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1.
Proc Natl Acad Sci U S A ; 117(36): 22580-22589, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848066

RESUMO

The global movement of pathogens is altering populations and communities through a variety of direct and indirect ecological pathways. The direct effect of a pathogen on a host is reduced survival, which can lead to decreased population densities. However, theory also suggests that increased mortality can lead to no change or even increases in the density of the host. This paradoxical result can occur in a regulated population when the pathogen's negative effect on survival is countered by increased reproduction at the lower density. Here, we analyze data from a long-term capture-mark-recapture experiment of Trinidadian guppies (Poecilia reticulata) that were recently infected with a nematode parasite (Camallanus cotti). By comparing the newly infected population with a control population that was not infected, we show that decreases in the density of the infected guppy population were transient. The guppy population compensated for the decreased survival by a density-dependent increase in recruitment of new individuals into the population, without any change in the underlying recruitment function. Increased recruitment was related to an increase in the somatic growth of uninfected fish. Twenty months into the new invasion, the population had fully recovered to preinvasion densities even though the prevalence of infection of fish in the population remained high (72%). These results show that density-mediated indirect effects of novel parasites can be positive, not negative, which makes it difficult to extrapolate to how pathogens will affect species interactions in communities. We discuss possible hypotheses for the rapid recovery.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Modelos Biológicos , Infecções por Nematoides/epidemiologia , Poecilia/parasitologia , Dinâmica Populacional/estatística & dados numéricos , Animais , Feminino , Masculino
2.
Vet Parasitol ; 280: 109087, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32220696

RESUMO

Mixed grazing of breeding goats and cattle (goats to cattle ratio: about 50 %, based on metabolic weight) was monitored for 2 years on a rotational pasture with the two species grazing together, then for 5 years with cattle grazing immediately after goats. For both modalities, the level of goat parasite infection was not significantly different from that of the control groups. Nevertheless, the association allowed a slight improvement in kid growth and goat productivity, probably in relation to a better food quality. The response of adult goats to mixed grazing is therefore very different from that previously obtained with kids post-weaning. The question of the relationship between heterogeneity of pastures, knowledge of their environment, grazing behaviour of adult goats and risk of infection with gastrointestinal nematodes requires further investigation.


Assuntos
Criação de Animais Domésticos , Comportamento Alimentar , Doenças das Cabras/epidemiologia , Nematoides/fisiologia , Infecções por Nematoides/veterinária , Animais , Bovinos/fisiologia , Doenças das Cabras/parasitologia , Cabras/fisiologia , Pradaria , Guadalupe/epidemiologia , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia
3.
Vet Clin North Am Food Anim Pract ; 36(1): 1-15, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029177

RESUMO

This article reviews the basics of gastrointestinal nematode biology and pathophysiology in cattle and describes how gastrointestinal nematode epidemiology is driven by environmental, host, and farm economic determinants. Adverse effects from gastrointestinal nematodes on their hosts are caused by tissue damage, nutrient absorption, immunopathologic effects, and reduced food intake induced by hormonal changes. Weather and microenvironmental factors influence the development and survival of free-living parasitic stages. A holistic control approach entails the consideration of environmental, immunologic, and socioeconomic aspects of nematode epidemiology and is key for the development and communication of sustainable control strategies.


Assuntos
Doenças dos Bovinos/parasitologia , Gastroenteropatias/veterinária , Infecções por Nematoides/veterinária , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Indústria de Laticínios/estatística & dados numéricos , Fezes/parasitologia , Feminino , Gastroenteropatias/parasitologia , Trato Gastrointestinal/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia
4.
Vet Clin North Am Food Anim Pract ; 36(1): 17-30, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029182

RESUMO

Control of gastrointestinal nematodes has been based on anthelmintics. However, this strategy is unsustainable owing to anthelmintic resistance. Parasitic nematodes have biologic and genetic features that favor the development of drug resistance, making the emergence of resistant nematodes inevitable. The rate of resistance development is affected controllable factors. There is a need to change the paradigm of how gastrointestinal nematodes are controlled to decrease the rate at which resistance develops. This article reviews the biology and prevalence of anthelmintic resistance, and provides recommendations for diagnosing resistance and for strategies that should be implemented to reduce the development of resistance.


Assuntos
Anti-Helmínticos/farmacologia , Doenças dos Bovinos/tratamento farmacológico , Doenças das Cabras/tratamento farmacológico , Gado/parasitologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/tratamento farmacológico , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Resistência a Medicamentos , Doenças das Cabras/epidemiologia , Doenças das Cabras/parasitologia , Cabras , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Prevalência , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia
5.
Vet Clin North Am Food Anim Pract ; 36(1): 45-57, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029188

RESUMO

Control of gastrointestinal nematodes (GIN) can have both economic and health benefits for cattle operations in the southern United States. In the past several decades, GIN control has relied almost exclusively on the use of anthelmintics. With the increase in anthelmintic resistance new strategies must be developed. Anthelmintic use should be minimized by integrating grazing management and a good herd health program into GIN control programs. This takes knowledge of GIN biology and epidemiology in the region (climate and weather) combined with specific information from the ranch.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , Gastroenteropatias/veterinária , Infecções por Nematoides/veterinária , Animais , Anti-Helmínticos/administração & dosagem , Canadá/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Clima , Fezes/parasitologia , Gastroenteropatias/epidemiologia , Gastroenteropatias/parasitologia , Gastroenteropatias/prevenção & controle , Trato Gastrointestinal/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/prevenção & controle , Estados Unidos/epidemiologia
6.
Vet Clin North Am Food Anim Pract ; 36(1): 59-71, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029189

RESUMO

Parasite species infecting cattle throughout northern North American are generally the same as those found throughout North America. Throughout Canada, cattle are primarily infected with Ostertagia ostertagi and Cooperia oncophora, whose larvae survive cold winters within soil of pastures. Overwintering larvae of these species maintain a temporary population of refugia available in spring to grazing cattle. Cattle from northern United States are also infected with Cooperia punctata and Haemonchus placei, whose larvae cannot survive cold winters within pastures. Anthelmintics with persistent activity are used during spring to recover some of these losses; however, anthelmintic resistance limits effectiveness of this strategy.


Assuntos
Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/prevenção & controle , Infecções por Nematoides/veterinária , Animais , Anti-Helmínticos/administração & dosagem , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Indústria de Laticínios/métodos , Feminino , Trato Gastrointestinal/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/prevenção & controle , América do Norte/epidemiologia , Estações do Ano
7.
Vet Clin North Am Food Anim Pract ; 36(1): 73-87, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029190

RESUMO

Strongylid gastrointestinal nematodes are an important cause of disease and economic loss in small ruminants. These parasites are important in most of the United States, with the bloodsucking parasite Haemonchus contortus being the predominant species of concern. Sheep and goats are infected while grazing, and the biology of infective larvae on pastures is important in the design of parasite management programs. Widespread resistance to anthelmintics requires strategies designed to preserve remaining drug activity; these include combination treatments with multiple classes of anthelmintics and targeted treatments.


Assuntos
Doenças das Cabras/epidemiologia , Doenças das Cabras/prevenção & controle , Infecções por Nematoides/veterinária , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/prevenção & controle , Animais , Anti-Helmínticos/administração & dosagem , Trato Gastrointestinal/parasitologia , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Cabras , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/prevenção & controle , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia
8.
Trop Anim Health Prod ; 52(4): 1787-1793, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31898027

RESUMO

An epidemiological study of gastrointestinal nematodes was carried out in naturally infected goats in the North West of Algeria. Coprological analyses were performed for 2 years from January 2014 to December 2015.Examination of 1591 goat samples revealed an overall prevalence of parasite eggs in feces of 96%; the values were very similar in both years at 97% in 2014 and 94.96% in 2015. Five types of nematode eggs were identified: strongyle (95.5%), Nematodirus spp. (19.4%), Marshallagia spp. (3.9%), Trichuris spp. (0.6%), and Skrjabinema spp. (2%).Also, fecal cultures showed the presence of Teladorsagia spp. (56%), Trichostrongylus spp. (20%), Chabertia spp. (10%), Haemonchus spp. (9%), and Oesophagostomum spp. (5%).Season, age, type of grazing, and area affected the epidemiology of gastrointestinal nematodes of goats. The season did not influence the prevalence observed in the 2 years, since no significant differences between the four seasons were observed. On the other hand, egg production was highest in winter and spring. The level of infection decreased with the animal's age. There were no significant differences between the prevalence in animals on irrigated and non-irrigated pastures, but there were differences in egg excretion. Additionally, no significant difference was observed between the coastal (Oran) and lowland (Mascara) regions in the prevalence or in average egg excretion.


Assuntos
Doenças das Cabras/parasitologia , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária , Argélia/epidemiologia , Animais , Fezes/parasitologia , Doenças das Cabras/epidemiologia , Cabras , Nematoides/classificação , Infecções por Nematoides/epidemiologia , Prevalência
9.
Int J Parasitol ; 50(2): 133-144, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31981671

RESUMO

Gastrointestinal nematodes are a significant threat to the economic and environmental sustainability of keeping livestock, as adequate control becomes increasingly difficult due to the development of anthelmintic resistance in some systems and climate-driven changes to infection dynamics. To mitigate any negative impacts of climate on gastrointestinal nematode epidemiology and slow anthelmintic resistance development, there is a need to develop effective, targeted control strategies that minimise the unnecessary use of anthelmintic drugs and incorporate alternative strategies such as vaccination and evasive grazing. However, the impacts climate and gastrointestinal nematode epidemiology may have on the optimal control strategy are generally not considered, due to lack of available evidence to drive recommendations. Parasite transmission models can support control strategy evaluation to target field trials, thus reducing the resources and lead-time required to develop evidence-based control recommendations incorporating climate stochasticity. Gastrointestinal nematode population dynamics arising from natural infections have been difficult to replicate and model applications have often focussed on the free-living stages. A flexible framework is presented for the parasitic phase of gastrointestinal nematodes, GLOWORM-PARA, which complements an existing model of the free-living stages, GLOWORM-FL. Longitudinal parasitological data for two species that are of major economic importance in cattle, Ostertagia ostertagi and Cooperia oncophora, were obtained from seven cattle farms in Belgium for model validation. The framework replicated the observed seasonal dynamics of infection in cattle on these farms and overall, there was no evidence of systematic under- or over-prediction of faecal egg counts. However, the model under-predicted the faecal egg counts observed on one farm with very young calves, highlighting potential areas of uncertainty that may need further investigation if the model is to be applied to young livestock. The model could be used to drive further research into alternative parasite control strategies such as vaccine development and novel treatment approaches, and to understand gastrointestinal nematode epidemiology under changing climate and host management.


Assuntos
Trato Gastrointestinal/parasitologia , Gado/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides , Animais , Anti-Helmínticos/uso terapêutico , Bélgica/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Clima , Fezes/parasitologia , Ivermectina/uso terapêutico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/veterinária , Ostertagia/isolamento & purificação , Ostertagíase/epidemiologia , Ostertagíase/veterinária , Contagem de Ovos de Parasitas/veterinária , Dinâmica Populacional , Estações do Ano , Strongyloidea/isolamento & purificação , Trichostrongyloidea/isolamento & purificação
10.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(5): 525-528, 2019 Oct 12.
Artigo em Chinês | MEDLINE | ID: mdl-31713385

RESUMO

OBJECTIVE: To investigate the related factors of soil-transmitted nematode infections in Chongqing City, so as to provide the basis for scientific prevention and treatment of the infections. METHODS: From 2011 to 2015, the stool samples of residents of the surveillance sites in Chongqing City were collected every year, and the soil-transmitted nematode eggs were examined by the modified Kato-Katz thick smear method (three smears for a single stool sample). The respondents were surveyed by questionnaires, and the factors affecting soil-transmitted nematode infections were identified. RESULTS: The prevalence of human soil-transmitted nematode infections were 6.44%, 7.30%, 6.85%, 6.93% and 5.56% in Chongqing City from 2011 to 2015, respectively. The more unclean drinking water and the lower frequency of washing hands after using the toilet were the risk factors for Ascaris lumbricoides infection. The more harmless toilets, the higher level of fertilizer application, the lower frequency of drinking raw water, and the lower frequency of food without washing were the protective factors for A. lumbricoides infection. CONCLUSIONS: The local soil-transmitted nematode infections are at a low epidemic level in Chongqing City, and it is necessary to ad-here to the classified guidance, comprehensive prevention and further monitoring on the basis of health education, water and toilet improvement, and environmental sanitation improvement in order to consolidate the prevention and control achievements.


Assuntos
Infecções por Nematoides , Solo , Animais , China/epidemiologia , Humanos , Infecções por Nematoides/epidemiologia , Prevalência , Fatores de Risco , Saneamento/normas , Solo/parasitologia , Inquéritos e Questionários
11.
J Parasitol ; 105(5): 697-703, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31580786

RESUMO

Snappers from the southern Gulf of Mexico (SGM) and Mexican Caribbean (CAR) were examined for parasitic nematodes to determine their richness, composition, and infection parameters (prevalence and mean intensity). From February 2016 to March 2018, 431 individuals of 8 snapper species were collected in 6 localities. In all, these fishes were parasitized by 2,275 individual nematodes belonging to 13 taxa: Terranova sp. was found in 7 of 8 host species and showed the highest prevalence (23%), while the rest had lower values (<10%). Lutjanus griseus (Linnaeus) harbored the highest species richness (10 species), followed by Lutjanus apodus (Walbaum) (8 species). Most localities were similar in terms of species richness but differed in the specific composition. Eight nematode taxa represent new host records for the family Lutjanidae (Gill), thus increasing to 22 the nematode taxa in the SGM and CAR. There is a potential risk to public health due to the presence of nematodes with zoonotic potential (as Anisakis sp.) and the habit in the region of eating raw fish (cebiche).


Assuntos
Doenças dos Peixes/parasitologia , Nematoides/classificação , Infecções por Nematoides/veterinária , Perciformes/parasitologia , Animais , Região do Caribe/epidemiologia , Doenças dos Peixes/epidemiologia , Golfo do México/epidemiologia , Humanos , México/epidemiologia , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Infecções por Nematoides/transmissão , Prevalência , Alimentos Crus/parasitologia , Zoonoses
12.
Vet Parasitol ; 275: 108933, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31606485

RESUMO

We have validated ITS-2 rDNA nemabiome next-generation amplicon sequencing to determine relative species abundance of gastrointestinal nematode species in ovine fecal samples. In order to determine species representation biases, ITS-2 rDNA amplicon sequencing was applied to mock communities or field populations with known proportions of L3 for eight of the major ovine gastrointestinal nematode species: Teladorsagia circumcincta, Trichostrongylus vitrinus, Haemonchus contortus, Cooperia curticei, Trichostrongylus axei, Trichostrongylus colubriformis, Chabertia ovina and Oesophagostumum venulosum. Correction factors, calculated from this data, were shown to reduce species representation biases when applied to an independent set of field samples of known composition. We compared ITS-2 rDNA amplicon sequencing data that was generated from harvested eggs, freshly hatched L1 or L3 larvae following fecal culture and no statistically significant differences were found for the more abundant parasite species. We then applied the validated ITS-2 rDNA nemabiome amplicon sequencing assay to a set of archived L1 gastrointestinal nematode populations, collected in 2008 from fecal samples from 93 groups of 20 ewes and 61 groups of 20 lambs derived from 99 UK sheep farms. The presence of the major gastrointestinal nematode species had previously been determined on this large sample set by species-specific PCR. We show how the ITS-2rDNA amplicon sequencing data provided much more detailed information on species abundance than the previous species-specific PCR. This new data represents the most comprehensive overview of the relative abundance of the major gastrointestinal nematode species across UK sheep farms to date. Substantial variance in the relative abundance of both T. circumcincta and T. vitrinus between farms was revealed with the former species being of statistically significantly higher abundance in all three regions sampled (England, Scotland and Wales). The data also revealed that the relative abundance of T. circumcinta was statistically significantly higher in ewes than in lambs with the opposite pattern being the case for T. vitrinus. The nemabiome sequencing data also clearly illustrated the sporadic nature and skewed distribution of H. controtus across UK sheep farms as well as a higher relative abundance on farms from England compared to Wales and Scotland. The nemabiome survey also provides the first widescale data on the relative abundance of the two major large intestinal nematodes C. ovina and O. venulosum. This work validates ITS-2 rDNA nemabiome sequencing for use in sheep and illustrates the power of the approach for large scale surveillance of ovine gastrointestinal nematodes.


Assuntos
DNA Espaçador Ribossômico/química , Microbioma Gastrointestinal/genética , Enteropatias Parasitárias/veterinária , Infecções por Nematoides/veterinária , Doenças dos Ovinos/parasitologia , Abomaso/parasitologia , Animais , Biologia Computacional , DNA Espaçador Ribossômico/genética , Feminino , Enteropatias Parasitárias/epidemiologia , Enteropatias Parasitárias/parasitologia , Intestino Grosso/parasitologia , Intestino Delgado/parasitologia , Larva/genética , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Óvulo , Reação em Cadeia da Polimerase/veterinária , Prevalência , Ovinos , Doenças dos Ovinos/epidemiologia , Especificidade da Espécie , Reino Unido/epidemiologia
13.
Prev Vet Med ; 171: 104752, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31479849

RESUMO

Gastrointestinal nematodes (GIN) are a serious concern for sheep producers worldwide. However, there is a paucity of evidence describing the epidemiology of GIN on modern UK sheep farms. The aim of this paper was to understand whether expected seasonal variations of infection are still found in ewes and lambs under varying management strategies in temperate climates. Faecal egg counts (FEC) were conducted on freshly voided samples collected from groups of ewes and lambs every third week for twelve months on three farms in southeast Scotland. The patterns of egg output have been described here in relation to management practices undertaken on the farms. Despite changes in farming practice and climatic conditions, the findings complement historical studies detailing the epidemiology of GIN. Findings include a periparturient rise in ewe FEC on two of the farms, while lambing time treatment appeared to suppress this on the third farm. On the same two farms lamb FEC increased during the summer, reaching a peak in the autumn. The work also highlights how the ad hoc use of anthelmintics does little to impact these patterns.


Assuntos
Animais Lactentes/parasitologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia , Criação de Animais Domésticos/métodos , Animais , Anti-Helmínticos/uso terapêutico , Estudos de Coortes , Fazendas , Fezes/parasitologia , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Contagem de Ovos de Parasitas/veterinária , Escócia/epidemiologia , Estações do Ano , Ovinos , Doenças dos Ovinos/tratamento farmacológico
14.
Parasit Vectors ; 12(1): 430, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488192

RESUMO

BACKGROUND: The three most commonly diagnosed gastrointestinal parasites of pet dogs within the USA are the whipworm, the hookworm, and the roundworm. The collection of large data sets from various sources throughout the industry have produced a number of publications on parasite prevalence in recent years. In this study, we look at data captured by the Companion Animal Parasite Council from 2012-2018, which includes 4.3-7.2 million annual fecal exams, to evaluate not only changes in prevalence, but also possible seasonal fluctuations of the three most common canine gastrointestinal parasites. METHODS: Annual and monthly data were collected from the CAPC parasite prevalence maps for canine roundworms, hookworms and whipworm. The map data were provided to CAPC by two large national reference laboratories. The data were evaluated for changes in prevalence on a monthly basis throughout each year as well as changes in prevalence from year to year from 2012-2018. Additionally, positive test results and total tests performed for each of the three parasites from 2012-2018 during individual months were totaled without using the year as a variable in order to evaluate the results for seasonality (i.e. all tests and positive results occurring in January, regardless of year, were totaled and analyzed). RESULTS: Evaluation of gastrointestinal nematode prevalence data from over 39 million fecal samples examined over a 7-year period revealed a subtle, yet significant, increasing prevalence for roundworms, an increasing prevalence for hookworms, and a slightly decreasing prevalence for whipworms. Seasonality was demonstrated for roundworms, hookworms, and to our knowledge, for the first time canine whipworms. Highest seasonal prevalence for roundworms, hookworms, and whipworms occurred during December-January, July-August, and January-February, respectively. CONCLUSIONS: Evaluation of monthly gastrointestinal parasite prevalence data from over 39 million fecal samples collected over a 7-year period revealed a slightly increasing prevalence for roundworms, an increasing prevalence for hookworms, and a slightly decreasing prevalence for whipworms. In addition to the annual changes in prevalence, seasonal prevalence was shown for the first time for whipworms. Prevalence of both whipworm and roundworm peaked in the winter, while prevalence of hookworm peaked in the late summer and early autumn.


Assuntos
Doenças do Cão/epidemiologia , Enteropatias Parasitárias/veterinária , Infecções por Nematoides/veterinária , Estações do Ano , Animais , Doenças do Cão/parasitologia , Cães , Fezes/parasitologia , Infecções por Uncinaria/epidemiologia , Enteropatias Parasitárias/epidemiologia , Infecções por Nematoides/epidemiologia , Prevalência , Tricuríase/epidemiologia , Estados Unidos/epidemiologia
15.
Res Vet Sci ; 126: 51-58, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31437776

RESUMO

Cardiopulmonary nematodes are among the most pathogenic parasites of domestic and wild canids. The aim of this study was to describe the species diversity, prevalence and infection intensity of these parasites in the Iberian wolf (Canis lupus signatus) and the red fox (Vulpes vulpes) in the northwest of the Iberian Peninsula. 257 foxes and 74 wolves were necropsied between 2008 and 2014. Four nematode species were identified: Angiostrongylus vasorum, Eucoleus aerophilus, Crenosoma vulpis and Filaroides hirthi. This last species was only found in wolves, being the first time that is cited worldwide in this wild canid. The overall parasite prevalence was significantly higher in foxes (70%) than in wolves (28%). Specifically, prevalences in foxes and wolves were, respectively, 43% and 22% for A. vasorum, 33% and 5% for E. aerophilus, and 30% and 9% for C. vulpis. The prevalence of F. hirthi was 16%. The A. vasorum intensity was significantly higher in foxes than in wolves. Differences between host species in the risk of infection would be associated to diverging feeding behavior, and possibly reflects a parasite-host adaptation related to host's hunting strategies and cardiorespiratory requirements. This study revealed an association between infection and environmental factors, and highlighted a wide variation in the spatial distribution of A. vasorum. Our results indicate that cardiopulmonary parasites are widespread in wild canids in northwest Spain, and further agrees with other studies indicating the expansion of A. vasorum in Europe and, therefore, the urgent need to investigate infection in dogs in sympatric areas.


Assuntos
Raposas/parasitologia , Cardiopatias/veterinária , Pneumopatias Parasitárias/veterinária , Infecções por Nematoides/veterinária , Lobos/parasitologia , Angiostrongylus , Animais , Animais Selvagens , Coração/parasitologia , Cardiopatias/epidemiologia , Cardiopatias/parasitologia , Pneumopatias Parasitárias/epidemiologia , Pneumopatias Parasitárias/parasitologia , Metastrongyloidea , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Prevalência , Espanha/epidemiologia
16.
J Helminthol ; 94: e81, 2019 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-31469060

RESUMO

Currently, descriptive information on the host range and geographic distribution of helminth parasites associated with naturally occurring rodents in South and southern Africa is scant. Therefore, we embarked on a countrywide study to: (1) identify gastrointestinal helminths and their host range, and (2) provide baseline data on the geographic distribution of helminths across the country. Altogether, 55 helminth taxa were recovered from at least 13 rodent species (n = 1030) at 26 localities across South Africa. The helminth taxa represented 25 genera (15 nematodes, nine cestodes and one acanthocephalan). Monoxenous nematodes were the most abundant and prevalent group, while the occurrence of heteroxenous nematodes and cestodes was generally lower. The study recorded several novel helminth-host associations. Single-host-species infections were common, although multiple-host-species infections by helminth species were also recorded. Monoxenous nematodes and some cestodes were recovered countrywide, whereas heteroxenous nematodes were restricted to the eastern regions of South Africa. The study highlights the as yet unexplored diversity of helminth species associated with naturally occurring rodent species and provides initial data on their geographical distribution in South Africa.


Assuntos
Biodiversidade , Cestoides/classificação , Especificidade de Hospedeiro , Nematoides/classificação , Roedores/parasitologia , Animais , Trato Gastrointestinal/parasitologia , Geografia , Helmintíase Animal/parasitologia , Interações Hospedeiro-Parasita , Infecções por Nematoides/epidemiologia , Prevalência , Doenças dos Roedores/parasitologia , Roedores/classificação , África do Sul
17.
Parasitol Res ; 118(10): 2863-2875, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31399870

RESUMO

A fundamental aim of parasite ecology is to understand the mechanisms behind spatial variation in diversity and structure of parasite assemblages. To understand the contribution of individual parasite species and their assemblages to spatial variation in parasite communities, we examined species contributions to beta diversity (SCBD) and local contributions to beta diversity (LCBD) of parasitic gastrointestinal helminths (nematodes and cestodes) in two closely related rodents, Rhabdomys dilectus and Rhabdomys pumilio, from 20 localities across South Africa. Although the two Rhabdomys spp. are morphologically similar, they differ substantially in body size, habitat preference, and sociality. We asked whether the variation in life history traits and infection parameters are associated with SCBD of helminths and whether variation in environmental factors, host population density, and species richness of host communities are associated with LCBD of component assemblages of helminths. We also considered spatial factors to test whether LCBD of helminth assemblages demonstrate geographic structure. We found that the contribution of helminth species parasitic in both hosts to beta diversity significantly increased with characteristic prevalence of these species, whereas mean abundance, type of life cycle, and location in the host's gut had no effect on SCBD. The LCBD of helminth assemblages showed a significant positive correlation with environmental factors in both host species. Our results suggest that predictors of variation in SCBD and LCBD may substantially differ between parasites with different infection parameters and/or parasite communities at different hierarchical scales.


Assuntos
Cestoides/isolamento & purificação , Infecções por Cestoides/epidemiologia , Trato Gastrointestinal/parasitologia , Murinae/parasitologia , Nematoides/isolamento & purificação , Infecções por Nematoides/epidemiologia , Animais , Cestoides/classificação , Infecções por Cestoides/parasitologia , Infecções por Cestoides/veterinária , Ecologia , Ecossistema , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Especificidade de Hospedeiro , Estágios do Ciclo de Vida , Nematoides/classificação , Infecções por Nematoides/parasitologia , Infecções por Nematoides/veterinária , Densidade Demográfica , Prevalência , África do Sul/epidemiologia
18.
PLoS One ; 14(7): e0218681, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31291262

RESUMO

Rural children are one of the populations that are most vulnerable to gastrointestinal parasite infections. Such diseases decrease the quality of life and result in growth and cognitive delays in the long term. This cross-sectional study was conducted to determine the frequency of intestinal parasite infections among rural schoolchildren in the municipality of Apulo, Colombia. A total of 97 stool samples from children aged between 5 and 15 years were collected and examined via direct light microscopy. Microscopic examination was repeated with sediments obtained using a fecal parasite concentrator, and the Kato-Katz test was performed. Frequency of intestinal parasite infection was 100%. Endolimax nana (77.35%), Blastocystis sp. (71.1%), Giardia intestinalis (39.1%), Entamoeba coli (25.7%), and the Entamoeba histolytica/dispar/moshkovskii complex (9.2%) were the most prevalent protozoa. Trichuris trichiura was the most prevalent helminth (12.3%), followed by Enterobius vermicularis (6.15%) and Ascaris lumbricoides (5.1%). Among the analyzed associated factors, consumption of untreated water increased the risk of acquiring pathogenic intestinal parasites. Finally, because G. intestinalis was the most prevalent pathogenic protozoan, molecular analysis was conducted to establish genetic assemblages and subassemblages of Giardia through sequence-based genotyping of the glutamate dehydrogenase, triose phosphate isomerase, and beta-giardin genes. A total of 14 G. intestinalis-positive samples were genotyped, which revealed the presence of subassemblages AI (n = 1), AII (n = 7), BIII (n = 2), BIV (n = 2), and BIII/BIV (n = 1) as well as a mixed subassemblage AII + BIII (n = 1). Our results indicate that gastrointestinal parasite infections in the tested population were mainly caused by suboptimal water quality. Moreover, molecular typing of G. intestinalis suggested contamination of water by animal- and human-derived cysts.


Assuntos
Água Potável/parasitologia , Fezes/parasitologia , Infecções por Nematoides/epidemiologia , Infecções por Protozoários/epidemiologia , Adolescente , Animais , Ascaris lumbricoides/classificação , Ascaris lumbricoides/isolamento & purificação , Blastocystis/classificação , Blastocystis/isolamento & purificação , Criança , Pré-Escolar , Colômbia/epidemiologia , Estudos Transversais , Endolimax/classificação , Endolimax/isolamento & purificação , Entamoeba/classificação , Entamoeba/isolamento & purificação , Enterobius/classificação , Enterobius/isolamento & purificação , Feminino , Giardia lamblia/classificação , Giardia lamblia/genética , Giardia lamblia/isolamento & purificação , Humanos , Higiene , Masculino , Infecções por Nematoides/parasitologia , Infecções por Nematoides/transmissão , Prevalência , Infecções por Protozoários/parasitologia , Infecções por Protozoários/transmissão , Qualidade de Vida , População Rural , Trichuris/classificação , Trichuris/isolamento & purificação
19.
J Dairy Sci ; 102(9): 8251-8263, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31326168

RESUMO

Information is scarce regarding the epidemiology of gastrointestinal nematodes in Canadian dairy heifers. The objectives of this study were to estimate the prevalence and fecal egg counts of gastrointestinal nematodes in dairy heifers, and using a novel deep-amplicon sequencing approach, to identify the predominant gastrointestinal nematode species in Canadian dairy replacement heifers. Fresh environmental fecal samples (n = 2,369) were collected from replacement heifers on 306 dairy farms across western Canada, Ontario, Québec, and Atlantic Canada. Eggs per gram of feces (EPG) were determined using a modified Wisconsin double-centrifugation sugar flotation technique. Predominant nematode species at the farm level were identified by deep-amplicon nemabiome sequencing of the internal transcribed spacer-2 rDNA locus of nematode third-stage larvae. Generalized estimating equations were used to estimate predicted parasite prevalence and mean EPG in all heifers and by province, allowing for clustering within herds. Individual heifer egg counts ranged from 0 to 141 EPG (median: 0 EPG; interquartile range: 0 to 71 EPG). Gastrointestinal nematodes were detected in 20.9% (95% confidence interval: 17.2 to 24.6%) of heifers, and the predicted mean strongylid EPG accounting for clustering on farms was 1.1 (95% confidence interval: 0.6 to 1.6). The predominant parasite species were Cooperia oncophora and Ostertagia ostertagi. This is the first study in Canada to use a combination of deep-amplicon nemabiome sequencing and a traditional egg count method to describe the epidemiology of gastrointestinal nematodes in dairy heifers.


Assuntos
Doenças dos Bovinos/epidemiologia , Fezes/parasitologia , Trato Gastrointestinal/parasitologia , Nematoides/classificação , Infecções por Nematoides/veterinária , Contagem de Ovos de Parasitas/veterinária , Animais , Canadá/epidemiologia , Bovinos , Feminino , Infecções por Nematoides/epidemiologia , Prevalência
20.
Trop Anim Health Prod ; 51(8): 2269-2278, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31152335

RESUMO

Natural compounds from medicinal plants provide safe and sustainable alternatives to synthetic anthelmintics. In this study, we assessed in vitro and in vivo anthelmintic activity of Cassia occidentalis (NH-A) and Euphorbia hirta (NH-B) and compared it with levamisole-HCl. The shoots of NH-A and whole plant of NH-B were used to prepare extracts using 70% methanol which were used in the in vitro and in vivo assays. In vitro assays of crude methanolic extracts (CMEs) of NH-A and NH-B on larvae of mixed gastrointestinal nematodes (GINs) of goats revealed mortalities of 95.7% (at 100 mg ml-1) and 98.1% (at 50 mgml-1) 24 h postexposure. In vivo assays of NH-A administered orally at doses of 100, 300, 900, and 2700 mg kg-1 bwt revealed dose- and time-dependent anthelmintic effects in goats experimentally infected with mixed species of GINs. NH-B exhibited similar properties when administered at doses of 50, 100, 200, and 400 mg kg-1 bwt. Both NH-A (900 mg kg-1 bwt) and levamisole (7.5 mg kg-1 bwt) achieved a 100% reduction in fecal egg count per gram (EPG) on day 21 and day 14 respectively posttreatment. NH-B (400 mg kg-1 bwt) achieved 93.1% and 86.1% reduction in fecal EPG 7 and 14 days postexposure respectively compared with 88.2% and 82.3% reduction with levamisole-HCl 7 and 14 days postexposure. Our results show that extracts of both plants can disrupt helminth lifecycles by suppressing the egg-laying capacity in adult worms but also kill their infective larvae. Future studies should aim at establishing synergies or antagonisms between the two plant extracts and further development for control of helminths in goats.


Assuntos
Anti-Helmínticos/uso terapêutico , Euphorbia/química , Doenças das Cabras/tratamento farmacológico , Infecções por Nematoides/veterinária , Extratos Vegetais/uso terapêutico , Senna (Planta)/química , Animais , Fezes/parasitologia , Doenças das Cabras/epidemiologia , Doenças das Cabras/parasitologia , Cabras , Levamisol , Nematoides , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas/veterinária , Extratos Vegetais/administração & dosagem , Uganda/epidemiologia
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