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Natural infestation of Hydrochoerus hydrochaeris by Amblyomma dubitatum ticks.  


Natural infestation of Amblyomma dubitatum in relation to individual specific attributes of Hydrochoerus hydrochaeris such as sex, body mass and body condition was analyzed. The anatomical distribution of A. dubitatum on H. hyrochaeris was also evaluated. Prevalence of adults and nymphs were significantly higher than prevalence of larvae. Non-significant differences in the infestation levels were found among host sex. Multiple regression analysis did not show any statistically significant association among the level of infestation with ticks and body mass and body condition of the host. All parasitic tick stages were collected in all five anatomical areas of the host, but they exhibited significant differences in feeding site preference. Factors associated to the host which determine the high levels of infestation with A. dubitatum could be assigned to a combination of population-level properties of the host as abundance, ubiquity and aggregation, rather than individual specific attributes related to body condition, body mass or sex. PMID:24469297

Debárbora, Valeria N; Mangold, Atilio J; Eberhardt, Ayelén; Guglielmone, Alberto A; Nava, Santiago



Differences in natural antibody titres comparing free-ranging guanacos (Lama guanicoe) and capybaras (Hydrochoerus hydrochaeris).  


Natural antibodies are an important component of innate humoral immunity but have not been investigated to any great extent in wild mammals. In the current study, serum natural antibody titres were measured by hemagglutination assay for two South American herbivores, the guanaco (Lama guanicoe) and the capybara (Hydrochoerus hydrochaeris). Results indicated that capybaras had antibody titres on average more than four times higher than guanacos (median titres 1:256 and 1:4, respectively), suggesting differences in investment in constitutive humoral immunity between the two species. PMID:24321369

Racca, Andrea L; Eberhardt, Ayelen T; Moreno, Pablo G; Baldi, Cecilia; Beldomenico, Pablo M



The capybara (Hydrochoerus hydrochaeris) as a reservoir host for Trypanosoma evansi.  


Discovery of two ill horses and three dogs naturally infected with Trypanosoma evansi near an experimental station in the Eastern Plains of Colombia led to a search for reservoir hosts of the parasite. Infection was detected in 8/33 healthy capybaras (Hydrochoerus hydrochaeris), none of the remaining 14 horses, and none of 32 Zebu cattle (Bos indicus), 18 paca (Cuniculus paca) and 20 spiny rats (Proechimys sp.). Contrary to common opinion, the results indicated a carrier state in the capybara. Diagnosis was based on morphology, behaviour in albino rats, and pathogenicity and host range in domestic animals. PMID:16502701

Morales, G A; Wells, E A; Angel, D



Rickettsial infection in capybaras (Hydrochoerus hydrochaeris) from São Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri  

Microsoft Academic Search

Introducción. En Brasil, los capibaras (Hydrochoerus hydrochaeris) son importantes huéspedes para garrapatas del género Amblyomma, las cuales transmiten rickettsiosis a humanos y animales. Por lo tanto, estos roedores pueden ser potenciales centinelas para detectar infección por rickettsia. Objetivos. Este trabajo evaluó la infección por rickettsia en capibaras de diferentes regiones del estado de São Paulo, donde las rickettsiosis nunca han

Richard C. Pacheco; Mauricio C. Horta; Jonas Moraes-Filho; Alexandre C. Ataliba; Adriano Pinter; Marcelo B. Labruna



Health evaluation and survey of zoonotic pathogens in free-ranging capybaras (hydrochoerus hydrochaeris).  


Abstract Capybaras (Hydrochoerus hydrochaeris) are the world's largest rodents and play an epidemiologic role in the transmission of zoonotic pathogens, including the causative agents of Brazilian spotted fever, leptospirosis, and others. We surveyed the health of 31 free-ranging capybaras at the Alberto Löfgren State Park, São Paulo, Brazil using a variety of diagnostic methods. Hematology and serum chemistry were consistent with mild malnutrition and parasitism but did not indicate severe physiologic imbalance or disease. All animals were serologically negative for Rickettsia rickettsii, Leishmania spp., and Trypanosoma sp., but antibodies against rabies virus (71%), Leptospira sp. (26%), and Toxoplasma sp. (23%) were detected. Salmonella sp. was not cultured from fecal samples. Frequently cultured enterobacteria included Escherichia coli (61%), Enterococcus casseiflavus (35%), Enterococcus faecalis (35%), Enterobacter aerogenes (32%), Klebisella pneumoniae (32%), and Serratia marcescens (32%). No potentially pathogenic fungi were cultured from hair samples. Fecal parasitology revealed infection by Protozoophaga sp. (58%), Viannella spp. (23%), Strongyloides spp. (10%), and Ancilostomatidae (10%). A total of 218 ticks was retrieved from the animals: Amblyomma sp. larvae and nymphs (43%), A. dubitatum adults (52%), and A. cajennense adults (5%). The capybaras were free from most potentially zoonotic pathogens evaluated; however, the presence of Amblyomma spp. ticks (potential vectors of Rickettsia spp.) and indirect evidence of exposure to the rabies virus, Leptospira sp., and Toxoplasma sp. warrant the maintenance of public health programs and wildlife health monitoring. PMID:24779462

Chiacchio, Rosely Gioia-Di; Prioste, Fabiola Eloisa Setim; Vanstreels, Ralph Eric Thijl; Knöbl, Terezinha; Kolber, Milton; Miyashiro, Samantha Ive; Matushima, Eliana Reiko



Primary isolation of spotted fever group rickettsiae from Amblyomma cooperi collected from Hydrochaeris hydrochaeris in Brazil.  


This paper reports the first isolation of a spotted fever group rickettsia from an Amblyomma cooperi ixodid collected from a capybara (Hydrochaeris hydrochaeris) in an endemic area of spotted fever in the County of Pedreira, State of São Paulo, Brazil. Isolation was performed in Vero cell culture and submitted to immunofluorescence, using antibody from Rickettsia rickettsii-positive human serum. PMID:9040845

de Lemos, E R; Melles, H H; Colombo, S; Machado, R D; Coura, J R; Guimarães, M A; Sanseverino, S R; Moura, A



[Diet of the capybara Hydrochaeris hydrochaeris (Rodentia: Hydrocharidae) in Caño Limón, Arauca, Colombia].  


We studied the composition and seasonal variation of the diet of the capybara (Hydrochaeris hydrochaeris) in the flooded savannas of Caño Limón, Colombia. This was achieved by direct observation of the consumption patterns of these animals. The capybaras only consumed plants, and their diet included 89 species of 22 families. Sixty three percent of these plant species had not been reported before. The most commonly consumed plants (94% of the diet), belonged to the Poaceae, Cyperaceae, Leguminosae and Pontederiaceae. Only seven species represented 60% of the total diet: the grasses Hymenachne amplexicaulis (16.9%), Digitaria bicornis (4.5%) and Panicum maximum (4.4%) and the Cyperaceae Rynchospora corymbosa (4.4%). There was seasonal variation in the diet composition of capybaras. PMID:15162750

Forero-Montaña, Jimena; Betancur, Julio; Cavelier, Jaime



Observations of sylvatic rabies in Northern Argentina during outbreaks of paralytic cattle rabies transmitted by vampire bats (Desmodus rotundus).  


During rabies outbreaks in cattle (paralytic rabies) in Argentina associated with the common vampire bat Desmodus rotundus, rabies was observed in marsh deer (Blastocerus dichotomus), red brocket deer (Mazama americana), capybara (Hydrochoerus hydrochaeris), savanna fox (Cerdocyon thous), and great fruit-eating bat (Artibeus lituratus). Rabies could constitute a threat to the survival of marsh deer in places where they live in small groups, and infection of both great fruit-eating bats and savanna fox represent a risk for humans; both species exhibit aggressiveness and fury when infected. PMID:19901391

Delpietro, H A; Lord, R D; Russo, R G; Gury-Dhomen, F



Growth and development of the placenta in the capybara (Hydrochaeris hydrochaeris)  

PubMed Central

Background The guinea pig is an attractive model for human pregnancy and placentation, mainly because of its haemomonochorial placental type, but is rather small in size. Therefore, to better understand the impact of body mass, we studied placental development in the capybara which has a body mass around 50 kg and a gestation period of around 150 days. We paid attention to the development of the lobulated arrangement of the placenta, the growth of the labyrinth in the course of gestation, the differentiation of the subplacenta, and the pattern of invasion by extraplacental trophoblast. Methods Material was collected from six animals at pregnancy stages ranging from the late limb bud stage to mid gestation. Methods included latex casts, standard histology, immunohistochemistry for cytokeratin, vimentin, alpha-smooth muscle actin, and proliferating cell nuclear antigen as well as transmission electron microscopy. Results At the limb bud stage, the placenta was a pad of trophoblast covered by a layer of mesoderm from which fetal vessels were beginning to penetrate at folds in the surface. By 70 days, the placenta comprised areas of labyrinth (lobes) separated by interlobular areas. Placental growth resulted predominantly from proliferation of cellular trophoblast situated in nests at the fetal side of the placenta and along internally directed projections on fetal mesenchyme. Additional proliferation was demonstrated for cellular trophoblast within the labyrinth. Already at the limb bud stage, there was a prominent subplacenta comprising cellular and syncytial trophoblast with mesenchyme and associated blood vessels. At 90 days, differentiation was complete and similar to that seen in other hystricognath rodents. Overlap of fetal vessels and maternal blood lacunae was confirmed by latex injection of the vessels. At all stages extraplacental trophoblast was associated with the maternal arterial supply and consisted of cellular trophoblast and syncytial streamers derived from the subplacenta. Conclusion All important characteristics of placental development and organization in the capybara resembled those found in smaller hystricognath rodents including the guinea pig. These features apparently do not dependent on body size. Clearly, placentation in hystricognaths adheres to an extraordinarily stable pattern suggesting they can be used interchangeably as models of human placenta.

Kanashiro, Claudia; Santos, Tatiana C; Miglino, Maria Angelica; Mess, Andrea M; Carter, Anthony M



Assessment of historical fecal contamination in Curitiba, Brazil, in the last 400years using fecal sterols.  


A 400-year sedimentary record of the Barigui River was investigated using fecal biomarkers and nutrient distribution. The temporal variability in cholesterol, cholestanol, coprostanol, epicoprostanol, stigmastanol, stigmasterol, stigmastenol, sitosterol, and campesterol between 1600 and 2011 was assessed. Anthropogenic influences, such as deforestation and fecal contamination from humans and livestock, were observed from 1840. The sterol ratios exhibit evidence of hens, horses, cows, and an unknown herbivore, which may be a capybara (Hydrochoerus hydrochaeris), from 1820 and has been observed more markedly from 1970 onward. Human fecal contamination was detected from 1840 and was observed more markedly from 1930 due to population growth. Thus, the sanitation conditions and demographic growth of Curitiba seemed to be the main factors of human sewage pollution, as the coprostanol concentration over time was strongly correlated with the population growth (r=0.71, p<0.001) although diagenetic processes have also been observed.(1.) PMID:25016471

Machado, Karina S; Froehner, Sandro; Sánez, Juan; Figueira, Rubens C L; Ferreira, Paulo A L



New tick records in Rondônia, Western Brazilian Amazon.  


In the present study, we provide new tick records from Vilhena Municipality, in the Southeast of the State of Rondônia, Northern Brazil. Ticks collected from a capybara, Hydrochoerus hydrochaeris (Linnaeus), were identified as Amblyomma romitii Tonelli-Rondelli (1 female), and Amblyomma sp. (1 larva). Ticks collected from a harpy eagle, Harpia harpyja (Linnaeus), were identified as Amblyomma cajennense (Fabricius) (16 nymphs) and Haemaphysalis juxtakochi Cooley (1 nymph). Ticks collected from a yellow-footed tortoise, Chelonoidis denticulada (Linnaeus), were identified as Amblyomma rotundatum Koch (10 females, 2 nymphs), and Amblyomma sp. (2 larvae). The present record of A. romitii is the first in the State of Rondônia, and represents the southernmost record for this tick species, indicating that its distribution area is much larger than currently recognized. Although both A. cajennense and H. juxtakochi have been reported parasitizing various bird species, we provide the first tick records on a harpy eagle. A. rotundatum is widespread in the State of Rondônia, and has been previously reported on the yellow-footed tortoise. The present records increase the tick fauna of Rondônia to 26 species. PMID:20943027

Labruna, Marcelo Bahia; Barbieri, Fábio Silva; Martins, Thiago Fernandes; Brito, Luciana Gatto; Ribeiro, Francisco Dimas Sales



Intra-phylum and inter-phyla associations among gastrointestinal parasites in two wild mammal species.  


A growing body of literature reveals that the interactions among the parasite community may be strong and significant for parasite dynamics. There may be inter-specific antagonistic interactions as a result of competition and cross-effective immune response, or synergistic interactions where infection by one parasite is facilitated by another one, either by an impoverishment of the host's defenses, parasite-induced selective immunosuppression, or trade-offs within the immune system. The nature of these interactions may depend on how related are the parasite species involved. Here we explored the presence of associations among gastrointestinal parasites (coccidia and helminths) in natural populations of two wild mammal species, the capybara (Hydrochoerus hydrochaeris) and the guanaco (Lama guanicoe). The associations explored were between the oocyst outputs of a selected Eimeria species and the other coccidia of that parasite community, and between Eimeria spp. and the predominant nematodes. The statistical analysis included adjustment for potential confounders or effect modifiers. In guanacos, the prevailing interactions were synergistic among the coccidia and between coccidia and nematodes (Nematodirus spp.). However, in capybaras, the interaction between nematodes (Viannaiidae) and Eimeria spp. depended on environmental and host factors. The relationship was positive in some circumstances (depending on season, year, sex, or animal size), but it appeared to become antagonistic under different scenarios. These antagonist interactions did not follow a particular seasonal pattern (they occurred in autumn, spring, and summer), but they were predominantly found in females (when they depended on sex) or in 2010 and 2011 (when they depended on the sampling year). These results suggest that the relationship between coccidia and nematodes in capybaras may be context dependent. We propose that the context-dependent immune investment documented in capybaras may be the cause of these varying interactions. PMID:23820605

Moreno, P G; Eberhardt, M A T; Lamattina, D; Previtali, M A; Beldomenico, P M



Seasonal dynamics and hosts of Amblyomma triste (Acari: Ixodidae) in Argentina.  


The seasonal dynamics and host usage of Amblyomma triste in Argentina were analyzed. Adults of A. triste were present from early winter to mid-summer, with the peak of abundance from late winter to mid-spring (August to October). Larvae and nymphs were found from December to June, with the peak of abundance in summer. There were no differences among the biological parameters (pre-moult period of larvae and nymphs, pre-oviposition period of females, and minimum incubation period of eggs) of engorged ticks exposed to different photoperiod regimens at the laboratory, but the periods for each biological parameter obtained from ticks exposed in the field were significantly longer than those from the laboratory. Field results fit better with the data of seasonal distribution of each stage. Morphogenetic diapause was not detected, but complementary studies should test the presence of behavioral diapause. Rodents of the subfamily Sigmodontinae (Akodon azarae, Oligoryzomys flavescens, Oligoryzomys nigripes, Oxymycterus rufus and Scapteromys aquaticus) are the principal hosts for immature stages of A. triste, the caviid Cavia aperea could be another potential host for these stages, and birds are exceptional hosts for larvae and nymphs. Regarding hosts of adults in Argentina, domestic and wild large-sized mammals belonging to different orders (cattle, dog, horse, Blastocerus dichotomus and Hydrochoerus hydrochaeris) serve as hosts for adults of this tick species. In conclusion, A. triste has a life cycle of 1 year with adults feeding on large endemic and introduced mammals and immature stages using sigmodontine and caviid rodents as hosts. PMID:21536384

Nava, Santiago; Mangold, Atilio J; Mastropaolo, Mariano; Venzal, José M; Fracassi, Natalia; Guglielmone, Alberto A



Detection of Trypanosoma evansi infection in wild capybaras from Argentina using smear microscopy and real-time PCR assays.  


Trypanosoma evansi is a flagellated protozoan that parasitizes a wide variety of mammals, occasionally including humans. In South America, it infects horses, cattle, buffaloes, dogs and wild mammals, causing a disease known as "Mal de Caderas", which results in important economic losses due to a wide range of pathological expressions. Argentina represents the southern limit of its distribution. The capybara (Hydrochoerus hydrochaeris) is a large rodent found in tropical to temperate freshwater wetlands of South America. As capybaras infected with T. evansi present no clinical signs of disease, withstanding high parasitaemia, this species was proposed as a reservoir host. In this study we investigated the prevalence and parasitaemic intensity of T. evansi in samples obtained from 60 free-ranging capybaras of Esteros del Iberá (Corrientes province, northeastern Argentina) using smear microscopy and real-time PCR assays. All the cases of capybaras infected with T. evansi were found during one of the years studied, with no evidence of seasonality. The overall infection prevalence was 10%, but between years it ranged from 0% to 17% (in 2011). This is the first confirmation of T. evansi infection in Argentina by molecular biology techniques. Our results showed no differences between the methods used to detect the presence of T. evansi in capybaras, which indicates that simple methods like microscopy can generate important data on the ecoepidemiology of this parasite. Both techniques used in this study represent a viable tool for ecoepidemiological studies, and can be used to produce good estimates of prevalence and parasitaemic level of the infection, which inform for the implementation of strategies for the control of the disease. PMID:24636712

Eberhardt, A T; Monje, L D; Zurvera, D A; Beldomenico, P M



Terrestrial and aquatic mammals of the Pantanal.  


Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1) to establish the ecotone limit between the floodplain (which is the Pantanal) and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2) the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3) the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant--for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare--for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened as in danger. PMID:21537603

Alho, C J R; Camargo, G; Fischer, E



Non-legalized commerce in game meat in the Brazilian Amazon: a case study.  


In tropical forests, wild game meat represents an option or the only protein source for some human populations. This study analyzed the wildlife meat trade destined to human consumption in an open market of the Amazon rainforest, Brazil. Wildlife meat trade was monitored during 2005 through interviews to vendors and consumers in order to evaluate the socioeconomic profile of the sellers, the main species and byproducts sold, their geographical origin, commercial value, frequency of sale and product demand. Data indicated that vendors were financially highly dependant of this activity, getting a monthly income up to US$271.49. During the survey, the amount of wildlife meat on sale added a total of 5 970kg, as follows: 63.2% capybara (Hydrochoerus hydrochaeris), 34.4% cayman (Melanosuchus niger and/or Caiman crocodilus crocodilus), 1.1% paca (Cuniculus paca); 0.6% armadillo (Dasypus novemcinctus), 0.5% deer (Mazama americana), 0.2% matamata (Chelus fimbriatus), and 0.1% opossum (Didelphis marsupialis). Most of the commercialized species were not slaughtered locally. The consumption of wildlife meat was admitted by 94% of the interviewed, consisting of 27 ethno-species: 19 mammals, 6 reptiles, and 2 birds. The same percentage of the interviewed (94%) already bought wildlife meat of 18 species: 12 mammals and 6 reptiles. The great amount of wildlife meat traded and the important demand for these products by the local population, point out the necessity to adopt policies for a sustainable management of cinegetic species, guaranteeing the conservation of the environment, the improvement of living standards, and the maintenance of the local culture. PMID:20737856

Baía Jr, Pedro Chaves; Guimarães, Diva Anelie; Le Pendu, Yvonnick



Rickettsial infection in ticks collected from road-killed wild animals in Rio de Janeiro, Brazil.  


During 2008-2010, ticks were collected from road-killed wild animals within the Serra dos Orgãos National Park area in the state of Rio de Janeiro, Brazil. In total, 193 tick specimens were collected, including Amblyomma dubitatum Neumann and Amblyomma cajennense (F.) from four Hydrochoerus hydrochaeris (L.), Amblyomma calcaratum Neumann and A. cajennense from four Tamandua tetradactyla (L.), Amblyomma aureolatum (Pallas) and A. cajennense from five Cerdocyon thous L., Amblyomma longirostre (Koch) from one Sphiggurus villosus (Cuvier), Amblyomma varium Koch from three Bradypus variegatus Schinz, and A. cajennense from one Buteogallus meridionalis (Latham). Molecular analyses based on polymerase chain reaction targeting two rickettsial genes (gltA and ompA) on tick DNA extracts showed that 70.6% (12/17) of the A. dubitatum adult ticks, and all Amblyomma sp. nymphal pools collected from capybaras were shown to contain rickettsial DNA, which after DNA sequencing, revealed to be 100% identical to the recently identified Rickettsia sp. strain Pampulha from A. dubitatum ticks collected in the state of Minas Gerais, Brazil. Phylogenetic analysis with concatenated sequences (gltA-ompA) showed that our sequence from A. dubitatum ticks, referred to Rickettsia sp. strain Serra dos Orgãos, segregated under 99% bootstrap support in a same cluster with Old World rickettsiae, namely R. tamurae, R. monacensis, and Rickettsia sp. strain 774e. Because A. dubitatum is known to bite humans, the potential role of Rickettsia sp. strain Serra dos Orgãos as human pathogen must be taken into account, because both R. tamurae and R. monacencis have been reported infecting human beings. PMID:23270184

Spolidorio, Mariana G; Andreoli, Guilherme S; Martins, Thiago F; Brandão, Paulo E; Labruna, Marcelo B



Hosts, distribution and genetic divergence (16S rDNA) of Amblyomma dubitatum (Acari: Ixodidae).  


We supply information about hosts and distribution of Amblyomma dubitatum. In addition, we carry out an analysis of genetic divergence among specimens of A. dubitatum from different localities and with respect to other Neotropical Amblyomma species, using sequences of 16S rDNA gene. Although specimens of A. dubitatum were collected on several mammal species as cattle horse, Tapirus terrestris, Mazama gouazoubira, Tayassu pecari, Sus scrofa, Cerdocyon thous, Myocastor coypus, Allouata caraya, Glossophaga soricina and man, most records of immature and adult stages of A. dubitatum were made on Hydrochoerus hydrochaeris, making this rodent the principal host for all parasitic stages of this ticks. Cricetidae rodents (Lundomys molitor, Scapteromys tumidus), opossums (Didelphis albiventris) and vizcacha (Lagostomus maximus) also were recorded as hosts for immature stages. All findings of A. dubitatum correspond to localities of Argentina, Brazil, Paraguay and Uruguay, and they were concentrated in the Biogeographical provinces of Pampa, Chaco, Cerrado, Brazilian Atlantic Forest, Parana Forest and Araucaria angustifolia Forest. The distribution of A. dubitatum is narrower than that of its principal host, therefore environmental variables rather than hosts determine the distributional ranges of this tick. The intraspecific genetic divergence among 16S rDNA sequences of A. dubitatum ticks collected in different localities from Argentina, Brazil and Uruguay was in all cases lower than 0.8%, whereas the differences with the remaining Amblyomma species included in the analysis were always bigger than 6.8%. Thus, the taxonomic status of A. dubitatum along its distribution appears to be certain at the specific level. PMID:20084537

Nava, Santiago; Venzal, José M; Labruna, Marcelo B; Mastropaolo, Mariano; González, Enrique M; Mangold, Atilio J; Guglielmone, Alberto A



Sustainability of a constructed wetland faced with a depredation event.  


A free water surface constructed wetland (CW) designed for effluent treatment was dominated by the emergent macrophyte Typha domingensis reaching a cover of roughly 80% for 5 years. Highly efficient metal and nutrient removal was reported during this period. In June 2009, a population of approximately 30 capybaras (Hydrochoerus hydrochaeris) caused the complete depredation of the aerial parts of macrophytes. However, plant roots and rhizomes were not damaged. After depredation stopped, T. domingensis showed a luxuriant growth, reaching a cover of 60% in 30 days. The objective of this work was to evaluate the sustainability of the CW subjected to an extreme event. Removal efficiency of the system was compared during normal operation, during the depredation event and over the subsequent recovery period. The CW efficiently retained contaminants during all the periods studied. However, the best efficiencies were registered during the normal operation period. There were no significant differences between the performances of the CW over the last two periods, except for BOD. The mean removal percentages during normal operation/depredation event/recovery period, were: 84.9/73.2/74.7% Cr; 66.7/48.0/51.2% Ni; 97.2/91.0/89.4% Fe; 50.0/46.8/49.5% Zn; 81.0/84.0/80.4% NO3(-); 98.4/93.4/84.1% NO2(-); 73.9/28.2/53.2% BOD and 75.4/40.9/44.6% COD. SRP and TP presented low removal efficiencies. Despite the anoxic conditions, contaminants were not released from sediment, accumulating in fractions that proved to be stable faced with changes in the operating conditions of the CW. T. domingensis showed an excellent growth response, consequently the period without aerial parts lasted a few months and the CW could recover its normal operation. Plants continued retaining contaminants in their roots and the sediment increased its retention capacity, balancing the operating capacity of the system. This was probably due to the fact that the CW had reached its maturity, with a complete root-rhizome development. These results demonstrated that faced with an incidental problem, this mature CW was capable of maintaining its efficiency and recovering its vegetation, demonstrating the robustness of these treatment systems. PMID:23694854

Maine, M A; Hadad, H R; Sánchez, G C; Mufarrege, M M; Di Luca, G A; Caffaratti, S E; Pedro, M C



Life cycle and host specificity of Amblyomma triste (Acari: Ixodidae) under laboratory conditions  

Microsoft Academic Search

We report biological data of two generations of Amblyomma triste in laboratory and compared the suitability of different host species. Infestations by larval and nymphal stages were performed\\u000a on guinea pigs (Cavia porcellus), chickens (Gallus gallus), rats (Rattus norvegicus), rabbits (Oryctolagus cuniculus), wild mice (Calomys callosus), dogs (Canis familiaris) and capybaras (Hydrochaeris hydrochaeris). Infestations by adult ticks were performed on

Marcelo B. Labruna; Eric Y. M. Fugisaki; Adriano Pinter; José Maurício B. Duarte; Matias J. P. Szabó



Ticks (Acari: Ixodidae) on wild animals from the Porto-Primavera Hydroelectric power station area, Brazil.  


From June 2000 to June 2001, a total of 741 ticks were collected from 51 free-living wild animals captured at the Porto-Primavera Hydroelectric power station area, located alongside an approximately 180 km course of the Paran river, between the states of S o Paulo and Mato Grosso do Sul, comprising 9 species of 3 genera: Ambly-omma (7 species), Boophilus (1) and Anocentor (1). A total of 421 immature Amblyomma ticks were reared in laboratory until the adult stage, allowing identification of the species. A. cajennense was the most frequent tick species (mostly immature stages) collected on 9 host species: Myrmecophaga tridactyla, Tamandua tetradactyla,Cerdocyon thous, Puma concolor,Tayassu tajacu, Mazama gouazoubira,Hydrochaeris hydrochaeris,Alouatta caraya, Cebus apella. Other tick species were less common, generally restricted to certain host taxa. PMID:12563479

Labruna, Marcelo B; de Paula, Cátia D; Lima, Thiago F; Sana, Dênis A



Report on ticks collected in the Southeast and Mid-West regions of Brazil: analyzing the potential transmission of tick-borne pathogens to man.  


Specimens of ticks were collected in 1993, 1996, 1997, and 1998, mostly from wild and domestic animals in the Southeast and Mid-West regions of Brazil. Nine species of Amblyommidae were identified: Anocentor nitens, Amblyomma cajennense, Amblyomma ovale, Amblyomma fulvum, Amblyomma striatum, Amblyomma rotundatum, Boophilus microplus, Boophilus annulatus, and Rhipicephalus sanguineus. The potential of these tick species as transmitters of pathogens to man was analyzed. A Flaviviridade Flavivirus was isolated from Amblyomma cajennense specimens collected from a sick capybara (Hydrochaeris hydrochaeris). Amblyomma cajennense is the main transmitter of Rickettsia rickettsii (=R. rickettsi), the causative agent of spotted fever in Brazil. Wild mammals, mainly capybaras and deer, infested by ticks and living in close contact with cattle, horses and dogs, offer the risk of transmission of wild zoonosis to these domestic animals and to man. PMID:10881097

Figueiredo, L T; Badra, S J; Pereira, L E; Szabó, M P



Ticks infesting wildlife species in northeastern Brazil with new host and locality records.  


From September 2008 to March 2010, 397 ticks (315 larvae, 33 nymphs, 23 females, and 26 males) were collected from captive and free-living wildlife species in northeastern Brazil. Six tick species were identified, including Amblyomma auricularium (Conil) on Tamandua tetradactyla (L.), Amblyomma dubitatum Neumann on Hydrochaeris hydrochaeris (L.), Nectomys rattus (Pelzen) and T. tetradactyla, Amblyomma parvum Aragão on T. tetradactyla, Amblyomma rotundatum Koch on Boa constrictor L., Chelonoidis carbonaria (Spix), Kinosternon scorpioides (L.) and Rhinella jimi (Stevaux), Amblyomma oarium Koch on Bradypus variegatus Schinz, and Rhipicephalus sanguineus (Latreille) on Lycalopex vetulus (Lund). Nectomys rattus and T. tetradactyla are new hosts for A. dubitatum. This study extends the known distribution ofA. dubitatum in South America and provides evidence that its geographical range has been underestimated because of the lack of research. Four (A. dubitatum, A. parvum, A. rotundatum, and R. sanguineus) of six tick species identified in this study have previously been found on humans in South America, some of them being potentially involved in the transmission of pathogens of zoonotic concern. PMID:21175080

Dantas-Torres, Filipe; Siqueira, Daniel B; Rameh-De-Albuquerque, Luciana C; Da Silva E Souza, Denisson; Zanotti, Alexandre P; Ferreira, Débora R A; Martins, Thiago F; De Senna, Michelle B; Wagner, Paulo G C; Da Silva, Marcio A; Marvulo, Maria F V; Labruna, Marcelo B



Response of wild mammals to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal, Brazil.  


The Pantanal is a large savanna wetland (138,183 km2 in Brazil), important for its wildlife, fed by tributaries of the upper Paraguay River, center of South America (Brazil, touching Bolivia and Paraguay). Uplands are plateaus (250-1,200 m high, 215,000 km2 in Brazil) and flatland is the Pantanal (80-150 m high, 147,574 km2 in Brazil). Rivers are slow moving when they meet the flatland (slope 0.3-0.5 m/km east-west; 0.03-0.15 m/km north-south), periodically overflowing their banks, creating a complex seasonal habitat range. Recurrent shallow flooding occupies 80% of the Pantanal; during the dry season flooded areas dry up. Fluctuating water levels, nutrients and wildlife form a dynamic ecosystem. A flooding regime forms distinct sub-regions within the Pantanal. A mammal survey was carried out in the sub-region of the Rio Negro from April, 2003 through March, 2004 to study the diversity and abundance of terrestrial mammals during the dry and flooding seasons. A total of 36 species were observed in the field. The capybara Hydrochaeris hydrochaeris was the most frequent species, followed by the crab-eating-fox Cerdocyon thous and the marsh deer Blastocerus dichotomus. The highest abundance of species was observed during the dry season (August and September), when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Animal abundance (in terms of observed individual frequencies) varied during the dry and wet seasons and the seasonally flooded grassland was the most utilized habitat by mammals in the dry season. PMID:17299935

Mamede, S B; Alho, C J R



Molecular detection of Leishmania spp. in road-killed wild mammals in the Central Western area of the State of S?o Paulo, Brazil  

PubMed Central

Background Road-killed wild animals have been classified as sentinels for detecting such zoonotic pathogens as Leishmania spp., offering new opportunities for epidemiological studies of this infection. Methods This study aimed to evaluate the presence of Leishmania spp. and Leishmania chagasi DNA by PCR in tissue samples (lung, liver, spleen, kidney, heart, mesenteric lymph node and adrenal gland) from 70 road-killed wild animals. Results DNA was detected in tissues of one Cavia aperea (Brazilian guinea pig), five Cerdocyon thous (crab-eating fox), one Dasypus septemcinctus (seven-banded armadillo), two Didelphis albiventris (white-eared opossum), one Hydrochoerus hydrochoeris (capybara), two Myrmecophaga tridactyla (giant anteater), one Procyon cancrivorus (crab-eating raccoon), two Sphiggurus spinosus (porcupine) and one Tamandua tetradactyla (lesser anteater) from different locations in the Central Western part of São Paulo state. The Leishmania chagasi DNA were confirmed in mesenteric lymph node of one Cerdocyon thous. Results indicated common infection in wild animals. Conclusions The approach employed herein proved useful for detecting the environmental occurrence of Leishmania spp. and L. chagasi, as well as determining natural wild reservoirs and contributing to understand the host-parasite interaction.



Foot-and-mouth disease in the Americas: epidemiology and ecologic changes affecting distribution.  


Foot-and-mouth disease(FMD) was first recorded in South America (SA) circa 1870, in Buenos Aires, Argentina, in Uruguay, and in southern Brazil as a result of the introduction of cattle from Europe during the early days of colonization. Livestock production to trade with neighboring countries was established in the La Plata Region, and the trade of livestock and products with Chile, northeastern and central western states of Brazil, to Peru, Bolivia, and Paraguay spread FMD, which reached Venezuela and Colombia in the 1950s and finally Ecuador in 1961. The traditional forms of livestock husbandry influence the diffusion and maintenance of the FMD virus (FMDV) in different areas. Cattle production in SA depends mainly on a strong relation between cattle-calf operations and fattening operations in a complementary cycle, revealing the vulnerability and susceptibility of these areas to FMDV. Understanding the relationship between time-space behavior of the disease and the forms of production defines the FMD ecosystems, a key concept to elaborating the control/eradication strategies of national FMD eradication programs, which must be modified when trade opportunities between zones of differing sanitary status change. The role of other susceptible species besides bovines, including wildlife, in maintaining and spreading FMDV has been the subject of several studies, but in SA, bovines are so far considered to determine disease presentation. Buffalo (Bubalus bubalis) have been implicated in the spread of the disease between farms in at least one case in Brazil. Sheep are almost on a par with bovine in terms of number, especially in the Southern Cone, but their role in the maintenance of infection is not considered important, possibly owing to rearing practices. Camelid populations in the Andean region do not play an important role in the maintenance of FMD, because of short persistence of infection and low population densities in these species. The importance of wildlife is not clear, but it is accepted that animals are mostly affected as a spinoff during outbreaks in domestic species. Experimentally infected capybaras (Hydrochoerus hydrochoeris hydrochoeris) showed clinical signs and infected other susceptible species, but their role in the maintenance of infection in nature is so far not clear. PMID:15604472

Saraiva, Victor