively) compared to CE (4.6%, 5/109 and 6.4%, 7/109 respectively). In E.granulosus s.s., a total of 34 haplotypes were detected, and 4 haplotypes were inferred from E.multilocularis. The haplotype networks of the 2 species exhibited a similar star-shaped feature with a dominant haplotype in the center. Geographically specific haplotypes were observed in Ganzi and Aba respectively. This study provides insight into the current species causing human echinococcosis in the Tibetan districts of Sichuan. E.granulosus s.s. and E.multilocularis are confirmed to be the main causative agents, and the existence of E.canadensis (G6/7) is also observed in the region. Molecular diagnosis was proven to be essential for the confirmation of human echinococcosis in the area.


Assuntos
Echinococcus granulosus/genética , Echinococcus multilocularis/genética , Adulto , Idoso , Animais , Equinococose/parasitologia , Feminino , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade
16.
Parasit Vectors ; 11(1): 516, 2018 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-30236150

RESUMO

BACKGROUND: Whipworms (Nematoda: Trichuridae), among the most common soil-transmitted helminths (STHs), can cause the socioeconomically important disease trichuriasis in various mammalian hosts including humans and non-human primates. For many years, Trichuris from non-human primates has been assigned to the same species as the one infecting humans Trichuris trichiura. More recently, several molecular reports challenged this assumption following recognition of a Trichuris species complex observed in humans and non-human primates. A refined concept for species limits within Trichuris contributes to an understanding of diversity and the potential (zoonotic) transmission among humans and non-human primates. In this study, we expanded previous investigations by exploring the diversity of Trichuris among eight primates including three Asian autochthonous species (i.e. Rhinopithecus roxellana, Rhinopithecus bieti and Nomascus leucogenys). Species-level identification, whether novel or assignable to known lineages of Trichuris, was based on analyses of nuclear internal transcribed spacers (ITS) and mitochondrial cytochrome c oxidase subunit 1 (cox1) genes. RESULTS: In total, seven genetically distinct subgroups of whipworms were determined to be present among the primates sampled. Most Trichuris lineages, including Subgroups 1, 1', 3, 5 and 6, showed a broad host range and were not restricted to particular primate species; in addition to T. trichiura, a complex of Trichuris species was shown infecting primates. Furthermore, it was assumed that Trichuris spp. from either N. leucogenys and P. hamadryas or R. roxellana and R. bieti, respectively, were conspecific. Each pair was indicated to be a discrete lineage of Trichuris, designated, respectively, as Subgroups 1 or 1' and 2, based on integrated genetic and phylogenetic evidence. CONCLUSION: These results emphasise that the taxonomy and genetic variations of Trichuris are more complicated than previously acknowledged. These cumulative molecular and phylogenetic data provide a better understanding of the taxonomy, genetics and evolutionary biology of the whipworms.


Assuntos
Variação Genética , Tricuríase/veterinária , Trichuris/genética , Animais , Evolução Biológica , Cercopithecidae , China/epidemiologia , DNA de Helmintos/química , DNA de Helmintos/genética , DNA Espaçador Ribossômico/química , DNA Espaçador Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Especificidade de Hospedeiro , Hylobates , Masculino , Filogenia , Primatas , Análise de Sequência de DNA/veterinária , Tricuríase/epidemiologia , Tricuríase/parasitologia , Trichuris/classificação , Trichuris/isolamento & purificação
17.
Infect Genet Evol ; 21: 436-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24380893

RESUMO

Taenia solium taeniasis/cysticercosis is a major public health problem in developing countries. This study reports genotypic analysis of T. solium cysticerci collected from two different endemic areas of North (Chandigarh) and North East India (Dibrugarh) by the sequencing of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. The variation in cox1 sequences of samples collected from these two different geographical regions located at a distance of 2585 km was minimal. Alignment of the nucleotide sequences with different species of Taenia showed the similarity with Asian genotype of T. solium. Among 50 isolates, 6 variant nucleotide positions (0.37% of total length) were detected. These results suggest that population in these geographical areas are homogenous.


Assuntos
Cisticercose/veterinária , Cysticercus/genética , Doenças dos Suínos/parasitologia , Taenia solium/classificação , Taenia solium/genética , Animais , Cisticercose/parasitologia , Países em Desenvolvimento , Evolução Molecular , Genes de Helmintos , Variação Genética , Genótipo , Índia , Filogenia , Análise de Sequência de Proteína , Suínos
18.
J Phycol ; 47(4): 904-10, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27020025

RESUMO

Gelidium is an economically and ecologically important agar-producing genus. Although the taxonomy of Gelidium has been the focus of many published studies, there is still a need to reevaluate species-level diversity. Herein, we describe Gelidium eucorneum sp. nov. based on specimens collected off Geojedo on the southern coast of Korea. G. eucorneum is distinguished by cartilaginous thalli with brush-like haptera, rhizoidal filaments concentrated in the medulla, and globose cytocarps that are horned with multiple determinate branchlets. The species occurs in wave-exposed intertidal sites, sometimes in association with other mat-forming algae. Phylogenetic analyses (rbcL, psaA, and cox1) reveal that G. eucorneum is unique and clearly distinct from other species of the genus. The clade containing Gelidium vagum and Acanthopeltis longiramulosa was resolved as a sister group to G. eucorneum. We suggest that the diverse morphologies of G. eucorneum, G. vagum, and Acanthopeltis developed from a common ancestor in East Asian waters. This study shows that even in well-studied areas, more agarophyte species are to be added to the world inventory of red algae.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA