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1.
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
2.
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
3.
Parasitol Res ; 119(8): 2667-2678, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32627078

RESUMO

Coccidian parasites possess complex life cycles involving asexual proliferation followed by sexual development leading to the production of oocysts. Coccidian oocysts are persistent stages which are secreted by the feces and transmitted from host to host guaranteeing life cycle progression and disease transmission. The robust bilayered oocyst wall is formed from the contents of two organelles, the wall-forming bodies type I and II (WFBI, WFBII), located exclusively in the macrogametocyte. Eimeria nieschulzi has been used as a model parasite to study and follow gametocyte and oocyst development. In this study, the gametocyte and oocyst wall formation of E. nieschulzi was analyzed by electron microscopy and immuno-histology. A monoclonal antibody raised against the macrogametocytes of E. nieschulzi identified a tyrosine-rich glycoprotein (EnGAM82) located in WFBII. Correlative light and electron microscopy was used to examine the vesicle-specific localization and spatial distribution of GAM82-proteins during macrogametocyte maturation by this monoclonal antibody. In early and mid-stages, the GAM82-protein is ubiquitously distributed in WFBII. Few hours later, the protein is arranged in subvesicular structures. It was possible to show that the substructure of WFBII and the spatial distribution of GAM82-proteins probably represent pre-synthesized cross-linked materials prior to the inner oocyst wall formation. Dityrosine-cross-linked gametocyte proteins can also be confirmed and visualized by fluorescence microscopy (UV light, autofluorescence of WFBII).


Assuntos
Eimeria/citologia , Eimeria/ultraestrutura , Animais , Eimeria/crescimento & desenvolvimento , Glicoproteínas/química , Glicoproteínas/metabolismo , Estágios do Ciclo de Vida , Microscopia Eletrônica , Microscopia de Fluorescência , Oocistos/citologia , Oocistos/crescimento & desenvolvimento , Oocistos/metabolismo , Oocistos/ultraestrutura , Organelas/metabolismo , Organelas/ultraestrutura , Proteínas de Protozoários/metabolismo , Tirosina/análogos & derivados , Tirosina/química
4.
Parasitol Res ; 119(7): 2139-2147, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32476061

RESUMO

Coccidian parasites of fish have received considerably less attention than their terrestrial counterparts, and within piscine hosts, most studies have focused on freshwater fish. The present study aimed to describe oocyst morphology, phylogenetic affinities, and the impacts of coccidian parasites infecting the internal organs of a commercially valuable marine fish, the blue whiting (Micromesistius poutassou), captured off the Portuguese coast. As part of the phylogenetic analysis, sequences from coccidians infecting the pout (Trisopterus luscus) and the Atlantic chub mackerel (Scomber colias) were included, and the oocyst morphology of the coccidians infecting the former was also reported. Results showed that the prevalence of coccidiosis in the blue whiting was very high (> 82%), occurring in all analyzed organs, despite being more abundant in the liver. A significant negative correlation was found between the abundance of the parasites in the liver and host condition index (p < 0.05), which indicates a negative effect on the fitness of this host. Phylogenetic analyses of the parasites found in all three species examined identified three different species of Goussia, closely related to Goussia clupearum. Adding to previous research, we propose the existence of a fourth group of Goussia, the clupearum type, able to infect multiple organs and phylogenetic related with G. clupearum.


Assuntos
Coccidiose/veterinária , Eimeriidae/classificação , Eimeriidae/patogenicidade , Doenças dos Peixes/parasitologia , Gadiformes/parasitologia , Animais , Coccidiose/parasitologia , Eimeriidae/citologia , Eimeriidae/genética , Fígado/parasitologia , Oocistos/classificação , Oocistos/citologia , Oocistos/genética , Perciformes/parasitologia , Filogenia , Portugal , Alimentos Marinhos/parasitologia
5.
J Vet Med Sci ; 82(4): 494-496, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32147622

RESUMO

Up to now, four coccidian species have been identified in Rallidae (Aves: Gruiformes): Eimeria mongolica, E. alakuli, E. paludosa and E. porphyrulae. Here, we described an Eimeria species, E. paludosa, from a common gallinule (Gallinula galeata) in Mexico. Oocysts were ovoid and wall pitted single-layered. A prominent micropyle was present, the oocyst residuum absent and the polar granule was present. On histological examination of tissues, endogenous stages (meronts, microgametocytes and macrogametocytes) were seen in the epithelial cells of the small intestine (upper and lower intestine). In addition to a new locality, this is the first description of E. paludosa from G. galeata and is the third description of a coccidian infecting Rallidae in the Americas.


Assuntos
Doenças das Aves/parasitologia , Coccidiose/veterinária , Eimeria/isolamento & purificação , Animais , Doenças das Aves/epidemiologia , Aves , Coccidiose/epidemiologia , Mucosa Intestinal/parasitologia , México/epidemiologia , Oocistos/citologia
6.
Eur J Protistol ; 73: 125688, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32143143

RESUMO

The molecular divergence, morphology and pathology of a cryptic gregarine that is related to the bee parasite Apicystis bombi Lipa and Triggiani, 1996 is described. The 18S ribosomal DNA gene sequence of the new gregarine was equally dissimilar to that of A. bombi and the closest related genus Mattesia Naville, 1930, although phylogenetic analysis supported a closer relation to A. bombi. Pronounced divergence with A. bombi was found in the ITS1 sequence (69.6% similarity) and seven protein-coding genes (nucleotide 78.05% and protein 90.2% similarity). The new gregarine was isolated from a Bombus pascuorum Scopoli, 1763 female and caused heavy hypertrophism of the fat body tissue in its host. In addition, infected cells of the hypopharyngeal gland tissue, an important excretory organ of the host, were observed. Mature oocysts were navicular in shape and contained four sporozoites, similar to A. bombi oocysts. Given these characteristics, we proposed the name Apicystis cryptica sp. n. Detections so far indicated that distribution and host species occupation of Apicystis spp. overlap at least in Europe, and that historical detections could not discriminate between them. Specific molecular assays were developed that can be implemented in future pathogen screens that aim to discriminate Apicystis spp. in bees.


Assuntos
Apicomplexa/classificação , Abelhas/parasitologia , Animais , Apicomplexa/citologia , Apicomplexa/genética , DNA de Protozoário/genética , Europa (Continente) , Corpo Adiposo/parasitologia , Oocistos/citologia , Especificidade da Espécie
7.
Eur J Protistol ; 73: 125668, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31927140

RESUMO

The Javan ferret-badger Melogale orientalis (Carnivora: Mustelidae: Helictidinae) is a small carnivore endemic to Indonesia. In the family Mustelidae, 10 Eimeria, 12 Cystoisopora, one Isospora, and one Hammondia species are known, but no eimeriid coccidia has been yet described in the subfamily Helictinidae (ferret badgers). Coproscopic examination of Javan ferret-badgers imported into the Czech Republic revealed the presence of coccidian oocysts. Sporulated oocysts differ from other Eimeria known in the family Mustelidae by their small size (12.4-16.1 × 10.4-13.4 µm) and ovoidal shape. Morphological data and phylogenetic analyses of 18S rRNA and COI genes indicated a new species of Eimeria found in faecal samples of Javan ferret badgers. The species is described as E. melogale n. sp.


Assuntos
Eimeria/classificação , Mustelidae/parasitologia , Filogenia , Animais , República Tcheca , Eimeria/citologia , Eimeria/genética , Fezes/parasitologia , Oocistos/citologia , RNA Ribossômico 18S/genética , Especificidade da Espécie
8.
Parasitol Int ; 75: 102040, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31843685

RESUMO

In the current work, Isospora massardi Lopes, Berto, Luz, Galvão, Ferreira & Lopes, [10] is identified from white-necked thrushes Turdus albicollis Vieillot, 1818, rufous-bellied thrushes Turdus rufiventris Vieillot, 1818 and from a new host, the yellow-legged thrush Turdus flavipes (Vieillot, 1818) in a new locality, the Itatiaia National Park, in Southeastern Brazil, providing a preliminary genotypic characterization via sequencing of the mitochondrial cytochrome c oxidase subunit 1 (COI) and 18S small subunit ribosomal RNA genes. The oocysts and sporocysts of I. massardi of the current study are morphologically similar to the original description and are uniform in the proportionality of width on length, but exhibited different patterns of size associated with each host species. Furthermore, a genotypic difference of 3% was found in the COI sequences from T. flavipes and T. albicollis. Therefore, an ecological discussion is introduced aimed at associating these morphometric and genotypic differences with an ongoing speciation process.


Assuntos
Doenças das Aves/epidemiologia , Isospora/isolamento & purificação , Isosporíase/veterinária , Animais , Doenças das Aves/parasitologia , Brasil/epidemiologia , Isospora/citologia , Isospora/genética , Isosporíase/epidemiologia , Isosporíase/parasitologia , Oocistos/citologia , Oocistos/genética , Oocistos/isolamento & purificação , Prevalência , Aves Canoras
9.
Parasitol Res ; 119(1): 291-298, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31820167

RESUMO

We describe three new coccidian species of the genus Eimeria Schneider 1875 (Apicomplexa: Eimeriidae) and redescribe and report Eimeria zygodontomyis Lainson and Shaw, 1990 in the montane grass mouse, Akodon montensis Thomas, 1913 from the Serra dos Órgãos National Park in southeastern Brazil. Sporulated oocysts of Eimeria zygodontomyis are ellipsoidal to cylindrical with a 0.6 (0.5-0.8) µm thick very delicate bi-layered wall; length × width (n = 49) 18.3 × 12.5 (16-20 × 11-13) µm; length/width ratio of 1.4 (1.2-1.6); 1 polar granule occasionally present; micropyle, residuum both absent. Sporocysts are ellipsoidal; length × width 8.5 × 5.2 (8-11 × 5-6) µm; length/width ratio of 1.5 (1.3-1.7) µm; Stieda body is prominent; sub-Stieda body is absent; sporocyst residuum is compact. Sporulated oocysts of Eimeria montensis n. sp. are spheroidal to subspheroidal with a 1.2 (1.0-1.4) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 30) 16.3 × 12.5 (15-17 × 13-15) µm; length/width ratio of 1.3 (1.0-1.4); 1 polar granule present; micropyle, residuum both absent. Sporocysts are ellipsoidal; length × width 7.2 × 5.1 (6-8 × 4-6) µm; length/width ratio of 1.4 (1.2-1.6); Stieda body is present, sub-Stieda body is absent; sporocyst residuum consists of small, scattered granules. Sporulated oocysts of Eimeria uricanensis n. sp. are ovoidal to pyriform with a 1.4 ( 1.3-1.6) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 40) 26.6 × 18.6 (23-30 × 17-20) µm; length/width ratio of 1.4 (1.3-1.6); 1 polar granule present; micropyle, residuum both absent. Sporocysts are ellipsoidal, length × width 13.3 × 8.0 (10-16 × 7-9) µm; length/width ratio of 1.7 (1.5-1.9); Stieda body, sub-Stieda body both absent; sporocyst residuum consists of a cluster of granules, forming a spheroid mass. Sporulated oocysts of Eimeria parnasiensis n. sp. are subspheroidal to ellipsoidal with a 1.8 ( 1.3-2.4) µm thick bi-layered wall; outer layer lightly pitted; length × width (n = 54) 28.2 × 21.9 (26-32 × 19-28) µm; length/width ratio of 1.3 (1.2-1.4); 1 polar granule present; micropyle is absent; oocyst residuum is present and consists of a cluster of granules of varying thickness. Sporocysts are ovoidal, tapering towards the Stieda body; length × width 12.2 × 7.6 (10-13 × 6-9) µm; length/width ratio of 1.6 (1.4-1.9); Stieda body is present; sub-Stieda body is absent; sporocyst residuum is present and consists of an aggregate of thin granules.


Assuntos
Coccidiose/veterinária , Eimeria/classificação , Doenças dos Roedores/parasitologia , Sigmodontinae/parasitologia , Animais , Brasil , Coccidiose/parasitologia , Eimeria/citologia , Fezes/parasitologia , Oocistos/citologia , Parques Recreativos
10.
Parasitol Res ; 119(1): 255-266, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760498

RESUMO

A large-scale cross-sectional epidemiological study was conducted to evaluate prevalence, species diversity, and associated risk factors of Eimeria infections in 55 cattle farms across seven states of Colombia, including subtropical and tropical regions. In total, 1333 fecal samples from young animals (< 1 year of age) were examined at a single sampling date from August 2016 to December 2016. Flotation and McMaster techniques were conducted for parasitological investigation. Excreted Eimeria oocysts were allowed to sporulate in vitro and thereafter identified to species level based on morphological and morphometric characteristics. The overall Eimeria prevalence was 75.5% (1006/1333), with no difference observed between age categories. In total, 13 different Eimeria species were identified. The most prevalent species was E. bovis (33.5%), followed by E. auburnensis (12.5%) and E. zuernii (11.9%). Analysis of extrinsic associated risk factors revealed the floor type, feeding system, watering system, and herd size as significant (p < 0.05) risk factors for Eimeria spp. infections. Based on these data, it can be assumed that bovine coccidiosis infections occur ubiquitously in the country and might play an important role especially in its subclinical form by affecting production parameters in conventional cattle management systems.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Coccidiose/veterinária , Eimeria/isolamento & purificação , Animais , Bovinos , Coccidiose/epidemiologia , Coccidiose/parasitologia , Colômbia/epidemiologia , Estudos Transversais , Eimeria/classificação , Eimeria/citologia , Fazendas , Fezes/parasitologia , Oocistos/citologia , Oocistos/isolamento & purificação , Prevalência , Fatores de Risco
11.
Parasitol Res ; 119(1): 267-281, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31760500

RESUMO

Coccidia (Chromista: Miozoa: Eimeriidae) of columbiform birds (Aves: Columbiformes) have been described since the end of the nineteenth century; however, some of these descriptions were poorly detailed or inconclusive. In this sense, the current work makes a detailed taxonomic revision reconsidering and organizing 18 Eimeria spp. and two Isospora spp. previously described or reported of Columbiformes. Along with this, a new species of Eimeria is morphologically and molecularly identified by the mitochondrial cytochrome c oxidase subunit 1 (COI) gene and by the 18S small subunit ribosomal RNA (18S) gene from the ruddy ground-dove Columbina talpacoti (Temminck, 1809) in the Médio Paraíba region of the State of Rio de Janeiro, southeastern Brazil. Eimeria columbinae n. sp. has subspheroidal oocysts, 14.7 × 13.2 µm, with smooth, bi-layered wall, ~ 1.1 µm and length/width ratio of 1.1. Micropyle and oocyst residuum are present, but polar granule is absent. Sporocysts are ellipsoidal to slightly asymmetrical, 9.0 × 5.1 µm, with both Stieda and sub-Stieda bodies. Sporocyst residuum present and sporozoites with refractile body and nucleus. This is the 19th description of an eimerian from Columbiformes in the World, and the second to have a molecular identification of the COI and 18S genes.


Assuntos
Doenças das Aves/parasitologia , Coccidiose/veterinária , Columbiformes/parasitologia , Eimeriidae/classificação , Animais , Doenças das Aves/epidemiologia , Brasil/epidemiologia , Coccidiose/epidemiologia , Coccidiose/parasitologia , Ciclo-Oxigenase 1/genética , Eimeriidae/citologia , Eimeriidae/genética , Eimeriidae/isolamento & purificação , Oocistos/citologia , Oocistos/isolamento & purificação , Proteínas de Protozoários/genética , RNA Ribossômico 18S/genética , Esporozoítos/citologia , Esporozoítos/isolamento & purificação
12.
Parasitol Res ; 119(1): 243-248, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31754858

RESUMO

Cryptosporidiosis has been reported as an important cause of neonatal diarrhea and mortality in cattle, sheep, and other ruminants, but its impact on alpaca health has not been studied thoroughly. In this study, we have determined the prevalence and evaluated the role of cryptosporidiosis as a risk factor for diarrhea occurrence in newborn alpacas. During the calving season (January-March) of 2006, stool specimens (N = 1312) were collected from 24 herds of newborn alpacas in Puno and Cuzco, departments that account for the largest populations of alpacas in Peru. All the specimens were microscopically screened for Cryptosporidium spp. using the acid-fast technique. The association between Cryptosporidium detection and diarrhea was analyzed using χ2 test and generalized lineal model. Cryptosporidium species were determined by PCR-RFLP analysis of the small subunit rRNA gene. Cryptosporidium oocysts were detected in 159 of 1312 (12.4%) newborn alpacas. Results of the analyses demonstrated that crypstosporidiosis was significantly associated with diarrhea (PR = 3.84; CI95% 2.54-5.81; p < 0.0001). Only Cryptosporidium parvum was detected in the 153 Cryptosporidium-infected animals. Thus, there is an association of C. parvum infection with diarrhea in neonatal alpacas.


Assuntos
Camelídeos Americanos/parasitologia , Criptosporidiose/epidemiologia , Criptosporidiose/parasitologia , Cryptosporidium parvum/isolamento & purificação , Diarreia/veterinária , Animais , Animais Recém-Nascidos , Cryptosporidium parvum/classificação , Cryptosporidium parvum/citologia , Cryptosporidium parvum/genética , Diarreia/epidemiologia , Diarreia/parasitologia , Fezes/parasitologia , Oocistos/citologia , Peru/epidemiologia , Prevalência , Subunidades Ribossômicas Menores/genética , Fatores de Risco
13.
Parasit Vectors ; 12(1): 596, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31856894

RESUMO

BACKGROUND: Although more modern methods are available, quantitative PCR (qPCR) is reproducible, sensitive and specific with instruments and expertise readily available in many laboratories. As such, the use of qPCR in Cryptosporidium research is well established and still widely used by researchers globally. This method depends upon the generation of standards at different concentrations to generate standard curves subsequently used for the quantification of DNA. METHODS: We assessed four types of DNA template used to generate standard curves in drug screening studies involving Cryptosporidium spp.: (i) serially diluted Cryptosporidium parvum oocysts (106-1); (ii) diluted template DNA from pure oocysts (×10-×106 dilution of 106 oocyst DNA template); (iii) oocysts incubated in human ileocecal adenocarcinoma (HCT-8) cells (105-1 and 5 × 104-50); and (iv) diluted DNA template (5 × 104) from cell culture incubated parasites (×10-×1000). RESULTS: Serial dilutions of both cell culture and pure oocyst suspension DNA template yielded better linearity than cell culture derived standards, with dilutions of 106 oocysts exhibiting similar quantification cycle (Cq) values to those obtained from DNA template dilutions of 106 oocysts. In contrast, cell culture incubated oocysts demonstrated significantly higher DNA content than equivalent freely suspended oocysts and diluted DNA template from both cell culture derived and freely suspended oocysts across numerous concentrations. CONCLUSIONS: For many studies involving Cryptosporidium, only relative DNA content is required and as such, the superior linearity afforded by freely suspended oocysts and diluted DNA template (from either cell culture derived standards or freely suspended oocysts) will allow for more accurate relative quantification in each assay. Parasite division in the cell culture standards likely explains the higher DNA content found. These standards, therefore, have the potential to more accurately reflect DNA content in cell culture assays, and despite more modern methods available for absolute quantification, i.e. droplet digital PCR (ddPCR), the ubiquity of qPCR for the foreseeable future encourages further investigation into the reduced linearity observed in these standards such as varying oocyst seeding density, non-linear growth rates and assay efficiency.


Assuntos
Criptosporidiose/parasitologia , Cryptosporidium parvum/genética , DNA de Protozoário/genética , Técnicas de Cultura de Células , Cryptosporidium parvum/classificação , Cryptosporidium parvum/crescimento & desenvolvimento , Cryptosporidium parvum/isolamento & purificação , DNA de Protozoário/análise , Humanos , Oocistos/citologia , Oocistos/genética , Oocistos/crescimento & desenvolvimento , Reação em Cadeia da Polimerase em Tempo Real/métodos
14.
PLoS Pathog ; 15(10): e1008048, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31600347

RESUMO

Kinesin-8 proteins are microtubule motors that are often involved in regulation of mitotic spindle length and chromosome alignment. They move towards the plus ends of spindle microtubules and regulate the dynamics of these ends due, at least in some species, to their microtubule depolymerization activity. Plasmodium spp. exhibit an atypical endomitotic cell division in which chromosome condensation and spindle dynamics in the different proliferative stages are not well understood. Genome-wide shared orthology analysis of Plasmodium spp. revealed the presence of two kinesin-8 motor proteins, kinesin-8X and kinesin-8B. Here we studied the biochemical properties of kinesin-8X and its role in parasite proliferation. In vitro, kinesin-8X has motility and depolymerization activities like other kinesin-8 motors. To understand the role of Plasmodium kinesin-8X in cell division, we used fluorescence-tagging and live cell imaging to define its location, and gene targeting to analyse its function, during all proliferative stages of the rodent malaria parasite P. berghei life cycle. The results revealed a spatio-temporal involvement of kinesin-8X in spindle dynamics and an association with both mitotic and meiotic spindles and the putative microtubule organising centre (MTOC). Deletion of the kinesin-8X gene revealed a defect in oocyst development, confirmed by ultrastructural studies, suggesting that this protein is required for oocyst development and sporogony. Transcriptome analysis of Δkinesin-8X gametocytes revealed modulated expression of genes involved mainly in microtubule-based processes, chromosome organisation and the regulation of gene expression, supporting a role for kinesin-8X in cell division. Kinesin-8X is thus required for parasite proliferation within the mosquito and for transmission to the vertebrate host.


Assuntos
Cinesina/metabolismo , Malária/parasitologia , Malária/transmissão , Oocistos/citologia , Plasmodium/fisiologia , Proteínas de Protozoários/metabolismo , Fuso Acromático/fisiologia , Animais , Segregação de Cromossomos , Feminino , Cinesina/genética , Masculino , Camundongos Endogâmicos BALB C , Microtúbulos/metabolismo , Mitose , Oocistos/fisiologia , Proteínas de Protozoários/genética
15.
Syst Parasitol ; 96(9): 789-793, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31612376

RESUMO

Isospora toxostomai n. sp. (Apicomplexa: Eimeriidae) is described based on material from the curved-billed thrasher Toxostoma curvirostre (Swainson) in the Central Highlands of Mexico. The new species possesses subspherical oöcysts, with a smooth, bi-layered wall. Sporulated oöcysts measure 22-25 × 21-24 (23.4 × 22.3) µm; length/width (L/W) ratio of 1.0-1.1 (1.1). Sporocysts are ellipsoidal, 15-17 × 10-11 (15.8 × 10.5); L/W ratio of 1.3-1.6 (1.5). Micropyle and oöcyst residuum are both absent, and a polar granule present (many fibrils). Mean dimensions of both sporulated oöcysts and sporocysts of I. toxostomai n. sp. appear to be considerably larger than those of Isospora mimusi Coelho, Berto, Neves, Oliveira Flausino & Lopes, 2011 from the tropical mockingbird Mimus gilvus (Vieilot) in Brazil. This is the second species of Isospora Schneider, 1881 infecting a host of the Mimidae in the Americas.


Assuntos
Isospora/classificação , Passeriformes/parasitologia , Animais , Isospora/citologia , Oocistos/citologia , Especificidade da Espécie
16.
Syst Parasitol ; 96(9): 795-798, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31612377

RESUMO

Isospora phainopepla n. sp. is described from the faeces of Phainopepla nitens (Swainson) collected in Joshua Tree National Park, California, USA. To our knowledge, there are no metazoan or protist parasites described yet from any species in the Ptiliogonatidae of the Americas. Sporulated oöcysts of the isosporan are ellipsoidal, 30-35 × 22-29 (32.9 × 25.4) µm, with a length/width (L/W) ratio 1.20-1.35 (1.30); one rice-shaped polar granule is present, but both oöcyst residuum and micropyle are absent. Sporocyts are elongate-ellipsoidal, 22-27 × 11-14 (23.9 × 12.0) µm, with L/W ratio 1.97-2.02 (2.00); prominent Stieda and sub-Stieda bodies are both present, but para-Stieda body is absent. Sporocyst residuum of many scattered granules is present and the sporozoites have prominent anterior and posterior refractile bodies. This parasite is clearly new to science and represents the first species of Isospora hosted by a New World bird species from this small family of silky flycatchers (Ptiliogonatidae). This article was registered in the Official Register of Zoological Nomenclature (ZooBank) as 7F664B0D-DF0E-4CAD-8CEA-45D79C8BBF92. This article was published as an Online First article on the online publication date shown on this page. The article should be cited by using the doi number. This is the Version of Record.


Assuntos
Isospora/classificação , Parques Recreativos , Passeriformes/parasitologia , Animais , California , Isospora/citologia , Oocistos/citologia , Especificidade da Espécie , Estados Unidos
17.
Bull Soc Pathol Exot ; 112(2): 61-70, 2019.
Artigo em Francês | MEDLINE | ID: mdl-31478617

RESUMO

In order to evaluate the abundance of oocysts in the Mezam watershed in Bamenda, Northwest Region of Cameroon, a study was carried out from January to June 2017. Samples were collected monthly from 13 stations within the watershed. The direct concentration method and the Ziehl-Neelsen technique were employed in the identification of these parasites. The physicochemical analysis showed that the water samples had a neutral pH (7.46±0.46), lowly mineralized (165.61±110.02µS/cm), moderately oxygenated (60.64 ± 17, 25%), present moderate organic pollution (2.85±2.49mg/l KMnO4). KMnO4) and low levels of orthophosphate (1.8±1.88 mg/l PO43-) and nitrates (2.47±5.06 mg/l NO3-). Biological analysis revealed the presence of Cryptosporidium spp. (143.98±203.35 oocysts/l), Isospora belli (88.47 ± 123.19 oocysts/l), Cyclospora cayetanensis (141.31±143.19 oocysts/l) and Sarcocystis hominis (76 ± 111.04 oocysts/l). The highest densities of these parasites were recorded at the Mufueh stream, situated in the periurban area. Meanwhile, the lowest densities were found in the urban area (Formuki, Mankon, Ayaba and Mezam streams). The dry season showed higher densities of oocysts (471.42±216.32 oocysts /l). Statistical analysis revealed a significant correlation (P ≤ 0.05) between the density of the organisms and the physico-chemical parameters such as pH, oxidability, dissolved oxygen and nitrates. Respecting basic hygienic rules as well as treating water before use would reduce the risk of contamination of the population.


Assuntos
Oocistos/isolamento & purificação , Rios/parasitologia , Poluição da Água/análise , Animais , Camarões , Contagem de Células , Cryptosporidium/citologia , Cryptosporidium/isolamento & purificação , Cyclospora/citologia , Cyclospora/isolamento & purificação , Fezes/parasitologia , Humanos , Isospora/citologia , Isospora/isolamento & purificação , Oocistos/citologia , Doenças Parasitárias/parasitologia , Rios/química , Sarcocystis/citologia , Sarcocystis/isolamento & purificação , Poluentes Químicos da Água/análise , Abastecimento de Água
18.
Parasitol Res ; 118(10): 3043-3051, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31471745

RESUMO

Using a combination of morphological and molecular data, we describe a new apicomplexan parasite, Isospora svecica sp. n., from the white-spotted bluethroat, Luscinia svecica cyanecula, from the Czech Republic. Oocysts were found in its intestinal tract. Sporulation was exogenous and took 1-3 days. The oocysts were slightly ellipsoidal, of average size 26.17 × 20.33 µm, with a smooth bilayered wall. Micropyle, oocyst residuum, and polar granules were absent. Sporocysts were bottle-shaped, of an average size of 18.82 × 8.82 µm, with a thin, colourless wall. A conspicuous knob-like Stieda body was present. Substieda body was barely visible. Sporocyst residuum was present in the form of granules of various sizes. Sporozoites were banana-shaped and contained large anterior and small posterior refractile bodies. Partial DNA sequences of three genes were obtained from oocysts of Isospora svecica sp. n., being most closely related to other isosporans described from passerines. Little is known about the parasites of the avian family Muscicapidae, including coccidia, a highly prevalent parasitic protist group in all vertebrate classes. Only six species of the genus Isospora have so far been described in Muscicapidae, together with several "Isospora sp." that in fact most likely represent Isospora lacazei. The newly described Isospora svecica sp. n. differs morphologically from other coccidia reported from muscicapid birds, and represents the first coccidian species described from Luscinia svecica.


Assuntos
Isospora/classificação , Isosporíase/veterinária , Passeriformes/parasitologia , Animais , República Tcheca , Genes de Protozoários/genética , Intestinos/parasitologia , Isospora/citologia , Isospora/genética , Isospora/crescimento & desenvolvimento , Isosporíase/parasitologia , Oocistos/classificação , Oocistos/citologia , Oocistos/genética , Oocistos/crescimento & desenvolvimento , Esporozoítos/classificação , Esporozoítos/citologia , Esporozoítos/genética , Esporozoítos/crescimento & desenvolvimento
19.
Malar J ; 18(1): 287, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31455343

RESUMO

BACKGROUND: The human infectious reservoir for malaria consists of individuals capable of infecting mosquitoes. Oocyst prevalence and density are typical indicators of human infectivity to mosquitoes. However, identification of oocysts is challenging, particularly in areas of low malaria transmission intensity where few individuals may infect mosquitoes, and infected mosquitoes tend to have few oocysts. Here, features that differentiate oocysts from other oocyst-like in mosquito midguts are explained and illustrated. In addition, the establishment and maintenance of infrastructure to perform malaria transmission experiments is described. This work may support other initiatives to set up membrane feeding infrastructure and guide oocyst detection in low transmission settings. METHODS: In 2014, an insectary was developed and equipped in Tororo district, Uganda. A colony of Anopheles gambiae s.s. mosquitoes (Kisumu strain) was initiated to support infectivity experiments from participants enrolled in a large cohort study. Venous blood drawn from participants who were naturally infected with malaria parasites was used for membrane feeding assays, using 60-80 mosquitoes per experiment. Approximately 9-10 days after feeding, mosquitoes were dissected, and midguts were stained in mercurochrome and examined by light microscopy for Plasmodium falciparum oocysts and similar structures. In supportive experiments, different staining procedures were compared using in vitro cultured parasites. RESULTS: A stable colony of the Kisumu strain of An. gambiae s.s. was achieved, producing 5000-10,000 adult mosquitoes on a weekly basis. Challenges due to temperature fluctuations, mosquito pathogens and pests were successfully overcome. Oocysts were characterized by: presence of malaria pigment, clearly defined edge, round shape within the mosquito midgut or on the peripheral tissue and always attached to the epithelium. The main distinguishing feature between artifacts and mature oocysts was the presence of defined pigment within the oocysts. CONCLUSIONS: Oocysts may be mistaken for other structures in mosquito midguts. Distinguishing real oocysts from oocyst-like structures may be challenging for inexperienced microscopists due to overlapping features. The characteristics and guidelines outlined here support identification of oocysts and reliable detection at low oocyst densities. Practical advice on sustaining a healthy mosquito colony for feeding experiments is provided. Following the reported optimization, the established infrastructure in Tororo allows assessments of infectivity of naturally infected parasite carriers.


Assuntos
Anopheles/parasitologia , Mosquitos Vetores/parasitologia , Oocistos/isolamento & purificação , Plasmodium falciparum/isolamento & purificação , Animais , Feminino , Humanos , Oocistos/citologia , Oocistos/crescimento & desenvolvimento , Plasmodium falciparum/citologia , Plasmodium falciparum/crescimento & desenvolvimento , Uganda
20.
Syst Parasitol ; 96(7): 585-594, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31332671

RESUMO

While nine nominal species of Eimeria Schneider, 1875 have been described from strigiform birds, molecular sequence data are not available for any of these species. In the present study, oöcysts of a coccidian were isolated by faecal flotation from the lower intestinal contents of an opportunistically collected, recently deceased great horned owl Bubo virginianus (Gmelin), sporulated in potassium dichromate, and subjected to morphological and molecular characterisation. Comparisons of morphological data with previous accounts of Eimeria spp. from owls were consistent with Eimeria megabubonis Upton, Campbell, Weigel & McKown, 1990. Novel molecular data for the 18S ribosomal RNA gene region and the mitochondrial cytochrome c oxidase subunit 1 gene are provided. The results of phylogenetic analysis based on concatenated sequence data from these regions are presented and implications for the evolutionary history of Eimeria are discussed.


Assuntos
Eimeria/classificação , Eimeria/fisiologia , Filogenia , Estrigiformes/parasitologia , Animais , Ciclo-Oxigenase 1/genética , Eimeria/genética , Oocistos/citologia , Oocistos/genética , RNA Ribossômico 18S/genética
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