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1.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 32(6): 640-642, 2020 Aug 12.
Artigo em Chinês | MEDLINE | ID: mdl-33325202

RESUMO

OBJECTIVE: To evaluate the effectiveness of Oncomelania snails control following the implementation of integrated schistosomiasis control measures in river channels connecting the Yangtze River in endemic areas of Nanjing City. METHODS: The river channels connecting the Yangtze River with snails in Nanjing City were selected as the study pilots. The integrated schistosomiasis control measures implemented in the study pilots were investigated by means of retrospective analyses and field surveys from 1998 to 2019, and the effectiveness of snail control was evaluated. RESULTS: Integrated control measures with emphases on environmental improvements including water resource projects for schistosomiasis control were implemented in the study pilots during the period from 1998 to 2019, including river bank concretion with 84.51 km in length, marshland cutting and dredging with 50.41 km in length, building 2 sluices and 3 overflow dams, digging one floodway and snail control with chemical treatment that covered an area of 3 370.80 hm2. No Schistosoma japonicum infection had been detected in snails since the completion of the integrated control measures. In addition, snails had been eliminated in 6 river channels connecting the Yangtze River until 2019, with the snail habitats reducing from 214.33 hm2 to 52.22 hm2 in 10 river channels connecting the Yangtze River and the snail density reducing to below 0.1 snails/0.1 m2 in snail-breeding river channels connecting the Yangtze River. CONCLUSIONS: The integrated schistosomiasis control measures with emphases on environmental improvements may effectively control snail breeding and spread in rivers connecting the Yangtze River in endemic areas of schistosomiasis; however, the maintenance of the project and snail surveillance and control should be intensified following the completion of the integrated schistosomiasis control measures.


Assuntos
Rios/parasitologia , Esquistossomose , Caramujos/parasitologia , Animais , China/epidemiologia , Reservatórios de Doenças/parasitologia , Humanos , Estudos Retrospectivos , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Esquistossomose Japônica
2.
Parasitol Res ; 119(12): 4259-4265, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32901342

RESUMO

The present study describes Henneguya lacustris n. sp. parasitizing Astyanax lacustris (Lütken 1875), from the Tietê River, State of São Paulo, Brazil, through morphological and molecular analysis. Myxospores of the parasites were found in the gills of A. lacustris with 13% prevalence of infection. The myxospores were oval and presented as measures (mean ± standard deviation): total length 18.3 ± 2.2 µm, body length 10.4 ± 1.6 µm, body width 4.9 ± 0.9 µm, tail length 7.2 ± 2.5 µm. The polar capsule was 4.8 ± 0.3 µm long and 1.5 ± 0.2 µm wide. The polar tubules, present inside the polar capsules, had 6 to 7 turns. The ultrastructural analysis allowed the observation of the asynchronous development of the myxospores. Phylogenetic analysis showed H. lacustris n. sp. as a sister species of H. chydadea Barassa and Cordeiro 2003 in a subclade formed by species that parasitize the gills of Characiform fish from Brazil. Using molecular and morphological characterization, this parasite was identified as a new species of the genus Henneguya Thélohan 1892.


Assuntos
Characidae/parasitologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Myxozoa/classificação , Doenças Parasitárias em Animais/parasitologia , Animais , Brasil/epidemiologia , Doenças dos Peixes/epidemiologia , Myxozoa/genética , Myxozoa/crescimento & desenvolvimento , Myxozoa/ultraestrutura , Doenças Parasitárias em Animais/epidemiologia , Filogenia , Prevalência , Rios/parasitologia
3.
Parasitol Res ; 119(11): 3627-3637, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32852620

RESUMO

This study increases the known biodiversity of cnidarian parasites in neotropical bryconid fishes. Two novel Myxobolus species are described based on morphology, ultrastructure and small subunit ribosomal DNA (ssrDNA) sequencing: Myxobolus vetuschicanus n. sp. infecting fins of Salminus franciscanus and Myxobolus mineirus n. sp. infecting the mesentery of Brycon orthotaenia from the São Francisco River basin, Minas Gerais State, Brazil. Ultrastructural analysis of the two species revealed an asynchronous sporogenesis process, with germinative cells and young developmental stages of myxospores in the periphery of the plasmodia. In M. vetuschicanus n. sp., the plasmodia were surrounded by a layer of fibroblasts and in M. mineirus n. sp., the plasmodial membrane had direct contact with the host tissue. The phylogenetic analysis based on the ssrDNA of Henneguya/Myxobolus species showed that the two novel Myxobolus species grouped in subclades together with other parasite species of bryconid fishes.


Assuntos
Biodiversidade , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Myxobolus/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Nadadeiras de Animais/parasitologia , Animais , Brasil , DNA Ribossômico , Brânquias/parasitologia , Myxobolus/classificação , Filogenia , Subunidades Ribossômicas Menores de Eucariotos , Rios/parasitologia
4.
Parasitol Res ; 119(10): 3243-3254, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32710171

RESUMO

The composition and diversity of parasite communities are useful tools to characterise ecosystem health and integrity. Environmental disturbances may affect parasite infection in fish directly, by their effects on the free-living stages, or indirectly, on the intermediate hosts. Slimy sculpins, Cottus cognatus, a small fish inhabiting cold waters of North America, have been considered as sentinels due to their limited mobility, often occupying relatively small areas throughout their lives and thus reflecting the local environment. Ninety-six specimens of C. cognatus were sampled from four tributaries of the Athabasca River to assess patterns of helminth parasite community structure in this fish and to study the composition and diversity of its parasite communities in relation to water quality. The localities included single samples from High Hills, Horse and Dunkirk rivers, and two from the Steepbank River. Twelve metazoan parasite species were found, most of them being larval forms. Significant differences occurred in the structure and composition of parasite assemblages of sculpins from the tributaries, although similarities were observed in connected and nearby sites. Parasite communities were influenced mainly by a combination of local environmental conditions, distance and connectivity, and were separated based on the distribution and abundance of autogenic and allogenic parasites. Water quality appeared to influence the distribution of trematode species that use gastropods as intermediate hosts, while proximity and connectivity of sites led to sharing allogenic parasite species in slimy sculpin.


Assuntos
Perciformes/parasitologia , Trematódeos/isolamento & purificação , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Animais , Drenagem , Ecossistema , Peixes , Cavalos , América do Norte/epidemiologia , Rios/parasitologia , Qualidade da Água
5.
J Water Health ; 18(3): 292-305, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32589616

RESUMO

A Quantitative Microbial Risk Assessment (QMRA) technique was applied to assess the public health risk from exposure to infectious microorganisms at bathing areas of three rivers in Bangladesh. The QMRA assessed the probability of illness due to the accidental ingestion of river water impacted by untreated sewage. The simplified QMRA was based on average concentrations of four reference pathogens Escherichia coli (E. coli) O157:H7, Cryptosporidium spp, norovirus and rotavirus relative to indicator bacterium E. coli. Public health risk was estimated as the probability of infection and illness from a single exposure of bathers. The risks of illness were ranged from 7 to 10% for E. coli O157:H7, 13 to 19% for Cryptosporidium, 7 to 10% for norovirus and 12 to 17% for rotavirus. The overall risk of illness at the rivers was slightly higher in children (9-19%) compared to adults (7-16%). The risks of illness in individuals exposed to the river bathing were unacceptably high, exceeding the USEPA acceptable risk of 3-6 illnesses per hundred bathing events. This study gives a basis for reducing the burden of disease in the population by applying appropriate risk management. Findings and methods of this study will be helpful for other countries with similar socio-economic and geographic settings.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Rios/microbiologia , Rios/parasitologia , Microbiologia da Água , Adulto , Animais , Bangladesh/epidemiologia , Criança , Criptosporidiose , Cryptosporidium , Escherichia coli , Humanos , Saúde Pública , Medição de Risco
6.
BMC Public Health ; 20(1): 769, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32448159

RESUMO

BACKGROUND: Schistosoma mansoni (S. mansoni) infection is a significant public health problem in Ethiopia, and has wide distribution in the country. The impact of the disease is particularly high on school-age children. Nationwide 385 endemic districts were identified, whereby control and elimination interventions are underway using school-based annual mass drug administration (MDA) with praziquantel. The national elimination program targets endemic districts as a whole. The aim of this study was to identify the transmission foci of Schistosoma mansoni and determine prevalence of soil-transmitted helminths (STHs) in Abeshge district. METHODS: The study was conducted from April to May, 2019 among school-age children randomly selected from public elementary schools in Abeshge district, South-central Ethiopia. Demographic information and data on risk factors of S. mansoni infection were gathered using pre-tested questionnaire. Moreover, a stool sample was collected from each child and examined using Kato-Katz thick smear technique. The data were analyzed using STATA_MP version 12. RESULTS: A total of 389 school-age children from five public elementary schools were included in the study. The overall prevalence of S. mansoni and STHs was 19.3% (75/389) and 35% (136/389), respectively. The prevalence of S. mansoni was 60.6% in Kulit Elementary school, while it was zero in Geraba. The prevalence of S. mansoni was significantly higher among males (AOR = 2.6, 95% CI 1.3-5.1), those with habit of swimming and/or bathing in rivers (AOR = 2.9, 95%CI 1.3-5.1) and involved in irrigation activities (AOR = 2.9, 95% CI 1.0-8.3). Overall, the prevalence of S. mansoni was significantly higher among school children attending Kulit Elementary School compared to those attending the remaining schools (AOR = 12.5, 95%CI 6.2-25.1). CONCLUSION: A wide variation of S. mansoni prevalence was observed among the school children in the different schools. Control interventions better identify and target foci of S. mansoni transmission, instead of targeting the district homogenously.


Assuntos
Anti-Helmínticos/uso terapêutico , Transmissão de Doença Infecciosa/prevenção & controle , Praziquantel/uso terapêutico , Schistosoma mansoni , Esquistossomose mansoni/transmissão , Adolescente , Animais , Criança , Pré-Escolar , Estudos Transversais , Etiópia/epidemiologia , Fezes/parasitologia , Feminino , Humanos , Masculino , Administração Massiva de Medicamentos/estatística & dados numéricos , Prevalência , Saúde Pública , Fatores de Risco , Rios/parasitologia , Esquistossomose mansoni/epidemiologia , Esquistossomose mansoni/prevenção & controle , Serviços de Saúde Escolar/estatística & dados numéricos , Instituições Acadêmicas , Solo/parasitologia , Inquéritos e Questionários
7.
Rev Bras Parasitol Vet ; 29(2): e016119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32428184

RESUMO

Among 164 fish from the upper São Francisco river, caught in the Três Marias reservoir (18º 12' 59" S; 45º 17' 34" W) or downstream from this reservoir (18º 12' 32" S; 45º 15' 41" W) in 2007, 2008, 2016 and 2017, four specimens of Argulus elongatus Heller, 1857 were found, one specimen per fish, in the following host species: Brycon orthotaenia Günther (two fish parasitized out of 38 examined) and Salminus hilarii Valenciennes (one fish parasitized out of 45 examined) (both in Bryconidae); and Metynnis lippincottianus (Cope) (one fish parasitized out of 81 examined) (Serrasalmidae). This opportunistic ectoparasite deserves attention even in the case of low infestation in fish in a natural water system. This is the first record of a branchiuran species in B.orthotaenia; the host list of A.elongatus is extended through addition of the three fish species examined in this study, and the known Brazilian geographical distribution of this argulid is enlarged to the São Francisco river basin.


Assuntos
Arguloida/parasitologia , Peixes/parasitologia , Rios/parasitologia , Distribuição Animal , Animais , Arguloida/anatomia & histologia , Brasil , Peixes/classificação
8.
Parasit Vectors ; 13(1): 187, 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32272977

RESUMO

BACKGROUND: Monogenea van Beneden, 1858 is a group of parasitic flatworms, commonly found infecting bony fish. Several genera, such as Cichlidogyrus Paperna, 1960, are reported to include potential pathogenic species that can negatively impact aquaculture fish stocks. They can switch from introduced to native fish and vice versa. In Africa (and all over the world), fish species belonging to Cichlidae are often kept in aquaculture and represent a major source of food. Thus, research on the biodiversity and occurrence of monogenean species on these fish is of importance for aquaculture and conservation. The present study is a survey of the diversity of species of Cichlidogyrus in the south of the Democratic Republic of the Congo (DRC) on three cichlid species: Orthochromis sp. 'Lomami', Serranochromis cf. macrocephalus, and Tilapia sparrmanii Smith, 1840. METHODS: Specimens of Cichlidogyrus were isolated from the gills and mounted on glass slides with Hoyer's medium. The genital and haptoral hard parts were measured and drawn using interference contrast. RESULTS: In total, six species of Cichlidogyrus were found, all new to science: C. bulbophallus n. sp. and C. pseudozambezensis n. sp. on S. cf. macrocephalus, C. flagellum n. sp. and C. lobus n. sp. on T. sparrmanii, C. ranula n. sp. on S. cf. macrocephalus and Orthochromis sp. 'Lomami', and C. maeander n. sp. found on Orthochromis sp. 'Lomami' and T. sparrmanii. The first four species are considered to be strict specialists, C. ranula n. sp. an intermediate generalist and C. maeander n. sp. a generalist. These parasite species show morphological similarities to species found in the Lower Guinea and Zambezi ichthyofaunal provinces, which might be explained by past river capture events between river systems of the Congo Province and both these regions. CONCLUSIONS: Serranochromis cf. macrocephalus and Orthochromis sp. 'Lomami' can harbour respectively three and two species of Cichlidogyrus, all described in this study. Tilapia sparrmanii can harbour seven species, of which three are described in the present study. These results highlight the species diversity of this parasite genus in the Congo Basin.


Assuntos
Ciclídeos/parasitologia , Classificação , Trematódeos/classificação , Animais , Aquicultura , Biodiversidade , Coinfecção/parasitologia , Doenças dos Peixes/parasitologia , Produtos Pesqueiros/parasitologia , Peixes , Brânquias/parasitologia , Filogenia , Rios/parasitologia , Tilápia/parasitologia , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação
9.
J Water Health ; 18(2): 186-199, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32300091

RESUMO

The present study aims to investigate the occurrence of free living amoeba (FLA) in water resources (rivers and tap water) in Samsun in the Black Sea. The presence of Acanthamoeba spp. was confirmed in 98 of 192 water samples collected from 32 sites of Samsun province (Samsun centre, Terme, Carsamba, Tekkekoy, Bafra) by PCR. Acanthamoeba spp. were found in 15/36 river samples from Samsun, in 58/90 from Terme, in 12/30 from Carsamba, in 7/18 from Tekkekoy and in 6/18 from Bafra. No Acanthamoeba species were detected in tap water samples. The highest rate in river waters contaminated with Acanthamoeba species was in Terme followed by Samsun centre (41.7%), Carsamba (40%), Tekkekoy (38.9%) and Bafra districts (33.3%), respectively. The result of the subsequent sequence analysis showed Haplotype I (A. triangularis) in 5%, Haplotype II (A. polyphaga) in 29.6%, Haplotype III (Acanthamoeba spp.) in 62% and Haplotype IV (A. lenticulata) in 3%. The most common genotype was Acanthamoeba T4 (Acanthamoeba spp., A. polyphaga, A. triangularis) and T5 genotype was also found in 3%. The T4 genotype is the most common genotype associated with Acanthamoeba keratitis (AK) worldwide; therefore, humans and animals living in the area are at risk after contact with such waters.


Assuntos
Acanthamoeba/isolamento & purificação , Monitoramento Ambiental , Rios/parasitologia , Mar Negro , Genótipo , Turquia
10.
J Helminthol ; 94: e137, 2020 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-32154780

RESUMO

In the last years, a growing number of studies have focused on the search for biological indicators of human impact in freshwater environments. Given their susceptibility to different types of impact, larval digeneans have been considered as useful tools for the study of temporal variations in parasite communities. However, few studies have been carried out in lotic environments. For that reason, the spatio-temporal variations of the larval digenean assemblages parasitizing the gastropod Heleobia parchappii were analysed in four human-impacted streams, located on the coast of Argentina. In total, 4800 specimens of H. parchappii were collected seasonally, and 12 digenean species belonging to eight families were registered. Three of the streams showed similar species presence but, during spring and summer, the streams located within the city presented lower species presence than the streams located in the urban periphery. By contrast, the spatial prevalence values evidenced a higher variation between the environments. Streams located in the urban periphery showed higher prevalence values throughout the year, compared to those calculated for streams located within the city. The spatio-temporal variations of larval digenean assemblages parasitizing H. parchappii seem to be mainly influenced by the diversity and vagility of definitive hosts, the types of digenean life cycles and habitat characteristics. However, environmental disturbances derived from anthropogenic activities are highlighted as the probable main factors that may affect the composition and dynamic of these parasite assemblages.


Assuntos
Ecossistema , Gastrópodes/parasitologia , Interações Hospedeiro-Parasita , Rios/parasitologia , Trematódeos/isolamento & purificação , Animais , Argentina , Humanos , Larva , Estágios do Ciclo de Vida , Prevalência , Estações do Ano , Análise Espaço-Temporal , Trematódeos/classificação , Trematódeos/fisiologia
11.
Eur J Protistol ; 73: 125687, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32113083

RESUMO

Paramonosiga coloniensis sp. nov., Salpingoeca amphoriscia sp. nov., S. fluviatilis sp. nov. and S. loutrophoria sp. nov. are frequently found craspedid species in the River Rhine which have not yet been described, despite their high abundance. All new species are characterized based on a distinct morphology which is different from all up to now described species and on a molecular level based on transcriptome data. In addition, we give extended redescriptions of S. amphoridium and S. angulosa, based on SSU and LSU rDNA data and morphology. The six-gene phylogenetic analyses place all species into freshwater clades of the craspedids. The separation of the freshwater and marine clades of this group is becoming more distinct with every craspedid sequence added. The River Rhine is one of the largest rivers in Europe but its protist biodiversity is fairly undescribed, especially regarding choanoflagellates. We conclude that the biodiversity of craspedid choanoflagellates is broadly underestimated.


Assuntos
Biodiversidade , Coanoflagelados/classificação , Rios/parasitologia , Coanoflagelados/citologia , Coanoflagelados/genética , DNA de Protozoário/genética , DNA Ribossômico/genética , Alemanha , Filogenia
12.
Parasitol Res ; 119(5): 1505-1514, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32189057

RESUMO

The study provides descriptions of two new species of Enterogyrus coexisting in the stomach of the Mozambique tilapia, Oreochromis mossambicus (Peters). Enterogyrus multispiralis n. sp. and Enterogyrus mashegoi n. sp. were collected from hosts sampled at Nwanedi-Luphephe Dam, Limpopo River System, South Africa. The two new species can be differentiated from other members of the genus based on the spirality characteristics of the cirrus. Enterogyrus multispiralis n. sp. has an unique 8/9-2-4 cirrus spiral formula. The length of the cirrus and its spriral formula 5-2-3 make E. mashegoi n. sp. morphometrically unique from other Enterogyrus spp. Sequences of the nuclear ribosomal DNA partial 18S and internal transcribed spacer (ITS1) and 28S were obtained and compared with available sequences of Enterogyrus in GenBank. This is the first record of data on 18S rDNA region of Enterogyrus spp. A phylogenetic comparison was conducted, which included all data available for Enterogyrus spp., but this was limited to 28S data. The closest species to both new species of the present study was an undescribed Enterogyrus sp. 2 from Sarotherodon galilaeus (Linnaeus) described from Senegal (i.e. 2.1 and 2.9% uncorrected pairwise genetic distance to E. multispiralis n. sp. and E. mashegoi n. sp., respectively). These species represent new records for Africa resulting in a total number of 12 described valid species.


Assuntos
Doenças dos Peixes/parasitologia , Platelmintos/classificação , Tilápia/parasitologia , Animais , DNA Ribossômico/genética , Filogenia , Platelmintos/citologia , Platelmintos/genética , Rios/parasitologia , África do Sul , Especificidade da Espécie , Estômago/parasitologia
13.
Proc Natl Acad Sci U S A ; 117(7): 3670-3677, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32015108

RESUMO

The number of horizontally drilled shale oil and gas wells in the United States has increased from nearly 28,000 in 2007 to nearly 127,000 in 2017, and research has suggested the potential for the development of shale resources to affect nearby stream ecosystems. However, the ability to generalize current studies is limited by the small geographic scope as well as limited breadth and integration of measured chemical and biological indicators parameters. This study tested the hypothesis that a quantifiable, significant relationship exists between the density of oil and gas (OG) development, increasing stream water concentrations of known geochemical tracers of OG extraction, and the composition of benthic macroinvertebrate and microbial communities. Twenty-five headwater streams that drain lands across a gradient of shale gas development intensity were sampled. Our strategy included comprehensive measurements across multiple seasons of sampling to account for temporal variability of geochemical parameters, including known shale OG geochemical tracers, and microbial and benthic macroinvertebrate communities. No significant relationships were found between the intensity of OG development, shale OG geochemical tracers, or benthic macroinvertebrate or microbial community composition, whereas significant seasonal differences in stream chemistry were observed. These results highlight the importance of considering spatial and temporal variability in stream chemistry and biota and not only the presence of anthropogenic activities in a watershed. This comprehensive, integrated study of geochemical and biological variability of headwater streams in watersheds undergoing OG development provides a robust framework for examining the effects of energy development at a regional scale.


Assuntos
Ecossistema , Campos de Petróleo e Gás/química , Rios/química , Animais , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Monitoramento Ambiental , Invertebrados/classificação , Invertebrados/crescimento & desenvolvimento , Pennsylvania , Rios/microbiologia , Rios/parasitologia
14.
Exp Parasitol ; 210: 107848, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32004534

RESUMO

Marine bivalves are usually cultivated in shallow, estuarine waters where there is a high concentration of nutrients. Many micro-pollutants, including the protozoan parasites Giardia duodenalis and Cryptosporidium spp., which also occur in such environments, may be concentrated in shellfish tissues during their feeding process. Shellfish can thus be considered as vehicles for foodborne infections, as they are usually consumed lightly cooked or raw. Therefore, the main objective of this study was to investigate the presence of both parasites in Mediterranean mussels, Mytilus galloprovincialis that are cultivated in Thermaikos Gulf, North Greece, which is fed by four rivers that are contaminated with both protozoa. Moreover, the occurrence of these protozoa was monitored in treated wastewaters from 3 treatment plants that discharge into the gulf. In order to identify potential sources of contamination and to estimate the risk for human infection, an attempt was made to genotype Giardia and Cryptosporidium in positive samples. Immunofluorescence was used for detection and molecular techniques were used for both detection and genotyping of the parasites. In total, 120 mussel samples, coming from 10 farms, were examined for the presence of both protozoa over the 6-month farming period. None of them were found positive by immunofluorescence microscopy for the presence of parasites. Only in 3 mussel samples, PCR targeting the GP60 gene detected Cryptosporidium spp. DNA, but sequencing was not successful. Thirteen out of 18 monthly samples collected from the 3 wastewater treatment plants, revealed the presence of Giardia duodenalis cysts belonging to sub-assemblage AII, at relatively low counts (up to 11.2 cysts/L). Cryptosporidium oocysts (up to 0.9 oocysts/L) were also detected in 4 out of 8 samples, although sequencing was not successful at any of the target genes. At the studied location and under the sampling conditions described, mussels tested were not found to be harboring Giardia cysts and the presence of Cryptosporidium was found only in few cases (by PCR detection only). Our results suggest that the likelihood that mussels from these locations act as vehicles of human infection for Giardia and Cryptosporidium seems low.


Assuntos
Bivalves/parasitologia , Cryptosporidium/isolamento & purificação , Doenças Transmitidas por Alimentos/parasitologia , Giardia/isolamento & purificação , Animais , Criptosporidiose/transmissão , Cryptosporidium/genética , DNA de Protozoário/isolamento & purificação , Giardia/genética , Giardíase/transmissão , Grécia , Humanos , Oocistos/isolamento & purificação , Reação em Cadeia da Polimerase , Rios/parasitologia , Águas Residuárias/parasitologia
15.
J Helminthol ; 94: e126, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-32077391

RESUMO

This study describes two new species, Trinigyrus anthus n. sp. and Trinigyrus carvalhoi n. sp., from gills of Hypostomus spp. from the Upper Paraná River basin, Brazil. Trinigyrus peregrinus is redescribed based on examination of its holotype, paratypes and new material of specimens parasitizing Pterygoplichthys ambrosettii, also from the Upper Paraná River basin, Brazil. New morphological features were included in the diagnosis of the genus, such as the presence of a sclerotized border on the anchor base, and a weakly sclerotized fringe on the base of the male copulatory organ (MCO). Trinigyrus anthus n. sp. differs from other congeners by the shape of the MCO, presenting an enlarged base with sclerotized fringes resembling flower petals. Trinigyrus carvalhoi n. sp. and T. peregrinus are similar but can be differentiated from each other mainly by the sclerotization of the vagina (absent in the new species), and the morphology of the MCO (C-shaped versus one counterclockwise circle, respectively). For the first time, gene sequences of Trinigyrus spp. from Brazil were obtained (partial ribosomal 28S and mitochondrial cytochrome c oxidase I (mtCOI)). The genetic divergences among the new species and T. peregrinus varied from 2 to 3% (6‒18 pb) based on sequences of 28S ribosomal DNA (rDNA), and 6-7% (83‒92 pb) using mtCOI. Phylogenetic analyses based on partial 28S rDNA revealed that Trinigyrus, Heteropriapulus and Unilatus formed a monophyletic and well-supported clade of monogeneans from Neotropical freshwater loricariids, suggesting a closer relationship among these dactylogyrids and their hosts.


Assuntos
Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Brasil , DNA Ribossômico/genética , Complexo IV da Cadeia de Transporte de Elétrons/genética , Feminino , Água Doce/parasitologia , Brânquias/parasitologia , Masculino , Filogenia , RNA Ribossômico 28S/genética , Rios/parasitologia , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação
16.
J Helminthol ; 94: e120, 2020 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-31984933

RESUMO

Bithynids snails are a widespread group of molluscs in European freshwater systems. However, not much information is available on trematode communities from molluscs of this family. Here, we investigate the trematode diversity of Bithynia tentaculata, based on molecular and morphological data. A total of 682 snails from the rivers Lippe and Rhine in North Rhine-Westphalia, Germany, and 121 B. tentaculata from Curonian Lagoon, Lithuania were screened for infections with digeneans. In total, B. tentaculata showed a trematode prevalence of 12.9% and 14%, respectively. The phylogenetic analyses based on 55 novel sequences for 36 isolates demonstrated a high diversity of digeneans. Analyses of the molecular and morphological data revealed a species-rich trematode fauna, comprising 20 species, belonging to ten families. Interestingly, the larval trematode community of B. tentaculata shows little overlap with the well-studied trematode fauna of lymnaeids and planorbids, and some of the detected species (Echinochasmus beleocephalus and E. coaxatus) constitute first records for B. tentaculata in Central Europe. Our study revealed an abundant, diverse and distinct trematode fauna in B. tentaculata, which highlights the need for further research on this so far understudied host-parasite system. Therefore, we might currently be underestimating the ecological roles of several parasite communities of non-pulmonate snail host families in European fresh waters.


Assuntos
Filogenia , Caramujos/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Ecossistema , Água Doce/parasitologia , Alemanha , Larva/genética , Larva/fisiologia , Lituânia , Prevalência , Rios/parasitologia , Trematódeos/fisiologia
17.
Parasitol Int ; 76: 102061, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31978596

RESUMO

Two new Myxobolus species were described infecting Brycon orthotaenia from the São Francisco River, in the state of Minas Gerais, Brazil. From a total of 39 B. orthotaenia collected, two specimens (5.1%) exhibited infection of the ovary and 12 specimens (30.8%) displayed infection of the liver. The plasmodia of both Myxobolus species were white and spherical measuring around 1 mm in length. The plasmodium found in the ovary showed mature myxospores, which were oval shaped from the frontal view and measured 9.2-11.0 (9.8 ± 0.4) µm in length, 5.9-6.9 (6.5 ± 0.3) µm in width and 4.6-5 (4.9 ± 0.1) µm in diameter. The two polar capsules were the same size and measured 3.9-6.2 (4.7 ± 0.5) µm in length and 1.8-2.4 (2.1 ± 0.2) µm in width. The polar tubules had 9 coils. The plasmodium found in the liver showed mature myxospores which were ellipsoidal in shape from the frontal view and measured 10.0-11.4 (10.7 ± 0.5) µm in length, 7.3-8.6 (8.1 ± 0.4) µm in width and 5.3-7.0 (6.8 ± 0.4) µm in diameter. The two polar capsules were the same size and measured 4.2-5.4 (4.9 ± 0.3) µm in length and 1.9-2.9 (2.7 ± 0.3) µm in width. The polar tubules had 8 coils. Ultrastructural analysis revealed an asynchronous sporogenesis process, with young developmental myxospore stages more often found in the periphery of the plasmodium and mature myxospores in the centre of the plasmodium. The plasmodial wall was formed by a single membrane which was not surrounded by a layer of host tissue. A thick layer of fibrous material was found in the peripheral ectoplasm close to the plasmodial wall of the plasmodium found in the ovary. Phylogenetic analysis based on the small-subunit ribosomal DNA - ssrDNA sequences and using the closest myxozoan sequences to each one of the species studied here based on previous GenBank data and Henneguya/Myxobolus/Thelohanellus species parasitizing fish from South American, revealed that the new species are grouped in a subclade together with other Myxobolus species parasitizing bryconid hosts.


Assuntos
Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Interações Hospedeiro-Parasita , Myxobolus/classificação , Doenças Parasitárias em Animais/parasitologia , Filogenia , Animais , Brasil , Microscopia Eletrônica , Myxobolus/anatomia & histologia , Myxobolus/ultraestrutura , Rios/parasitologia
18.
Parasite ; 27: 4, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31967542

RESUMO

Two species of Cosmetocleithrum Kritsky, Thatcher & Boeger, 1986 (both new) and two species of Demidospermus Suriano, 1983 (one new) are reported from the gills of the catfish Auchenipterus nuchalis, popularly known as "mapará", from the Tocantins River and tributaries, North Region of Brazil. Cosmetocleithrum berecae n. sp. differs from all other species presently known in the genus by the morphology of the anchors presenting an elongate shaft and short recurved point, a coiled male copulatory organ (MCO) with three rings, and an elongate slender accessory piece with a bifurcated distal end. Cosmetocleithrum nunani n. sp. differs from its congeners by the combination of the following features: (1) Ventral and dorsal anchors with moderately long curved shaft and short point; (2) Hooks with poorly developed thumb; (3) Hook pairs 5 and 6 similar to each other, but morphologically distinct from remaining hook pairs; and (4) MCO coiled, with approximately 1.5 rings. Demidospermus tocantinensis n. sp. is easily distinguished from other species of the genus by presenting an inverted-G-shaped MCO with a median knee-like expansion. Demidospermus osteomystax Tavernari, Takemoto, Lacerda & Pavanelli, 2010 is redescribed based on paratypes and specimens from the gills of A. nuchalis from the Tocantins River, a new host and locality records for this species. The monotypic Paracosmetocleithrum Acosta, Scholz, Blasco-Costa, Alves & Silva, 2017, the only other Neotropical genus reported in siluriforms besides Cosmetocleithrum with species presenting two ribbon-like projections on the posterior margin of the dorsal bar, is considered a junior subjective synonym of Cosmetocleithrum.


Assuntos
Peixes-Gato/parasitologia , Doenças dos Peixes/parasitologia , Brânquias/parasitologia , Rios/parasitologia , Trematódeos/classificação , Infecções por Trematódeos/veterinária , Animais , Brasil , Genitália , Masculino , Trematódeos/anatomia & histologia , Trematódeos/isolamento & purificação
19.
Parasitol Res ; 119(3): 893-901, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31938889

RESUMO

We surveyed introduced yellow perch Perca flavescens (Mitchill, 1814) from the Willamette River, OR, USA, to determine if these fish have co-introduced myxosporean parasites. Mature parasite myxospores were observed in brains of 3/19 fish, and were morphologically and molecularly consistent with Myxobolus neurophilus (Guilford 1963), a parasite known from yellow perch in their native range. We identified another Myxobolus species from the gill filaments of 1/22 fish. The spores from the gill filaments were oval-shaped, 11.7 (10.7-12.3) µm long × 8.6 (7.7-9.0) µm wide × 5.2 (4.6-5.6) µm thick, with two oval-shaped polar capsules 5.7 (5.1-6.5) µm × 2.7 (2.4-3.2) µm, each containing a polar tubule with 8-9 turns. Small-subunit ribosomal DNA sequences from each of four plasmodia were identical, and 4.0% different (over 1800 nucleotides) from the closest known myxosporeans. Interestingly, these sequences had overlapping peaks in their chromatograms, which suggested that DNA from multiple species was present. Hence, we isolated and sequenced three individual myxospores and found that they too had mixed chromatograms, which indicated presence of at least two sequence types of small-subunit ribosomal DNA in each spore (GenBank accession MK592012, MK592013), a rare character among described myxosporeans. The spore morphology, morphometry, tissue tropism, and DNA sequence supported a diagnosis of a novel species, Myxobolus doubleae n. sp. This parasite is unknown from yellow perch in its native range, despite extensive historical surveys, which suggests that introduced yellow perch might have acquired an endemic Myxobolus species via spillback from another fish host.


Assuntos
Doenças dos Peixes/parasitologia , Myxobolus/isolamento & purificação , Doenças Parasitárias em Animais/parasitologia , Percas/parasitologia , Animais , DNA de Protozoário/genética , DNA Ribossômico/genética , Brânquias/parasitologia , Filogenia , Subunidades Ribossômicas Menores/genética , Rios/parasitologia , Esporos de Protozoários
20.
Sci Rep ; 10(1): 335, 2020 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-31942007

RESUMO

The free-living amoebae Naegleria spp. and Acanthamoeba spp. exist in the natural environment and are sometimes causal agents of lethal primary amoebic meningoencephalitis (PAM), amoebic keratitis (AK) and granulomatous amebic encephalitis (GAE) in humans, respectively. To ascertain the existence of free-living amoebae in Korea, water samples were collected from the Korean hydrosphere, Namhangang (southern Han River), an active location for water skiing and recreation. Samples underwent two-step filtration and were cultured on non-nutrient agar medium with inactivated E. coli. The remaining samples were subjected to PCR for primarily the 18S small ribosomal RNA gene and gene sequencing. Similarities in 18S rDNA sequences, in comparison with various reference amoebae in GenBank, showed 86~99% homology with N. gruberi, N. philippinensis, N. clarki, A. polyphaga, A. castellannii, and Hartmannella (Vermamoeba) vermiformis. Therefore, this study will be useful for seasonal detection of free-living amoebae from various Korean hydrospheres in future studies.


Assuntos
Amoeba/metabolismo , Rios/parasitologia , Amoeba/classificação , Amoeba/genética , Amoeba/isolamento & purificação , Sequência de Bases , Filogenia , RNA Ribossômico 18S/química , RNA Ribossômico 18S/classificação , RNA Ribossômico 18S/genética , República da Coreia , Alinhamento de Sequência , Análise de Sequência de DNA
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