Anthelmintic efficacy of an oral formulation of Aurixazol against gastrointestinal nematodes of naturally and experimentally infected sheep

As a result of the need to develop new active principles for the control of endoparasites in ruminants, the present in vivo study evaluated a formulation containing 24% Aurixazol (48 mg/kg), a parasiticide molecule based on disophenolate of levamisole. Two experiments were conducted: one evaluating the anthelmintic efficacy of 24% Aurixazol (48 mg/kg) against gastrointestinal nematodes in naturally infected sheep, compared to an association of ivermectin (0.2 mg/kg) + albendazole (5.0 mg/kg) + levamisole (7.5 mg/kg) (IAL), and a second one which evaluated the persistent efficacy of the same formulation against immature stages (L4) and adults of Haemonchus contortus in experimentally infected animals. In experiment I, against H. contortus, the formulation of Aurixazol and the IAL association reached efficacies (arithmetic means) of 99.32% and 96.11%, respectively. For Trichostrongylus colubriformis, the efficacy values were 88.92% and 98.08% for Aurixazol and the IAL association, respectively. Both formulations were totally effective against Oesophagostomum columbianum (100%). The results of the statistical analysis demonstrated that the mean parasitic burden of treated animals was significantly different (P ≤ 0.05) compared to the average number of helminths diagnosed in animals from the control group for H. contortus, T. colubriformis and O. columbianum. Comparing only the treated groups, it was possible to verify that the average number of H. contortus recovered from animals treated with Aurixazol was different (P ≤ 0.05) when compared to the mean amount recovered from sheep treated with the IAL association. When evaluating the prevention of H. contortus infection in experiment II, Aurixazol did not present preventive efficacy. Up until 21 days after treatment the groups treated with Aurixazol contained less adults and L4 of H. contortus (P ≤ 0.05) when compared to the non-medicated control group. However, future studies will be necessary to assess the effectiveness of Aurixazol against nematode strains resistant to levamisole and disophenol, but the efficacy results described in this study allow to state that Aurixazol can, associated with other measures, become an important tool in the control of sheep nematodes. © 2013.

HEMATOLOGICAL ASSESSMENT IN FOUR BRAZILIAN TELEOST FISH WITH PARASITIC INFECTIONS, COLLECTED IN FEEFISHING FROM FRANCA, São Paulo, BRAZIL

The effects of parasitic infections in condition factor, hematocrit, hemoglobin, mean corpuscular hemoglobin concentration (MCHC), and leucocytes and thrombocytes distribution in Piaractus mesopotamicus, Leporinus macrocephalus, hybrid tambacu (P. mesopotamicus x Colossoma macropomum and Brycon amazonicus collected in feefishing from Franca, São Paulo, Brazil were evaluated. Parasitized tambacu and L. macrocephalus had higher (p<0.05) condition factor than unparasitized fish. However, the contrary occurred in P. mesopotamicus and B. amazonicus. Changes in the hematocrit, hemoglobin and MCHC were not related to parasitism. Parasitic infections did not cause effect on leucocytes and thrombocytes percentage (p>0.05) of tambacu. In P. mesopotamicus parasitized by Monogenea Anacanthorus penilabiatus and dinoflagellate Piscinoodinium pillulare, increase in monocytes and decrease in thrombocytes percentage (p<0.05) were found. However, the same parasitic association in L. macrocephalus caused a decrease in lymphocytes percentage accompanied by increase in neutrophils percentage (p<0.05). In B. amazonicus, infection by Ichthyophthirius multifiliis, P. pillulare and monogeneans caused increase in neutrophils percentage.

Evaluation of the possible role of ants (Hymenoptera: Formicidae) as mechanical vectors of nematodes and protists

Os Nematoda e Protista podem ser transmitidos ao homem de diversas maneiras, mas pouca ênfase é dada para a transmissão mecânica por intermédio de formigas. Assim, esse trabalho procurou investigar a transmissão mecânica de ovos de Ascaris lumbricoides e cistos de Entamoeba coli pelos Formicidae. Através de experimentos com espécies mantidas em ninhos no laboratório (Tapinoma melanocephalum, Linepithema humile e Monomorium pharaonis) e com 17 espécies de formigas de uma área antropizada na região de Mogi as Cruzes (SP), foi possível constar que os ovos A. lumbricoides foram transportados por L. humile, tanto no campo (1 operária) como no laboratório (1 operária), por Camponotus rufipes (2), por Solenopsis saevissima (1) e por Acromyrmrex niger (1). em três operárias de C. rufipes foram encontrados cistos de E. coli. Apesar da baixa incidência de transporte, as três primeiras espécies pelo fato de viverem muito próximas ao ser humano, podem levar para dentro do ambiente domiciliar patógenos de Nematoda e Protista.

Natural infection of gastrointestinal nematodes in long-nosed armadillos Dasypus novemcinctus Linnaeus, 1758 from Pantanal wetlands, Aquidauana sub-region, Mato Grosso do Sul State, with the description of Hadrostrongylus speciosum n. gen. et n. sp (Molineidae : Anoplostrongylinae)

This study evaluated the gastrointestinal helminth fauna of long-nosed armadillos, Dasypus novemcinctus, from the Pantanal wetlands, Aquidauana sub-region, Aquidauana County, Mato Grosso do Sul State, Brazil. Thirteen species of nematodes, comprising seven genera and four families, were recovered from their gastrointestinal tracts. The following descriptors of infection were determined: prevalence, variation of intensity, average intensity and abundance. Hadrostrongylus speciosum n. gen. et n. sp. is first described here. (c) 2006 Published by Elsevier B.V.

Observations on helminth infections of free-living and captive rheas (Rhea americana) in Brazil

The present work describes helminth infection of eight free-living and 12 captive rheas (Rhea americana) from, respectively, Pantanal of Mato Grosso do Sul State, and Jaboticabal, São Paulo State, Brazil. Captive birds were young and had a high mortality rate, while free-living birds were adult and apparently healthy. Infections were evaluated by post-mortem examination of internal organs and recovery of helminths using standard parasitological procedures. Seven species of nematodes (Sicarius uncinipenis, Torquatoides crotophaga, Deletrocephalus dimidiatus, D. cesarpintoi, Paradeletrocephalus minor, Capillaria venteli and Dicheilonema rheae) and two species of cestodes (Houttuynia struthionis and Chapmania tauricolis) were identified. P. minor, which inhabits the large intestine, was the most common helminth in free-living birds (63.9%). In captive rheas, a mean parasitic load of 173 helminths per host was found. The gizzard of these birds was the most parasitized organ and S. uncinipenis was most common (92.5%). Parasitism of free-living and captive birds and associated pathology are discussed. (c) 2005 Published by Elsevier B. V.

Natural infections with filarioidea nematodes in Hydrochaerus hydrochaeris in the floodplain of Mato Grosso do Sul, Brazil

Foram coletados 570 nematódeos Filaroidea de 36 capivaras, sacrificadas entre 1989 e 1996, onze jovens menores que seis meses e 25 adultas, provenientes da região do pantanal do Mato Grosso do Sul (Paiaguás). Cento e setenta e seis (176) espécimes de Yatesia hydrochoerus foram encontrados nas fáscias dos músculos esqueléticos, principalmente da região do obliquus externus abdominis e na face interna dos membros posteriores e trezentos e noventa e quatro (394) espécimes de Cruorifilaria tuberocauda foram coletados das artérias renais (380) e das artérias pulmonares (14) dos animais.

Infecções naturais em cervídeos (Mammalia: Cervidae) procedentes dos Estados do Mato Grosso do Sul e São Paulo, por nematódeos Trichostrongyloidea Cram, 1927

No período compreendido entre 1985 e 1996 foram necropsiados, para pesquisa de helmintos, 42 cervídeos, sendo sete Mazama americana, 16 M. gouazoubira, 13 Ozotoceros bezoarticus e seis Blastocerus dichotomus. Desses animais, foram colhidos 14.426 nematódeos Trichostrongyloidea, sendo 13.281 (92,06%) parasitos de abomaso e 1.145 (7,94%), de intestino delgado. Nesses órgãos, foram identificadas seis espécies de nematódeos: Haemonchus contortus, H. similis, Trichostrongylus axei, T. colubriformis, Cooperia punctata e C. pectinata. Todos os animais apresentaram infecções helmínticas por uma ou mais espécies, ocorrendo grande variação na intensidade de infecção (1 a 4.345 nematódeos). Ainda com relação à intensidade de infecção, os dados expressavam valores menores que 100 parasitos em 25 (59,52%) animais. Os valores mais altos de intensidade média das infecções foram observados em M. gouazoubira (596,37 helmintos) e em O. bezoarticus (331), e os menores, em M. americana (17,57) e B. dichotomus (75,5). Os dados mais expressivos de intensidade de infecção, abundância e prevalência foram observados para Haemonchus (larvas de 4º estágio), H. contortus, H. similis e T. axei. O gênero Haemonchus foi constatado em 35 animais, com prevalência de 83,33%; apresentou carga parasitária de 11.616 exemplares, representando 80,52% dos nematódeos verificados, sendo a maioria (8.903) constituída por formas imaturas. Por outro lado, H. similis foi a espécie predominante nas infecções e, portanto, a que apresentou maiores valores de abundância. Verificou-se o gênero Trichostrongylus em 24 (57,14%) animais, com carga parasitária de 2.444 exemplares, sendo 1.665 espécimes de T. axei, que representou 11,54% da carga parasitária obtida. As seis espécies de vermes identificadas nos cervídeos são comuns aos ruminantes domésticos nos Estados de São Paulo e Mato Grosso do Sul e dessa maneira não se observou nenhuma espécie de Trichostrongyloidea exclusiva dos cervídeos.

Helminth fauna of bovines from the Central-Western region, Minas Gerais State, Brazil

A prevalência e a intensidade de parasitismo por diferentes espécies de helmintos foram estudadas em bovinos da microrregião de Formiga, região Centro-oeste de Minas Gerais. Para tanto, foram necropsiados 76 bovinos naturalmente infectados, machos e fêmeas, SRD (sem raça definida) e de oito a 12 meses de idade. Os resultados necroscópicos revelaram a presença de nove gêneros e 16 espécies de helmintos, com a seguinte prevalência e média de intensidade de infecção: Haemonchus placei (100,0%; 3895,5); Haemonchus similis (29,0%; 159,6); Cooperia punctata (100,0%; 5595,0); Cooperia spatulata (32,9%; 137,8); Cooperia pectinata (34,2%; 1010,5); Trichostrongylus axei (69,7%; 239,2); Trichostrongylus colubriformis (10,5%; 10,8); Trichostrongylus longyspicularis (2,6%; 0,5); Ostertagia ostertagi (2,6%; 3,1); Ostertagia lyrata (2,6%; 1,5); Ostertagia trifurcata (1,3%; 0,3); Oesophagostomum radiatum (94,7%; 470,9); Trichuris discolor (47,4%; 32,5); Strongyloides papillosus (1,3%; 0,1); Capillaria bovis (9,2%; 10) e Bunostomum phlebotomum (2,6%; 0,3). A carga parasitária média foi de 11.558,5 helmintos por animal. Dos 76 bovinos necropsiados, 92,1% estavam infectados por três a sete espécies de helmintos. Apenas 7,9% dos hospedeiros mostravam-se parasitados por oito espécies diferentes de helmintos. Este estudo mostra o primeiro relato das espécies Ostertagia lyrata e Ostertagia trifurcata no Estado de Minas Gerais. É importante ressaltar que, no presente trabalho, por meio da identificação dos helmintos colhidos nas necropsias, foi possível observar que está ocorrendo uma inversão na intensidade parasitária média, com uma diminuição no número de Cooperia e um aumento nos valores de Haemonchus, em comparação com os valores relatados na literatura.

Application technology for the entomopathogenic nematodes Heterorhabditis indica and Steinernema sp. (Rhabditida: Heterorhabditidae and Steinernematidae) to control Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) in corn

O efeito de diversas tecnologias de aplicação foi avaliado sobre a concentração, viabilidade e eficácia dos juvenis infectantes dos nematóides Heterorhabditis indica Poinar, Karunakar & David (IBCB-n5) e Steinernema sp. (IBCB-n6) no controle da lagarta-do-cartucho Spodoptera frugiperda Smith na cultura do milho. Para o controle da lagarta-do-cartucho no terceiro estádio em placas de Petri foram necessários 280 juvenis infectantes de Steinernema sp., enquanto que 400 juvenis infectantes de H. indica controlaram apenas 75% das lagartas. Podem-se pulverizar os entomopatógenos, sem que haja perda significativa na sua concentração e viabilidade, com equipamentos que forneçam carga elétrica à calda, ponta centrífuga e pontas hidráulicas. Entretanto, o emprego de pulverizadores com pontas que requerem elementos filtrantes com malha igual a 100 resultou em decréscimo na concentração de juvenis infectantes de H. indica e Steinernema sp., de 28% e 53%, respectivamente. Os tensoativos organosiliconado e etoxilados não afetaram a viabilidade dos juvenis infectantes de Steinernema sp. Nos experimentos de pulverização em plantas de milho (V6) com Steinernema sp., doses equivalentes a até 288 milhões de juvenis infectantes por hectare, diluídos em volume de calda de até 800 L ha-1 com 0,01 % do tensoativo etoxilado, ou nesse volume seguido de exposição a chuva artificial (lâmina de água de 6 mm), não foram suficientes para o controle de S. frugiperda em casa-de-vegetação.

Separating interface state response from parasitic effects in conductance measurements on organic metal-insulator-semiconductor capacitors

A simple model is developed for the admittance of a metal-insulator-semiconductor (MIS) capacitor which includes the effect of a guard ring surrounding the Ohmic contact to the semiconductor. The model predicts most of the features observed in a MIS capacitor fabricated using regioregular poly(3-hexylthiophene) as the active semiconductor and polysilsesquioxane as the gate insulator. In particular, it shows that when the capacitor is driven into accumulation, the parasitic transistor formed by the guard ring and Ohmic contact can give rise to an additional feature in the admittance-voltage plot that could be mistaken for interface states. When this artifact and underlying losses in the bulk semiconductor are accounted for, the remaining experimental feature, a peak in the loss-voltage plot when the capacitor is in depletion, is identified as an interface (or near interface) state of density of similar to 4 x 10(10) cm(-2) eV(-1). Application of the model shows that exposure of a vacuum-annealed device to laboratory air produces a rapid change in the doping density in the channel region of the parasitic transistor but only slow changes in the bulk semiconductor covered by the gold Ohmic contact. (C) 2008 American Institute of Physics.

Intestinal parasitic infections in HIV/AIDS patients: epidemiological, nutritional and immunological aspects

This study applied a socioeconomic questionnaire designed to evaluate the frequency of intestinal parasites and characterize epidemiological, nutritional, and immunological variables in 105 HIV/AIDS patients - with and without parasitic infections, attending the Day Hospital in Botucatu, UNESP, from 2007 to 2008. Body mass index was calculated and the following tests performed: parasitological stool examinations; eosinophil, IgE, CD4(+) T and CD8(+) T lymphocyte cell counts; albumin test; viral load measure; and TNF-alpha, IFN-gamma, IL-2, IL-5 and IL-10 cytokine levels. Results were positive for parasitic intestinal infections in 12.4% of individuals. Most patients had good socioeconomic conditions with basic sanitation, urban dwellings, treated water supply and sewage, good nutritional and immunological status and were undergoing HAART. Parasites were found at the following frequencies: Entamoeba - five patients (38.5%), Giardia lamblia-four (30.7%), Blastocystis hominis-three (23.0%), Endolimax nana-two (15.4%), and Ascaris lumbricoides - one (7.7%). There were no significant differences between the two groups for eosinophils, albumin, IgE, CD4(+) T and CD8(+) T lymphocytes, INF-gamma, IL-2, or IL-10. Most patients also showed undetectable viral load levels. Significant differences were found for TNF-alpha and IL-5. These results show the importance of new studies on immunodeficient individuals to increase understanding of such variables.

Parasitic infection of the appendix as a cause of acute appendicitis

The association between parasitic infection of the appendix and acute appendicitis has been widely investigated. The aim of this retrospective study was to evaluate the prevalence of parasitic infection of the appendix in a tropical area at southeast Brazil and to assess its possible relation to acute appendicitis in surgically removed appendices. of the 1,600 appendectomies performed during a 10-year period, 24 (1.5%) were found to have helminths within the appendix. Enterobius vermicularis was observed in 23 of the 24 specimens (95.8%), and Taenia sp. was detected in only one case. Sixteen patients (66.7%) were less than 10 years old; 15 patients were male and nine female; 21 patients were white, and three were nonwhites. Pathologic analysis disclosed acute neutrophilic inflammation in the appendix wall in 12 of the 24 specimens and lymphoid hyperplasia in 10 of the 24 appendices. Gangrenous appendicitis was diagnosed in three cases, and peritonitis was found in 11 of the 24 infected appendices. The results of the present study indicate that E. vermicularis is the commonest worm found in the appendix and that its presence can cause pathologic changes ranging from lymphoid hyperplasia to acute phlegmonous inflammation with life-threatening complications like gangrene and peritonitis.

Host specificity of sheep and cattle nematodes in São Paulo state, Brazil

The trial was carried out to investigate parasite host specificity and to analyse the dynamics of infection with nematodes parasitizing sheep and catt:le raised together or separately in São Paulo state, Brazil, and, also to clarify doubts about the systematics of species of the genus Haemonchus on the basis of cytological and morphological studies. Ten steers and 32 ewes were randomly assigned to three paddocks (P), as follows: P1, 5 steers; P2, 5 steers and 16 ewes; and P3, 16 ewes. The animals remained on these paddocks in continuous grazing throughout the trial (1-yr period). Faecal exams and larvae counting on pasture were performed fortnightly. Once a month two tracer lambs were placed in each paddock, while two tracer calves were also placed, but only in the eighth month of the trial. All these animals were slaughtered for worm identification and counting. At the end of the trial, one steer and one ewe from P2, which showed high faecal egg counts, were also slaughtered for the same purpose. Nematodes identified cytogenetically as H. placei presented spicule hooks longer than those identified as H. contortus. The following distribution of parasites in cattle and sheep was observed: Bunostomum phlebotomum, H. similis, Mammomonogamus laryngeus strongly adapted to cattle, H. placei and Cooperia punctata more adapted to cattle than to sheep, Trichostrongylus axel and C. spatulata apparently more adapted to cattle, T. colubriformis strongly adapted to sheep, H. contortus more adapted to sheep than to cattle and C. curticei apparently more adapted to sheep. Cross-infection was shown to occur involving some species, however, with time the animals apparently eliminate the species that are not well adapted to them. Therefore, grazing management systems using cattle and sheep appear to be promising for worm control in southeastern Brazil. (C) 1997 Elsevier B.V. B.V.

Anthelmintic resistance in cattle nematodes in northwestern São Paulo state, Brazil

The present study was carried out in the northwestern region of São Paulo State, Brazil, to determine the anthelmintic resistance status in cattle naturally infected with gastrointestinal nematodes. The anthelmintics tested were levamisole phosphate (Ripercol (R), Fort Dodge), albendazole sulphoxide (Ricobendazole, Fort Dodge), ivermectin (Ivomec (R), Merial) and moxidectin (Cydectin (R), Fort Dodge), administered at the doses recommended by the manufacturers. From April 2002 to May 2004, 25 cattle farms were evaluated. on each farm, steers were divided into treatment and control (not treated) groups based on fecal egg counts (FEC). Between 7 and 10 days after the anthelmintics administration, fecal samples were collected from each animal for post-treatment FEC. Fecal cultures from each group were also prepared for larval identification. After treatment, mean FEC reduction (FECR) in treatment groups (compared with control groups) was assessed on each farm. FECR was lower than 90% on 23 farms after ivermectin treatment. on 19 farms, FECR of 100% was recorded following moxidectin treatment; on the remaining 6, FECR ranged from 90% to 97.2%. After albendazole treatment, FECR was higher than 90% on 20 farms and ranged from 47.4% to 84.6% on other 5. After levamisole treatment, FECR was higher than 90% on 23 farms and equal to 47.4% and 73.7% on other 2 farms. Results indicated the presence of resistant Cooperia spp. and Haemonchus spp., especially to ivermectin; on some farms, resistance to albendazole and levamisole was also observed. (C) 2007 Elsevier B.V. All rights reserved.

Lung infection rates in two sympatric Tropiduridae lizard species by pentastomids and nematodes in northeastern Brazil

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)