Gerromorpha (Insecta: Hemiptera: Heteroptera) from the state of Rio Grande do Norte, northeastern Brazil, including a new synonymy.

A list of Gerromorpha species collected from 2016 to 2023 in the State of Rio Grande do Norte, northeastern Brazil, is presented. Previously, only five species had been recorded from this state. In the present study, based on the compilation of data and new collections, 27 species are recorded from the state, of which 23 represent new records. These species belong to 17 genera and five families: Brachymetra Mayr, 1865; Cylindrostethus Fieber, 1861; Halobates Eschscholtz, 1822; Halobatopsis Bianchi, 1896; Husseyella Herring, 1955; Limnogonus Stl, 1868; Microvelia Westwood, 1834; Neogerris Matsumura, 1913; Ovatametra Kenaga, 1942; Rheumatobates Bergroth, 1892 (Gerridae); Lipogomphus Berg, 1879 (Hebridae); Hydrometra Latreille, 1797 (Hydrometridae); Mesovelia Mulsant & Rey, 1852 (Mesoveliidae); Paravelia Breddin, 1898; Platyvelia Polhemus & Polhemus, 1993; Rhagovelia Mayr, 1865; Stridulivelia Hungerford, 1929 (Veliidae). All collected species are illustrated, and their distributions in the state of Rio Grande do Norte are represented in maps. Also, Neogerris celeris (Drake & Harris, 1934) is proposed here as a junior synonym of N. lotus (White, 1879); the lectotype of the latter is designated.

Philophthalmus gralli in domestic waterfowl: An environmental study in an urban area from Brazil.

Philophthalmosis is a zoonotic ocular disease that affects mainly domestic and wild avian species in different parts of the world. However, aspects related to its epizoology in domestic animals are not completely known. In the present study, 47 Muscovy duck (Cairina moschata), 8 mallards (Anas platyrhynchos platyrhynchos) and 6 African geese (Anser cygnoides), free-living in an urban lake in Belo Horizonte, Minas Gerais, Brazil, were evaluated for eye fluke infection. The animals were manually contained, and the conjunctival sac and nictitating membrane were evaluated by direct ophthalmic examination (DOE), in which the fluke burden was estimated by a semiquantitative scale. Moreover, the conjunctival sac lavage (CSL) technique was applied for the search of parasite eggs. When possible, the detected trematodes were carefully removed for fixed for taxonomic identification. In order to characterize the parasite-host-environmental system, malacological collections were performed at the locality, and the collected intermediate host mollusks (Melanoides tuberculata) were evaluated for infection with larval philophthalmids. In addition, wild vertebrates found dead in the locality, including one common gallinule (Gallinula galeata) and two capybaras (Hydrochoerus hydrochaeris), were necropsied for the search of eye flukes. Samples from the developmental stages obtained from the hosts were subjected to morphological and molecular studies (amplification and sequencing of a partial region of the Nad-1 gene). In the DOE, the presence of eye flukes was verified in 67% (4/6), 31% (15/47) and 25% (2/8) in geese, Muscovy ducks and mallards, respectively. In most cases, the birds showed mild parasitism (1-5 trematodes), with no apparent eye damage, characterizing a subclinical infection. In only one goose, which had a high fluke burden (20 trematodes), it was possible to obtain eggs by CSL. Regarding the malacological survey, 73/4545 (1.6%) specimens of M. tuberculata evaluated were found infected with megalurous cercariae, compatible with representatives of the family Philophthalmidae. Additionally, 147 flukes were recovered from a specimen of G. galeata found dead at the lake. The morphological and molecular study of parasites obtained from different hosts evaluated in this study enabled the identification of Philophthalmus gralli, a species native from Asia and introduced in the Americas. Factors such as the wide distribution of the intermediate host and the participation of domestic and wild reservoirs in the parasite transmission chain may favor the occurrence of parasite spillover from wild to domestic birds. Furthermore, the occurrence of the life cycle of P. gralli in an urban waterbody serves as an alert to the possibility of human cases of this zoonotic eye parasite.

First report of Melanoides tuberculata (Mollusca: Thiaridae) harboring a xiphidiocercaria in Brazil: A new parasite introduced in the Americas?

Xiphidiocercariae were found in the invasive snail Melanoides tuberculata collected during a malacological survey in Ceará-Mirim, State of Rio Grande do Norte, Northeastern Brazil in November 2018 and submitted to morphological and molecular analyses. The morphology revealed similarities between the larvae here reported for the first time in M. tuberculata from Brazil and other xiphidiocercariae described in thiarid snails from Asia and Africa. Phylogenetic analyses based on 28S and ITS-2 sequences revealed that the larvae correspond to an unidentified species of the family Lecithodendriidae. Aspects related to the morphology and taxonomy of xiphidiocercariae found in M. tuberculata are briefly discussed. It is possible that the parasite here reported is a newly introduced species transmitted by M. tuberculata in the American continent.

Molecular, morphological and experimental assessment of the life cycle of Posthodiplostomum nanum Dubois, 1937 (Trematoda: Diplostomidae) from Brazil, with phylogenetic evidence of the paraphyly of the genus Posthodiplostomum Dubois, 1936.

Species of the genus Posthodiplostomum are intestinal parasites of piscivorous birds with worldwide distribution. Recent molecular surveys have focused on developmental stages from vertebrate hosts, with few sequences from larvae found in molluscs. Moreover, most published molecular data are from collections in North America, Europe and Asia, and there are no data for South American species. In the present study, cercariae found in the freshwater limpet Gundlachia ticaga from Brazil were used for morphological, experimental and molecular studies. The longifurcate cercariae, Neascus-type metacercariae obtained in experimentally infected guppies (Poecilia reticulata), and an adult parasite recovered from a mouse were morphologically identified as Posthodiplostomum nanum. Sequences of DNA from internal transcribed spacer (ITS) rDNA and cytochrome c oxidase 1 (cox1) from the cercariae and metacercariae were compared with published data, yielding no matches (ITS divergence ≥ 5.5%, cox1 ≥ 13.9%). Phylogenetic analyses of the ITS sequences suggest paraphyly within the genus Posthodiplostomum, or misidentifications of parasites in molecular studies. For example, ITS sequences of Mesoophorodiplostomum pricei and Posthodiplostomum centrarchi or the unnamed species Posthodiplostomum sp. 8 diverge by only 1.1-1.2% and 0.6%, respectively, and all three species fall within a well-supported clade, suggesting that these isolates are congeneric. The phylogenetic tree obtained for cox1 sequences, although not well resolved, reveals that the type species of the genus, Posthodiplostomum cuticola, does not group with any species previously identified as Posthodiplostomum. Overall, the analyses of molecular data here obtained for P. nanum compared with sequences of related species suggest that a review of this group is necessary. Such studies may result in a split of the genus Posthodiplostomum and the transference of some species currently assigned in this genus to other already described genera.

Predicting the distribution of Omalonyx (Mollusca: Pulmonata: Succineidae) species from literature review, museum databases and new sampling efforts in Brazil / Predição da distribuição de Omalonyx (Mollusca: Pulmonata: Succineidae) a partir da revisão da literatura, dados de museu e novo esforço amostral no Brasil

Abstract Accurate distributional information is crucial for studies on systematics, biodiversity and conservation. To improve the knowledge regarding the geographical distribution of Omalonyx in South America, we present updated information based on data from a literature review, institutional collections and malacological surveys. All this information composed the dataset used to predict species distribution employing the Maximum Entropy Algorithm (MaxEnt). The model was run using data on species distribution, altitude and bioclimatic variables (WorldClim database). The model had consistent performance, and areas presenting similar conditions to areas where the species were recorded were considered areas of occurrence. The predicted occurrence areas included those that were already surveyed and those that are considered potential occurrence areas. The results demonstrate that the genus has widespread distribution in the Neotropical region and occurs in the tropical, temperate and arid regions of South America and Lesser Antilles. Omalonyx spp. were recorded in all South American countries and hydrographic regions. However, in some countries, there were only isolated records (ex: Colombia and Ecuador). Here, we also present the first record of Omalonyx spp. in four Brazilian States (Acre, Rondônia, Piaui, and Amapá). The genus was found in all hydrographic regions within Brazil and among 27 federative unities; it was absent from only two unities (Roraima State and Distrito Federal). This work contributes to the knowledge on Omalonyx spp. distribution and provides an important basis for the work of ecologists and taxonomists.

Resumo A informação precisa sobre a distribuição é crucial para os estudos sobre sistemática, biodiversidade e conservação. Para melhorar o conhecimento sobre a distribuição geográfica de Omalonyx na América do Sul, apresentamos informações atualizadas com base em dados de revisão de literatura, coleções institucionais e pesquisas malacológicas. Toda essa informação compôs o conjunto de dados usado para predição da distribuição de espécies empregando o Algoritmo de Entropia Máxima (MaxEnt). O modelo foi executado usando dados de distribuição de espécies, altitude e variáveis bioclimáticas (banco de dados WorldClim). O modelo apresentou um desempenho consistente e as áreas que apresentaram condições semelhantes às áreas onde as espécies foram registradas, foram consideradas áreas de ocorrência. As áreas de ocorrências previstas incluíram aquelas que já foram pesquisadas e aquelas que são consideradas áreas de ocorrência potencial. Os resultados demonstram que o gênero tem uma distribuição Neotropical ampla e que ocorre nas regiões tropical, temperada e árida da América do Sul e nas Pequenas Antilhas. Omalonyx spp. foram registradas em todos os países e bacias sul-americanas. No entanto, em alguns países, apenas registros isolados foram encontrados (ex: Colômbia e Equador). Aqui, também apresentamos o primeiro registro de Omalonyx spp. em quatro estados brasileiros (Acre, Rondônia, Piauí e Amapá). O gênero foi encontrado em todas as regiões hidrográficas no Brasil e nas 27 unidades federativas; sendo ausente em apenas duas unidades federativas (Estado de Roraima e Distrito Federal). Esse trabalho contribui para o conhecimento da distribuição das espécies de Omalonyx e fornece uma importante base para trabalhos de ecólogos e taxonomistas.

Evaluation of Kato-Katz and spontaneous sedimentation methods for the diagnosis of platynosomiasis in Neotropical primates / Avaliação dos métodos de sedimentação espontânea e Kato-Katz para o diagnóstico da platinossomose em primatas neotropicais

Platynosomiasis is a parasitic infection reported in non-human primates, including marmosets, and is frequently difficult to diagnose. In this study, the Kato-Katz method and the spontaneous sedimentation method were evaluated for their usefulness in identifying Platynosomum eggs in fecal samples from Callithrix penicillata that naturally harbor Platynosomum illiciens. Spontaneous sedimentation allowed the diagnosis of 41.7% (5/12) and 66.7% (8/12) of infected marmosets from one and three slides, respectively, prepared from the same fecal sample. The examination of a single Kato-Katz thick smear detected 83.3% (10/12) of infection cases. The analysis of feces on three different days increased the rate of diagnosis, since 75% (9/12) and 100% (12/12) of the primates with platynosomiasis were identified using serial spontaneous sedimentation (3 slides/day) and the Kato-Katz method, respectively. The mean number of Platynosomum eggs per gram of feces determined via the Kato-Katz method was 71.7 (8-240). The spontaneous sedimentation method when performed in series is acceptable for the diagnosis of platynosomiasis. However, the Kato-Katz method, which was here used for the first time to detect this infection, has a higher diagnostic sensitivity and the advantage that a quantitative analysis of the eggs released in the host feces is possible.

A platinossomose é uma infecção parasitária relatada em primatas não-humanos, inclusive saguis, cujo diagnóstico é frequentemente difícil. Neste estudo, os métodos de sedimentação espontânea e Kato-Katz foram avaliados quanto à sua utilidade na identificação de ovos de Platynosomum em amostras fecais de Callithrix penicillata naturalmente albergando Platynosomum illiciens. A sedimentação espontânea permitiu o diagnóstico de 41,7% (5/12) e 66,7% (8/12) dos saguis infectados a partir da análise de uma e três lâminas, respectivamente, preparadas de uma mesma amostra fecal. O exame de uma única lâmina de Kato-Katz detectou 83,3% (10/12) dos casos de infecção. A análise de fezes em três dias diferentes aumentou as taxas de diagnóstico, uma vez que 75% (9/12) e 100% (12/12) dos primatas que apresentaram a platinossomose foram identificados, usando-se a sedimentação espontânea (três lâminas/dia) e o Kato-Katz em série, respectivamente. O número médio de ovos de Platynosomum por g de fezes, determinado através do método de Kato-Katz, foi de 71,7 (8-240). O método de sedimentação espontânea, quando realizado em série, é aceitável para o diagnóstico da platinossomose. Entretanto, o método de Kato-Katz, o qual foi pela primeira vez usado para se detectar essa infecção, mostrou uma maior sensibilidade diagnóstica, com a vantagem de que é possível uma análise quantitativa dos ovos liberados nas fezes do hospedeiro.

Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism.

Eggs of Toxocara cati were found in the feces of Didelphis albiventris from a peridomestic urban environment in Brazil. Negative fecal tests following short-term captivity of the opossums, as well as the absence of ascaridids during necropsy, suggest the occurrence of pseudoparasitism. Implications of the findings for the epidemiology of toxocariasis are discussed.

Toxocara cati (Nematoda: Ascarididae) in Didelphis albiventris (Marsupialia: Didelphidae) from Brazil: a case of pseudoparasitism / Toxocara cati (Nematoda: Ascarididae) em Didelphis albiventris (Marsupialia: Didelphidae) do Brasil: um caso de pseudoparasitismo

Eggs of Toxocara cati were found in the feces of Didelphis albiventris from a peridomestic urban environment in Brazil. Negative fecal tests following short-term captivity of the opossums, as well as the absence of ascaridids during necropsy, suggest the occurrence of pseudoparasitism. Implications of the findings for the epidemiology of toxocariasis are discussed.

Ovos de Toxocara cati foram encontrados nas fezes de Didelphis albiventris oriundos de um ambiente peridomiciliar urbano no Brasil. A negatividade dos exames de fezes após um curto período de cativeiro dos gambás e a ausência de nematódeos ascaridídeos durante a necropsia sugerem a ocorrência de pseudoparasitismo. As implicações dos achados para a epidemiologia da toxocarose são discutidas.

Petasiger Dietz, 1909 (Trematoda: Echinostomatidae) in birds and mollusks from Brazil / Petasiger Dietz, 1909 (Trematoda: Echinostomatidae) em aves e moluscos do Brasil

Species of Petasiger Dietz, 1909 are intestinal trematodes of aquatic birds. Despite the diversity of described species in Europe and North America, only two South American species are known and no species have been previously reported in birds from Brazil. During a study of helminths recovered from the Least Grebe, Tachybaptus dominicus (Linnaeus, 1766), from the state of Minas Gerais, Brazil, adult trematodes identified as Petasiger novemdecim Lutz, 1928 were found. The prevalence of infection was 55% (5/9), and the mean intensity of infection was 8 (1-32) parasites. Additionally, Biomphalaria straminea (Dunker, 1848) and Biomphalaria tenagophila (d'Orbigny, 1835) obtained from aquatic collections in the same state were found to harbor two species of echinostome cercariae of the Magnacauda group. These cercariae developed into metacercariae in experimentally infected Poecilia reticulata Peters, 1859. Attempts to obtain adult parasites in vertebrate host models (mice, chickens, ducks and canaries) were unsuccessful. The present study is the first report of Petasiger in Brazilian birds and the first morphological description of larvae of these parasites in Brazilian mollusks. Taxonomic aspects related to South American species of Petasiger are discussed. It is suggested that, based on significant morphological differences observed in larval stages (i.e., larval dimensions) and adult parasites (i.e., disposition of the testes), Petasiger caribbensis Nassi, 1980 should be reconsidered as a distinct species from P. novemdecim.

Espécies do gênero Petasiger Dietz, 1909 são trematódeos intestinais de aves aquáticas. Apesar da diversidade de espécies descritas na Europa e América do Norte, somente duas espécies são conhecidas na América do Sul, e nenhuma espécie reportada previamente em aves do Brasil. Durante o estudo de helmintos recuperados de Mergulhão pequeno, Tachybaptus dominicus (Linnaeus, 1766), do estado de Minas Gerais, Brasil, trematódeos adultos identificados como Petasiger novemdecim Lutz, 1928 foram encontrados. A prevalência de infecção foi 55% (5/9) e a intensidade média de infecção 8 (1-32) parasitos. Adicionalmente, Biomphalaria straminea (Dunker, 1848) e Biomphalaria tenagophila (d'Orbigny, 1835) obtidas em coleções aquáticas do mesmo estado foram encontradas albergando duas espécies de cercárias do tipo equinóstoma pertencentes ao grupo Magnacauda. Estas cercárias desenvolveram-se em metacercárias em Poecilia reticulata Peters, 1859 experimentalmente infectados. Tentativas de obtenção de parasitos adultos em modelos experimentais (camundongos, frangos, patos e canários) demonstraram-se sem sucesso. O presente estudo é o primeiro relato de Petasiger em aves brasileiras e primeira descrição morfológica de larvas destes parasitos em moluscos do Brasil. Aspectos taxonômicos relacionados às espécies sul-americanas de Petasiger são discutidos. Sugere-se que, em vista das diferenças morfológicas observadas nos estágios larvais (i.e., dimensões das larvas) e dos parasitos adultos (i.e., disposição dos testículos), Petasiger caribbensis Nassi, 1980 seja reconsiderada espécie distinta de P. novemdecim.

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite.

INTRODUCTION: The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. METHODS: The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. RESULTS: Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235) of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644) and 13% (83/640), respectively. Thirteen (2%) specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. CONCLUSIONS: The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified.

The Pampulha reservoir remains a potential urban focus of schistosomiasis mansoni in Brazil: changes in the occurrence patterns of Biomphalaria species and a new record of the parasite

Introduction The Pampulha reservoir has long been a focus of schistosomiasis transmission in Belo Horizonte, State of Minas Gerais, Brazil. The last malacological study conducted in this urban reservoir was more than two decades ago, and thus, an update on the distribution of the species of Biomphalaria as well as new data on the presence of Schistosoma mansoni in this water body are required. Methods The current distribution of Biomphalaria spp. in the Pampulha reservoir and their infection with S. mansoni was evaluated during 55 malacological surveys conducted between 2009 and 2012. Results Biomphalaria straminea displayed a high population density and distribution, and 13.7% (2,233/16,235) of the specimens collected were infected with larval trematodes other than Schistosoma mansoni. Biomphalaria tenagophila and Biomphalaria glabrata, species currently presenting a restricted distribution and small populations, displayed trematode infection rates of 15.2% (98/644) and 13% (83/640), respectively. Thirteen (2%) specimens of B. glabrata were found to be infected with S. mansoni. In addition, a historical review based on previous and new data on the occurrence patterns of Biomphalaria species in this reservoir is presented. Conclusions The results indicate that the Pampulha reservoir remains a potential focus of urban schistosomiasis in Brazil, and significant changes in the occurrence patterns of Biomphalaria species were verified. .

Trypanoxyuris (Paraoxyuronema) lagothricis (Nematoda: Oxyuridae) in Lagothrix cana (Primates: Atelidae) from Brazil.

During necropsy of a specimen of Lagothrix cana (É. Geoffroy, 1812) (Primates: Atelidae) from the Brazilian Amazon, pinworms were found in the large intestine. The intensity of infection was 64 parasites (17 males and 47 females) and there were no gross pathological changes related to parasitism. After morphological analysis the parasites were identified as Trypanoxyuris (Paraoxyuronema) lagothricis (Buckley, 1931) (Nematoda: Oxyuridae). This is the first record of this oxyurid species in primates in Brazil.

Trypanoxyuris (Paraoxyuronema) lagothricis (Nematoda: Oxyuridae) in Lagothrix cana (Primates: Atelidae) from Brazil / Trypanoxyuris (Paraoxyuronema) lagothricis (Nematoda: Oxyuridae) em Lagothrix cana (Primates: Atelidae) no Brasil

During necropsy of a specimen of Lagothrix cana (É. Geoffroy, 1812) (Primates: Atelidae) from the Brazilian Amazon, pinworms were found in the large intestine. The intensity of infection was 64 parasites (17 males and 47 females) and there were no gross pathological changes related to parasitism. After morphological analysis the parasites were identified as Trypanoxyuris (Paraoxyuronema) lagothricis (Buckley, 1931) (Nematoda: Oxyuridae). This is the first record of this oxyurid species in primates in Brazil.

Durante a necropsia de Lagothrix cana (É. Geoffroy, 1812) (Primates: Atelidae) oriundo da Amazônia brasileira, oxiurídeos foram encontrados no intestino grosso. A intensidade de infecção foi de 64 parasitos (17 machos e 47 fêmeas), não havendo alterações patológicas macroscópicas relacionadas ao parasitismo. Após análise morfológica os parasitos foram identificados como Trypanoxyuris (Paraoxyuronema) lagothricis (Buckley, 1931) (Nematoda: Oxyuridae). Este é o primeiro relato desta espécie de oxiurídeo em primatas no Brasil.

Experimental infection of Swiss and AKR/J mice with Centrocestus formosanus (Trematoda: Heterophyidae).

In order to better understand the biology of Centrocestus formosanus in a definitive host model, mice of Swiss and AKR/J strains were experimentally infected with 100 metacercariae of the parasite. Fourteen days post-infection, the rodents were killed and adult trematodes were recovered from the small intestine. The percentage of parasite recovery from AKR/J mice (11.4%) was significantly higher than that from Swiss mice (5.3%). Moreover, trematodes recovered from the AKR/J strain were more developed and had greater fecundity. Peculiarities concerning the mice's immune system could explain the difference in susceptibility and in worm development seen in the present study. The data obtained confirm that mice are susceptible to infection with C. formosanus and indicate that the AKR/J strain provides a more favorable environment for parasite development.

New records and checklist of aquatic and semi-aquatic Heteroptera (Insecta: Hemiptera: Gerromorpha and Nepomorpha) from the Southern region of Mato Grosso do Sul, Brazil / Novos registros e checklist de Heteroptera semi-aquáticos e aquáticos (Insecta: Hemiptera: Gerromorpha e Nepomorpha) para o Sul do Estado do Mato Grosso do Sul, Brasil

A list of aquatic and semi-aquatic Heteroptera species from the southern region of Mato Grosso do Sul State is presented. The material was collected between 2008 and 2009. Samples were obtained from 10 streams (Água Boa, Cerro Verde, Cumprida, Ponte, Doradão, Guaçú, Guaporites, Nhu-Verá, Perobão and Santa Maria), one river (Iguatemi River) and nine ponds (Bacal, Balan, Ponte, Cinco, Macrófitas, Bugão, Sítio, Cascalho, and Oxbow). A total of 63 aquatic and semi-aquatic species of Heteroptera were recorded, of which 32 are new records.

Uma lista das espécies de Heteroptera aquáticos e semi-aquáticos para a região sul do Estado de Mato Grosso do Sul é apresentada. O material foi coletado entre 2008 e 2009. As amostras foram obtidas a partir de 10 córregos (Água Boa, Cerro Verde, Cumprida, Ponte, Doradão, Guaçú, Guaporites, Nhú-Verá, Perobão e Santa Maria), um rio (rio Iguatemi) e nove lagoas (Bacal, Balan, da Ponte, Cinco, Macrófitas, Bugão, Sítio, Cascalho, Oxbow). Um total de 63 espécies de heterópteros aquáticos e semi-aquáticos foram registrados, das quais 32 são novos registros.

Effects of benzodiazepine and ivermectin on Girardiatigrina (Platyhelminthes: Turbellaria) / Efeitos de benzodiazepínico e ivermectina em Girardia tigrina (Platyhelminthes: turbellaria)

Four hundred specimens of Girardia (=Dugesia) tigrina separated in groups of 5 were subjected to concentrations of 10, 25 and 50 ppm diazepam (DZP) and 1, 5 and 10 ppm of ivermectin (IVM), substances with actions associated with ionophore chlorine and GABA receptors in neuromuscular endings in various animals. The period of turbellarians exposure at different concentrations used was 3 h, for DZP while those to IVM were 30, 60, 120 minutes, 12 and 24 h for each tested concentration. In groups exposed to DZP hyperkinetic and type "C" and screw like movements were observed in all concentrations. However, at concentrations of 50 and 25 ppm, the pharynx was protruded in 100% of the specimens followed by detachment at concentration of 50 ppm and 60% at a concentration of 25 ppm. Mortality reached 100% 24 hours after exposure to a concentration of 50 ppm and 30% of planarians became degenerated at a concentration of 25 ppm. Planarians submitted to concentrations of 10 and 25 ppm remained alive and without hyperkinetic movements 48 hours after exposure. In IVM exposed groups, hyperkinetic and contractile movements were observed as well as type "C" screw like movements in all tested concentrations and time dependent. The group exposed for 24 hours showed a time dependent variation in mortality from 0 to 100%. The turbellarians were alive for 48 hours in 1 ppm during 12 hours of exposure but with 24 hours of exposure the mortality reaches 20%. The data indicate a time and concentration dependent relationship in the mode of action of these drugs.

Quatrocentos exemplares de Girardia (=Dugesia) tigrina separados em grupos de 5 foram submetidos a concentrações de 10, 25 e 50ppm de diazepam (DZP) e 1, 5 e 10ppm de ivermectina (IVM), substâncias com ações associadas ao ionóforo cloro e receptores GABA em terminações neuromusculares em vários animais. O tempo de exposição dos turbelários às diferentes concentrações utilizadas de DZP foi de 3 horas, enquanto para cada concentração de IVM os exemplares permaneceram expostos durante 30, 60, 120 minutos, 12 e 24 horas. Nos grupos expostos ao DZP foram verificados movimentos hipercinéticos tipo parafuso e tipo "C" e exposição da faringe ao exterior em todas as concentrações. Houve perda da faringe em 90% dos espécimes na concentração de 50ppm e 60% em 25ppm. Foi verificado também 100% de mortalidade após 24 horas em concentração de 50ppm e 30% de degeneração dos platyhelminthes na concentração de 25ppm. No exame realizado 48 horas após a exposição, as planárias submetidas às concentrações de 25 e 10 ppm permaneceram vivas e não mais apresentaram movimentos hipercinéticos. Nos grupos expostos à IVM, foram observados movimentos contráteis e movimentos hipercinéticos tipo parafuso e tipo "C" em todas as concentrações e foi dependente do tempo de exposição. O percentual de mortalidade variou de 0 a 100 nas primeiras 24 horas de observação também dependente do tempo de exposição. Em concentração de 1 ppm e até 12 horas de exposição não foi observada mortalidade dos animais até 48 horas após. Entretanto com 24 horas de exposição e exame 24 horas após a mortalidade chega a 20% dos exemplares persistindo até o final do período de observação. Os dados indicam uma relação dependente da concentração e do tempo no modo de ação destas substâncias.

Larvas de trematódeos em moluscos do Brasil: panorama e perspectivas após um século de estudos / Larval trematodes in molluscs of Brazil: overview and perspectives after a century of studies

O estudo de larvas de trematódeos encontradas em moluscos no Brasil foi iniciado há cerca de um século e, desde então, dezenas de cercárias e alguns ciclos biológicos destes parasitos foram descritos no país. Na presente atualização, são discutidos aspectos relacionados ao diagnóstico diferencial entre as cercárias de espécies de importância médico-veterinária, como Schistosoma mansoni e Fasciola hepatica, e outras larvas de parasitos de animais silvestres. Uma chave de identificação dos principais tipos cercarianos e suas características biológicas gerais são apresentadas. Além disso, são discutidos os estudos destes parasitos com enfoque em biodiversidade, biologia evolutiva e ecologia, bem como sua possível utilização como bioindicadores e controladores biológicos, abordagens pouco utilizadas no Brasil...

Dermatite cercariana por esquistossomatídeos de aves: é possível a ocorrência de casos no Brasil? / Swimmers’ itch by avian schistosomes: is it possible in Brazil?

A dermatite cercariana causada por larvas de esquistossomatídeos de aves tem sido considerada uma enfermidade emergente. Embora ainda não haja relato de casos no Brasil, algumas espécies destes trematódeos já foram encontradas em aves e os potenciais hospedeiros intermediários (moluscos) estão amplamente distribuídos pelo país. Em razão da dificuldade de diagnósticoclínico diferencial da dermatite causada por larvas de Schistosoma mansoni, é possível que outras dermatites cercarianas sejam negligenciadas em nosso meio. Neste trabalho são discutidos aspectos relacionados à identificação de áreas de risco, à pesquisa de formas larvares em moluscos aquáticos, às alterações clínicas verificadas em humanos, ao tratamento e à profilaxia desta enfermidade. Concluiu-se que são necessários esforços para o diagnóstico da dermatite cercariana por outrosesquistossomatídeos e também que sejam desenvolvidos estudos visando ampliar o conhecimento sobre a ocorrência destes parasitos no Brasil.

Metacercariae of Centrocestus formosanus (Trematoda: Heterophyidae) in Australoheros facetus (Pisces: Cichlidae) in Brazil / Metacercárias de Centrocestus formosanus (Trematoda: Heterophyidae) em Australoheros facetus (Pisces: Cichlidae) no Brasil

Heterophyid metacercariae were found in the gills of Australoheros facetus (Jenyns, 1842) collected from the Pampulha reservoir, Belo Horizonte, Minas Gerais, Brazil, between February and April 2010. The cysts were counted and used to perform experimental studies (artificial excystment and infection of mice). Fifty specimens of A. facetus were analyzed and it was found that the prevalence of infection was 100% and mean infection intensity was 134 metacercariae/fish (range: 4-2,510). Significant positive correlations were seen between total fish length and intensity of infection; between fish weight and intensity of infection, and between parasite density and fish length. Morphological analyses on metacercariae and adult parasites obtained from experimentally infected mice made it possible to identify Centrocestus formosanus (Nishigori, 1924). This is the first report of C. formosanus in A. facetus in Brazil.

Metacercárias de Heterophyidae foram encontradas nas brânquias de Australoheros facetus (Jenyns, 1842) coletados na represa da Pampulha, Belo Horizonte, Minas Gerais, Brasil, entre fevereiro e abril de 2010. Os cistos obtidos foram contados e utilizados em estudos experimentais (desencistamento artificial e infecção de camundongos). Cinquenta exemplares de A. facetus foram analisados, sendo verificada prevalência de infecção de 100% e intensidade média de infecção de 134 metacercárias/peixe (variando entre 4 e 2510). Verificou-se correlação positiva entre a intensidade de infecção e comprimento total dos peixes; entre a intensidade de infecção e o peso dos peixes e entre a densidade parasitária e o comprimento total. A análise morfológica das metacercárias e dos parasitos adultos obtidos em camundongos experimentalmente infectados permitiu a identificação de Centrocestus formosanus (Nishigori, 1924). Este é o primeiro relato de C. formosanus em A. facetus no Brasil.

[Susceptibility of Culex quinquefasciatus larvae to different insecticides]. / Suscetibilidade de larvas de Culex quinquefasciatus a diferentes inseticidas.

INTRODUCTION: This study aimed to assess the susceptibility of Culex quinquefasciatus larvae to two pyrethroids (Cypermethrin and Deltamethrin), two derivatives of Avermectin (Ivermectin and Abamectin) and an organophosphate (Temephos). METHODS: Third- and fourth-instar larvae of C. quinquefasciatus were exposed to different concentrations of insecticides (eleven repetitions) according to the World Health Organization's protocol. One hour after exposure, larvae were washed in dechlorinated tap water, transferred to plastic containers containing water without chlorine, fed and observed for periods of 24h until reaching adulthood. To determine lethal concentrations, the obtained values were submitted to regression analysis using the probit model with the Minitab 15 program. RESULTS: The highest concentration used for the LC50 from probit analysis was for Temephos. The evaluated insecticides caused more pronounced larvae mortality in the first 24h with the exception of those exposed to ivermectin. CONCLUSIONS: This study demonstrates that larvae are susceptible to all tested insecticides and that there is a need for monitoring the use of insecticides.