Expression of transporter genes in anthelmintic resistant isolates of Haemonchus contortus.

ATP-binding cassette (ABC) transporters, including P-glycoproteins (PGP), have been implicated in drug resistance in different organisms including Haemonchus contortus. This study confirmed the resistance status of H. contortus isolates selected for ivermectin (IVM) and oxfendazole (OXF) resistances using the fecal egg count reduction test and evaluated the gene expression of seven ABC transporters using RT-qPCR for two biological scenarios: the effect of selection for anthelmintic resistance and the effect of drug exposure on gene expression. Gene expression results showed that selection for IVM resistance led to the significant upregulation of Hco-pgp-9a (1.5-fold), Hco-pgp-11 (3-fold) and Hco-haf-9 (1.5-fold) (p < 0.05). Similarly, selection for OXF resistance led to the significant upregulation of Hco-pgp-9a (3-fold), Hco-pgp-11 (4-fold) and Hco-haf-9 (2-fold) when comparing with the unselected ISE isolate (p < 0.05). Exposure of selected isolates to anthelmintics lead to no significant upregulation of the studied transporter genes. We also observed instances where there was strong intragroup variation regarding samples originating from parasites obtained from different individual hosts pointing that the interactions of the animal host with the tested anthelmintics may also play a role in the expression of the studied nematode genes.

Biological activity of cinnamaldehyde, citronellal, geraniol and anacardic acid on Haemonchus contortus isolates susceptible and resistant to synthetic anthelmintics.

Parasitism by gastrointestinal nematodes is a challenge for small ruminant farming worldwide. It causes productive and economic losses, especially due to parasite resistance to conventional anthelmintics. Natural compounds with antiparasitic activity are a potential alternative for controlling these parasites especially when considering the widespread occurrence of anthelmintic resistance. Our objective was to evaluate the activity of anacardic acid, geraniol, cinnamaldehyde and citronellal on Haemonchus contortus isolates with different levels of anthelmintic resistance profiles. These compounds were tested using egg hatch assays (EHAs), larval development tests (LDTs) as well as LDTs on mini-fecal cultures, on the Haemonchus contortus isolates Kokstad (KOK-resistant to all anthelmintics), Inbred-Strain-Edinburgh (ISE-susceptible to all anthelmintics) and Echevarria (ECH-susceptible to all anthelmintics). Effective concentrations to inhibit 50% (EC50) and 95% (EC95) of egg hatching and larval development were calculated. Results for EHA and LDT for all tested compounds, considering EC50 and EC95 values, showed low variation among the studied isolates with most RF values below 2x. All studied compounds showed efficacy against egg hatching and larval development of H. contortus isolates regardless of anthelmintic resistance profiles. The compounds with the smallest EC50 and EC95 values were cinnamaldehyde and anacardic acid making them promising candidates for future in vivo studies.

Castor cake as organic fertilizer to control gastrointestinal nematodes in pasture-raised sheep.

Gastrointestinal parasitism is one of the factors that discourages farmers from raising small ruminants in cultivated pastures. To validate a soil treatment strategy to control the free-living stages of gastrointestinal nematodes (GIN), castor cake (CC) was used as a fertilizer on a pasture where sheep grazed on guinea grass under continuous stocking. On day zero, the pasture was divided into three paddocks, contaminated by GIN and treated, respectively, with CC divided into two applications (2CC1/2), CC in a single application (CC1) and organic compost in a single application (control). On day 21, eight GIN-free sheep were placed in each paddock. On day 58, significant differences (P<0.05) were observed: reduction of up to 66.10% in larvae.g-1 of dry mass in pastures fertilized with CC, decrease of up to 60.72% in infection rates among the animals in the groups treated with CC, higher average daily weight gain (over 185 g.day-1) and packed cell volume (over 26%) in the groups treated with CC, when compared to the control (128 g.day-1; 20.9%). In view of the results, the use of CC, mainly CC1, as a fertilizer for guinea grass pastures, under continuous stocking, proved to be promising, with 63.41% effectiveness in controlling worm infestations.

Castor cake as organic fertilizer to control gastrointestinal nematodes in pasture-raised sheep / Torta de mamona como adubo orgânico para o controle de nematoides gastrintestinais em ovinos criados a pasto

Abstract Gastrointestinal parasitism is one of the factors that discourages farmers from raising small ruminants in cultivated pastures. To validate a soil treatment strategy to control the free-living stages of gastrointestinal nematodes (GIN), castor cake (CC) was used as a fertilizer on a pasture where sheep grazed on guinea grass under continuous stocking. On day zero, the pasture was divided into three paddocks, contaminated by GIN and treated, respectively, with CC divided into two applications (2CC1/2), CC in a single application (CC1) and organic compost in a single application (control). On day 21, eight GIN-free sheep were placed in each paddock. On day 58, significant differences (P<0.05) were observed: reduction of up to 66.10% in larvae.g-1 of dry mass in pastures fertilized with CC, decrease of up to 60.72% in infection rates among the animals in the groups treated with CC, higher average daily weight gain (over 185 g.day-1) and packed cell volume (over 26%) in the groups treated with CC, when compared to the control (128 g.day-1; 20.9%). In view of the results, the use of CC, mainly CC1, as a fertilizer for guinea grass pastures, under continuous stocking, proved to be promising, with 63.41% effectiveness in controlling worm infestations.

Resumo O parasitismo gastrintestinal é um dos fatores que fragiliza a exploração de pequenos ruminantes em pastagens cultivadas. Objetivando validar a estratégia de tratamento do solo para o controle dos estágios de vida livre de nematoides gastrintestinais (NGI), a torta de mamona (TM) foi utilizada como adubo, com ovinos pastejando em capim-tanzânia sob lotação contínua. No dia zero, o pasto foi dividido em três piquetes, contaminados por NGI e tratados, respectivamente, com TM parcelada em duas aplicações (2TM1/2), TM em uma única aplicação (TM1) e composto orgânico em única aplicação (testemunha). No dia 21, cada piquete recebeu oito ovinos livres de NGI. No dia 58, observaram-se diferenças significativas (P<0,05): redução de até 66,10% de larvas.g-1 de massa seca nas pastagens adubadas com TM; redução de até 60,72% da infecção dos animais nos grupos tratados com TM; ganho de peso médio diário (acima de 185 g.dia-1) e volume globular (acima de 26%) superior nos grupos tratados com TM, quando comparados com a testemunha (128 g.dia-1; 20,9%). Diante dos resultados, o uso da TM, principalmente TM1, como adubo em pasto de capim-tanzânia, sob lotação contínua, mostrou-se promissor, com eficácia de 63,41% para controlar a verminose.

Crop residues activity against the free-living stages of small ruminant nematodes.

The nematicidal effect of different organic materials was evaluated in order to develop a non-chemical alternative soil treatment for control of the free-living stages of small ruminant gastrointestinal nematodes. The selected organic materials were residues from the juice industry of acerola, cashew, grape, guava, papaya and pineapple, as well as castor residue from the biodiesel industry. LC90 results showed that pineapple residue was the most efficient inhibitor of larval development, followed by castor, grape, cashew, acerola, guava and papaya. Castor residue was also a good source of nitrogen and was used in a greenhouse experiment to prevent larval development in contaminated goat faeces that was deposited in pots containing the grasses Brachiaria brizantha (var. Paiaguás) or Megathyrsus maximus x M. infestum (var. Massai). Castor residue caused a significant (P < 0.05) reduction (85.04%) in Paiaguás grass contamination (L3.dry mass-1) and a reduction of 17.35% in Massai grass contamination (P > 0.05), with an increase in the biomass production of Massai (251.43%, P < 0.05) and Paiaguás (109.19%, P > 0.05) grasses. This strategy, called Econemat®, with good results in vitro shows to be promising on pasture increasing phytomass production.

Quantitative molecular diagnosis of levamisole resistance in populations of Haemonchus contortus.

Parasitism by Haemonchus contortus is one of the main limiting factors in small ruminant production around the globe. Although several studies suggest the use of integrated management practices, these parasites have been controlled essentially with synthetic anthelmintic drugs. The resistance mechanism against the imidazothiazole derivative levamisole in Haemonchus contortus has not been fully described. Recently, resistance was associated with a 63bp deletion in the Hco-acr-8b gene that encodes a subunit for a nicotinic acetylcholine receptor. This study aimed to standardize a real time PCR (qPCR) protocol for levamisole resistance diagnosis in H. contortus populations based on this polymorphism and use it to characterize 23 field H. contortus populations obtained from different localities of Ceará State, Northeast Brazil. In addition, two populations of H. contortus were used as a standard of susceptibility and resistance, Inbred Strain Edinburgh (ISE) and Kokstad, respectively. Larval development tests (LDT) were performed on five field isolates and both EC50 and EC95 were estimated. LDT EC95 values provided a wider interval between susceptible and resistant populations than EC50 values (EC95 = 1.96-57.93 µM; EC50 = 0.05-0.39 µM), and were found to be more appropriate for differentiating them. Real time PCR results showed resistance allele frequencies ranged from 20.9 to 76.7%. Our results suggest that levamisole resistance may be present in field populations but it is not as widespread as benzimidazole resistance. This methodology may be useful to monitor levamisole resistance in field populations of H. contortus.

Crop residues activity against the free-living stages of small ruminant nematodes / Atividade de resíduos de culturas contra os estágios de vida livre de nematoides de pequenos ruminantes

Abstract The nematicidal effect of different organic materials was evaluated in order to develop a non-chemical alternative soil treatment for control of the free-living stages of small ruminant gastrointestinal nematodes. The selected organic materials were residues from the juice industry of acerola, cashew, grape, guava, papaya and pineapple, as well as castor residue from the biodiesel industry. LC90 results showed that pineapple residue was the most efficient inhibitor of larval development, followed by castor, grape, cashew, acerola, guava and papaya. Castor residue was also a good source of nitrogen and was used in a greenhouse experiment to prevent larval development in contaminated goat faeces that was deposited in pots containing the grasses Brachiaria brizantha (var. Paiaguás) or Megathyrsus maximus x M. infestum (var. Massai). Castor residue caused a significant (P < 0.05) reduction (85.04%) in Paiaguás grass contamination (L3.dry mass-1) and a reduction of 17.35% in Massai grass contamination (P > 0.05), with an increase in the biomass production of Massai (251.43%, P < 0.05) and Paiaguás (109.19%, P > 0.05) grasses. This strategy, called Econemat®, with good results in vitro shows to be promising on pasture increasing phytomass production.

Resumo O efeito nematicida de diferentes materiais orgânicos foi avaliado, com o objetivo de desenvolver um tratamento alternativo não químico do solo para o controle dos estágios de vida livre de nematoides gastrintestinais de pequenos ruminantes. Os materiais orgânicos selecionados foram resíduos da indústria de suco de acerola, caju, uva, goiaba, mamão e abacaxi, além do resíduo de mamona da indústria de biodiesel. Os resultados da LC90 mostraram que o resíduo de abacaxi foi o mais eficiente inibidor do desenvolvimento larval, seguido pela mamona, uva, caju, acerola, goiaba e mamão. O resíduo de mamona também se mostrou uma boa fonte de nitrogênio, sendo usado em experimento em casa de vegetação para prevenir o desenvolvimento larval em fezes contaminadas, depositadas em vasos, contendo as gramíneas Brachiaria brizantha (var. Paiaguás) ou Megathyrsus maximus x M. infestum (var. Massai). O resíduo de mamona reduziu (85,04%) significativamente (P < 0,05) a contaminação no capim-Paiaguás (L3.dry massa-1), 17,35% no capim Massai (P> 0,05), e aumentou a produção de biomassa das gramíneas Massai (251,43%, P <0,05) e Paiaguás (109,19%, P> 0,05). Essa estratégia, chamada Econemat®, com bons resultados in vitro, mostra-se promissora nas pastagens aumentando a produção de fitomassa.

Haemonchus contortus ß-tubulin isotype 1 gene F200Y and F167Y SNPs are both selected by ivermectin and oxfendazole treatments with differing impacts on anthelmintic resistance.

Parasitism by Haemonchus contortus is one of the main limiting factors in small ruminant production in tropical areas. Benzimidazoles (BZ) and macrocyclic lactones (ML) are the most used anthelmintic classes in gastrointestinal nematodes control. There is considerable scientific evidence of a possible relation between the anthelmintic resistance to BZ and ML. This study aimed to characterize the dynamics of anthelmintic resistance in an H. contortus susceptible isolate under selection pressure for BZ and ML alone or in combination and the role of isotype 1 ß-tubulin gene SNPs in these situations. A total of 12 Somali sheep were infected with 5000 third stage larvae of H. contortus Inbred-Susceptible Edinburgh (ISE) isolate. Once infection was established, animals were distributed in three groups (n=4), each treated with crescent doses of oxfendazole (OXF), ivermectin (IVM) and oxfendazole plus ivermectin (IVMOXF). An additional control group with untreated animals was maintained during the entire experiment. After each treatment, eggs were collected and real-time PCR was performed to identify single nucleotide polymorphisms (SNPs) F167Y, F200Y and E198A, in addition to egg hatch test (EHT) for BZ and larval development test (LDT) for ivermectin resistance. All treatments led to increased resistance allelic frequencies at SNPs F200Y and F167Y (p <0.05). In vitro results showed increased phenotypic resistance against both anthelmintic classes in groups IVM and IVMOXF while group OXF only developed resistance against BZ. Finally, we provide evidence that while isotype 1 ß-tubulin gene SNPs may have some involvement with ML resistance, the presence of these ß-tubulin SNPs alone are not sufficient to develop ML resistance.

Ocorrência da infecção por Cryptosporidium spp. em cabritos (Capra hircus) / Occurrence of infection by Cryptosporidium spp. in goat kids (Capra hircus)

O presente estudo teve como objetivo determinar a ocorrência da infecção por Cryptosporidium spp. em cabritos de Quixadá, Ceará, Brasil. Participaram do estudo 400 cabritos, com idade entre três e 360 dias, de ambos os sexos, com e sem padrão racial definido, procedentes de 25 estabelecimentos rurais distribuídos em três circuitos. As fezes foram cadastradas de acordo com o aspecto e cor, distribuídas em tubos tipo "eppendorf®" e congeladas in natura a -20°C, até o momento das extrações de DNA genômico do parasito com auxílio de kit comercial. Para amplificação de fragmentos da subunidade 18S do RNA ribossômico (rRNA) foi utilizada a "Nested"-PCR. A ocorrência de Cryptosporidium spp em cabritos de Quixadá foi de 7,50% (30/400). A frequência no período seco e no chuvoso foi de 9,55% (19/199) e 5,47% (11/201), respectivamente (χ²=2,39 e P>0,05). Amostras positivas foram identificadas em 64,00% (16/25) das propriedades estudadas e dessas amostras 50,00% (15/30) e 70,00% (21/30) tinham as fezes com aspecto e cor normais, respectivamente, sugerindo que cabritos assintomáticos estão eliminando oocistos. Não foi observada positividade para Cryptosporidium spp. em animais com 301 a 360 dias, demonstrando que animais mais velhos apresentam menos possibilidade de se infectarem com o parasito...

The present study aimed to determine the occurrence of infection by Cryptosporidium spp. in goat kids from Quixadá, Ceará, Brazil. The study included 400 goat kids of both sexes, 3 to 360 days old, with or without defined breed, originating from 25 farms distributed in three circuits. Feces were registered in accordance with the appearance and color, distributed into tubes Eppendorf tubes and frozen in natura at-20°C until the moment of extraction of genomic DNA from the parasite with the aid of a commercial kit. For amplification of fragments of the 18S subunit of ribosomal RNA (rRNA) was used to Nested PCR. The occurrence of Cryptosporidium spp. in goats kids of the Quixadá was 7.50% (30/400). The frequency in the dry period and rainy was 9.55% (19/199) and 5.47% (11/201) respectively (χ²=2.39 and P>0.05). Positive samples were identified in 64.00% (16/25) of the studied farms, and from these samples 50.00% (15/30) and 70.00% (21/30) had feces with normal appearance and color respectively, suggesting that the asymptomatic goats were eliminating oocysts. No positivity for Cryptosporidium spp. was observed in 301 to 360-day-old goats, demonstrating that older animals have less chance to become infected with the parasite...

Lectin, hemolysin and protease inhibitors in seed fractions with ovicidal activity against Haemonchus contortus.

Bioactive molecules of plant species are promising alternatives for the chemical control of gastrointestinal nematodes in ruminants. Extracts of native and exotic seed species from Brazil's semi-arid region were tested in vitro in an egg hatch assay and the bioactivity of their proteins was investigated. Each seed species was subjected to three extractions with three types of solvents. All the seeds showed ovicidal activity, which varied according to the solvents. Higher ovicidal activity was found in the molecule fractions of low molecular weight (<12 kDa) for Albizia lebbeck, Ipomoea asarifolia, Jatropha curcas, Libidibia ferrea, Moringa oleifera and Ricinus communis (P<0.05, Bonferroni test). The two fractions of Crotalaria spectabilis showed the same ovicidal activity (P>0.05, Bonferroni test). Hemagglutinating activity was detected in the fractions of C. spectabilis and M. oleifera fractions, hemolysin activity in the A. lebbeck and M. oleifera fractions, serine protease inhibitory activity in the A. lebbeck, I. asarifolia, J. curcas, M. oleifera and R. communis fractions, cysteine protease inhibitor activity in the M. oleifera fraction, and no protein activity in the L. ferrea fraction. The results of this work reveal new plant species with a potential for use in controlling nematode parasites in goats, thus opening a new field of research involving plant protein molecules with ovicidal properties.

Lectin, hemolysin and protease inhibitors in seed fractions with ovicidal activity against Haemonchus contortus / Lectina, hemolisina e inibidores de protease em frações de sementes com atividade ovicida contra Haemonchus contortus

Bioactive molecules of plant species are promising alternatives for the chemical control of gastrointestinal nematodes in ruminants. Extracts of native and exotic seed species from Brazil's semi-arid region were tested in vitro in an egg hatch assay and the bioactivity of their proteins was investigated. Each seed species was subjected to three extractions with three types of solvents. All the seeds showed ovicidal activity, which varied according to the solvents. Higher ovicidal activity was found in the molecule fractions of low molecular weight (<12 kDa) for Albizia lebbeck, Ipomoea asarifolia, Jatropha curcas, Libidibia ferrea, Moringa oleifera and Ricinus communis (P<0.05, Bonferroni test). The two fractions of Crotalaria spectabilis showed the same ovicidal activity (P>0.05, Bonferroni test). Hemagglutinating activity was detected in the fractions of C. spectabilis and M. oleifera fractions, hemolysin activity in the A. lebbeck and M. oleifera fractions, serine protease inhibitory activity in the A. lebbeck, I. asarifolia, J. curcas, M. oleifera and R. communis fractions, cysteine protease inhibitor activity in the M. oleifera fraction, and no protein activity in the L. ferrea fraction. The results of this work reveal new plant species with a potential for use in controlling nematode parasites in goats, thus opening a new field of research involving plant protein molecules with ovicidal properties.

Moléculas bioativas de espécies vegetais são alternativas promissoras ao controle químico dos nematoides gastrintestinais em ruminantes. Extratos de sementes de espécies nativas e exóticas do Semiárido Brasileiro foram testados in vitro em ensaio de eclosão de ovos e investigada a natureza proteica da bioatividade. Três extrações com três solventes foram feitas para cada semente estudada. Todas as sementes apresentaram atividade ovicida, variando com o solvente utilizado. Maior taxa de inibição da eclosão concentrou-se nas frações de moléculas de baixa massa molecular (<12 kDa) para Albizia lebbeck, Ipomoea asarifolia, Jatropha curcas, Libidibia ferrea, Moringa oleifera e Ricinus communis (P<0,05, teste de Bonferroni). Crotalaria spectabilis mostrou atividade nas duas frações, sem diferença entre elas (P>0,05, teste de Bonferroni). Observou-se atividade hemaglutinante nas frações de C. spectabilis e M. oleifera, de hemolisina em A. lebbeck e M. oleifera, de atividade inibidora de protease da serina em A. lebbeck, I. asarifolia, J. curcas, M. oleifera e R. communis, de atividade inibidora de protease da cisteína em M. oleifera e nenhuma atividade proteica na fração de L. ferrea. Os resultados revelaram novas espécies botânicas com potencial de controle de nematoides em caprinos e um novo campo de pesquisa, o estudo de moléculas de origem proteica com atividade ovicida.

Identification and quantification of benzimidazole resistance polymorphisms in Haemonchus contortus isolated in Northeastern Brazil.

Haemonchus contortus is the most prevalent nematode in Brazil. The objective of this study was to select 6 populations of H. contortus of known or suspected benzimidazole resistance status and characterize these using quantitative real-time polymerase chain reaction (qPCR) for single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A in the ß-tubulin isotype 1 gene. qPCR was performed using DNA from a pool of 10 adult male H. contortus from a single animal per farm. Faecal egg count reduction test (FECRT) and egg hatch test (EHT) were used to determine the resistance status. Samples were obtained from 6 farms located in 5 counties in the Ceará State: Tauá, Boa Viagem, Quixadá, Santa Quitéria and Solonópole. The inbred-susceptible-Edinburgh (ISE) isolate was used as reference for comparative purposes in the qPCR. Benzimidazole resistance was detected by FECRT on all farms with efficacy values ranging from 0 to 51%. EC50 values as determined by EHT were all above 1.49µg/ml. High frequencies of the resistant SNPs F200Y and F167Y alleles were detected but no resistance was detected at SNP E198A. Our results suggest that the SNPs F167Y and F200Y are both important for benzimidazole resistance in the studied populations.

Evaluation of Eucalyptus citriodora essential oil on goat gastrointestinal nematodes.

Phytotherapy may be an alternative strategy for controlling gastrointestinal parasites. This study evaluated the anthelmintic efficacy of Eucalyptus citriodora essential oil (EcEO). The in vitro effects of EcEO were determined through testing the inhibition of egg hatching and larval development of Haemonchus contortus. EcEO was subjected to acute toxicity testing on mice, orally and intraperitoneally. The in vivo effects of EcEO were determined by the fecal egg count reduction test (FECRT) in goats infected with gastrointestinal nematodes. The results showed that 5.3 mg.mL(-1) EcEO inhibited egg hatching by 98.8% and 10.6 mg.mL(-1) EcEO inhibited H. contortus larval development by 99.71%. The lethal doses for 50% of the mice were 4153 and 622.8 mg.kg(-1), for acute toxicity orally and intraperitoneally. In the FECRT, the efficacy of EcEO and ivermectin was 66.25 and 79.16% respectively, on goat gastrointestinal nematodes eight days after treatment. EcEO showed in vitro and in vivo anthelmintic activity.

Evaluation of Eucalyptus citriodora essential oil on goat gastrointestinal nematodes / Avaliação do óleo essencial de Eucalyptus citriodora sobre nematóides gastrintestinais de caprinos

Phytotherapy may be an alternative strategy for controlling gastrointestinal parasites. This study evaluated the anthelmintic efficacy of Eucalyptus citriodora essential oil (EcEO). The in vitro effects of EcEO were determined through testing the inhibition of egg hatching and larval development of Haemonchus contortus. EcEO was subjected to acute toxicity testing on mice, orally and intraperitoneally. The in vivo effects of EcEO were determined by the fecal egg count reduction test (FECRT) in goats infected with gastrointestinal nematodes. The results showed that 5.3 mg.mL-1 EcEO inhibited egg hatching by 98.8 percent and 10.6 mg.mL-1 EcEO inhibited H. contortus larval development by 99.71 percent. The lethal doses for 50 percent of the mice were 4153 and 622.8 mg.kg-1, for acute toxicity orally and intraperitoneally. In the FECRT, the efficacy of EcEO and ivermectin was 66.25 and 79.16 percent respectively, on goat gastrointestinal nematodes eight days after treatment. EcEO showed in vitro and in vivo anthelmintic activity.

Fitoterapia pode ser uma estratégia alternativa para o controle de parasitas gastrintestinais. Este estudo avaliou a eficácia anti-helmintica do óleo essencial de Eucalyptus citriodora (OeEc). Os efeitos in vitro do OeEc foram determinados através do teste de eclosão de ovos e inibição do desenvolvimento larvar de Haemonchus contortus. O OeEc foi submetido ao teste de toxicidade aguda oral e intraperitoneal, em camundongos. Os efeitos in vivo do OeEc foram avaliados através do teste de redução da contagem de ovos nas fezes (FECRT) com caprinos infectados com nematóides gastrintestinais. Os resultados mostraram que 5,3 mg.mL-1 OeEc inibiram 98,8 por cento a eclosão de ovos e 10,6 mg.mL-1 OeEc inibiram 99,71 por cento o desenvolvimento larvar de H. contortus. As doses letais para 50 por cento dos camundongos foram de 4153 e 622,8 mg.kg-1 pela via oral e intraperitoneal. No FECRT, a eficácia de OeEc e ivermectina foi de 66,25 e 79,16 por cento, respectivamente, em caprinos 8 dias após o tratamento. OeEc mostrou atividade anti-helmintica in vitro e in vivo.

Management practices to control gastrointestinal parasites in dairy and beef goats in Minas Gerais; Brazil.

Parasitic infection is recognized worldwide as a limiting factor in the production of goats, and various control methods are used to reduce economic losses, often without considering the epidemiology of the parasites. This has led to the development of highly tolerant parasite populations and the presence of chemical residues in the beef and milk. The objective of this study was to determine the level of knowledge of goat farmers about parasitic diseases and to correlate this with the epidemiology of endoparasites and parasite control practices in goat farms in the state of Minas Gerais, Brazil. The analysis was based on a questionnaire applied by trained veterinarians. The sample was homogeneous throughout the state, covering 18.4% (157/853) of municipalities. Eighty-four dairy goat farms in 81 municipalities and 200 properties with beef goats in 76 municipalities were evaluated. The herd size per goat farm ranged from 4 to 57 (average 24) for beef herds and from 2 to 308 (average 63) for dairy farms. The majority of the beef herd production was extensive and semi-extensive (98.5%), while the dairy herds were maintained under intensive farming (98.8%). The mixed production of goats and sheep was reported by 36.5% of beef goat farmers and by 20.2% of dairy goat farmers. Among the beef goats farms on which the technological level was determined, 2.0% were categorized as having high technological level, 34.5% as medium, and 63.5% as low. Of the 84 dairy farms, 30% operated at a high, 47% at a medium, and 23% at a low technological level. The adoption of practices to reduce parasitism, such as the quarantine of animals, treatment of newly arrived animals, regular cleaning of the floor, and technical assistance, was significantly higher on dairy farms than on beef farms. Although 85.7% of dairy farmers and 83% of beef farmers medicate their animals, the treatments were performed without technical criteria, and deworming intervals ranged from 30 to 120 days or more. The average interval between treatments was significantly longer in dairy goat herds (4.8 months) than in the beef herds (3.6 months). The most commonly used drugs were macrocyclic lactones (37.7% in dairy and 39.5% in beef herds) and benzimidazoles (48.9% in dairy and 31.5% in beef herds). Goat production in Minas Gerais is still in its infancy, and even though using a control program associated with other health practices, producers still rely heavily on chemicals to get satisfactory results.

Evaluation of reference genes for real-time PCR studies of Brazilian Somalis sheep infected by gastrointestinal nematodes

Precise normalization with reference genes is necessary, in order to obtain reliable relative expression data in response to gastrointestinal nematode infection. By using sheep from temperate regions as models, three reference genes, viz., ribosomal protein LO (RPLO), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and succinate dehydrogenase complex subunit A (SDHA), were investigated in the abomasum, abomasal lymph nodes and small intestine of Brazilian Somalis sheep, either resistant or susceptible to gastrointestinal nematodes infections. Real time PCR was carried out by using SYBR Green I dye, and gene stability was tested by geNorm. RPLO was an ideal reference gene, since its expression was constant across treatments, presented lower variation, and was ranked as the most stable in abomasum and lymph node tissues. On the other hand, SDHA was the most stable in the small intestine followed by RPLO and GAPDH. These findings demonstrate the importance of correctly choosing reference genes prior to relative quantification. In addition, we determined that reference genes used in sheep from temperate regions, when properly tested, can be applied in animals from tropical regions such as the Brazilian Somalis sheep.

Ação de Azadirachta indica (Neem) em nematódeos gastrintestinais de caprinos / Azadirachta indica (Neem) action in goats gastrintestinal nematodes

O problema da resistência em nematódeos gastrintestinais de caprinos, associado ao crescente interesse por alternativas de controle, levou à investigação da ação de Azadirachta indica sobre estes parasitas. No teste in vitro observou-se a ação ovicida e larvicida de extratos aquosos de folhas verdes e secas de Neem, em cinco concentrações. No teste in vivo administrou-se 30g de folhas secas por animal/dia, durante cinco dias. Os animais foram monitorados através de OPG diário durante 28 dias e as larvas foram quantificadas e identificadas através de coprocultura. Detectou-se a predominância de Haemonchus sp. na estação chuvosa e de Trichostrongylus spp. na estação seca. O extrato aquoso de folhas secas in vitro, na concentração de 240.000ppm, reduziu em 89% a eclosão das larvas de nematódeos gastrintestinais. Entretanto, esta concentração é muita elevada e inviabiliza sua aplicação no controle da verminose. A administração oral de folhas secas trituradas não reduziu o OPG dos animais durante um período de 28 dias após o tratamento. Estudos investigativos com A. indica devem se concentrar na ação biológica do óleo extraído diretamente da semente, que possui maior quantidade de azadirachtina que as folhas. A administração do óleo também é mais fácil, já que as folhas têm sabor amargo e são evitadas pelos animais.

The resistance problem in goats gastrointestinal nematodes, associated to the increasing interest for control alternatives, induced the investigation of the Azadirachta indica action on these parasites. In in vitro test it was detected ovicida and larvicida action of Neem dry and fresh leaves aqueous extracts in five concentrations. In in vivo test each animal received orally 30g of dry leaves for a five days period. To monitor the animals were used diary fecal eggs per gram count (FEC) by 28 days and larvae were quantified and identified through fecal culture. Predominance of Haemonchus sp. in rainy season and Trichostrongylus spp. in dry season were detected. The dry leaves aqueous extract reduced in 89% the larvae hatching of goats’ gastrointestinal nematodes, in 240.000ppm concentration. However this is a very high concentration to be applied on vermin’s control. The oral administration of Azadirachta indica triturated dry leaves did not reduce the medicated animals FEC during a period of 28 days after treatment. A. indica investigated studies must be concentrated in biological action of the seed oil extracted, because it possess bigger amount of azadirachtina than leaves. The oil administration also is easier, whereas the leaves have bitter taste and are prevented by animals.

A salinomicina para o controle da eimeriose de caprinos leiteiros nas fases de cria e recria / The salinomicin in the control of eimeriosis in dairy goats at pre and post-weaning phases

A salinomicina foi avaliada no controle da eimeriose caprina em 27 cabritos mestiços distribuídos aleatoriamente em três tratamentos num delineamento inteiramente casualizado: T0, não medicados (grupo controle); T1 e T2, medicados com doses de 1 e 2mg de salinomicina/kg de peso vivo/dia, respectivamente. Na fase de cria, não houve diferença estatística (P>0,005) no ganho médio de peso (GP) entre os três tratamentos. Na fase de recria, o grupo T0 apresentou GP significativamente inferior (P<0,01) aos grupos T1 e T2; entre estes não houve diferença significativa (P>0,005). O número médio de oocistos por grama de fezes (OOPG) do grupo T0, nas duas fases estudadas, foi significativamente maior (P<0,01) ao dos grupos T1 e T2; sendo que os grupos tratados não diferiram (P>0,005) entre si. O grupo T0 apresentou rendimento médio de carcaça (RC) significativamente inferior (P<0,05) aos grupos T1 e T2; entre estes não houve diferença significativa (P>0,005). O peso médio da massa corporal (MC) do grupo T0 foi inferior (P<0,05) ao do grupo T2 e, não diferiu (P>0,005) do grupo T1; entre os grupos T1 e T2, não houve diferença significativa (P>0,005) no peso médio da massa corporal (MC). O uso da salinomicina nas doses de 1 e 2mg/kg, resultou em maior ganho de peso dos animais dos grupos T1 e T2 e, consequentemente, maior valor da margem bruta destes tratamentos. Os resultados obtidos mostraram que os T1 e T2 foram equivalentes para o controle da eimeriose caprina, uma vez que ambos os tratamentos apresentaram maior ganho de peso e oocistograma inferior ao grupo T0. Conclui-se que o tratamento com a salinomicina na dose de 1,0mg/kg é eficaz, desde que seja administrada a partir da segunda semana de vida.

Nematódeos resistentes a anti-helmíntico em rebanhos de ovinos e caprinos do estado do Ceará, Brasil / Nematodes resistant to anthelmintics in sheep and goat flock in the State of Ceará, Brazil

O controle do parasitismo por nematódeos gastrintestinais é feito basicamente com a utilizaçäo de anti-helmínticos. Falhas no controle säo o primeiro sinal do aparecimento de resistência anti-helmíntica. A real situaçäo da prevalência da resistência anti-helmíntica, em fazendas comerciais de criaçäo de ovinos e caprinos no Brasil, é desconhecida. Esse experimento teve como objetivo, estimar a ocorrência de resistência ao oxfendazol, levamisol e ivermectina em propriedades comerciais de criaçäo de ovinos e caprinos, na regiäo do médio e baixo Jaguaribe, através do teste de reduçäo na contagem de ovos nas fezes acompanhados de coproculturas. O trabalho foi realizado em 25 criaçöes, sendo 16 de ovinos, 7 de caprinos e uma de ovinos e caprinos. Os dados obtidos foram analisados pelo programa estatístico RESO (1989). A prevalência de nematódeos resistentes ao oxfendazol, levamisol e ivermectina em ovinos foi de 88 por cento, 41 por cento e 59 por cento, e em caprinos de 87,5 por cento, 75 por cento e 37,5 por cento, respectivamente. Observou-se que o gênero Haemonchus foi o mais prevalente na populaçäo resistente a todos os anti-helmínticos, tanto em ovinos quanto em caprinos, seguido de Trichostrongylus e Oesophagostomum.

Açäo do ivermectin e do netobimin sobre a reduçäo e esterilizaçäo de ovos de Haemonchus sp em caprinos e ovinos / Activity of ivermectin and netobimin on the reduction and sterilization of Haemonchus sp eggs, in goats and sheep

Utilizaram-se 24 caprinos e 24 ovinos sem raça definida (SRD), machos, castrados com idade entre seis e doze meses e experimentalmente infectados com larvas infectantes de Haemonchus sp. Trinta e seis dias após a infecçäo, formaram-se seis grupos de oito animais, sendo os grupos um, dois e três compostos por caprinos e os grupos quatro, cinco e seis, por ovinos. Os grupos um e quatro foram tratados com invermectin oral (0,2 mg/kg), os grupos dois e cinco com netobimin oral (20 mg/kg) e os grupos três e seis serviram como testemunhas. Realizaram-se colheitas de fezes no momento da medicaçäo (hora zero) e as três, seis, nove e doze horas e a partir daí, em intervalos de doze horas até completar 168 horas. As fezes colhidas foram utilizadas para determinar o OPG individual dos animais e coprocultura por grupo. Ivermectin e netobimin foram 100% eficientes na reduçäo do OPG de Haemonchus sp em caprinos. O ivermectin apresentou reduçäo significativa (P<0,05) do OPG a partir de 12ª hora em ovinos e da 36ª hora em caprinos, enquanto que o netobimin apresentou a partir de 24ª hora, nas duas espécies. Ambos os produtos apresentaram alta atividade na esterilizaçäo de ovos de Haemonchus sp. As doses utilizadas para ovinos foram também eficazes para caprinos