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1.
J Parasitol ; 107(1): 74-88, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33556183

RESUMO

Herein, we describe several newly-collected specimens of Neopolystoma cf. orbiculare from the urinary bladder of 2 alligator snapping turtles, Macrochelys temminckii (Troost in Harland, 1835) (Cryptodira: Chelydridae Gray, 1831) from Comet Lake (30°35'46.94″N, 88°36'3.12″W), Pascagoula River, Mississippi. Our specimens differed from all previous descriptions of N. orbiculare and its junior subjective synonyms by the combination of having intestinal ceca adorned with triangular pockets and that terminate dorsal to the haptor, distinctive hooklets each having a handle and guard of approximately equal length and having a much longer and curved blade, 16 genital coronet spines that each possess 1-2 flanges per spine, pre-testicular vaginal pores, and vaginal ducts that are anterior to the junction of the oviduct and genito-intestinal canal. Some of our specimens were enantiomorphic (4 and 3 had a dextral and sinistral ovary, respectively). Nucleotide sequences (large subunit ribosomal DNA [28S], small subunit ribosomal DNA [18S], and cytochrome oxidase subunit 1 mitochondrial gene [COI]) for our specimens were most similar to GenBank sequences ascribed to N. orbiculare. Single-gene and concatenated phylogenetic analyses confirmed that NeopolystomaPrice, 1939 is polyphyletic and that our isolates share a recent common ancestor with those ascribed to N. orbiculare. This is the first record of a polystomatid from Mississippi, from the Pascagoula River, and from the alligator snapping turtle (and only the second species of Neopolystoma reported from any snapping turtle).


Assuntos
Platelmintos/classificação , Infecções por Trematódeos/veterinária , Tartarugas/parasitologia , Animais , Teorema de Bayes , DNA de Helmintos/isolamento & purificação , DNA Ribossômico/química , Complexo IV da Cadeia de Transporte de Elétrons/genética , Genes Mitocondriais , Lagos/parasitologia , Mississippi/epidemiologia , Filogenia , Platelmintos/anatomia & histologia , Platelmintos/genética , Platelmintos/isolamento & purificação , Prevalência , RNA Ribossômico 18S/genética , RNA Ribossômico 28S/genética , Rios/parasitologia , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia , Bexiga Urinária/parasitologia
2.
Folia Parasitol (Praha) ; 672020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32764186

RESUMO

Eudiplozoon nipponicum (Goto, 1891) Khotenovsky, 1985 (Monogenea: Diplozoidae), is known to parasitise Cyprinus carpio Linnaeus and species of Carassius. In this study, we conducted a taxonomic re-examination of E. nipponicum using genetic analysis and morphological comparisons from different host species from a single water system. rDNA nucleotide sequences of the internal transcription spacer 2 (ITS-2) region (645 bp) showed interspecific-level genetic differences among diplozoids from species of Carassius and C. carpio (p-distance: 3.1-4.0%) but no difference among those from different species of Carassius (0-0.4%) or between those from C. carpio collected in Asia and Europe (0-1.1%). Large variation was observed among 346 bp cytochrome c oxidase subunit I (COI) sequences (0.3-16.0 %); the topology of the phylogenetic tree showed no relationship to host genera or geographical regions of origin. Morphological observation showed that average clamp size of diplozoids from C. carpio was larger than those from Carassius spp. The number of folds on the hindbody was 10-25 for diplozoids from C. carpio and 12-19 for those from Carassius spp. Thus, our ITS-2 sequence and morphological comparison results indicate that diplozoids from C. carpio and species of Carassius belong to different species. The scientific name E. nipponicum should be applied to the species infected to the type host, Carassius sp. of Nakabo (2013) (Japanese name ginbuna). The diplozoid infecting C. carpio (Eurasian type) should be established as a new species: Eudiplozoon kamegaii sp. n. A neotype of E. nipponicum is designated in this report because the original E. nipponicum specimens are thought to have been lost.


Assuntos
Carpas , Doenças dos Peixes/epidemiologia , Trematódeos/classificação , Trematódeos/fisiologia , Infecções por Trematódeos/veterinária , Animais , DNA Ribossômico/análise , Doenças dos Peixes/parasitologia , Japão/epidemiologia , Lagos/parasitologia , Filogenia , Trematódeos/anatomia & histologia , Trematódeos/genética , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/parasitologia
3.
Parasitol Res ; 119(8): 2531-2537, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32562067

RESUMO

Human cercarial dermatitis is a parasitic disease that causes an allergic reaction in the skin (swimmer's itch) as a consequence of contact with cercariae of bird schistosomes present in water, mainly of the genus Trichobilharzia Skrjabin et Zakarow, 1920. The main objective of the study was to confirm the presence of the zoonotic disease agent following reports of human infections in recreational water in Slovakia. We identified two species of freshwater snails at Kosice Lake, Radix auricularia (Linnaeus, 1758) and Physa acuta (Draparnaud, 1805). Trematode infections were observed only in R. auricularia. Of the 62 snails collected, 11 (17.7%) were infected with 5 different species of larval stages of trematodes. The blood fluke Trichobilharzia franki was found in 2 (3.2%) of the examined snails. The present record provides the first evidence that T. franki from the pulmonate snail R. auricularia represents a source of human cercarial dermatitis in recreational water in Slovakia. Our finding complements the easternmost records of both swimmer's itch and the confirmed occurrence of a bird schistosome in a waterbody in Europe. The present work suggests that the health risks associated with trichobilharziasis need to be further studied by detailed monitoring of the occurrence of the major causative agent of human cercarial dermatitis, T. franki.


Assuntos
Dermatite/parasitologia , Lagos/parasitologia , Schistosomatidae/isolamento & purificação , Esquistossomose/transmissão , Dermatopatias Parasitárias/parasitologia , Infecções por Trematódeos/parasitologia , Zoonoses/parasitologia , Animais , Dermatite/epidemiologia , Surtos de Doenças , Humanos , Schistosomatidae/classificação , Schistosomatidae/genética , Esquistossomose/epidemiologia , Esquistossomose/parasitologia , Dermatopatias Parasitárias/transmissão , Eslováquia/epidemiologia , Caramujos/parasitologia , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/transmissão , Zoonoses/epidemiologia , Zoonoses/transmissão
4.
Ann Parasitol ; 66(1): 111­114, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32199003

RESUMO

Acanthamoeba spp. are ubiquitous in both natural and man-made environments and have been isolated in lakes, recreational pools, tap water, and air conditioning systems. Twenty surface water (SW) samples were collected from different sampling areas of Lake Buhi. Water samples were pelleted, cultured in NNA lawned with Escherichia coli and observed microscopically. 10% of samples (2/20) were positive for amoebic growth and were furthered tested using molecular techniques. Polymerase chain reaction showed the presence of Acanthamoeba sp. DNA. The presence of potentially pathogenic Acanthamoeba sp. poses a public health concern. The formulation of policies for proper information dissemination and control measures to avert the contraction of pathogenic FLA as well as other WBPP should be seriously considered.


Assuntos
Acanthamoeba , Lagos , Acanthamoeba/classificação , Acanthamoeba/genética , Acanthamoeba/isolamento & purificação , DNA de Protozoário/genética , Lagos/parasitologia , Filipinas , Reação em Cadeia da Polimerase
5.
Microb Ecol ; 79(4): 801-814, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31705158

RESUMO

Freshwater planktonic communities comprise a tremendous diversity of microorganisms. This study investigated the distribution patterns of microbial kingdoms (bacteria, fungi, protists, and microbial metazoans) within a lake ecosystem. Water samples were collected from 50 sites along the shoreline in a lake during an early eutrophication period, and MiSeq sequencing was performed with different marker genes. Metacommunity analyses revealed a bimodal occupancy-frequency distribution and a Clementsian gradient persisting throughout all microbial kingdoms, suggesting similar regional processes in all kingdoms. Variation partitioning revealed that environmental characteristics, macrophyte/macroinvertebrate composition, space coordinates, and distance-based Moran's eigenvector maps (dbMEM) together could explain up to 29% of the community variances in microbial kingdoms. Kingdom synchrony results showed strong couplings between kingdoms (R2 ≥ 0.31), except between Fungi and Metazoa (R2 = 0.09). Another variation partitioning revealed that microbial kingdoms could well explain their community variances up to 73%. Interestingly, the kingdom Protista was best synchronized with the other kingdoms. A correlation network showed that positive associations between kingdoms outnumbered the negative ones and that the kingdom Protista acted as a hub among kingdoms. Module analysis showed that network modules included multi-kingdom associations that were prevalent. Our findings suggest that protists coordinate community assembly and distribution of other kingdoms, and inter-kingdom interactions are a key determinant in shaping their community structures in a freshwater lake.


Assuntos
Lagos/microbiologia , Microbiota , Animais , Bactérias/isolamento & purificação , Fungos/isolamento & purificação , Lagos/parasitologia , República da Coreia , Análise Espacial
6.
Microb Ecol ; 79(2): 443-458, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31432244

RESUMO

Arcellinida (testate lobose amoebae) are widely used as bio-indicators of lacustrine environmental change. Too much obscuring organic material in a gridded wet Petri dish preparation makes it difficult to observe all specimens present and slows quantification as the organic material has to be carefully worked through with a dissection probe. Chemical deflocculation using soda ash (Na2CO3·H2O), potassium hydroxide (KOH), or sodium hexametaphosphate ((NaPO3)6) has previously been shown to disaggregate and reduce organic content in lake sediments, but to date, no attempt has been made to comparatively evaluate the efficiency of these deflocculants in disaggregating organic content and their impact on Arcellinida analysis in lacustrine sediments. Here, we assess the effectiveness of soda ash, potassium hydroxide, and sodium hexametaphosphate treatments on removing organic content and the impact of those digestions on Arcellinida preservation in 126 sample aliquots subdivided from three sediment samples (YK-20, YK-25, and YK-57) collected from three lakes near Yellowknife, Northwest Territories, Canada. Following treatment, cluster analysis and Bray-Curtis dissimilarity matrix (BCDM) were utilized to determine whether treatments resulted in dissolution-driven changes in Arcellinida assemblage composition. Observed Arcellinida tests in aliquots increased drastically after treatment of organic-rich samples (47.5-452.7% in organic-rich aliquots and by 14.8% in aliquots with less organic matter). The BCDM results revealed that treatment with 5% KOH resulted in the highest reduction in observed organic content without significantly affecting Arcellinida assemblage structure, while soda ash and sodium hexametaphosphate treatments resulted in marginal organic matter reduction and caused severe damage to the arcellinidan tests.


Assuntos
Floculação , Sedimentos Geológicos/parasitologia , Lobosea/isolamento & purificação , Técnicas Microbiológicas/instrumentação , Lagos/parasitologia , Territórios do Noroeste , Parasitologia/métodos
7.
J Eukaryot Microbiol ; 67(1): 86-99, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31432582

RESUMO

Reclamation of anthropogenically impacted environments is a critical issue worldwide. In the oil sands extraction industry of Alberta, reclamation of mining-impacted areas, especially areas affected by tailings waste, is an important aspect of the mining life cycle. A reclamation technique currently under study is water-capping, where tailings are capped by water to create an end-pit lake (EPL). Base Mine Lake (BML) is the first full-scale end-pit lake in the Alberta oil sands region. In this study, we sequenced eukaryotic 18S rRNA genes recovered from 92 samples of Base Mine Lake water in a comprehensive sampling programme covering the ice-free period of 2015. The 565 operational taxonomic units (OTUs) generated revealed a dynamic and diverse community including abundant Microsporidia, Ciliata and Cercozoa, though 41% of OTUs were not classifiable below the phylum level by comparison to 18S rRNA databases. Phylogenetic analysis of five heterotrophic phyla (Cercozoa, Fungi, Ciliata, Amoebozoa and Excavata) revealed substantial novel diversity, with many clusters of OTUs that were more similar to each other than to any reference sequence. All of these groups are entirely or mostly heterotrophic, as a relatively small number of definitively photosynthetic clades were amplified from the BML samples.


Assuntos
Cercozoários/classificação , Cilióforos/classificação , Lagos/parasitologia , Microbiota , Microsporídios/classificação , Alberta , Mineração , Campos de Petróleo e Gás/parasitologia , Filogenia
8.
Appl Environ Microbiol ; 86(3)2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31732569

RESUMO

Human viruses are ubiquitous contaminants in surface waters, where they can persist over extended periods of time. Among the factors governing their environmental persistence, the control (removal or inactivation) by microorganisms remains poorly understood. Here, we determined the contribution of indigenous bacteria and protists to the decay of human viruses in surface waters. Incubation of echovirus 11 (E11) in freshwater from Lake Geneva and seawater from the Mediterranean Sea led to a 2.5-log10 reduction in the infectious virus concentration within 48 h at 22°C, whereas E11 was stable in sterile controls. The observed virus reduction was attributed to the action of both bacteria and protists in the biologically active matrices. The effect of microorganisms on viruses was temperature dependent, with a complete inhibition of microbial virus control in lake water at temperatures of ≤16°C. Among three protist isolates tested (Paraphysomonas sp., Uronema marinum, and Caecitellus paraparvulus), Caecitellus paraparvulus was particularly efficient at controlling E11 (2.1-log10 reduction over 4 days with an initial protist concentration of 103 cells ml-1). In addition, other viruses (human adenovirus type 2 and bacteriophage H6) exhibited different grazing kinetics than E11, indicating that the efficacy of antiviral action also depended on the type of virus. In conclusion, indigenous bacteria and protists in lake water and seawater can modulate the persistence of E11. These results pave the way for further research to understand how microorganisms control human viral pathogens in aquatic ecosystems and to exploit this process as a treatment solution to enhance microbial water safety.IMPORTANCE Waterborne human viruses can persist in the environment, causing a risk to human health over long periods of time. In this work, we demonstrate that in both freshwater and seawater environments, indigenous bacteria and protists can graze on waterborne viruses and thereby reduce their persistence. We furthermore demonstrate that the efficiency of the grazing process depends on temperature, virus type, and protist species. These findings may facilitate the design of biological methods for the disinfection of water and wastewater.


Assuntos
Cadeia Alimentar , Lagos , Viabilidade Microbiana , Viroses/virologia , Fenômenos Fisiológicos Virais , Doenças Transmitidas pela Água/virologia , Oceano Atlântico , Fenômenos Fisiológicos Bacterianos , Chrysophyta/fisiologia , Lagos/microbiologia , Lagos/parasitologia , Lagos/virologia , Mar Mediterrâneo , Oligoimenóforos/fisiologia , Água do Mar/microbiologia , Água do Mar/parasitologia , Água do Mar/virologia , Espanha , Especificidade da Espécie , Estramenópilas/fisiologia , Suíça , Vírus/classificação
9.
Parasite ; 26: 76, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31859621

RESUMO

A new species of Gyrodactylus von Nordmann, 1832 is described from the gills of Alcolapia grahami, a tilapian fish endemic to Lake Magadi. This alkaline soda lake in the Rift Valley in Kenya is an extreme environment with pH as high as 11, temperatures up to 42 °C, and diurnal fluctuation between hyperoxia and virtual anoxia. Nevertheless, gyrodactylid monogeneans able to survive these hostile conditions were detected from the gills the Magadi tilapia. The worms were studied using light microscopy, isolated sclerites observed using scanning electron microscopy, and molecular techniques used to genetically characterize the specimens. The gyrodactylid was described as Gyrodactylus magadiensis n. sp. and could be distinguished from other Gyrodactylus species infecting African cichlid fish based on the comparatively long and narrow hamuli, a ventral bar with small rounded anterolateral processes and a tongue-shaped posterior membrane, and marginal hooks with slender sickles which are angled forward, a trapezoid to square toe, rounded heel, a long bridge prior to reaching marginal sickle shaft, and a long lateral edge of the toe. The species is also distinct from all other Gyrodactylus taxa based on the ITS region of rDNA (ITS1-5.8s-ITS2), strongly supporting the designation of a new species. These findings represent the second record of Gyrodactylus from Kenya, with the description of G. magadiensis bringing the total number of Gyrodactylus species described from African cichlids to 18.


Assuntos
Ciclídeos/parasitologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Lagos/parasitologia , Trematódeos/ultraestrutura , Infecções por Trematódeos/veterinária , Animais , DNA Espaçador Ribossômico/genética , Ambientes Extremos , Quênia , Masculino , Filogenia , Especificidade da Espécie , Trematódeos/classificação
10.
J Helminthol ; 94: e108, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31779720

RESUMO

The adult and metacercaria life stages of a new species of the microphallid genus Atriophallophorus Deblock & Rosé, 1964 are described from specimens collected at Lake Alexandrina (South Island, New Zealand). In addition to molecular analyses of ribosomal and mitochondrial genes, metacercariae of Atriophallophorus winterbourni n. sp. from the snail host Potamopyrgus antipodarum (Gray) were grown in vitro to characterize internal and external morphology of adults using light and scanning electron microscopy and histological techniques. Atriophallophorus winterbourni n. sp. is readily distinguishable from Atriophallophorus coxiellae Smith, 1973 by having a different structure of the prostatic chamber, sub-circular and dorsal to genital atrium, rather than cylindrical, fibrous, elongate and placed between the seminal vesicle and the genital atrium. The new species is most similar to Atriophallophorus minutus (Price, 1934) with regards to the prostatic chamber and the morphometric data, but possesses elongate-oval testes and subtriangular ovary rather than oval and transversely oval in A. minutus. Phylogenetic analyses including sequence data for A. winterbourni n. sp. suggested a congeneric relationship of the new species to a hitherto undescribed metacercariae reported from Australia, both forming a strongly supported clade closely related to Microphallus and Levinseniella. In addition, we provide an amended diagnosis of Atriophallophorus to accommodate the new species and confirm the sinistral interruption of the outer rim of the ventral sucker caused by the protrusion of the dextral parietal atrial scale at the base of the phallus.


Assuntos
Filogenia , Caramujos/parasitologia , Trematódeos/anatomia & histologia , Trematódeos/classificação , Animais , Austrália , DNA Ribossômico/genética , Feminino , Genes Mitocondriais , Genitália/anatomia & histologia , Lagos/parasitologia , Masculino , Metacercárias/anatomia & histologia , Metacercárias/classificação , Nova Zelândia
11.
Infect Dis Poverty ; 8(1): 93, 2019 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-31744539

RESUMO

BACKGROUND: Determination of infection rates of snail populations is one of the basic tools for epidemiological studies of snail borne diseases. In this study, we opted to determine the trematode infection of freshwater snails in the Omo-Gibe River Basin, southwest Ethiopia. METHODS: We collected snail samples from 130 observation sites in lakes, wetlands, rivers, reservoirs and irrigation canals surveyed during the dry season (March to May) in 2016. The snail samples were examined for trematode infections by cercarial shedding immediately after collection. Habitat conditions, water quality, human water contact practices and other human activities were assessed at each survey site. A redundancy analysis (RDA) was used to examine the relationship between cercarial infection and environmental variables. The statistical significance of eigenvalues and cercariae-environment correlations generated by the RDA were tested using Monte Carlo permutations at 499 permutations. RESULTS: A total of 3107 snails belonging to five species were collected. The most abundant species was Biomphalaria pfeifferi, representing 66% of the total collection. Overall, 109 (3.6%) of the snails were found infected with trematodes (cercariae). Biomphalaria pfeifferi was found to be the most highly infected, accounting 85% of all infected snails. A total of eight morphologically different types of cercariae were recorded, which included: Echinostoma cercariae, brevifurcate apharyngeate distome cercariae, amphistome cercariae, brevifurcate apharyngeate monostome cercariae, xiphidiocercariae, longifurcate pharyngeate distome cercariae, strigea cercariae and unidentified cercariae. Brevifurcate apharyngeate distome cercariae, and Echinostoma cercariae were the most abundant cercariae, accounting for 36 and 34% of all infection, respectively. The mean concentration of water conductivity and 5 days biological oxygen demand were higher in irrigation canals and lake sampling points. Human activities such as open field defecation, urination, livestock grazing, farming, and swimming were highly correlated with trematode infection. CONCLUSIONS: The abundance, occurrence and infection rates of snail species were largely influenced by water physicochemical quality, sanitation and water contact behaviour of the inhabitants. Human activities, such as open field defecation and urination, livestock grazing, farming, and swimming were important predictors of the abundance of cercariae. Therefore, awareness creation should be implemented for proper containment of excreta (urine and faeces) and reducing human and animal contacts with surface waters to reduce snail-borne disease transmission.


Assuntos
Lagos/parasitologia , Rios/parasitologia , Caramujos/parasitologia , Trematódeos/fisiologia , Áreas Alagadas , Animais , Biomphalaria/parasitologia , Vetores de Doenças , Etiópia , Estações do Ano
12.
Parasit Vectors ; 12(1): 565, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31775865

RESUMO

BACKGROUND: Human schistosomiasis is the second most important tropical disease and occurs in two forms in Africa (intestinal and urogenital) caused by the digenetic trematodes Schistosoma mansoni and Schistosoma haematobium, respectively. A proposed recent shift of schistosomiasis above a previously established altitudinal threshold of 1400 m above sea level in western Ugandan crater lakes has triggered more research interest there. METHODS: Based on extensive field sampling in western Uganda and beyond and employing an approach using sequences of the mitochondrial barcoding gene cytochrome c oxidase subunit 1 (cox1) this study aims were: (i) identification and establishment of the phylogenetic affinities of Bulinus species as potential hosts for Schistosoma spp.; (ii) determining diversity, frequency and distribution patterns of Bulinus spp.; and (iii) establishing genetic variability and phylogeographical patterns using Bayesian inference and parsimony network analyses. RESULTS: Out of the 58 crater lakes surveyed, three species of Bulinus snails were found in 34 crater lakes. Bulinus tropicus was dominating, Bulinus forskalii was found in two lakes and Bulinus truncatus in one. The latter two species are unconfirmed potential hosts for S. haematobium in this region. However, Bulinus tropicus is an important species for schistosomiasis transmission in ruminants. Bulinus tropicus comprised 31 haplotypes while both B. forskalii and B. truncatus exhibited only a single haplotype in the crater lakes. All species clustered with most of the haplotypes from surrounding lake systems forming source regions for the colonization of the crater lakes. CONCLUSIONS: This first detailed malacological study of the crater lakes systems in western Uganda revealed presence of Bulinus species that are either not known or not regionally known to be hosts for S. haematobium, the causing agent of human urogenital schistosomiasis. Though this disease risk is almost negligible, the observed dominance of B. tropicus in the crater lakes shows that there is a likelihood of a high risk of infections with Schistosoma bovis. Thus, extra attention should be accorded to safeguard wild and domestic ruminants in this region as the population benefits from these animals.


Assuntos
Bulinus/classificação , Bulinus/genética , Monitoramento Epidemiológico/veterinária , Lagos/parasitologia , Esquistossomose Urinária/transmissão , Animais , Bulinus/parasitologia , Haplótipos , Filogenia , Filogeografia , Ruminantes/parasitologia , Schistosoma haematobium , Esquistossomose Urinária/prevenção & controle , Uganda
13.
Parasitol Res ; 118(10): 2811-2817, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31493065

RESUMO

The main fish host reaction to an infection with third stage anisakid nematode larvae is a response in which host immune cells (macrophages, granulocytes, lymphocytes) in affected internal organs initially are attracted to the parasite whereafter fibroblasts may enclose the parasite forming granuloma. Generally, the reaction is non-lethal to the parasite which may survive for years in the fish host retaining infectivity to the final host. This may also apply for the anisakid nematode Contracaecum rudolphii (having the adult stage in cormorants, using copepods as first intermediate/paratenic host and zooplankton feeding fish as paratenic hosts). The present study has shown that most Contracaecum rudolphii larvae survive in bream (Abramis brama) (from Lake Balaton, Hungary) whereas the majority of the nematode larvae die in Cyprinus carpio (from Lake Hévíz, directly connected to Lake Balaton). Both cyprinid host species interacted with the nematode larvae through establishing a marked cellular encapsulation around them but with different effects. The differential survival in common carp and bream may theoretically be explained by ecological factors, such as the environmental temperature which either directly or indirectly affect the development of nematode larvae, and/or intrinsic host factors, such as differential immune responses and host genetics.


Assuntos
Infecções por Ascaridida/veterinária , Ascaridoidea/crescimento & desenvolvimento , Carpas/parasitologia , Doenças dos Peixes/parasitologia , Animais , Infecções por Ascaridida/parasitologia , Ascaridoidea/fisiologia , Cyprinidae/parasitologia , Especificidade de Hospedeiro , Hungria , Lagos/parasitologia , Larva/crescimento & desenvolvimento
14.
J Microbiol ; 57(10): 852-864, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31376109

RESUMO

Recent work suggests that microbial community composition in high-elevation lakes is significantly influenced by microbes entering from upstream terrestrial and aquatic habitats. To test this idea, we conducted 18S and 16S rDNA surveys of microbial communities in a high-alpine lake in the Colorado Rocky Mountains. We compared the microbial community of the lake to water entering the lake and to uphill soils that drain into the lake. Utilizing hydrological and abiotic data, we identified potential factors controlling microbial diversity and community composition. Results show a diverse community entering the lake at the inlet with a strong resemblance to uphill terrestrial and aquatic communities. In contrast, the lake communities (water column and outlet) showed significantly lower diversity and were significantly different from the inlet communities. Assumptions of neutral community assembly poorly predicted community differences between the inlet and lake, whereas "variable selection" and "dispersal limitation" were predicted to dominate. Similarly, the lake communities were correlated with discharge rate, indicating that longer hydraulic residence times limit dispersal, allowing selective pressures within the lake to structure communities. Sulfate and inorganic nitrogen and phosphorus concentrations correlated with community composition, indicating "bottom up" controls on lake community assembly. Furthermore, bacterial community composition was correlated with both zooplankton density and eukaryotic community composition, indicating biotic controls such as "top-down" interactions also contribute to community assembly in the lake. Taken together, these community analyses suggest that deterministic biotic and abiotic selection within the lake coupled with dispersal limitation structures the microbial communities in Green Lake 4.


Assuntos
Bactérias/isolamento & purificação , Eucariotos/isolamento & purificação , Lagos/microbiologia , Lagos/parasitologia , Bactérias/classificação , Bactérias/genética , Biodiversidade , Colorado , Eucariotos/classificação , Eucariotos/genética , Lagos/química , Microbiota , Nitrogênio/análise , Nitrogênio/metabolismo , Sulfatos/análise , Sulfatos/metabolismo
15.
Parasitology ; 146(14): 1785-1795, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31452477

RESUMO

We provide an update on diagnostic methods for the detection of urogenital schistosomiasis (UGS) in men and highlight that satisfactory urine-antigen diagnostics for UGS lag much behind that for intestinal schistosomiasis, where application of a urine-based point-of-care strip assay, the circulating cathodic antigen (CCA) test, is now advocated. Making specific reference to male genital schistosomiasis (MGS), we place greater emphasis on parasitological detection methods and clinical assessment of internal genitalia with ultrasonography. Unlike the advances made in defining a clinical standard protocol for female genital schistosomiasis, MGS remains inadequately defined. Whilst urine filtration with microscopic examination for ova of Schistosoma haematobium is a convenient but error-prone proxy of MGS, we describe a novel low-cost sampling and direct visualization method for the enumeration of ova in semen. Using exemplar clinical cases of MGS from our longitudinal cohort study among fishermen along the shoreline of Lake Malawi, the portfolio of diagnostic needs is appraised including: the use of symptomatology questionnaires, urine analysis (egg count and CCA measurement), semen analysis (egg count, circulating anodic antigen measurement and real-time polymerase chain reaction analysis) alongside clinical assessment with portable ultrasonography.


Assuntos
Antígenos de Helmintos/análise , Pesqueiros , Genitália Masculina/parasitologia , Esquistossomose Urinária/diagnóstico , Sêmen/parasitologia , Adolescente , Adulto , Idoso , Animais , Genitália Masculina/diagnóstico por imagem , Humanos , Lagos/parasitologia , Estudos Longitudinais , Malaui , Masculino , Pessoa de Meia-Idade , Contagem de Ovos de Parasitas , Sistemas Automatizados de Assistência Junto ao Leito , Polissacarídeos/análise , Schistosoma haematobium/química , Schistosoma haematobium/genética , Schistosoma haematobium/isolamento & purificação , Esquistossomose Urinária/urina , Sensibilidade e Especificidade , Ultrassonografia , Adulto Jovem
16.
J Invertebr Pathol ; 166: 107218, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31330144

RESUMO

The genus Aphanomyces (Oomycetes) comprises approximately 50 known species of water molds in three lineages. One of the most notorious is Aphanomyces astaci, the causative agent of crayfish plague. In this study, fresh isolates of Aphanomyces were collected from 20 live specimens of the signal crayfish Pacifastacus leniusculus (Dana, 1852) from Lake Tahoe, California, providing 35 axenic cultures of A. astaci as well as two apparently undescribed Aphanomyces spp. isolates. Based on the results of ITS-, chitinase-, mitochondrial rnnS- and rnnL-sequences and microsatellite markers combined, the Lake Tahoe A. astaci isolates were identical to isolates of A. astaci B-haplogroup commonly detected in Europe, and infection experiments confirmed their high virulence towards noble crayfish. One of the two undescribed Aphanomyces spp. isolates was highly similar to an Aphanomyces lineage detected previously in crustacean zooplankton (Daphnia) in Central Europe, while the other was distinct and most closely related (ITS sequence similarity of 93%) to either A. astaci or to Aphanomyces fennicus isolated recently from Astacus astacus in Finland. Neither of the two Aphanomyces spp. isolates caused crayfish mortality under experimental conditions. Our results indicate that the populations of North American signal crayfish can act as carriers of both pathogenic and non-pathogenic Aphanomyces at the same time. Furthermore, considering that a limited number of crayfish individuals from a single location yielded multiple distinct Aphanomyces isolates, our results suggest that substantial species diversity within this genus remains undescribed.


Assuntos
Aphanomyces/genética , Astacoidea/parasitologia , Animais , Lagos/parasitologia , Estados Unidos , Virulência
17.
Parasit Vectors ; 12(1): 366, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31349871

RESUMO

BACKGROUND: African tetras (Alestidae) belonging to Brycinus Valenciennes are known to be parasitized with monogeneans attributed to two genera, Annulotrema Paperna & Thurston, 1969 and Characidotrema Paperna & Thurston, 1968 (Dactylogyridae). During a survey of monogeneans parasitizing alestids, species of Characidotrema were collected in Cameroon, D. R. Congo, Senegal, South Africa, Sudan and Zimbabwe. This paper provides new morphological data and the first molecular analysis broadening our knowledge on the diversity of these parasites. RESULTS: Seven species (four known and three new) of Characidotrema are reported from two species of Brycinus: C. auritum n. sp. and C. vespertilio n. sp. from B. imberi (Peters); and C. brevipenis Paperna, 1969, C. nursei Ergens, 1973, C. pollex n. sp., C. spinivaginus (Paperna, 1973) and C. zelotes Kritsky, Kulo & Boeger, 1987 from B. nurse (Rüppell). Species identification was based on morphological analysis of the sclerotized structures supported by nuclear ribosomal DNA (partial 18S rDNA, ITS1, and 28S rDNA) sequence data. Morphological analysis confirmed that the most apparent character distinguishing species in the genus is the morphology of the male copulatory organ and vagina. Observations on the haptoral sclerotized elements of these parasites by means of phase contrast microscopy revealed the presence of a sheath-like structure relating to the ventral anchor, a feature that supplements the generic diagnosis of Characidotrema. Maximum Likelihood and Bayesian analyses of the large subunit (28S) rDNA sequences recovered Characidotrema species isolated from the two Brycinus hosts as monophyletic, and indicated a closer relationship of this group to monogeneans parasitizing African cyprinids (Dactylogyrus spp.) and cichlids (species of Cichlidogyrus Paperna, 1960, Scutogyrus Pariselle & Euzet, 1995, and Onchobdella Paperna, 1968) than to those from catfishes (species of Quadriacanthus Paperna, 1961, Schilbetrema Paperna & Thurston, 1968 and Synodontella Dossou & Euzet, 1993). The overall agreement between the morphological diversification of the MCOs and the molecular tree observed in this study indicates that significant phylogenetic signals for clarifying relationships among species of Characidotrema are present in the characteristics of the MCO. CONCLUSIONS: It seems that intra-host speciation is an important force shaping the present distribution and diversity of Characidotrema but further studies are necessary to confirm this hypothesis and assess questions related to the phylogeny of these parasites. To identify potential co-speciation events, co-phylogenetic analyses of these monogeneans and their alestid hosts are required.


Assuntos
Ciclídeos/parasitologia , Interações Hospedeiro-Parasita , Filogenia , Trematódeos/classificação , Trematódeos/isolamento & purificação , África ao Sul do Saara , Animais , DNA Ribossômico/genética , Feminino , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Lagos/parasitologia , Masculino
18.
Acta Trop ; 198: 105077, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31310730

RESUMO

The geographical distribution of snail (i.e., the intermediate host of schistosomiasis) is consistent with that of endemic areas. The suitable snail habitus requires necessary environmental conditions for snail population. The high-resolution remote sensing provides an important tool for the spatio-temporal analysis of disease monitoring and prediction. This study conducted a typical schistosomiasis epidemic area in the marshland and lake regions along the Yangtze River, Yueyang City, Hunan Province of China. And three types of environmental factors, i.e., NDVI, soil moisture, and shortest distance to water body, associated with the geographical distribution of snail population, were extracted from the high-resolution remoting sensing data. The predicted distribution of snail habitus from the high-resolution environmental factors were compared with the data of annual program of snail survey. The results have shown that the application of high-resolution remote sensing can improve the accuracy of the modeled and predicted the potential risk areas of schistosomiasis, and may become an important tool for the ongoing national schistosomiasis control program.


Assuntos
Lagos/parasitologia , Caramujos/parasitologia , Análise Espaço-Temporal , Água/parasitologia , Animais , China/epidemiologia , Demografia , Humanos , Tecnologia de Sensoriamento Remoto , Rios , Esquistossomose/epidemiologia , Caramujos/fisiologia , Solo
19.
J Water Health ; 17(4): 647-653, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31314001

RESUMO

Laguna de Bay or Laguna Lake is one of the six major lakes in the Philippines to be in close contact with population activities due to the expansion of urban settlements in the immediate cities surrounding the lake, thus pushing the population to settle upon its shores. To date, there are no data showing the biodiversity of free-living amoebae (FLA) present in this lake. The present study aims to isolate and identify the FLA present in Laguna de Bay, Philippines. Thirty subsurface water samples were taken from Laguna De Bay using random purposive sampling in May 2018 and were examined for amoebic growth under light microscopy (LM). Results show that 8 out of 30 (26.6%) water samples were positive for amoebic growth and were further tested for more advanced data and genetic variation of the species. Initial molecular analysis using polymerase chain reaction (PCR) and sequencing showed the presence of potentially pathogenic FLA Naegleria australiensis (MK418954). The detection of potential pathogenic FLA in lakes and dams may prove useful in preventing and controlling possible human infections in the country. More data from this study will aid in public awareness and establishing safety guidelines and control programs.


Assuntos
Amoeba , Lagos/parasitologia , Naegleria , Humanos , Filipinas , Reação em Cadeia da Polimerase
20.
BMC Res Notes ; 12(1): 410, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31307520

RESUMO

OBJECTIVES: This study was aimed to assess the prevalence and risk factors of gastrointestinal parasites on schoolchildren at Bochesa Elementary School around Lake Zwai, Ethiopia. Cross-sectional study was conducted on 384 schoolchildren in May 2016. The gastrointestinal parasites were examined with wet mount and formol-ether concentration techniques. Chi-square (χ2) test was used to evaluate the association between categorical variables and infection prevalence. Binary logistic regression on SPSS version 21 was used, values were considered significant when the p-value was less than 0.05. RESULTS: The overall prevalence of gastrointestinal parasites was 22.6%. Males, 54 (14.1%) were more infected than females, 32 (8.3%), and 1-4 grade category, 64 (16.7%) were more infected than 5-8 grade category, 22 (5.7%). Age groups of 7-14, 78 (20.3%) were also more infected than > 15, 8 (2.1%); however, the variation was not significant (p > 0.05). In this study, parasitic coinfection was common; however, single gastrointestinal parasites were more dominant. The overall rate of gastrointestinal parasites shows that the environmental conditions where students pass their times are conducive to water-related diseases. Health education on personal and environmental hygiene keeping should be given to schoolchildren and safe wetland playing grounds should be prepared.


Assuntos
Fezes/parasitologia , Enteropatias Parasitárias/diagnóstico , Lagos/parasitologia , Parasitos/isolamento & purificação , Estudantes/estatística & dados numéricos , Adolescente , Animais , Criança , Estudos Transversais , Etiópia/epidemiologia , Feminino , Humanos , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Masculino , Parasitos/classificação , Parasitos/fisiologia , Prevalência , Fatores de Risco , Instituições Acadêmicas , Inquéritos e Questionários
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