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1.
Ann Parasitol ; 67(4): 703-713, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35289996

RESUMO

Trematodes are known as a diverse group of endogenous parasites, which snails as their intermediate hosts can dramatically affect parasite transmission dynamics. Snails play a key role in life cycles of digenean trematode. However, there has not been much faunistic surveys in terms of snails' distribution in Iran. The current study was aimed to identify snail's fauna and their current geographic distribution in four regions of Guilan province, Iran. Several species of snails (land and freshwater snails) were obtained from 4 different areas (2018-2019), and then samples were separately transferred to the laboratory. Diagnosis of snails was then performed according to morphometric characteristics including dextral or sinistral shell, shape, color and size of shell. Moreover, radula was stained and then photographed under microscopic examination. Furthermore, 25% of any species were tested for cercarial infection. In total, 2082 snails belonging to 12 species were identified based on the morphological characteristics. Land snails were identified to be Helicella sp. (46.4%), Helix aspersa (34.1%), Helicopsis sp. (8%), Pomatia sp. (6.7%) and Oxyloma elegans (4.8%). Moreover, freshwater snails were Physa acuta (30.6%), Lymnaea auricularia (25.8%), Lymnaea gedrosiana (18.7%), Lymnaea palustris (8.9%), Lymnaea truncatula (8.1%), Planorbis sp. (6.4%) and Lymnaea stagnalis (1.5%). In collected snails, Lymnaea auricularia (0.66%) and Lymnaea gedrosiana (0.45%) were the only snails harboring cercariae (Gymnocephalus cercariae). There was no statistically significant difference between the cercarial infection and snail species (P<0.05). Comprehensive field studies are highly needed for better evaluation of the snail biodiversity in the Caspian Sea region due to the particular climatic conditions and the high prevalence of trematodosis.


Assuntos
Trematódeos , Infecções por Trematódeos , Animais , Mar Cáspio , Água Doce , Lymnaea/parasitologia
2.
Parasitol Res ; 119(9): 2917-2925, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32734308

RESUMO

Trematode-induced castration of snails is widespread and can lead to other life history changes of snails such as changes in trajectories of size and growth or survival. The changes produced likely depend on whether the parasite or host controls allocation of host resources remaining after partial or complete cessation of host current reproduction by castrating trematodes. Documenting host life history changes, like changes in host size in response to castration, is a first step in assessing whether these changes are beneficial to the parasite (increasing transmission success) or to the host (outliving the infection) or to neither. Herein, we test for differences in size and survival among individuals of two snail species in relation to infection by Echinostoma spp. trematodes. Active shedding of Echinostoma spp. was associated with castration of all Stagnicola elodes snails from a site in Eastern Ontario. Snails actively shedding cercariae were not different in size from non-shedding, egg-laying snails but had a higher mortality than egg-laying snails. Active shedding of Echinostoma spp. cercariae was also associated with castration of nearly all Helisoma trivolvis monitored, from a site in Southwestern Ontario. Actively shedding, non-laying H. trivolvis hosts were smaller on average than non-shedding egg-laying hosts, but both non-laying and egg-laying snails survived equally well. We discuss these results in light of what is known about effects of castration on snail hosts in terms of growth and survival for these and other trematode species and speculate on whether changes in size or survival benefits parasite or host.


Assuntos
Castração , Cercárias/crescimento & desenvolvimento , Echinostoma/crescimento & desenvolvimento , Lymnaea/parasitologia , Oviposição/fisiologia , Animais , Alimentos , Água Doce , Interações Hospedeiro-Parasita , Ontário , Reprodução
3.
Parasit Vectors ; 13(1): 171, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32252808

RESUMO

BACKGROUND: Fascioliasis is a snail-borne zoonotic trematodiasis emerging due to climate changes, anthropogenic environment modifications, and livestock movements. Many areas where Fasciola hepatica is endemic in humans have been described in Latin America altitude areas. Highest prevalences and intensities were reported from four provinces of the northern Bolivian Altiplano, where preventive chemotherapy is ongoing. New strategies are now incorporated to decrease infection/re-infection risk, assessment of human infection sources to enable efficient prevention measures, and additionally a One Health initiative in a selected zone. Subsequent extension of these pilot interventions to the remaining Altiplano is key. METHODS: To verify reproducibility throughout, 133 specimens from 25 lymnaeid populations representative of the whole Altiplano, and 11 used for population dynamics studies, were analyzed by rDNA ITS2 and ITS1 and mtDNA cox1 and 16S sequencing to assess their classification, variability and geographical spread. RESULTS: Lymnaeid populations proved to belong to a monomorphic group, Galba truncatula. Only a single cox1 mutation was found in a local population. Two cox1 haplotypes were new. Comparisons of transmission foci data from the 1990's with those of 2018 demonstrated an endemic area expansion. Altitudinal, northward and southward expansions suggest movements of livestock transporting G. truncatula snails, with increasing temperatures transforming previously unsuitable habitats into suitable transmission areas. Transmission foci appear to be stable when compared to past field observations, except for those modified by human activities, including construction of new roads or control measures undertaken in relation to fascioliasis. CONCLUSIONS: For a One Health initiative, the control of only one Fasciola species and snail vector species simplifies efforts because of the lower transmission complexity. Vector monomorphism suggests uniformity of vector population responses after control measure implementation. Hyperendemic area outer boundary instability suggests a climate change impact. All populations outside previously known boundaries were close to villages, human dwellings and/or schools, and should therefore be considered during disease control planning. The remarkable southward expansion implies that a fifth province, Aroma, should now be included within preventive chemotherapy programmes. This study highlights the need for lymnaeid molecular identification, transmission foci stability monitoring, and potential vector spread assessment.


Assuntos
Vetores de Doenças , Ecossistema , Fasciola hepatica/genética , Fasciolíase/epidemiologia , Lymnaea/parasitologia , Saúde Única , Animais , DNA Mitocondrial/genética , DNA Espaçador Ribossômico/genética , Doenças Endêmicas , Fasciolíase/parasitologia , Geografia , Haplótipos , Humanos , Filogenia , Prevalência
4.
Dev Comp Immunol ; 102: 103464, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31402190

RESUMO

Lymnaea stagnalis is a common freshwater gastropod. Importantly, the snail serves as the intermediate host for more than one hundred species of digenetic trematodes, including the avian schistosome Trichobilharzia szidati, a causative agent of cercarial dermatitis in humans. Infection of L. stagnalis by T. szidati initiates a dynamic confrontation between the host and the parasite that culminates in immunocompatibility ensuring survival and development of larvae. Unfortunately, the molecular mechanisms determining this immunocompatibility remain poorly characterised. By employing a variety of immune elicitors, including chemical compounds, PAMPs and bacteria, research in the last two decades has elucidated some of the molecular processes that regulate the snail internal defence response such as haemocyte signalling pathways. These discoveries provide a framework for future studies of molecular interactions between T. szidati and L. stagnalis to help elucidate factors and mechanisms enabling transmission of schistosome parasites. Moreover, support from recently available next generation sequence data and CRISPR-enabled functional genomics should further enable L. stagnalis as an important model for comparative immunology and contribute to a more comprehensive understanding of immune functions in gastropod molluscs.


Assuntos
Lymnaea/imunologia , Lymnaea/parasitologia , Schistosomatidae/fisiologia , Animais , Hemócitos/imunologia , Hemócitos/parasitologia , Interações Hospedeiro-Parasita/imunologia , Humanos , Imunomodulação , Estágios do Ciclo de Vida , Transdução de Sinais/imunologia , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/transmissão
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.
Vet Parasitol ; 276: 108979, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31778940

RESUMO

Glutathione peroxidases (GPx), major antioxidant enzymes, secreted by Fasciola spp., are important for the parasite evasion and protection against the host's immune responses. In the present study, a monoclonal antibody (MoAb) against recombinant F. gigantica glutathione peroxidase (rFgGPx) was produced by hybridoma technique using spleen cells from BALB/c mice immunized with rFgGPx. This MoAb (named 7B8) is IgG1 with κ light chains, and it reacted specifically with rFgGPx at a molecular weight 19 kDa as shown by immunoblotting, and reacted with the native FgGPx in the extracts of whole body (WB), metacercariae, newly excysted juveniles (NEJs), 4 week-old juveniles and adult F. gigantica as shown by indirect ELISA. It did not cross react with antigens in WB fractions from other adult trematodes, including Fischoederius cobboldi, Paramphistomum cervi, Setaria labiato-papillosa, Eurytrema pancreaticum, Gastrothylax crumenifer and Gigantocotyle explanatum. By immunolocalization, MoAb against rFgGPx reacted with the native protein in the tegument, vitelline cells, and eggs of adult F. gigantica. In addition, the sera from mice experimentally infected with F. gigantica were tested positive by this indirect sandwich ELISA. This result indicated that FgGPx is an abundantly expressed parasite protein that is secreted into the tegumental antigens (TA), therefore, FgGPx and its MoAb may be used for immunodiagnosis of both early and late fasciolosis gigantica in animals and humans.


Assuntos
Anticorpos Monoclonais/imunologia , Fasciola/enzimologia , Fasciola/imunologia , Fasciolíase/diagnóstico , Glutationa Peroxidase/imunologia , Animais , Antígenos de Helmintos/imunologia , Cricetinae , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Feminino , Imuno-Histoquímica , Lymnaea/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Coelhos
7.
Braz. j. biol ; 79(3): 446-451, July-Sept. 2019. graf
Artigo em Inglês | LILACS | ID: biblio-1001448

RESUMO

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.


Resumo Agricultura urbana é muito comum nas cidades, como Rio de Janeiro e adjacências, sendo uma importante atividade econômica de subsistência. No entanto, esta prática pode criar condições adequadas para o estabelecimento e manutenção do ciclo de vida de muitos parasitos. Os moluscos limneídeos podem atuar como hospedeiros intermédios de muitas espécies de trematódeos, incluindo aqueles que infectam humanos e animais selvagens e domésticos. No presente estudo, o molusco Lymnaea columella foi coletado de plantações urbanas de agrião e a morfologia das cercárias liberadas por eles foi analisada por microscopia eletrônica de varredura leve e de varredura. As larvas foram identificadas como xifidiocercárias, pertencentes ao grupo das Cercariae Ornatae, Ordem Plagiorchiiformes. Análises histológicas da glândula digestiva dos moluscos infectados evidenciaram esporocistos, com formação de granuloma e metaplasia do tecido epitelial.


Assuntos
Animais , Trematódeos/fisiologia , Lymnaea/parasitologia , Trematódeos/crescimento & desenvolvimento , Trematódeos/ultraestrutura , Brasil , Microscopia Eletrônica de Varredura , Cidades , Nasturtium/crescimento & desenvolvimento , Agricultura , Cercárias/crescimento & desenvolvimento , Cercárias/fisiologia , Cercárias/ultraestrutura
8.
Acta Parasitol ; 64(4): 839-849, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31420774

RESUMO

PURPOSE: Fascioliasis is a freshwater snail-borne zoonotic trematodiasis of high pathogenicity and wide veterinary repercussions. In South America, moreover, it causes serious public health problems, with high human infection rates in Andean countries. Ecuador offers a worrying risky scenario due to its physiography, including many human infection reports and animal endemicity throughout its Andean highlands. METHODS: Endemic areas with increasing animal fascioliasis were surveyed for lymnaeid snails in the province of Loja, southern Ecuador, close to the border of Peru, the country known to present the widest human fascioliasis endemic zone. The altitude of the sampling sites ranged between 150 and 1770 m a.s.l., and their location was close to human villages. Biotopes surveyed were characterized according to fascioliasis transmission needs. RESULTS: The species Lymnaea schirazensis and L. neotropica were identified by rDNA ITS-2 and ITS-1 sequencing. The non-transmitting L. schirazensis combined haplotype agreed with populations of this species previously reported from northern Ecuador. The finding of the efficient vector L. neotropica is reported for the first time in Ecuador and suggests a passive introduction from neighbouring Peru by uncontrolled livestock transport. CONCLUSIONS: Rice irrigation system implementation, lymnaeid finding on Taraxacum (dandelion) plants which are consumed fresh in salads by people, and Saccharum (sugarcane), whose bark is peeled off with the teeth, represent potential infection sources for humans. The closeness to the Cajamarca human hyperendemic area in northern Peru, where the same two lymnaeids have been also found and triclabendazole resistance reported, is an additional risk to be considered regarding the livestock transborder exchange.


Assuntos
Vetores de Doenças , Doenças Endêmicas/veterinária , Fasciolíase/veterinária , Lymnaea/classificação , Lymnaea/parasitologia , Análise de Sequência de DNA , Animais , DNA Espaçador Ribossômico/genética , Equador , Fasciolíase/transmissão , Geografia , Haplótipos , Peru
9.
Exp Parasitol ; 201: 11-20, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31022392

RESUMO

The characteristics of parasitic infections are often tied to host behavior. Although most studies have investigated definitive hosts, intermediate hosts can also play a role in shaping the distribution and accumulation of parasites. This is particularly relevant in larval stages, where intermediate host's behavior could potentially interfere in the molecules secreted by the parasite into the next host during infection. To investigate this hypothesis, we used a proteomic approach to analyze excretion/secretion products (ESP) from Fasciola hepatica newly excysted juveniles (NEJ) derived from two intermediate host species, Lymnaea viatrix and Pseudosuccinea columella. The two analyzed proteomes showed differences in identity, abundance, and functional classification of the proteins. This observation could be due to differences in the biological cycle of the parasite in the host, environmental aspects, and/or host-dependent factors. Categories such as protein modification machinery, protease inhibitors, signal transduction, and cysteine-rich proteins showed different abundance between samples. More specifically, differences in abundance of individual proteins such as peptidyl-prolyl cis-trans isomerase, thioredoxin, cathepsin B, cathepsin L, and Kunitz-type inhibitors were identified. Based on the differences identified between NEJ ESP samples, we can conclude that the intermediate host is a factor influencing the proteomic profile of ESP in F. hepatica.


Assuntos
Fasciola hepatica/metabolismo , Proteínas de Helminto/metabolismo , Lymnaea/parasitologia , Proteômica , Caramujos/parasitologia , Animais , Anidrases Carbônicas/classificação , Anidrases Carbônicas/metabolismo , Proteínas de Helminto/classificação , Larva/metabolismo , Peptídeo Hidrolases/classificação , Peptídeo Hidrolases/metabolismo , Peroxirredoxinas/classificação , Peroxirredoxinas/metabolismo , Inibidores de Proteases/classificação , Inibidores de Proteases/metabolismo , Receptores de Superfície Celular/classificação , Receptores de Superfície Celular/metabolismo
10.
J Helminthol ; 94: e38, 2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30773157

RESUMO

The main intermediate host of Fasciola gigantica in sub-Saharan Africa is Lymnaea (Radix) natalensis. Lymnaea (Pseudosuccinea) columella is capable of transmitting both F. gigantica and F. hepatica and has been reported to be present in South Africa. To date, no natural infection with F. gigantica has been reported despite the wide distribution of the snail. The aim of this study was to confirm whether L. (P.) columella was transmitting F. gigantica and/or F. hepatica in selected locations of KwaZulu-Natal and Eastern Cape provinces of South Africa. Lymnaea (Pseudosuccinea) columella snails were collected from two locations in two provinces of South Africa and screened for cercariae shedding. This was followed by humanely sacrificing the screened snails, and whole tissue of each individual snail was homogenized and amplified using primers designed to amplify the ITS-1 region of Fasciola spp. No cercariae were shed from the screened snails and molecular analysis showed that snails from the two locations were infected with F. gigantica. This study confirms natural infection of L. (P.) columella with F. gigantica in South Africa, where F. gigantica and F. hepatica have already been reported to coexist. Although L. (P.) columella is able to transmit the two species, surprisingly no infection with F. hepatica was detected from the screened snails. The natural intermediate host of F. gigantica in southern Africa, including South Africa, is Lymnaea (Radix) natalensis and comparative studies are needed to determine the competence of the two snail species in the transmission of F. gigantica.


Assuntos
Fasciola/genética , Fasciola/isolamento & purificação , Lymnaea/parasitologia , Animais , Cercárias/classificação , Cercárias/genética , Cercárias/crescimento & desenvolvimento , Cercárias/isolamento & purificação , Fasciola/crescimento & desenvolvimento , Fasciola/fisiologia , Lymnaea/classificação , África do Sul
11.
Braz J Biol ; 79(3): 446-451, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30304252

RESUMO

Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.


Assuntos
Lymnaea/parasitologia , Trematódeos/fisiologia , Agricultura , Animais , Brasil , Cercárias/crescimento & desenvolvimento , Cercárias/fisiologia , Cercárias/ultraestrutura , Cidades , Microscopia Eletrônica de Varredura , Nasturtium/crescimento & desenvolvimento , Trematódeos/crescimento & desenvolvimento , Trematódeos/ultraestrutura
12.
Exp Parasitol ; 194: 16-23, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30240576

RESUMO

Helminth 2-cys peroxiredoxin (Prx) is a major antioxidant enzyme that protects parasites against hydrogen peroxide-generating oxidative stress from the hosts' immune responses. This enzyme has been found in all stages of the tropical liver fluke, Fasciola gigantica. To investigate the potential of the recombinant F. gigantica Prx-2 (rFgPrx-2) as a vaccine candidate, vaccine trials in mice were carried out. In this study, the ICR mice were immunized with rFgPrx-2 combined with Freund's adjuvant and infected with F. gigantica metacercariae. The vaccine efficacy was estimated by quantitate fluke recovery, antibody levels and liver function. The protection by rFgPrx-2 against F. gigantica infection was achieved at 43-46% compared with adjuvant-infected and non-immunized-infected control groups, respectively. The vaccine elicited both Th1 and Th2 humoral immune responses with predominance of Th2 as indicated by the higher level of IgG1 in sera of immunized mice. However, the levels of liver damage markers, serum glutamate oxalic transaminase (SGOT) and serum glutamic pyruvate transaminase (SGPT) in rFgPrx-2 immunized group did not show significant difference in comparison with the controls. This study suggested that rFgPrx-2 may have a potential as a vaccine against tropical fasciolosis.


Assuntos
Fasciola/imunologia , Fasciolíase/prevenção & controle , Peroxirredoxinas/imunologia , Vacinas , Alanina Transaminase/sangue , Animais , Anticorpos Anti-Helmínticos/sangue , Aspartato Aminotransferases/sangue , Ensaio de Imunoadsorção Enzimática , Fasciolíase/imunologia , Feminino , Adjuvante de Freund/administração & dosagem , Imunoglobulina G/sangue , Fígado/enzimologia , Fígado/patologia , Fígado/fisiologia , Lymnaea/parasitologia , Camundongos , Camundongos Endogâmicos ICR , Distribuição Aleatória , Proteínas Recombinantes/imunologia
13.
Parasite ; 24: 55, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29272249

RESUMO

A retrospective study on the natural infection of Galba truncatula by Fasciola hepatica was carried out in the French department of Haute-Vienne to determine whether there are areas at risk for fasciolosis. Adult snails included in this analysis came from samples collected from pastures on 259 farms and from 121 wild watercress beds between 1970 and 2006. Fasciola hepatica infection rates were examined in relation to altitude and climatic data (mean annual rainfall, mean annual temperature) of each municipality. In a total of 108,481 snails collected in 151 municipalities, the overall prevalence of infection was 3.8% but varied according to the municipalities from which samples were taken (from 1% to 7.4%). The prevalence of F. hepatica infection in snails significantly decreased when the mean altitude of municipalities or their mean annual rainfall increased. However, this prevalence significantly increased with increasing mean annual temperatures. Studying the prevalence of infection in these snails makes it possible to delineate zones at risk for fasciolosis on the acid soils of Haute-Vienne. The risk of infection for livestock would be greater in areas of Haute-Vienne below 400 m above sea level and would gradually decrease when the altitude of the land increases.


Title: Détermination des zones à risque pour la fasciolose dans le département de la Haute-Vienne (France) : une étude rétrospective sur les infestations naturelles détectées chez 108.481 Galba truncatula pendant 37 années. Abstract: Une étude rétrospective sur l'infestation naturelle de Galba truncatula par Fasciola hepatica a été effectuée dans le département de la Haute-Vienne pour déterminer s'il existe des zones à risque pour la fasciolose. Les limnées adultes impliquées dans cette analyse proviennent d'échantillons prélevés dans les pâturages de 259 fermes et dans 121 cressonnières sauvages entre 1970 et 2006. Les taux d'infection par Fasciola hepatica ont été mis en relation avec l'altitude et les données climatiques (précipitations annuelles moyennes, température annuelle moyenne) de chaque municipalité. Sur un total de 108.481 limnées récoltées dans 151 municipalités, la prévalence globale de l'infestation était de 3,8 %, mais variait selon les municipalités dans lesquelles les échantillons ont été prélevés (de 1 % à 7,4 %). La prévalence de l'infestation par F. hepatica diminue considérablement lorsque l'altitude moyenne des municipalités ou leurs précipitations annuelles moyennes augmente. D'autre part, cette prévalence augmente considérablement avec l'augmentation de la température annuelle moyenne des municipalités. L'étude de la prévalence de l'infestation chez ces limnées permet de délimiter des zones à risque pour la fasciolose sur les sols acides de la Haute-Vienne. Le risque d'infestation pour le bétail serait plus élevé dans les zones de la Haute-Vienne situées en dessous de 400 m d'altitude et diminuerait graduellement lorsque l'altitude de ces terrains augmente.


Assuntos
Fasciola hepatica/isolamento & purificação , Fasciolíase/transmissão , Lymnaea/parasitologia , Altitude , Animais , Bovinos , Vetores de Doenças , Fazendas , Fasciola hepatica/anatomia & histologia , Fasciola hepatica/fisiologia , Fasciolíase/epidemiologia , França/epidemiologia , Nasturtium , Prevalência , Chuva , Estudos Retrospectivos , Fatores de Risco , Ovinos , Temperatura
14.
Acta Trop ; 173: 23-29, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28545895

RESUMO

This study elucidated for the first time, under laboratory conditions, the susceptibility of Lymnaea columella to infective juveniles of Heterorhabditis baujardi LPP7. Exposure to the nematodes induced an average mortality rate of 66.66% in the population of L. columella, with the highest values attained from the second week after exposure onward. In addition, all the reproductive parameters analyzed (total number of eggs, number of egg masses, number of eggs laid/snail, embryo hatching rate and content of galactogen stored in the albumen gland) changed as a result of the infection. The results indicate the occurrence of the phenomenon of parasitic castration in L. columella infected by H. baujardi LPP7, probably through depletion of energy reserves such as galactogen, necessary to meet the intense metabolic demands of the nematode's larval stages. Finally, histopathological analysis demonstrated an intense process of cell disorganization, characterized by the occurrence of granulomatous inflammatory reactions in tissues of exposed snails, induced by the spoliative action of the bacteria/nematode. The results suggest the use of H. baujardi LPP7 as an alternative for biological control of the population of this intermediate host, and thus of the diseases in whose epidemiological chain it participates, especially fasciolosis, in line with the recommendations of the World Health Organization (WHO).


Assuntos
Fasciolíase/transmissão , Lymnaea/parasitologia , Controle Biológico de Vetores/métodos , Rabditídios/fisiologia , Animais , Fasciolíase/prevenção & controle , Interações Hospedeiro-Parasita
15.
J Helminthol ; 91(1): 1-6, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26781336

RESUMO

A retrospective study on different Lymnaea glabra samples collected from central France between 1993 and 2010 was carried out to determine the prevalence of natural co-infections with Calicophoron daubneyi and Fasciola hepatica, and to specify the composition of redial burdens. Experimental infections of L. glabra performed during the same period of time were also analysed to study metacercarial production of each digenean in co-infected snails. Controls were naturally or experimentally co-infected Galba truncatula. In natural co-infections, prevalence was 0.7% in L. glabra (186/25,128) and 0.4% in G. truncatula (137/31,345). Low redial burdens were found in these snails, with F. hepatica rediae significantly more numerous in L. glabra than in G. truncatula (7.5 per snail instead of 5.2). In contrast, the total numbers of C. daubneyi rediae in both lymnaeids were close to each other (4.3 and 3.0 rediae, respectively). In experimentally co-infected groups, prevalence was greater in G. truncatula than in the other lymnaeid (6.3% instead of 3.0%). Significantly shorter patent periods and lower metacercarial production for each digenean were noted in L. glabra than in G. truncatula. However, in both lymnaeids, the two types of cercariae were released during the same shedding waves and several peaks during the patent period were synchronous. In spite of a greater shell height for L. glabra, metacercarial production of both digeneans in co-infected snails was lower than that in G. truncatula, thus indicating a still incomplete adaptation between these French L. glabra and both parasites.


Assuntos
Lymnaea/parasitologia , Trematódeos/crescimento & desenvolvimento , Experimentação Animal , Animais , Coinfecção/parasitologia , Coinfecção/patologia , França , Carga Parasitária , Prevalência , Estudos Retrospectivos , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/patologia
16.
Vet Parasitol ; 226: 124-31, 2016 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-27514897

RESUMO

In this study, we characterized and investigated the vaccine potential of FgCatL1G against Fasciola gigantica infection in mice. Recombinant mature FgCatL1G (rmFgCatL1G) was expressed in Escherichia coli BL21. The vaccination was performed in Imprinting Control Region (ICR) mice (n=10) by subcutaneous injection with 50µg of rmFgCatL1G combined with Freund's adjuvant. Two weeks after the second boost, mice were infected with 15 metacercariae by the oral route. The percents of protection of rmFgCatL1G vaccine were estimated to be 56.5% and 58.3% when compared with non vaccinated-infected and adjuvant-infected controls, respectively. Antibodies in the immune sera of vaccinated mice were shown by immunoblot to react with the native FgCatL1s in the extract of all stages of parasites and rmFgCatL1H, recombinant pro - FgCatL1 (rpFgCatL1). By immunohistochemistry, the immune sera also reacted with FgCatL1s in the caecal epithelial cells of the parasites. The levels of IgG1 and IgG2a in the immune sera, which are indicative of Th2 and Th1 immune responses, were also increased with IgG1 predominating. The levels of serum glutamic oxaloacetic transaminase (SGOT) and serum glutamic pyruvic transaminase (SGPT) in rmFgCatL1G-immunized group showed no significant difference from the control groups, but pathological lesions of livers in rmFgCatL1G-immunized group showed significant decrease when compared to the control groups. This study indicates that rmFgCatL1G has a vaccine potential against F. gigantica in mice, and this potential will be tested in larger livestock animals.


Assuntos
Catepsinas/imunologia , Cisteína Endopeptidases/imunologia , Fasciola/imunologia , Fasciolíase/prevenção & controle , Proteínas de Helminto/imunologia , Vacinas , Alanina Transaminase/sangue , Animais , Anticorpos Anti-Helmínticos/sangue , Aspartato Aminotransferases/sangue , Bovinos , Cricetinae , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Fasciolíase/patologia , Immunoblotting , Imunoglobulina G/sangue , Fígado/patologia , Lymnaea/parasitologia , Masculino , Mesocricetus , Camundongos , Camundongos Endogâmicos ICR , Vacinas Sintéticas
17.
Exp Parasitol ; 169: 81-9, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27475124

RESUMO

Fasciola hepatica is a well-known helminth parasite, with significant economic and public health importance all over the world. It has been known since more than 630 years ago and a considerable research work has been carried out on the life cycle of this important parasite. In the hepatic phase of the life cycle of F. hepatica, it is assumed that the young flukes, after about 6-7 weeks of migration in the liver parenchyma, enter into the bile ducts of the definitive hosts and become sexually mature. Even though the secretion of cysteine peptidases including cathepsin L and B proteases by F. hepatica may justify this opinion, because of several scientific reasons and based on the experimental studies conducted in different animals (reviewed in this article), the entry of parasites into the bile ducts, after their migration in the liver parenchyma seems to be doubtful. However, considering all the facts relating to the hepatic and biliary phases of the life cycle of F. hepatica, two alternative ideas are suggested: 1) some of the migrating juvenile flukes may enter into the bile ducts immediately after reaching the liver parenchyma while they are still very small, or 2) when newly excysted juvenile flukes are penetrating into the intestinal wall to reach the liver through the abdominal cavity, a number of these flukes may enter into the choleduct and reach the hepatic bile ducts, where they mature. According to the previously performed natural and experimental studies in different animals and human beings, the supporting and opposing evidences for the current opinion as well as the evidences that might justify the two new ideas are reviewed and discussed briefly. In conclusion, our present knowledge about the time and quality of the entry of F. hepaticas into the bile ducts, seems to be insufficient, therefore, there are still some dark corners and unknown aspects in this field that should be clarified.


Assuntos
Ductos Biliares/parasitologia , Fasciola hepatica/crescimento & desenvolvimento , Fasciolíase/parasitologia , Estágios do Ciclo de Vida/fisiologia , Animais , Fasciola hepatica/fisiologia , Humanos , Fígado/parasitologia , Lymnaea/parasitologia , Fatores de Tempo
18.
Mem Inst Oswaldo Cruz ; 111(7): 475-83, 2016 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-27384082

RESUMO

The presence and distribution of surface carbohydrates in the tissues of Galba truncatula snails uninfected or after infection with Fasciola hepatica as well as on the surface of the snail-pathogenic larval stages of the parasite were studied by lectin labelling assay. This is an attempt to find similarities that indicate possible mimicry, utilised by the parasite as an evasion strategy in this snail-trematode system. Different binding patterns were identified on head-foot-mantle, hepatopancreas, genital glands, renopericardial complex of the host as well as of the snail-pathogenic larval stages of F. hepatica. The infection with F. hepatica leads to changes of labelling with Glycine max in the head-mantle cells and Arachis hypogaea in the tubular epithelium of the hepatopancreas. The lectin binding on the other snail tissues is not changed by the development of the larvae. Our data clearly demonstrated the similarity in labelling of G. truncatula tissues and the surface of the snail-pathogenic larval stages of F. hepatica. The role of glycosylation of the contact surfaces of both organisms in relation to the host-parasite interactions is also discussed.


Assuntos
Carboidratos/fisiologia , Fasciola hepatica/metabolismo , Fasciolíase/metabolismo , Lectinas/metabolismo , Lymnaea/metabolismo , Animais , Arachis , Fasciola hepatica/parasitologia , Fasciolíase/parasitologia , Glicosilação , Larva/metabolismo , Larva/parasitologia , Lymnaea/parasitologia , Microscopia de Fluorescência , Oocistos/parasitologia , Valores de Referência , Coloração e Rotulagem , Triticum/parasitologia
19.
Mem. Inst. Oswaldo Cruz ; 111(7): 475-483, tab, graf
Artigo em Inglês | LILACS | ID: lil-787555

RESUMO

The presence and distribution of surface carbohydrates in the tissues of Galba truncatula snails uninfected or after infection with Fasciola hepatica as well as on the surface of the snail-pathogenic larval stages of the parasite were studied by lectin labelling assay. This is an attempt to find similarities that indicate possible mimicry, utilised by the parasite as an evasion strategy in this snail-trematode system. Different binding patterns were identified on head-foot-mantle, hepatopancreas, genital glands, renopericardial complex of the host as well as of the snail-pathogenic larval stages of F. hepatica. The infection with F. hepatica leads to changes of labelling with Glycine max in the head-mantle cells and Arachis hypogaea in the tubular epithelium of the hepatopancreas. The lectin binding on the other snail tissues is not changed by the development of the larvae. Our data clearly demonstrated the similarity in labelling of G. truncatula tissues and the surface of the snail-pathogenic larval stages of F. hepatica. The role of glycosylation of the contact surfaces of both organisms in relation to the host-parasite interactions is also discussed.


Assuntos
Animais , Carboidratos/fisiologia , Fasciola hepatica/metabolismo , Fasciolíase/metabolismo , Lectinas/metabolismo , Lymnaea/metabolismo , Arachis , Fasciola hepatica/parasitologia , Fasciolíase/parasitologia , Glicosilação , Larva/metabolismo , Larva/parasitologia , Lymnaea/parasitologia , Microscopia de Fluorescência , Oocistos/parasitologia , Valores de Referência , Coloração e Rotulagem , Triticum/parasitologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-27253741

RESUMO

Fasciolosis is a food borne zoonosis, caused by the digenetic trematode Fasciola. Freshwater lymnaeid snails are the intermediate host of the trematodes. Chlorophyllin, a semi-synthetic derivative of chlorophyll and its formulations obtained from freeze dried cow urine (FCU) had their toxicity tested against redia and cercaria larvae of F. gigantica. The larvicidal activity of chlorophyllin and its formulations were found to depend on both, time and concentration used against the larvae. Toxicity of chlorophyllin + FCU (1:1 ratio) in sunlight against redia larva (8 h LC50: 0.03 mg/mL) was more pronounced than using just chlorophyllin (8 h LC50: 0.06 mg/mL). Toxicity of chlorophyllin + FCU in sunlight against redia (8 h LC50: 0.03 mg/mL) was higher than against cercaria (8 h LC50: 0.06 mg/mL). The larvicidal activity of chlorophyllin in sunlight (redia/cercaria larvae: 8 h LC50: 0.06 mg/mL) was more pronounced than under laboratory conditions (redia: 8 h LC50: 22.21 mg/mL/, cercaria 8 h LC50: 96.21 mg/mL). Toxicity of FCU against both larvae was lower than that of chlorophyllin and chlorophyllin + FCU. Chlorophyllin and its formulations + FCU were 357.4 to 1603.5 times more effective against redia/cercaria larvae in sunlight than under laboratory conditions. The present study has shown that chlorophyllin formulations may be used as potent larvicides against fasciolosis.


Assuntos
Anti-Helmínticos/farmacologia , Clorofilídeos/farmacologia , Fasciola/efeitos dos fármacos , Animais , Bovinos , Larva/efeitos dos fármacos , Dose Letal Mediana , Lymnaea/parasitologia , Testes de Sensibilidade Parasitária , Fatores de Tempo , Urina
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