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1.
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
2.
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
3.
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
4.
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
5.
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
6.
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
7.
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
8.
Syst Parasitol ; 96(4-5): 423-431, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31077064

RESUMO

Isospora sporophilae Carvalho-Filho, Meireles, Ribeiro & Lopes, 2005 was morphologically and molecularly identified from the double-collared seedeater Sporophila frontalis (Verreaux), which is categorised as 'vulnerable' by the International Union for Conservation of Nature and Natural Resources (IUCN), and from the uniform finch Haplospiza unicolor Cabanis in conserved and anthropomorphic/fragmented areas of Atlantic Forest in the southeastern Brazil. The oöcysts recovered from S. frontalis and H. unicolor had small morphological and genotypic differences that were not considered sufficient for the description of new species, but only different genotypes of I. sporophilae related to each host. This coccidian species was originally described from double-collared seedeaters Sporophila caerulescens (Vieillot) in a center screening of wild animals; therefore, this new report emphasises a potential occurrence of anthropomorphic dispersion of coccidia through illegal trade, seizures and reintroductions in the wild.


Assuntos
Especificidade de Hospedeiro , Isospora/fisiologia , Passeriformes/parasitologia , Animais , Brasil , Isospora/citologia , Isospora/genética , Oocistos/citologia , Oocistos/genética
9.
Protist ; 170(1): 104-120, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30738338

RESUMO

Coccidia of the genus Isospora, their origin, taxonomy, and host specificity have been discussed for many years. The crucial point in question being the division of the genus, based on distinct evolutionary history and the presence/absence of the Stieda body, into the genera Isospora (Eimeriidae) parasitizing mainly birds and reptiles, and Cystoisospora (Sarcocystidae) parasitizing mammals. The description of the majority of Isospora species from rodents is based solely on the oocysts found in their faeces. Some of them have been described with the presence of the Stieda body, some without it, and, simultaneously, for all the described species the molecular data are entirely lacking. This study reveals the origin of isosporan oocysts found in faeces of bank voles based on morphological analyses, phylogenetic analyses, and experimental infections. Morphological analyses showed the presence of the Stieda body complex on sporocysts. Phylogenetic analyses demonstrated close phylogenetic relationships between Isospora from bank voles and avian isosporans. Experimental inoculations of bank voles with sporulated oocysts of Isospora did not result in the production of unsporulated oocysts. Hence, these organisms should be considered pseudoparasites of the bank voles/rodents (probably originating from avian Isospora species).


Assuntos
Arvicolinae/parasitologia , Fezes/parasitologia , Isospora/fisiologia , Animais , República Tcheca , Feminino , Isospora/citologia , Isospora/isolamento & purificação , Masculino , Oocistos/citologia , Oocistos/isolamento & purificação , Oocistos/fisiologia , Filogenia
10.
Syst Parasitol ; 96(2): 245-255, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30747404

RESUMO

In November 2017, oöcysts of the coccidian Eimeria macyi Wheat, 1975 were isolated from the faeces of a single eastern red bat Lasiurus borealis Müller in Lowndes County, Mississippi, USA. Sporulated oöcysts, morphologically consistent with previous accounts of E. macyi in other chiropterans, were spherical to sub-spherical in shape with a highly mamillated outer wall that appears bi-layered. Oöcysts allowed to sporulate in 2.5% potassium dichromate at ambient temperature (c.23°C) for 7 days were 17-25 × 15-20 (20.7 × 17.9) µm. Micropyle and oöcyst residuum were absent with one to two polar granules scattered among sporocysts. The four ovoid sporocysts were 7-12 × 6-8 (9.9 × 7.1) µm. Stieda bodies were prominent and sub-Stieda bodies were present. Two sporozoites were reflexed within each sporocyst. Nuclear 18S rRNA gene, plastid 23S rRNA gene and mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were sequenced from sporulated oöcysts and compared to other molecular data of Eimeria spp. from rodent and chiropteran hosts. No sequence data in the NCBI database matched E. macyi. Phylogenetic analyses of the sequence data of the 18S rRNA and 23S rRNA genes placed E. macyi within a clade containing Eimeria spp. from rodents and basal to a clade populated by sequences derived from Eimeria spp. of rodents and bats. This account represents a new host record of E. macyi in an eastern red bat and a new geographic locality. Additionally, the cox1 sequence data of Eimeria macyi represents the first mitochondrial sequence of an Eimeria sp. in bats.


Assuntos
Quirópteros/parasitologia , Eimeria/classificação , Eimeria/fisiologia , Filogenia , Animais , Eimeria/citologia , Eimeria/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Mississippi , Oocistos/citologia , RNA Ribossômico 18S/genética , RNA Ribossômico 23S/genética
11.
Parasitol Res ; 118(3): 969-976, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30694415

RESUMO

Rabbit coccidiosis is a common parasitic disease and responsible for enormous economic losses in the rabbit industry. Eimeria intestinalis, one of the highly pathogenic and common Eimeria species infecting rabbits, is considered as an indispensable species for the development of live oocyst vaccines against rabbit coccidiosis. In this study, we report the successful selection of a precocious line (EIP8) from a wild-type strain of E. intestinalis (WT) by successively collecting and propagating the early excreted progeny oocysts. The EIP8 line had a prepatent period of only 132 h compared to 204 h for the WT. Oocysts of EIP8 were notably different from those produced by the WT strain by their significantly larger size (mean length: 29.3 vs 27.6 µm and mean width 20.5 vs 19.8 µm). Examination of tissue sections prepared from EIP8-infected rabbits revealed that this precocious line undergoes only two generations of schizogony before differentiating into gametocytes by 120 h post-infection. In contrast, WT parasites undergo three generations of schizogony and gametocytes are present by 168 h post-infection. EIP8 multiplication capacity reduced by more than 35-fold and a concomitant decrease in pathogenicity was detected. Interestingly, immunization with 103 or 104 EIP8 oocysts provided sufficient protection against homologous challenge with wild-type parasites, as body weight gain of immunized and challenged rabbits was similar to that of untreated animals, as well as more than 90% reduction of oocyst output was detected in immunized and challenged animals when compared to unimmunized and challenged animals. Together, these results show that the EIP8 precocious line of E. intestinalis is an attenuated immunogenic strain and a suitable candidate for the development of a live vaccine against rabbit coccidiosis.


Assuntos
Coccidiose/veterinária , Eimeria/genética , Eimeria/fisiologia , Oocistos/citologia , Coelhos/parasitologia , Animais , Coccidiose/parasitologia , Coccidiose/prevenção & controle , Eimeria/imunologia
12.
Parasitol Int ; 68(1): 53-56, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30312668

RESUMO

Green-banded broodsacs of Leucochloridium sporocysts were obtained from land snails, Succinea lauta, collected in Esashi, Esashi District, Hokkaido, Japan. The broodsacs were similar to those of L. paradoxum, which have never been found on the Japanese archipelago. Here, we compare morphological and molecular genetic characteristics of the green-banded broodsacs to those of L. paradoxum. The broodsacs described in this study and those of L. paradoxum showed three equal parts; however, band characteristics of the second parts differed. Moreover, the sequences of nuclear 18S and 28S rRNA genes of the Leucochloridium flukes were not identical with those of L. paradoxum, and the sequences of the mitochondrial cytochrome c oxidase subunit 1 gene were paraphyletic to the species. These findings suggest that the broodsacs described in this study were distinct from those of L. paradoxum. In the future, genetic analyses on adult flukes from avian hosts should be performed, upon precise identification according to morphology, in order to clarify relationships between adult flukes and sporocysts of Leucochloridium species occurring in Japan.


Assuntos
Oocistos/citologia , Oocistos/genética , Caramujos/parasitologia , Trematódeos/genética , Infecções por Trematódeos/veterinária , Animais , Aves/parasitologia , DNA de Helmintos/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Japão , Oocistos/classificação , Filogenia , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Trematódeos/classificação , Trematódeos/citologia , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
13.
Syst Parasitol ; 96(1): 111-115, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30523609

RESUMO

Eimeria ammospermophili n. sp. (Apicomplexa: Eimeriidae) is described from 2 of 29 (7%) Harris's antelope squirrels Ammospermophilus harrisii Audubon & Bachman in Arizona, USA. Sporulated oöcysts of this new species are ovoidal to ellipsoidal, 24-32 × 20-25 (29.0 × 22.7) µm, with a pitted, bi-layered wall, an oöcyst residuum and, occasionally, a polar granule. Sporocysts are ellipsoidal, 10-12 × 7-9 (11.0 × 7.9) µm, with a Stieda body and sporocyst residuum; sporozoites are elongate with a spheroidal anterior refractile body and an ellipsoidal posterior refractile body. In addition, sporulated oöcysts of Eimeria vilasi Dorney, 1962 are described from A. harrisii. This is the first report on the coccidia of this host species.


Assuntos
Eimeria/classificação , Sciuridae/parasitologia , Animais , Arizona , Eimeria/citologia , Oocistos/citologia , Especificidade da Espécie
14.
Lab Chip ; 18(21): 3310-3322, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30283951

RESUMO

Concentrating diluted samples is a key step to improve detection capabilities. The wise use of scaling laws shows the advantages of working with sub-microliter-sized samples. Rapid progress in MEMS technologies has driven the design of integrated platforms performing many biochemical operations. Here we report a new concentrator device based on electro-hydrodynamic forces which can be easily integrated into electrowetting-on-dielectric (EWOD) platforms. This approach is label-free and applicable to a wide range of micro-objects. The detection and analysis of two common waterborne parasites, Cryptosporidium and Giardia, is a perfect test case due to their global health relevance. By fully controlling the interplay of the various forces acting on the micron-sized Cryptosporidium parvum and Cryptosporidium muris oocysts, we show that it is possible to concentrate them on the side of a 10 µL initial drop and then extract them efficiently from a droplet of a few hundred nanoliters. We performed a finite element modeling of the forces acting on the parasites' oocysts to optimize the electrodes' shapes. We obtained state-of-the-art concentration factors of 12 ± 0.4 times and 2 to 4 times in the sub-region of the drop and the extracted droplet, respectively, with an efficiency of 70 ± 6%. Furthermore, this device had the ability to selectively concentrate parasites of different species out of a mix. We demonstrated this by segregating C. parvum oocysts from either Giardia lamblia cysts or its related species, C. muris oocysts.


Assuntos
Cryptosporidium parvum/isolamento & purificação , Hidrodinâmica , Dispositivos Lab-On-A-Chip , Água/parasitologia , Animais , Cryptosporidium parvum/citologia , Impedância Elétrica , Eletrodos , Eletroforese , Monitoramento Ambiental , Oocistos/citologia
15.
ACS Sens ; 3(10): 2175-2181, 2018 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-30244571

RESUMO

Cryptosporidium parvum ( C. parvum) is a highly potent zoonotic pathogen, which can do significant harm to both human beings and livestock. However, existing technologies or methods are deficient for rapid on-site detection of water contaminated with C. parvum. Better detection approaches are needed to allow water management agencies to stop major breakouts of the pathogen. Herein, we present a novel detection method for cryptosporidium in a tiny drop of sample using a magnetic nanoparticle (MNP) probe combined with dark-field microscopy in 30 min. The designed MNP probes bind with high affinity to C. parvum, resulting in the formation of a golden garland-like structure under dark-field microscopy. This MNP-based dark-field counting strategy yields an amazing PCR-like sensitivity of 8 attomolar (aM) (5 pathogens in 1 µL). Importantly, the assay is very rapid (∼30 min) and is very simple to perform as it involves only one step of mixing and magnetic separation, followed by dropping on a slide for counting under dark-field microscope. By combining the advantages of the specific light-scattering characteristic of MNP probe under dark field and the selective magnetic separation ability of functionalized MNP, the proposed MNP-based dark-field enumeration method offers low cost and significant translational potential.


Assuntos
Cryptosporidium parvum/isolamento & purificação , Nanopartículas de Magnetita/química , Microscopia/métodos , Anticorpos Imobilizados/química , Anticorpos Imobilizados/imunologia , Cryptosporidium parvum/crescimento & desenvolvimento , Cryptosporidium parvum/imunologia , Oocistos/citologia , Oocistos/isolamento & purificação , Microbiologia da Água
16.
Ultrason Sonochem ; 48: 118-126, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30080534

RESUMO

Water reuse is currently considered an innovative way to addressing water shortage that can provide significant economic, social and environmental benefits, particularly -but not exclusively- in water deficient areas. The potential transmission of infectious diseases is the most common concern in relation to water reclamation. Cryptosporidium is an important genus of protozoan enteropathogens that infect a wide range of vertebrate hosts, including humans. The infective form (oocyst) is highly resistant to the environmental conditions and disinfection treatments. Consequently, Cryptosporidium is the most common etiological agent identified in waterborne outbreaks attributed to parasitic protozoa worldwide. The present study evaluates the efficacy of ultrasound disinfection, at three power levels (60, 80 and 100 W), pulsed at 50% or in continuous mode, for inactivating the waterborne protozoan parasite Cryptosporidium parvum in simulated and real effluents from municipal wastewater treatment plants (MWTPs). Overall interpretation of the results shows that the application of ultrasound irradiation at 80 W power in continuous mode for an exposure time of 10 min drastically reduced the viability of C. parvum. Thus, oocyst viabilities of 4.16 ±â€¯1.93%; 1.29 ±â€¯0.86%; 3.16 ±â€¯0.69%; and 3.15 ±â€¯0.87% were obtained in distilled water, simulated, real and filtered MWTP effluents, respectively (vs 98.57 ±â€¯0.01%, initial oocyst viability), as determined using inclusion/exclusion of the fluorogenic vital dye propidium iodide, an indicator of the integrity of the oocyst wall. Independently of the mode used (pulsed/continuous) and at 80 W power, higher level of oocyst inactivation was detected in MWTP effluents than in distilled water used as a control solution, may be due to the differences in the chemical composition of the samples. Comparison of the results obtained in both modes showed that use of the continuous mode yielded significantly lower oocyst viability. However, when the Dose parameter was considered (energy per volume unit), no statistically significant differences in oocyst viability were observed in relation to the type of mode used. The results demonstrate that ultrasound technology represents a promising alternative to the disinfection methods (ultraviolet irradiation and chlorine products) currently used in water reclamation as it drastically reduces the survival of Cryptosporidium oocysts, without changing the chemical composition of the water or producing toxic by-products.


Assuntos
Cryptosporidium parvum/efeitos da radiação , Oocistos/citologia , Ondas Ultrassônicas , Águas Residuárias/parasitologia , Purificação da Água/métodos , Cidades
17.
Nat Commun ; 9(1): 2883, 2018 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-30038430

RESUMO

Cryptosporidiosis in an enteric infection caused by Cryptosporidium parasites and is a major cause of acute infant diarrhea in the developing world. A major bottleneck to research progress is the lack of methods to cryopreserve Cryptosporidium oocysts, thus requiring routine propagation in laboratory animals. Here, we report a method to cryopreserve C. parvum oocysts by ultra-fast cooling. Cryopreserved oocysts exhibit high viability and robust in vitro excystation, and are infectious to interferon-γ knockout mice. The course of the infection is comparable to what we observe with unfrozen oocysts. Oocyst viability and infectivity is not visibly changed after several weeks of cryogenic storage. Cryopreservation will facilitate the sharing of oocysts from well-characterized isolates and transgenic strains among different laboratories.


Assuntos
Criopreservação/métodos , Cryptosporidium parvum/citologia , Oocistos/citologia , Animais , Temperatura Baixa , Fezes , Feminino , Ácido Hipocloroso/química , Interferon gama/metabolismo , Camundongos , Camundongos Knockout , Nitrogênio , Oócitos , Permeabilidade
18.
Elife ; 72018 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-29848446

RESUMO

Understanding the importance of gametocyte density on human-to-mosquito transmission is of immediate relevance to malaria control. Previous work (Churcher et al., 2013) indicated a complex relationship between gametocyte density and mosquito infection. Here we use data from 148 feeding experiments on naturally infected gametocyte carriers to show that the relationship is much simpler and depends on both female and male parasite density. The proportion of mosquitoes infected is primarily determined by the density of female gametocytes though transmission from low gametocyte densities may be impeded by a lack of male parasites. Improved precision of gametocyte quantification simplifies the shape of the relationship with infection increasing rapidly before plateauing at higher densities. The mean number of oocysts per mosquito rises quickly with gametocyte density but continues to increase across densities examined. The work highlights the importance of measuring both female and male gametocyte density when estimating the human reservoir of infection.


Assuntos
Anopheles/parasitologia , Células Germinativas/citologia , Malária Falciparum/parasitologia , Plasmodium falciparum/citologia , Caracteres Sexuais , Adolescente , Animais , Portador Sadio/parasitologia , Contagem de Células , Criança , Pré-Escolar , Comportamento Alimentar , Feminino , Humanos , Masculino , Oocistos/citologia , Razão de Masculinidade
19.
Syst Parasitol ; 95(4): 383-389, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29549562

RESUMO

Despite the great diversity of coccidians, to our knowledge, no coccidian infections have been described in Oecomys spp. In this context, we examined Oecomys mamorae Thomas (Rodentia: Cricetidae) from the Brazilian Pantanal for infections with enteric coccidia. Nine individuals were sampled, and one was found to be infected. The oöcysts were recovered through centrifugal flotation in sugar solution. Using morphological and morphometric features, we described a new species of Cystoisospora Frenkel, 1977. Sporulated oöcysts were ovoidal 20.0-29.1 × 16.4-23.2 (26.7 × 21.2) µm and contained two sporocysts, 12.9-19.1 × 9.4-13.9 (16.4 × 12.4) µm, each with four banana-shaped sporozoites. Polar granule and oöcyst residuum were both absent. We documented the developmental forms in the small intestine and described the histopathological lesions in the enteric tract. Our results indicate that the prevalence of Cystoisospora mamorae n. sp. in O. mamorae is low, and tissue damage in the enteric tract is mild, even in the presence of coccidian developmental stages.


Assuntos
Arvicolinae/parasitologia , Sarcocystidae/classificação , Animais , Brasil , Oocistos/citologia , Sarcocystidae/citologia , Sarcocystidae/fisiologia , Especificidade da Espécie , Esporozoítos/citologia
20.
Syst Parasitol ; 95(2-3): 271-279, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29457202

RESUMO

Three new species of coccidians (Apicomplexa: Eimeriidae) are described from eastern moles, Scalopus aquaticus (Linnaeus) from Arkansas. Oöcysts of Cyclospora duszynskii n. sp. are subspheroidal with a smooth bi-layered wall, measure 11.4 × 10.0 µm, and have a length/width (L/W) ratio of 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 7.2 × 5.4 µm, L/W 1.3; an indistinct Stieda body is present, but the sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Cyclospora yatesi n. sp. are subspheroidal to ovoidal with an ornate outer wall, measure 17.0 × 15.2 µm, L/W 1.1; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 9.7 × 7.3 µm, L/W 1.3; an indistinct Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. Oöcysts of Eimeria paulettefordae n. sp. are ovoidal to ellipsoidal with an ornate outer wall, measure 30.0 × 25.4 µm, L/W 1.2; both micropyle and oöcyst residuum are absent, but a single polar granule is present. Sporocysts are ellipsoidal and measure 12.6 × 9.2 µm, L/W 1.4; a button-like Stieda body is present, but sub-Stieda and para-Stieda bodies are absent and the sporocyst residuum is composed of medium to large granules of different sizes along the edge of the sporocyst. These are the first coccidians described from Arkansas populations of S. aquaticus. In addition, a summary is provided on the cyclosporans and eimerians from North American talpids.


Assuntos
Eimeria/classificação , Eimeria/citologia , Toupeiras/parasitologia , Animais , Arkansas , Oocistos/citologia , Especificidade da Espécie
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