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1.
PLoS Negl Trop Dis ; 14(3): e0008129, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32203507

RESUMO

BACKGROUND: Schistosomiasis is a neglected tropical parasitic disease associated with severe pathology, mortality and economic loss worldwide. Programs for disease control may benefit from specific and sensitive diagnostic methods to detect Schistosoma trematodes in aquatic environments. Here we report the development of novel environmental DNA (eDNA) qPCR assays for the presence of the human-infecting species Schistosoma mansoni, S. haematobium and S. japonicum. METHODOLOGY/PRINCIPAL FINDINGS: We first tested the specificity of the assays across the three species using genomic DNA preparations which showed successful amplification of target sequences with no cross amplification between the three focal species. In addition, we evaluated the specificity of the assays using synthetic DNA of multiple Schistosoma species, and demonstrated a high overall specificity; however, S. japonicum and S. haematobium assays showed cross-species amplification with very closely-related species. We next tested the effectiveness of the S. mansoni assay using eDNA samples from aquaria containing infected host gastropods, with the target species revealed as present in all infected aquaria. Finally, we evaluated the effectiveness of the S. mansoni and S. haematobium assays using eDNA samples from eight discrete natural freshwater sites in Tanzania, and demonstrated strong correspondence between infection status established using eDNA and conventional assays of parasite prevalence in host snails. CONCLUSIONS/SIGNIFICANCE: Collectively, our results suggest that eDNA monitoring is able to detect schistosomes in freshwater bodies, but refinement of the field sampling, storage and assay methods are likely to optimise its performance. We anticipate that environmental DNA-based approaches will help to inform epidemiological studies and contribute to efforts to control and eliminate schistosomiasis in endemic areas.


Assuntos
DNA Ambiental/isolamento & purificação , Água Doce/parasitologia , Schistosoma/classificação , Schistosoma/genética , Schistosoma/isolamento & purificação , Animais , DNA de Helmintos/isolamento & purificação , Monitoramento Ambiental , Genes de Helmintos/genética , Técnicas de Amplificação de Ácido Nucleico/veterinária , Filogenia , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Schistosoma haematobium/genética , Schistosoma haematobium/isolamento & purificação , Schistosoma japonicum/genética , Schistosoma japonicum/isolamento & purificação , Schistosoma mansoni/genética , Schistosoma mansoni/isolamento & purificação , Esquistossomose/epidemiologia , Esquistossomose/parasitologia , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/parasitologia , Caramujos/parasitologia , Especificidade da Espécie , Tanzânia
2.
Environ Pollut ; 259: 113903, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32023789

RESUMO

Biofilms containing pathogenic organisms from the water supply are a potential source of protozoan parasite outbreaks and a significant public health concern. The aim of the present study was to demonstrate the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens (WBPP) in substrate-associated biofilms (SAB) and compare it to surface water (SW) and sediments with bottom water (BW) counterparts using manual filtration and elution from low-volume samples. For scenario purposes, simulated environmental biofilm contamination was created from in-situ grown one-month-old SAB (OM-SAB) that were spiked with Cryptosporidium parvum oocysts. Samples were collected from the largest freshwater reservoirs in Luzon, Philippines and a University Lake in Thailand. A total of 69 samples (23 SAB, 23 SW, and 23 BW) were evaluated using traditional staining techniques for Cryptosporidium, and Immunofluorescence staining for the simultaneous detection of Cryptosporidium and Giardia. WBPP were found in 43% SAB, 39% SW, and 39% BW of the samples tested in the present study with SAB results reflecting SW and BW results. Further highlights were demonstrated in the potential of using low-volume samples for the detection of parasites in source water. Scanning electron microscopy of OM-SAB samples revealed a naturally-associated testate amoeba shell, while Cryptosporidium oocysts spiked samples provided a visual profile of what can be expected from naturally contaminated biofilms. This study provides the first evidence for the simultaneous and multi-spatial occurrence of waterborne protozoan pathogens in low-volume aquatic matrices and further warrants SAB testing along with SW and BW matrices for improved water quality assessment strategies (iWQAS).


Assuntos
Biofilmes , Cryptosporidium , Água Doce , Qualidade da Água , Animais , Criptosporidiose/prevenção & controle , Cryptosporidium/fisiologia , Monitoramento Ambiental , Água Doce/parasitologia , Oocistos/fisiologia , Filipinas , Tailândia , Qualidade da Água/normas , Abastecimento de Água/normas
3.
Parasit Vectors ; 13(1): 14, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924254

RESUMO

BACKGROUND: Bulinus species are freshwater snails that transmit the parasitic trematode Schistosoma haematobium. Despite their importance, the diversity of these intermediate host snails and their evolutionary history is still unclear in Zimbabwe. Bulinus globosus and B. truncatus collected from a urogenital schistosomiasis endemic region in the Madziwa area of Zimbabwe were characterized using molecular methods. METHODS: Malacological survey sites were mapped and snails were collected from water contact sites in four communities in the Madziwa area, Shamva district for a period of one year, at three-month intervals. Schistosoma haematobium infections in snails were determined by cercarial shedding and the partial mitochondrial cytochrome c oxidase subunit 1 gene (cox1) was used to investigate the phylogeny and genetic variability of the Bulinus spp. collected. RESULTS: Among the 1570 Bulinus spp. snails collected, 30 (1.9%) B. globosus were shedding morphologically identified schistosomes. None of the B. truncatus snails were shedding. The mitochondrial cox1 data from 166 and 16 samples for B. globosus and B. truncatus, respectively, showed genetically diverse populations within the two species. Twelve cox1 haplotypes were found from the 166 B. globosus samples and three from the 16 B. truncatus samples with phylogenetic analysis showing that the haplotypes fall into well-supported clusters within their species groups. Both B. truncatus and B. globosus clustered into two distinct lineages. Overall, significant negative values for both Tajima's D statistic and the Fu's Fs statistic were observed for B. globosus and B. truncatus. CONCLUSIONS: The study provided new insights into the levels of genetic diversity within B. globosus and additional information on B. truncatus collected from a small geographical area in Zimbabwe. Low prevalence levels of infection observed in the snails may reflect the low transmission level of urogenital schistosomiasis in the area. Our results contribute towards the understanding of the distribution and population genetic structure of Bulinus spp. supporting the mapping of the transmission or risk of transmission of urogenital schistosomiasis, particularly in Zimbabwe.


Assuntos
Bulinus/parasitologia , Schistosoma haematobium/genética , Esquistossomose Urinária/transmissão , Animais , Cercárias/isolamento & purificação , Complexo IV da Cadeia de Transporte de Elétrons/genética , Água Doce/parasitologia , Variação Genética , Especificidade de Hospedeiro , Filogenia , Prevalência , Schistosoma haematobium/parasitologia , Zimbábue
4.
Parasitol Int ; 74: 101978, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31470174

RESUMO

Sprentascaris mahnerti (Nematoda: Raphidascarididae) collected from Loricariichthys labialis (Siluriformes: Loricariidae) in the Pantanal wetlands, State of Mato Grosso do Sul (Brazil), was redescribed using light and scanning electron microscopy (SEM), and genetically characterised along with two other raphidascaridids: Raphidascaroides brasiliensis and Ro. moraveci. Due to the systematic discussion regarding Raphidascaris and Sprentascaris, as well as the poor knowledge about the phylogenetic relationships within Raphidascarididae, phylogenies were reconstructed based on partial sequences of the 18S and 28S nuclear rRNA gene, the nuclear ITS1-5.8S-ITS2 and the cytochrome c oxidase subunit I (cox1) mtDNA. Morphological study of S. mahnerti, confirmed some previously described features, revealed new characteristics and permitted to elucidate some inconsistencies noted in the literature. Morphological and genetic characterisation of S. mahnerti supported its validity. Phylogenetic reconstructions supported the monophyly of Sprentascaris, which has three pairs of interlabial conspicuous cuticular projections as a synapomorphy. The relationships among several lineages of raphidascaridids were unsolved, albeit Goezia and Ichthyascaris formed well-supported monophyletic assemblages, in which the first included species with no relations regarding the habitat of hosts and the geographic origin. The present findings represent one more step towards the understanding of the interrelationships of raphidascaridid nematodes. In this sense, Sprentascaris should be considered valid as an independent lineage from Raphidascaris.


Assuntos
Ascaridoidea/classificação , Ascaridoidea/genética , Doenças dos Peixes/parasitologia , Filogenia , Animais , Ascaridoidea/ultraestrutura , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Água Doce/parasitologia , Masculino , Microscopia Eletrônica de Varredura , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética
5.
Parasitol Res ; 118(12): 3561-3564, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31728721

RESUMO

Most invertebrate species exhibit immunological responses that can inactivate and eliminate penetrating parasites. Such immune responses in particular involve the formation of potentially toxic reactive oxygen species (ROS). We explored the immune capabilities of the first-generation (F1) offspring of naturally infected freshwater snails, Lymnaea stagnalis, in response to infection by trematode cercariae under laboratory conditions. The rates of ROS formation and peroxidase activity in the hemolymph of the F1 offspring of L. stagnalis parents infected by an asexual stage of trematodes were significantly higher than in F1 offspring of uninfected parents. Compared to offspring from uninfected parents, the growth rate of F1 snails from infected parents was higher, but survival was lower. After infection of F1 snails by trematode cercariae of Echinoparyphium aconiatum under laboratory conditions, the rate of ROS formation and peroxidase activity in the hemolymph of F1 offspring of uninfected parents increased compared to control snails. This pattern persisted throughout the entire 3-week observation period. In contrast, the rate of ROS formation in the hemolymph of F1 snails from infected parents after experimental infection by E. aconiatum cercariae did not differ from controls, and peroxidase activity even decreased. Thus, trematode parthenitae infection of parents could alter the immune response of their offspring.


Assuntos
Echinostomatidae/fisiologia , Lymnaea/parasitologia , Estresse Oxidativo , Infecções por Trematódeos/veterinária , Animais , Echinostomatidae/genética , Echinostomatidae/isolamento & purificação , Água Doce/parasitologia , Hemolinfa/parasitologia , Lymnaea/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Infecções por Trematódeos/metabolismo , Infecções por Trematódeos/parasitologia
6.
Parasitol Res ; 118(12): 3253-3265, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31729573

RESUMO

Metacercariae of Clinostomum Leidy, 1856 are frequently encountered in freshwater fish. In 2015, a provisional species of Clinostomum in People's Republic of China (PRC) was distinguished from C. complanatum (Rudolphi, 1819) in Europe based on divergent cytochrome c oxidase I (CO1). However, in subsequent studies in East Asia, the same divergent CO1 genotype was identified as C. complanatum. These matching sequences suggest that either the provisional East Asian species was incorrectly distinguished from C. complanatum in 2015 or that C. complanatum in East Asia was misidentified in later studies. We tested these alternatives by sequencing the mitochondrial genome of C. complanatum in Italy, which was 5.7% divergent from a previously published sequence from Clinostomum in PRC, including differences in 80 of 3390 (2.4%) translated amino acids. Partial CO1 sequences of specimens from PRC and those from Italy, Romania, and Turkey also each formed reciprocally monophyletic clades. Partial CO1 from the East Asian clade varied by mean 3.6% (range 2.4-4.8%) from C. complanatum from Italy, Romania, and Turkey; mean intra-clade CO1 variation was 0.3% (range 0-1.9%). Metacercariae from Europe and East Asia display significant morphometric variation, and data from the literature suggest morphological differences in the genital complex of adults. Although sequences of nuclear rDNA did not differ between isolates from the west and East Asia, taken together, these results lead us to describe a new species of Clinostomum.


Assuntos
Filogenia , Trematódeos/classificação , Animais , Ásia , DNA Ribossômico/genética , Peixes/parasitologia , Água Doce/parasitologia , Genoma Mitocondrial/genética , Metacercárias/anatomia & histologia , Metacercárias/classificação , Metacercárias/genética , Especificidade da Espécie , Trematódeos/anatomia & histologia , Trematódeos/genética
7.
J Helminthol ; 94: e93, 2019 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-31581954

RESUMO

We describe Hedruris dratini n. sp. (Nematoda, Hedruridae) from Hydromedusa tectifera and Phrynops hilarii in Argentina based on morphological and molecular characters. Also, we provide information about its life cycle. The new species differs from other species of the genus by possessing the excretory pore, nerve ring and deirids at equal distance from the anterior end. Additionally, H. dratini n. sp. has mammilated eggs and males possess nine pairs of caudal papillae. The subadults and adults of H. dratini n. sp and H. orestiae were characterized by sequencing the small subunit ribosomal DNA (18S). We present for the first time a life cycle of a species of Hedruris that includes an amphipod as intermediate host and a reptile as definitive host. Furthermore, we analysed the host and geographic distribution of all Hedruris species. Although the genus has a cosmopolitan distribution and parasitizes a great host diversity, the majority of species have a Gondwanian distribution, with amphibians being the preferred hosts.


Assuntos
Infecções por Spirurida/veterinária , Espirurídios/crescimento & desenvolvimento , Espirurídios/isolamento & purificação , Tartarugas/parasitologia , Anfípodes/parasitologia , Animais , Argentina , Feminino , Água Doce/parasitologia , Especificidade de Hospedeiro , Estágios do Ciclo de Vida , Masculino , Espirurídios/genética , Infecções por Spirurida/parasitologia
8.
J Water Health ; 17(5): 717-727, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31638023

RESUMO

This study aimed to detect the presence of Acanthamoeba spp. in different water resources of Zahedan, southeast of Iran, and also systematically reviewed all publications regarding Acanthamoeba in Iran (2005-2018). Fifty water samples were collected from different water resources in Zahedan. The positive samples were identified morphologically and subjected to polymerase chain reaction (PCR) using fragments of 18S rRNA. In the systematic review, data collection using particular terms was carried out using the following electronic databases including Science Direct, ISI Web of Science, MEDLINE, EBSCO, Scopus, and Google Scholar. A total of 17 (34%) samples were positive for Acanthamoeba spp., and nucleotide sequencing indicated that 15 samples (88.23%) belonged to the T4 genotype and the rest belonged to the T5 genotype. A total of 39 studies reported genotyping of Acanthamoeba spp. from various geographical areas of Iran and revealed that T4 (35 studies), T5 (19 studies), T3 (11 studies), T11 (8 studies), and T2 (6 studies) genotypes were the most prevalent in Iran. The T4 genotype of Acanthamoeba is a prevalent free-living amoeba and widely distributed not only in Zahedan but also in other provinces of Iran. Phylogenetic analysis reveals that A. castellanii and A. griffini predominantly colocalize with the T4 genotype.


Assuntos
Acanthamoeba/genética , Água Doce/parasitologia , Abastecimento de Água/estatística & dados numéricos , Monitoramento Ambiental , Genótipo , Irã (Geográfico) , Filogenia , RNA Ribossômico 18S
9.
Parasit Vectors ; 12(1): 492, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31639027

RESUMO

BACKGROUND: Water mites are among the most diverse organisms inhabiting freshwater habitats and are considered as substantial part of the species communities in springs. As parasites, Hydrachnidia influence other invertebrates and play an important role in aquatic ecosystems. In Europe, 137 species are known to appear solely in or near springheads. New species are described frequently, especially with the help of molecular species identification and delimitation methods. The aim of this study was to verify the mainly morphology-based taxonomic knowledge of spring-inhabiting water mites of central Europe and to build a genetic species identification library. METHODS: We sampled 65 crenobiontic species across the central Alps and tested the suitability of mitochondrial (cox1) and nuclear (28S) markers for species delimitation and identification purposes. To investigate both markers, distance- and phylogeny-based approaches were applied. The presence of a barcoding gap was tested by using the automated barcoding gap discovery tool and intra- and interspecific genetic distances were investigated. Furthermore, we analyzed phylogenetic relationships between different taxonomic levels. RESULTS: A high degree of hidden diversity was observed. Seven taxa, morphologically identified as Bandakia concreta Thor, 1913, Hygrobates norvegicus (Thor, 1897), Ljania bipapillata Thor, 1898, Partnunia steinmanni Walter, 1906, Wandesia racovitzai Gledhill, 1970, Wandesia thori Schechtel, 1912 and Zschokkea oblonga Koenike, 1892, showed high intraspecific cox1 distances and each consisted of more than one phylogenetic clade. A clear intraspecific threshold between 5.6-6.0% K2P distance is suitable for species identification purposes. The monophyly of Hydrachnidia and the main superfamilies is evident with different species clearly separated into distinct clades. cox1 separates water mite species but is unsuitable for resolving higher taxonomic levels. CONCLUSIONS: Water mite species richness in springs is higher than has been suggested based on morphological species identification alone and further research is needed to evaluate the true diversity. The standard molecular species identification marker cox1 can be used to identify species but should be complemented by a nuclear marker, e.g. 28S, to resolve taxonomic relationships. Our results contribute to the taxonomical knowledge on spring inhabiting Hydrachnida, which is indispensable for the development and implementation of modern environment assessment methods, e.g. metabarcoding, in spring ecology.


Assuntos
Biodiversidade , Ácaros/classificação , Nascentes Naturais/parasitologia , Animais , Áustria , Teorema de Bayes , Ciclo-Oxigenase 1/genética , DNA/química , DNA/isolamento & purificação , Água Doce/parasitologia , Alemanha , Funções Verossimilhança , Ácaros/anatomia & histologia , Ácaros/genética , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico 28S/genética , Alinhamento de Sequência , Suíça
10.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(3): 339-342, 2019 Jun 05.
Artigo em Chinês | MEDLINE | ID: mdl-31544423

RESUMO

OBJECTIVE: To evaluate the effect of integrated schistosomiasis control measures in Honghu City during the period from 2008 through 2018. METHODS: The data pertaining to schistosomiasis control measures and the endemic situation of schistosomiasis in Honghu City were collected from 2008 to 2018, and the effect of integrated schistosomiasis control measures implemented was evaluated. RESULTS: The resources from agriculture, water resources, forestry, land, education and communication sectors were integrated to implement the integrated schistosomiasis control strategy with the focus on the control of source of Schistosoma japonicum infection in Honghu City from 2008 to 2018. The prevalence of S. japonicum infection reduced from 3.03% in 2008 to 0 in 2018 in humans in the city, and no acute infection was detected since 2009. In addition, the prevalence of S. japonicum infection in cattle reduced from 2.85% in 2008 to 0 in 2018, and no snail infection was found since 2012. Transmission control of schistosomiasis was achieved in the city in 2013, and transmission interruption was achieved in 2018. CONCLUSIONS: The integrated schistosomiasis control measures achieve remarkable effects in Honghu City; however, there is still a risk of schistosomiasis transmission.


Assuntos
Doenças dos Bovinos , Serviços Preventivos de Saúde/normas , Esquistossomose , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , China/epidemiologia , Água Doce/parasitologia , Humanos , Prevalência , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose Japônica , Caramujos/parasitologia
11.
Parasitol Res ; 118(10): 2773-2779, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31456045

RESUMO

Based on morphology and morphometry of gametocytes in blood and molecular phylogenetic analysis, we described a new species of hemoparasite from the genus Haemogregarina isolated from Lepidosiren paradoxa in the eastern Amazon region. Haemogregarina daviesensis sp. nov. is characterized by monomorphic gametocytes of varying maturity stage and their dimensions were 16 ± 0.12 µm (range 13-18) in length and 6 ± 0.97 µm (range 5-8) in width. The morphological and morphometric data were not identical with other haemogregarine species from fish. All specimens of L. paradoxa analyzed were infected by H. daviesensis sp. nov. and the parasitemia level was moderate (1-28/2000 blood erythrocytes). Two sequences were obtained from L. paradoxa, and these constituted a monophyletic sister clade to the Haemogregarina species. In addition, H. daviesensis sp. nov. detected here grouped with Haemogregarina sp. sequences isolated from chelonian Macrochelys temminckii, with 99% bootstrap support. This study provides the first data on the molecular phylogeny of an intraerythrocytic haemogregarine of freshwater fish and highlights the importance of obtaining additional information on aspects of the general biology of these hemoparasites in fish populations, in order to achieve correct taxonomic classification.


Assuntos
Coccidiose/veterinária , Eucoccidiida/isolamento & purificação , Doenças dos Peixes/parasitologia , Animais , Coccidiose/parasitologia , Eucoccidiida/classificação , Eucoccidiida/genética , Eucoccidiida/fisiologia , Feminino , Peixes/parasitologia , Água Doce/parasitologia , Masculino , Parasitemia/parasitologia , Parasitemia/veterinária , Filogenia
12.
Korean J Parasitol ; 57(3): 291-294, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31284352

RESUMO

Primary amebic encephalitis (PAM) is a devastating central nervous system infection caused by Naegleria fowleri, a free-living amoeba, which can survive in soil and warm fresh water. Here, a 43-year-old healthy male was exposed to warm freshwater 5 days before the symptom onset. He rapidly developed severe cerebral edema before the diagnosis of PAM and was treated with intravenous conventional amphotericin B while died of terminal cerebral hernia finally. Comparing the patients with PAM who has similar clinical symptoms to those with other common types of meningoencephalitis, this infection is probably curable if treated early and aggressively. PAM should be considered in the differential diagnosis of purulent meningoencephalitis, especially in patients with recent freshwater-related activities during the hot season.


Assuntos
Meningoencefalite/parasitologia , Adulto , Evolução Fatal , Água Doce/parasitologia , Humanos , Masculino , Meningoencefalite/diagnóstico , Meningoencefalite/mortalidade , Naegleria fowleri/genética , Naegleria fowleri/isolamento & purificação , Naegleria fowleri/fisiologia
13.
Parasite ; 26: 47, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31359860

RESUMO

Trichodinids, which are ciliate protists, are causative agents of an aquatic animal disease, trichodiniasis, especially among both captive and wild fish. This disease can adversely affect aquaculture and have economic impacts. The objectives of this study were to evaluate the prevalence and mean intensity of Trichodina unionis infection, describe qualitative and quantitative morphological characters, and perform a molecular phylogenetic analysis. The gastropod samples were randomly collected by hand-picking and a hand net. Trichodina unionis was collected by the crushing method under a stereomicroscope. Among all 4977 examined gastropods, 55 individuals of two gastropod species, Gyraulus siamensis and Physella acuta, were found to be infected by T. unionis, with overall prevalence and mean intensity of infection of 1.11% and 16.65, respectively. The characteristics of the denticles indicated T. unionis as having moderately wide blades and moderately curved blade margins, with distinctive bend angles near the distal end. The quantitative characters showed some variations, which could be due to food availability. Molecular phylogenetic analysis conducted with 18S rRNA provided a monophyletic tree of our specimens and previously identified T. unionis, confirming species identification. This study represents the first record of T. unionis in Thailand.


Assuntos
Infecções por Cilióforos/parasitologia , Gastrópodes/parasitologia , Oligoimenóforos/classificação , Oligoimenóforos/isolamento & purificação , Filogenia , Animais , Água Doce/parasitologia , Especificidade da Espécie , Tailândia
14.
Nat Microbiol ; 4(10): 1620-1626, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31182800

RESUMO

We describe Idionectes vortex gen. nov., sp. nov., a unicellular microeukaryote that swims by continuous inversion of its surface, similar to a vortex ring. This previously unreported mode of motility approximates a hypothetical concept called the 'toroidal swimmer', in which a doughnut-shaped object rotates around its circular axis and travels in the opposite direction to its outer surface motion. During swimming, the flagellum of Idionectes rotates relative to its cell body, which is normally a hallmark of prokaryotic rather than eukaryotic flagella.


Assuntos
Eucariotos/classificação , Eucariotos/fisiologia , Flagelos/fisiologia , Locomoção , Movimento Celular , Eucariotos/citologia , Eucariotos/genética , Água Doce/parasitologia , Filogenia , Protoplastos/parasitologia , Pseudópodes , Especificidade da Espécie , Zygnematales/parasitologia
15.
Parasitol Int ; 72: 101940, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31201924

RESUMO

We performed the first host-parasite survey of the Philippine crocodile, Crocodylus mindorensis, a critically endangered species for which ecological information is lacking. We collected by gastric lavage samples of the stomach contents of crocodiles (n = 10) residing at the Palawan Wildlife Rescue and Conservation Center in Puerto Princesa, Palawan, Philippines. The only parasite detected was an acanthocephalan, which was identified as Neorhadinorhynchus nudus (n = 68), a parasite typically found in the marine fish species consumed by three crocodile individuals. Given the known hosts of N. nudus, its parasitism of C. mindorensis in captivity is likely established by consumption of marine fish. Our findings have implications for the conservation management of C. mindorensis, particularly in terms of preventing introduction of parasites that could lead to development of infectious disease or alter the fitness of captive animals.


Assuntos
Acantocéfalos/classificação , Acantocéfalos/isolamento & purificação , Jacarés e Crocodilos/parasitologia , Peixes/parasitologia , Trato Gastrointestinal/parasitologia , Acantocéfalos/anatomia & histologia , Animais , Conservação dos Recursos Naturais , Feminino , Água Doce/parasitologia , Interações Hospedeiro-Parasita , Masculino , Filipinas
16.
Parasitol Res ; 118(6): 1731-1739, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31049695

RESUMO

The aim of this study was to evaluate the effect of trypanosomes on cultured largemouth bass (Micropterus salmoides) and describe the taxonomic identification of the parasite. The effects of the parasite on M. salmoides were examined based on clinical symptoms, hemograms, histopathology, and serum biochemistry. Diseased fish showed typical clinical symptoms of trypanosomiasis, which included lethargy, anorexia, and histopathological lesions in the liver, head kidney, and spleen. The serum of diseased fish had significantly lower concentrations of glucose, triglyceride, and low-density lipoprotein, and significantly higher alanine transaminase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) activities. The morphology of the trypanosomes was also analyzed using light microscopy, and their 18S rDNA sequence was analyzed to establish genetic relationships with other known strains. We found that the trypomastigote form of the trypanosomes from M. salmoides was similar to those isolated from Pelteobagrus fulvidraco. The trypanosomes had a slender and narrow body with a relatively long free flagellum, not well-developed undulating membrane, and an oval kinetoplast located near the subterminal posterior end of the body. The 18S rDNA sequences of the trypanosome from M. salmoides had the highest similarity (99.8%) with that of P. fulvidraco, suggesting they are identical species. Based on the differences in morphological characteristics and 18S rDNA sequence compared to trypanosomes isolated from other freshwater fish, it is considered as a new species and we propose the name Trypanosoma micropteri n. sp.


Assuntos
Doenças dos Peixes/parasitologia , Trypanosoma/classificação , Tripanossomíase/veterinária , Animais , Bass/parasitologia , Peixes-Gato/parasitologia , China , DNA Ribossômico/genética , Água Doce/parasitologia , Filogenia , Trypanosoma/genética , Trypanosoma/isolamento & purificação , Tripanossomíase/parasitologia , Tripanossomíase/patologia
17.
Elife ; 82019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31112133

RESUMO

Female Aedes aegypti mosquitoes are deadly vectors of arboviral pathogens and breed in containers of freshwater associated with human habitation. Because high salinity is lethal to offspring, correctly evaluating water purity is a crucial parenting decision. We found that the DEG/ENaC channel ppk301 and sensory neurons expressing ppk301 control egg-laying initiation and choice in Ae. aegypti. Using calcium imaging, we found that ppk301-expressing cells show ppk301-dependent responses to water but, unexpectedly, also respond to salt in a ppk301-independent fashion. This suggests that ppk301 is instructive for egg-laying at low-salt concentrations, but that a ppk301-independent pathway is responsible for inhibiting egg-laying at high-salt concentrations. Water is a key resource for insect survival and understanding how mosquitoes interact with water to control different behaviors is an opportunity to study the evolution of chemosensory systems.


Assuntos
Aedes/genética , Canais Iônicos/genética , Larva/genética , Células Receptoras Sensoriais/efeitos dos fármacos , Aedes/crescimento & desenvolvimento , Animais , Água Doce/parasitologia , Humanos , Larva/crescimento & desenvolvimento , Mosquitos Vetores/genética , Mosquitos Vetores/metabolismo , Oviposição , Salinidade , Células Receptoras Sensoriais/metabolismo , Cloreto de Sódio/metabolismo , Água/parasitologia
18.
PLoS Negl Trop Dis ; 13(5): e0007323, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-31050672

RESUMO

BACKGROUND: Soil transmitted helminths (STH) infect >1.5 billion people. Mass drug administration (MDA) effectively reduces infection; however, there is evidence for rapid reinfection and risk of potential drug resistance. We conducted a randomized controlled trial in Bangladesh (WASH Benefits, NCT01590095) to assess whether water, sanitation, hygiene and nutrition interventions, alone and combined, reduce STH in a setting with ongoing MDA. METHODOLOGY/PRINCIPAL FINDINGS: In 2012-2013, we randomized 720 clusters of 5551 pregnant women into water treatment, sanitation, handwashing, combined water+sanitation+handwashing (WSH), nutrition, nutrition+WSH (N+WSH) or control arms. In 2015-2016, we enrolled 7795 children, aged 2-12 years, of 4102 available women for STH follow-up and collected stool from 7187. We enumerated STH infections with Kato-Katz. We estimated intention-to-treat intervention effects on infection prevalence and intensity. Participants and field staff were not blinded; laboratory technicians and data analysts were blinded. Prevalence among controls was 36.8% for A. lumbricoides, 9.2% for hookworm and 7.5% for T. trichiura. Most infections were low-intensity. Compared to controls, the water intervention reduced hookworm by 31% (prevalence ratio [PR] = 0.69 (0.50,0.95), prevalence difference [PD] = -2.83 (-5.16,-0.50)) but did not affect other STH. Sanitation improvements reduced T. trichiura by 29% (PR = 0.71 (0.52,0.98), PD = -2.17 (-4.03,-0.38)), had a similar borderline effect on hookworm and no effect on A. lumbricoides. Handwashing and nutrition interventions did not reduce any STH. WSH and N+WSH reduced hookworm prevalence by 29-33% (WSH: PR = 0.71 (0.52,0.99), PD = -2.63 (-4.95,-0.31); N+WSH: PR = 0.67 (0.50,0.91), PD = -3.00 (-5.14,-0.85)) and marginally reduced A. lumbricoides. Effects on infection intensity were similar. CONCLUSIONS/SIGNIFICANCE: In a low-intensity infection setting with MDA, we found modest but sustained hookworm reduction from water treatment and combined WSH interventions. Impacts were more pronounced on STH species with short vs. long-term environmental survival. Our findings suggest possible waterborne transmission for hookworm. Water treatment and sanitation improvements can augment MDA to interrupt STH transmission. TRIAL REGISTRATION: NCT01590095.


Assuntos
Água Doce/parasitologia , Desinfecção das Mãos/métodos , Helmintíase/prevenção & controle , Helmintos/isolamento & purificação , Saneamento/métodos , Animais , Bangladesh/epidemiologia , Criança , Pré-Escolar , Dieta , Fezes/parasitologia , Feminino , Helmintíase/epidemiologia , Helmintíase/transmissão , Helmintos/classificação , Helmintos/genética , Humanos , Masculino , Avaliação Nutricional , Gestantes , Solo/parasitologia
19.
Eur J Protistol ; 69: 152-164, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31039517

RESUMO

Globally, lakes and reservoirs ecosystems are integral parts of ecological processes. Nevertheless, global warming is rapidly changing their function and sustainability, especially in the populated area of the northern hemisphere. Here we examined testate amoebae community and 10 environmental variables from 51 lakes and reservoirs across China and developed testate amoebae transfer functions for temperature based on both abundance- and biomass-datasets. A total of 169 testate amoebae taxa were identified. Our partial CCA analyses revealed that water temperature explained 5.15% (P = 0.006) and 5.57% (P = 0.008) of the total variance in testate amoebae abundance and biomass, respectively. The WA-PLS was the best model in abundance-based temperature transfer function (RMSEP = 2.87 °Ð¡, R2 = 0.60), whereas the MAT proved to be the best model for biomass-based temperature transfer function (RMSEP = 3.34 °Ð¡, R2 = 0.67). The application of all models should be carried out with suitable precautions. Our results suggested that freshwater testate amoebae could contribute to a better understanding of the ecological integrity and its vulnerability in inland aquatic environments.


Assuntos
Amoeba/fisiologia , Meio Ambiente , Água Doce/parasitologia , Temperatura , Modelos Teóricos , Densidade Demográfica
20.
Parasitol Res ; 118(6): 1751-1759, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30968262

RESUMO

Vermamoeba vermiformis represents one of the most common free-living amoebae identified in worldwide environmental surveys. We analyzed 56 water samples with varying characteristics, including temperature and the particular settings in which humans may be exposed to water, plus one corneal scraping from a keratitis patient, with the following aims: (i) to investigate the presence of V. vermiformis; (ii) to identify the isolate subtypes; (iii) to place the Italian isolates in the broader picture of the genetic diversity within V. vermiformis. Twenty-two isolates were identified upon culturing and sequencing of > 600 bp in the 18S ribosomal RNA (rRNA) gene sequence, bringing to 27 the number of sequences recovered from Italian sources. By adding deposited sequences, we assembled a dataset of 74 isolates. Three of our isolates were characterized by allelic code 7-5-1-1, never reported before, and two showed 100% identity with an uncultured eukaryote and carried the 719T>C variant. We show that the variable segments E5, E3, F, and G convey most of the information on diversity, enabling the clustering of the isolates in a replicable fashion. The presence of different strains in natural thermal waters and in distribution systems indicated heterogeneity of the amoebic populations. Also, ours and the only other sequence from human infection were mapped in different clades. Overall, we enlarged the repertoire of single nucleotide and indel variants and the list of allelic codes, proceeding one step further in the description of the diversity within the genus.


Assuntos
Amoeba/genética , Amoeba/isolamento & purificação , Variação Genética , Amoeba/classificação , DNA de Protozoário/genética , Água Doce/parasitologia , Humanos , Itália , Filogenia , RNA Ribossômico 18S/genética
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