Use of heterologous antigens for the immunodiagnosis of abdominal angiostrongyliasis by an enzyme-linked immunosorbent assay

Angiostrongylus costaricensis has a broad geographic distribution spanning from North to South America and the infections of vertebrates with this nematode can result in abdominal complications. Human infections are diagnosed by histological or serological methods because the isolation of larvae from feces is not feasible, as most parasites become trapped in intestinal tissues due to intense eosinophilic inflammation. Because A. costaricensis is difficult to maintain in the laboratory, an immunodiagnostic IgG enzyme-linked immunosorbent assay (ELISA) using antigens from the congeneric Angiostrongylus cantonensis species was evaluated against a panel of serum samples from patients who were histologically diagnosed with A. costaricensis infections. Sera from uninfected individuals and individuals infected with other parasites were used as controls. The sensitivity and specificity of the assay were estimated at 88.4% and 78.7%, respectively. Because the use of purified or cloned antigens has not been established as a reliable diagnostic tool, the use of heterologous antigens may provide a viable alternative for the development of an ELISA-based immunodetection system for the diagnosis of abdominal angiostrongyliasis.

First report of Angiostrongylus cantonensis (Nematoda: Metastrongylidae) in Achatina fulica (Mollusca: Gastropoda) from Southeast and South Brazil

The rat lungworm Angiostrongylus cantonensis is a worldwide-distributed zoonotic nematode that can cause human eosinophilic meningoencephalitis. Here, for the first time, we report the isolation of A. cantonensis from Achatina fulica from two Brazilian states: Rio de Janeiro (specifically the municipalities of Barra do Piraí, situated at the Paraiba River Valley region and São Gonçalo, situated at the edge of Guanabara Bay) and Santa Catarina (in municipality of Joinville). The lungworms were identified by comparing morphological and morphometrical data obtained from adult worms to values obtained from experimental infections of A. cantonensis from Pernambuco, Brazil, and Akita, Japan. Only a few minor morphological differences that were determined to represent intra-specific variation were observed. This report of A. cantonensis in South and Southeast Brazil, together with the recent report of the zoonosis and parasite-infected molluscs in Northeast Brazil, provide evidence of the wide distribution of A. cantonensis in the country. The need for efforts to better understand the role of A. fulica in the transmission of meningoencephalitis in Brazil and the surveillance of molluscs and rodents, particularly in ports, is emphasized.

Rhabdias paraensis sp. nov.: a parasite of the lungs of Rhinella marina (Amphibia: Bufonidae) from Brazilian Amazonia

The nematode parasites of Rhinella marina include species of the genus Rhabdias (Rhabdiasidae: Rhabditoidea). The present study describes Rhabdias paraensis sp. nov., which parasitizes the lungs of R. marina in Brazilian Amazonia. Of the more than 70 known species of this genus, 18 are parasites of bufonids, of which, eight are Neotropical. The new species described here is similar to Rhabdias alabialis in the absence of lips is different by the presence of conspicuous cephalic papillae. We describe details of the four rows of pores, which are distributed equally along the whole of the length of the body and connected with hypodermal cells, using histology and scanning electron microscopy. Other histological aspects of the internal structure of this nematode are also described.

Proteolytic activity in the adult and larval stages of the human roundworm parasite Angiostrongylus costaricensis

Angiostrongylus costaricensis is a nematode that causes abdominal angiostrongyliasis, a widespread human parasitism in Latin America. This study aimed to characterize the protease profiles of different developmental stages of this helminth. First-stage larvae (L1) were obtained from the faeces of infected Sigmodon hispidus rodents and third-stage larvae (L3) were collected from mollusks Biomphalaria glabrata previously infected with L1. Adult worms were recovered from rodent mesenteric arteries. Protein extraction was performed after repeated freeze-thaw cycles followed by maceration of the nematodes in 40 mM Tris base. Proteolysis of gelatin was observed by zymography and found only in the larval stages. In L3, the gelatinolytic activity was effectively inhibited by orthophenanthroline, indicating the involvement of metalloproteases. The mechanistic class of the gelatinases from L1 could not be precisely determined using traditional class-specific inhibitors. Adult worm extracts were able to hydrolyze haemoglobin in solution, although no activity was observed by zymography. This haemoglobinolytic activity was ascribed to aspartic proteases following its effective inhibition by pepstatin, which also inhibited the haemoglobinolytic activity of L1 and L3 extracts. The characterization of protease expression throughout the A. costaricensis life cycle may reveal key factors influencing the process of parasitic infection and thus foster our understanding of the disease pathogenesis.

High occurrence of Calodium hepaticum (syn. Capillaria hepatica) spurious infection in a village in the Atlantic Forest of southern Brazil

Calodium hepaticum (syn. Capillaria hepatica) is a nematode of the Capillariidae family that infects rodents and other mammals. In Brazil, human spurious infections of C. hepaticum have been detected in indigenous or rural communities from the Amazon Basin, but not in the southern states of the country. Here, we report the highest occurrence (13.5% of 37 residents) of C. hepaticum human spurious infection detected in Brazil and the first record in a southern region, Guaraqueçaba. The finding is explained by the area being located in the Atlantic Forest of the state of Paraná, surrounded by preserved forests and because the inhabitants consume the meat of wild mammals.

Eosinophilic meningitis caused by Angiostrongylus cantonensis: an emergent disease in Brazil

Eosinophilic meningitis (EoM) is an acute disease that affects the central nervous system. It is primarily caused by infection with the nematode Angiostrongylus cantonensis. This infection was previously restricted to certain Asian countries and the Pacific Islands, but it was first reported in Brazil in 2007. Since then, intermediate and definitive hosts infected with A. cantonensis have been identified within the urban areas of many states in Brazil, including those in the northern, northeastern, southeastern and southern regions. The goals of this review are to draw the attention of the medical community and health centres to the emergence of EoM in Brazil, to compile information about several aspects of the human infection and mode of transmission and to provide a short protocol of procedures for the diagnosis of this disease.

Caracterização e classificação de Neossolos da Ilha de Fernando de Noronha (PE)

Na ilha principal do Arquipélago de Fernando de Noronha, condições peculiares de clima tropical, com franco domínio oceânico, e material de origem de natureza vulcânica contribuem para formação de solos pouco desenvolvidos, de especial interesse científico, particularmente no que tange à reestruturação do Sistema Brasileiro de Classificação de Solos (SiBCS). Com o objetivo de estudá-los, foram caracterizados morfológica, física, química e mineralogicamente e classificados sete perfis de Neossolos de ocorrência comum nesse ambiente insular, sendo dois Litólicos, um "Saprolítico", três Regolíticos e um Flúvico. Os Neossolos Litólicos apresentam contato lítico constituído por fragmentos de rocha a menos de 50 cm de profundidade. O Neossolo "Saprolítico" apresenta o contato lítico superior aos 50 cm de profundidade, porém precedido por rochas parcialmente decompostas (saprolito), que preservam ainda sua estrutura original. Os Neossolos Regolíticos estão relacionados aos depósitos sedimentares marinhos e são constituídos, predominantemente, por grãos bioclásticos carbonáticos. O Neossolo Flúvico, de origem colúvio-aluvial, apresenta camadas alternadas de materiais distintos, notoriamente, pela textura e mineralogia. Os Neossolos Litólicos foram adequadamente classificados segundo a nova versão do SiBCS (Embrapa, 2006), que inclui o subgrupo "fragmentário", sugerido durante o desenvolvimento deste trabalho. Os outros Neossolos não foram adequadamente enquadrados, ora por apresentarem características peculiares, ora pela ausência de termos mais apropriados, que melhor explicitassem suas características distintas. Sugere-se a inclusão no SiBCS da subordem dos Neossolos Saprolíticos, do grande grupo dos Neossolos Regolíticos Psamíticos, e dos subgrupos dos Neossolos Regolíticos Psamíticos bioclásticos carbonáticos e Neossolos Flúvicos Ta eutróficos bioclásticos carbonáticos.

Relação solo-relevo-substrato geológico nas restingas da planície costeira do estado de São Paulo

Atributos morfológicos de 28 pedons, descritos e amostrados em cronossequências, e datações absolutas por luminescência (TL e LOE) e 14C foram utilizados para elucidar os principais fatores envolvidos na formação e evolução dos Espodossolos nos depósitos marinhos quaternários da planície costeira do Estado de São Paulo. Os solos estudados localizam-se nos municípios de Bertioga (Baixada Santista), Cananeia e Ilha Comprida (Litoral Sul). Essa abordagem, pouco comum nos estudos dos ambientes de planície costeira brasileiros, possibilitou as seguintes interpretações: (a) o relevo, a dinâmica hídrica e o tempo (incluindo as variações do nível relativo do mar) são os principais condicionantes da diferenciação espacial dos Espodossolos nos terraços marinhos; (b) os Espodossolos mais antigos e bem drenados, devido às condições de relevo e rebaixamento do nível do lençol freático, apresentam grande variabilidade e diversidade de seus horizontes e atributos morfológicos, diferindo daqueles mal drenados (antigos ou jovens), em que os horizontes são mais homogêneos; (c) os Espodossolos mais antigos, quando bem drenados, mostram-se em avançado estádio de degradação, enquanto os mal drenados encontram-se bem preservados, indicando que a sua gênese e permanência na paisagem estão ligadas ao relevo, que, por sua vez, controla a dinâmica hídrica; (d) os Espodossolos mais evoluídos e antigos, dotados de horizontes cimentados (orstein), podem ser considerados indicadores pedolitoestratigráficos dos depósitos marinhos pleistocênicos da Formação Cananeia; e (e) a gênese do horizonte orstein se deu em condições topográficas e hidrológicas pretéritas diferentes das atuais, indicando se tratar de solos poligenéticos ou paleossolos.

Caracterização de Organossolos em ambientes de várzea do nordeste do Brasil

Os Organossolos são geralmente associados às regiões Sudeste e Sul do Brasil, e são poucos os estudos sobre a ocorrência e os efeitos do uso e manejo agrícola desses solos na região Nordeste. Os objetivos deste trabalho foram caracterizar física, química e morfologicamente seis perfis de Organossolos de várzeas dos Estados do Ceará, Rio Grande do Norte e da Paraíba e correlacionar seus atributos ao ambiente de formação, além de quantificar seus estoques de carbono e suas capacidades de armazenamento de água. Foram utilizados os métodos recomendados no Sistema Brasileiro de Classificação de Solos (SiBCS) para caracterizar química e fisicamente o solo, bem como a umidade e o volume residual dele. O aumento dos valores da Ds nos horizontes foi em decorrência da maior decomposição das fibras esfregadas (FE) e da redução dos teores de matéria orgânica. O volume residual apresentou correlações positiva e significativa a 5 % com o valor de resíduo mínimo (r = 0,64) e Ds (r = 0,74) e negativa com a porcentagem de FE (r = -0,75), podendo ser usado para avaliar a subsidência desses solos. As propriedades químicas foram influenciadas pelo material orgânico e pelos sedimentos fluviomarinhos. A variação da drenagem influenciada pela posição no relevo e pelo uso agrícola dos solos conduziu a classes de diferentes graus de decomposição da matéria orgânica e com isto às classes dos Organossolos Fíbrico, Hêmico e Sáprico. Um dos perfis CE1, com maior influência de sedimentos marinhos, foi classificado como Organossolo Tiomórfico com caráter solódico.

Influence of mineral fertilization on edaphic fauna in Acacia auriculiformis (A. Cunn) plantations

Fertilization and/or the accumulation of organic matter from plant residues can influence the composition of soil and litter community. The goal of this study was to evaluate the effects of P and K fertilization on total faunal and nematode faunal composition and richness in plant litter and soil for 360 days in an area reforested with Acacia auriculiformis (A. Cunn), located in the municipality of Conceição de Macabu in the State of Rio de Janeiro. For each treatment (fertilized and unfertilized plots), samples of litter and soil (to a depth of 5 cm) were collected and transferred into a Berlese-Tüllgren funnels for the extraction of fauna. Mesofauna and macrofauna were quantified, and the major taxa identified. Nematodes were extracted by centrifugal flotation in sucrose solution and identified according to feeding habits. Density (number of individuals m-2) of total fauna, microphages, social insects and saprophages varied significantly per treatment and sampling time in both litter and soil. The total number of individuals collected was 5,127, and the total number of nematodes 894. Phosphorus and potassium fertilization resulted in an increase in total fauna density and richness in the litter due to an increased abundance of social insects, saprophages and herbivores. In the soil, fertilization increased the saprophage and predator densities. Saprophages were the predominant taxa in the litter, while social insects (Formicidae) prevailed in the soil. Litter nematode populations were favored by mineral fertilization. Bacteriophages were the predominant nematode group in both litter and soil.

Soil solarization for weed control in carrot

Soil solarization is a technique used for weed and plant disease control in regions with high levels of solar radiation. The effect of solarization (0, 3, 6, and 9 weeks) upon weed populations, carrot (Daucus carota L. cv. Brasília) yield and nematode infestation in carrot roots was studied in São Luís (2º35' S; 44º10' W), MA, Brazil, using transparent polyethylene films (100 and 150 mm of thickness). The maximum temperature at 5 cm of depth was about 10ºC warmer in solarized soil than in control plots. In the study 20 weed types were recorded. Solarization reduced weed biomass and density in about 50% of weed species, including Cyperus spp., Chamaecrista nictans var. paraguariensis (Chod & Hassl.) Irwin & Barneby, Marsypianthes chamaedrys (Vahl) O. Kuntze, Mitracarpus sp., Mollugo verticillata L., Sebastiania corniculata M. Arg., and Spigelia anthelmia L. Approximately 40% of species in the weed flora were not affected by soil mulching. Furthermore, seed germination of Commelina benghalensis L. was increased by soil solarization. Marketable yield of carrots was greater in solarized soil than in the unsolarized one. It was concluded that solarization for nine weeks increases carrot yield and is effective for controlling more than half of the weed species recorded. Mulching was not effective for controlling root-knot nematodes in carrot.

Risk analysis of climate change on coffee nematodes and leaf miner in Brazil

The objective of this work was to assess the potential impact of climate change on the spatial distribution of coffee nematodes (races of Meloidogyne incognita) and leaf miner (Leucoptera coffeella), using a Geographic Information System. Assessment of the impacts of climate change on pest infestations and disease epidemics in crops is needed as a basis for revising management practices to minimize crop losses as climatic conditions shift. Future scenarios focused on the decades of the 2020's, 2050's, and 2080's (scenarios A2 and B2) were obtained from five General Circulation Models available on Data Distribution Centre from Intergovernmental Panel on Climate Change. Geographic distribution maps were prepared using models to predict the number of generations of the nematodes and leaf miner. Maps obtained in scenario A2 allowed prediction of an increased infestation of the nematode and of the pest, due to greater number of generations per month, than occurred under the climatological normal from 1961-1990. The number of generations also increased in the B2 scenario, but was lower than in the A2 scenario for both organisms.

Methodological adaptation for nematodes extration in forest soils of the southern Mata Atlântica

The objective of this work was to clarify whether the method to extract nematodes from European soils is suitable for forest soils and litter in the eastern of Paraná state, Brazil, and whether nematode abundance differs between sites with different ecosystems and levels of human interference. The study sites were situated in the coastal area of the Serra do Mar, near the town of Antonina, in Eastern Paraná, Brazil. Cobb's sieving and decanting method was more appropriate than ISO method, since extraction efficiency was higher and intra-sample variability was significantly lower. In order to achieve an extraction efficiency higher than 90%, Cobb's method was modified. For the extraction of nematodes from litter, the Baermann funnel, with an extraction time of 48 hours, yielded an extraction efficiency higher than 90%. Nematode abundance in litter was higher than in soil. The mean number of individuals extracted from the litter increased with the age stage of the forest sites sampled, and there was no difference in the number of individuals in the soil of the four forest sites. Mean nematode abundance in soil in banana plantations was about twice as high compared to the banana-palmito mixed stands and to the forest sites.

Métodos para determinação da digestibilidade aparente de dietas para camarão marinho suplementadas com probiótico

O objetivo deste trabalho foi determinar o método de coleta de fezes mais adequado para camarões marinhos (Litopenaeus vannamei) na determinação do coeficiente de digestibilidade aparente da proteína bruta e da matéria seca de dietas comerciais, e avaliar o efeito da suplementação de Lactobacillus plantarum na dieta sobre o coeficiente de digestibilidade aparente da proteína, da energia e da matéria seca. Foram testados três sistemas de coletas de fezes: decantação, sifonamento e dissecação dos animais. A coleta por decantação foi o sistema mais adequado para a determinação in vivo dos coeficientes de digestibilidade aparente da proteína bruta e da matéria seca das dietas, por apresentar baixo grau de lixiviação das fezes e por ser de fácil execução. Nos camarões alimentados com a dieta suplementada com L. plantarum, foi observado maior coeficiente de digestibilidade aparente da proteína (84,18±0,35%) e da energia (81,28±0,16%), quando comparado ao grupo controle (82,73±1,01 e 78,63±0,93%, respectivamente). O uso de L. plantarum como aditivo probiótico na ração pode trazer benefícios nutricionais a L. vannamei, com melhor aproveitamento dos nutrientes.

Entomopathogenic nematodes for the control of phorid and sciarid flies in mushroom crops

The objective of this work was to evaluate the efficacy of two nematodes, Steinernema feltiae and S. carpocapsae, to control mushroom flies and to evaluate the effect of these treatments on Agaricus bisporus production. Two mushroom cultivation trials were carried out in controlled conditions, in substrate previously infested with the diptera Megaselia halterata and Lycoriella auripila, with two treatments: 106infective juveniles (IJ) per square meter of S. feltiae and 0.5x106IJ m-2S. feltiae + 0.5x106IJ m-2S. carpocapsae. Another experiment was carried out using the same treatments to evaluate the possible nematode effect on mushroom yield. The number of adults emerging from the substrate was evaluated for each fly species. No decrease in the population of M. halterata was detected with nematode application, whereas the number of L. auripila was reduced in both treatments, particularly in the individual treatment with S. feltiae. The application of entomopathogenic nematodes has no adverse effect on mushroom production.