Divergent humoral responses between males and females against 24 kDa excretory-secretory protein of Haemonchus contortus and influence of ovine ß-globin polymorphism.

Lambs harboring the Hb-AA ß-globin haplotype present improved cell-mediated responses and increased resistance against Haemonchus contortus infection. The aim of the present study was to compare the effect of sex and ß-globin haplotypes on specific humoral responses and phenotypes of resistance during H. contortus infection in Morada Nova sheep. As expected, females displayed stronger resistance during the first and second experimental challenges. Differential systemic humoral immune responses were observed comparing sex groups, in which higher levels of specific antibodies targeting 24 kDa excretory-secretory (ES24) protein of H. contortus of IgG and IgM antibodies were respectively observed as predominant isotypes in males and females. The IgM levels were significantly correlated with phenotypes of resistance, evaluated by packed cell volume and fecal egg counts. To our knowledge this is the first study reporting divergent humoral responses profiles to H. contortus infection between male and female sheep. The impact of ß-globin haplotypes was less pronounced in females compared to males. Notably, only males showed significant weight differences across haplotypes, with Hb-AA lambs being the heaviest. Additionally, Hb-AA males had significantly higher PCV (indicating better red blood cell health) and lower FEC (indicating lower parasite burden). These findings suggest a more pronounced effect of ß-globin polymorphisms on H. contortus infection in males, potentially due to their generally weaker resistance compared to females. This study highlights the importance of sex and ß-globin haplotypes in shaping immune responses to H. contortus infection. Specifically, IgM antibodies targeting the ES24 protein appear to play a crucial role in host-parasite interactions and may hold promise for therapeutic development.

Multi-omics data elucidate parasite-host-microbiota interactions and resistance to Haemonchus contortus in sheep.

BACKGROUND: The integration of molecular data from hosts, parasites, and microbiota can enhance our understanding of the complex biological interactions underlying the resistance of hosts to parasites. Haemonchus contortus, the predominant sheep gastrointestinal parasite species in the tropics, causes significant production and economic losses, which are further compounded by the diminishing efficiency of chemical control owing to anthelmintic resistance. Knowledge of how the host responds to infection and how the parasite, in combination with microbiota, modulates host immunity can guide selection decisions to breed animals with improved parasite resistance. This understanding will help refine management practices and advance the development of new therapeutics for long-term helminth control. METHODS: Eggs per gram (EPG) of feces were obtained from Morada Nova sheep subjected to two artificial infections with H. contortus and used as a proxy to select animals with high resistance or susceptibility for transcriptome sequencing (RNA-seq) of the abomasum and 50 K single-nucleotide genotyping. Additionally, RNA-seq data for H. contortus were generated, and amplicon sequence variants (ASV) were obtained using polymerase chain reaction amplification and sequencing of bacterial and archaeal 16S ribosomal RNA genes from sheep feces and rumen content. RESULTS: The heritability estimate for EPG was 0.12. GAST, GNLY, IL13, MGRN1, FGF14, and RORC genes and transcripts were differentially expressed between resistant and susceptible animals. A genome-wide association study identified regions on chromosomes 2 and 11 that harbor candidate genes for resistance, immune response, body weight, and adaptation. Trans-expression quantitative trait loci were found between significant variants and differentially expressed transcripts. Functional co-expression modules based on sheep genes and ASVs correlated with resistance to H. contortus, showing enrichment in pathways of response to bacteria, immune and inflammatory responses, and hub features of the Christensenellaceae, Bacteroides, and Methanobrevibacter genera; Prevotellaceae family; and Verrucomicrobiota phylum. In H. contortus, some mitochondrial, collagen-, and cuticle-related genes were expressed only in parasites isolated from susceptible sheep. CONCLUSIONS: The present study identified chromosome regions, genes, transcripts, and pathways involved in the elaborate interactions between the sheep host, its gastrointestinal microbiota, and the H. contortus parasite. These findings will assist in the development of animal selection strategies for parasite resistance and interdisciplinary approaches to control H. contortus infection in sheep.

Enhanced mucosal response in sheep harbouring ßA beta-globin against haemonchosis.

Association between ovine ß-globin polymorphisms and resistance against haemonchosis was described and related to the mechanism of high oxygen affinity ßA ➔ ßC switch during anaemia, but there are no studies regarding the involved local host responses. Phenotypic parameters and local responses were evaluated in sheep from two ß-globin haplotypes naturally infected with Haemonchus contortus. Morada Nova lambs were monitored at 63, 84 and 105 days of age for faecal egg counts and packed cell volume (PCV) under natural infection with H. contortus. At 210 days of age, lambs of Hb-AA and Hb-BB ß-globin haplotypes were euthanised, and the fundic region of abomasum was sampled for evaluation of microscopic lesions and relative expression of genes related to immune, mucin and lectin activities. Lambs harbouring the ßA allele presented an improved resistance/resilience against clinical haemonchosis, showing higher PCV during infection. Hb-AA animals presented increased eosinophilia in the abomasum compared to Hb-BB animals, accompanied by higher Th2 profile, mucin and lectin activity transcripts, while the inflammatory response was increased in Hb-BB animals. This is the first report to demonstrate an enhanced local response in the primary site of H. contortus infection related to ßA allele of ß-globin haplotype.

In vitro culture of parasitic stages of Haemonchus contortus.

Haemonchus contortus is a constraint to sheep production. Seeking to reduce the use of hosts and produce parasitic stages in large-scale, a 42-day in vitro culture protocol of H. contortus third-stage larvae was optimized using Dulbecco's modified Eagle's medium (DMEM). In cell-free culture, larvae were maintained at 39.6°C, in acidic media (pH 6.1) for 3 or 6 days with Δ4-dafachronic acid followed by DMEM pH 7.4 supplemented or not with Fildes' reagent. In DMEM pH 7.4 at 37°C, supplementation with Caco-2 cells was compared to Fildes. On Day 14, fourth-stage larvae (L4) development rates in acidic media supplemented (86.8-88.4%) or not (74.4-77.8%) with Fildes and in Caco-2 cell co-culture (92.6%) were similar, and superior to DMEM pH 7.4 with Fildes (0.0%). On Day 21, Caco-2 cell co-culture resulted in higher larvae differentiation (25.0%) and lower degeneration (13.9%) compared to acidic media (1.5-8.1% and 48.6-69.9%, respectively). This is the first report of prolonged in vitro culture of H. contortus larvae using commercial media in co-culture with Caco-2 cells. Although no progression to the adult stage, Caco-2 cell co-culture resulted in morphological differentiation of H. contortus L4 and larval viability for up to 28 days.

Sheep immune-stimulated with Saccharomyces boulardii show reduced prolificacy of Haemonchus contortus.

Haemonchus contortus is the most pathogenic parasite for sheep. The objective was to evaluate immunomodulation of the probiotic Saccharomyces boulardii in sheep experimentally infected with H. contortus. Twenty-four sheep were divided into three groups: one infected with 500 H. contortus larvae/day for 26 days and supplemented with S. boulardii (40 ml with 1 × 108 CFU/ml/day); a control group only infected with H. contortus but not supplemented; and a naïve group that never came into contact with either parasites or S. boulardii. To assess the humoral immune response, production of specific serum IgG anti-somatic H. contortus antigen was evaluated through indirect ELISA. To assess the cellular immune response, cell populations and cytokine (IL-4, IL-5 and IL-10) production were evaluated through flow cytometry. For parasitological analyses, the counts of eggs per gram of faeces (EPG) and larvae per faecal culture were assessed. At all the study points, the concentration of IgG anti-H. contortus was higher (p < .05) in the S. boulardii group than in the other groups. The cell analysis revealed that there were significantly higher numbers (p < .05) of cells expressing MHC-II and significantly higher numbers (p < .05) of eosinophils in the mucosa in the S. boulardii group. Significant expression of IL-10 was observed only in the control infected group. There were significant reductions (p < .05) in EPG and larval counts in the S. boulardii supplemented group. These results show that S. boulardii supplementation modulated the immune response against H. contortus, thereby reducing its infection.

Genome-Wide Association Study for Haemonchus contortus Resistance in Morada Nova Sheep.

Among the gastrointestinal nematodes affecting sheep, Haemonchus contortus is the most prevalent and virulent, resulting in health problems and production losses. Therefore, selecting sheep resistant to H. contortus is a suitable and sustainable strategy for controlling endoparasites in flocks. Here, 287 lambs of the native Brazilian Morada Nova hair sheep breed were subjected to two consecutive artificial infections with H. contortus and assessed for fecal egg count (FEC), packed cell volume (PCV), and live weight (LW). Forty-four animals ranked as having extreme resistance phenotypes were genotyped using the Illumina OvineSNP50v3 chip. A case−control genome-wide association study (GWAS) detected 37 significant (p < 0.001) markers in 12 ovine chromosomes in regions harboring quantitative trait loci (QTL) for FEC, Trichostrongylus spp. adults and larvae, weight, and fat; and candidate genes for immune responses, mucins, hematological parameters, homeostasis, and growth. Four single-nucleotide polymorphisms (SNP; OAR1_rs427671974, OAR2_rs419988472, OAR5_rs424070217, and OAR17_rs401006318) genotyped by qPCR followed by high-resolution melting (HRM) were associated with FEC and LW. Therefore, molecular markers detected by GWAS for H. contortus resistance in Morada Nova sheep may support animal selection programs aimed at controlling gastrointestinal nematode infections in flocks. Furthermore, genotyping of candidate genes using HRM qPCR may provide a rapid and efficient tool for animal identification.

Investigating the benefits of targeted selective treatment according to average daily weight gain against gastrointestinal nematodes in Morada Nova lambs.

The objective of this study was to evaluate a method of targeted selective treatment (TST) of Morada Nova lambs, based on the average daily weight gain (DWG). For this, 114 lambs in the rainy and 102 in the dry season were randomized into three treatments: control (CT), routine (RT, treated every 42 days), and targeted selective (TST, treated according to DWG). Packed cell volume (PCV) and eggs per gram of feces (EPG) tests were performed. The anthelmintic resistance of parasites was assessed by the EPG count reduction test (FECRT), RESISTA-Test©, and molecular test. For CT, RT, and TST groups, the following results were obtained: mean EPG values were 4665.1, 3063.5, and 3462.1 in the rainy season and 4475.1, 1341.7, and 2863.4 in the dry season, respectively; mean PCV values were 32.1, 33.4, and 32.3% in the rainy season and 33.9, 36.0, and 35.1% in the dry season; mean DWG readings were 0.087, 0.101, and 0.094 kg in the rainy season and 0.102, 0.113, and 0.112 kg in the dry season; efficacies of levamisole in FECRT were 66.4, 24.1, and 76.4% in the rainy and 90.7, 12.4, and 64.8% in the dry season, respectively; in the RESISTA-Test©, the LC50 values were 0.482, 1.926, and 0.117 µg.mL-1 in the rainy and 0.437, 0.851, and 0.045 µg.mL-1 in the dry season, respectively; the frequencies of the homozygous-resistant genotype were 57.1, 71.4, and 40.0% in the rainy and 47.8, 55.9, and 41.9% in the dry season. In conclusion, TST reduced the development of resistance through refugia maintenance, without productive losses, contributing to the sustainability of sheep breeding.

Anthelmintic resistance of Haemonchus contortus from sheep flocks in Brazil: concordance of in vivo and in vitro (RESISTA-Test©) methods.

This study evaluated the resistance status of Haemonchus contortus from sheep flocks in the state of São Paulo, Brazil, through comparison between the fecal egg count reduction test (FECRT) and the larval development test (LDT). For the FECRT, 35 sheep were selected in each of five flocks and divided into groups treated with: benzimidazole, levamisole, ivermectin, monepantel and control. Feces were collected for EPG and fecal cultures. The LDT was performed using thiabendazole (TBZ), levamisole (LEV), ivermectin aglycone (IVM-A) and Zolvix (ZLV). Resistance to all drugs was detected using FECRT in 100% of the flocks, except in relation to ZLV (40% resistant and 20% suspected of resistance). LDT indicated resistance to TBZ and IVM-A in all flocks, to LEV in 80% of flocks and to ZLV in 10%. Total agreement was obtained between the two tests for TBZ and IVM (k = 1.0), while for LEV (k = 0.8) and ZLV (k = 0.9), substantial and almost perfect agreement were obtained, respectively. The concordance between the tests was significant, thus showing that it is possible to use the outcome of the LDT to predict the FECRT, and hence validating the former as a fast diagnostic test for use by sheep farmers in Brazil.

Anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from Paraná state, South Brazil: prevalence and associated factors.

The aim of this study was to evaluate the seroprevalence and factors associated with the presence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from Paraná state. The detection of antibodies for T. gondii and N. caninum was performed by homemade and commercial indirect ELISA, respectively. Multiple logistic regression analysis was used to verify the factors associated with the seroprevalence. Antibodies anti-T. gondii and anti-N. caninum were observed in 42.7% and in 17.6% of the animals, respectively. The protective factors associated to seropositive were "some level of confinement" (full or semi-extensive confinement) (OR=0.53) for T. gondii and "use of skilled labor" (OR=0.64) for N. caninum. The risk factors were "presence of cats" (OR=1.75) for T. gondii and "feeding of dogs with sheep placental remains" (OR=1.79) for N. caninum. In addition, to presenting a significant and simultaneous seroprevalence for both agents (9.9% of the animals), the results also indicate that deficiencies in management and environmental sanitation, the presence of reservoirs, and types of exploitation enhance the seropositivity. Thus, studies like this might support sanitary programs and public policies for the prevention of T. gondii and N. caninum in the sheep herds of Paraná state.

Anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from Paraná state, South Brazil: prevalence and associated factors / Anticorpos anti-Toxoplasma gondii e anti-Neospora caninum em ovinos do estado do Paraná, sul do Brasil: prevalência e fatores associados

Abstract The aim of this study was to evaluate the seroprevalence and factors associated with the presence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies in sheep from Paraná state. The detection of antibodies for T. gondii and N. caninum was performed by homemade and commercial indirect ELISA, respectively. Multiple logistic regression analysis was used to verify the factors associated with the seroprevalence. Antibodies anti-T. gondii and anti-N. caninum were observed in 42.7% and in 17.6% of the animals, respectively. The protective factors associated to seropositive were "some level of confinement" (full or semi-extensive confinement) (OR=0.53) for T. gondii and "use of skilled labor" (OR=0.64) for N. caninum. The risk factors were "presence of cats" (OR=1.75) for T. gondii and "feeding of dogs with sheep placental remains" (OR=1.79) for N. caninum. In addition, to presenting a significant and simultaneous seroprevalence for both agents (9.9% of the animals), the results also indicate that deficiencies in management and environmental sanitation, the presence of reservoirs, and types of exploitation enhance the seropositivity. Thus, studies like this might support sanitary programs and public policies for the prevention of T. gondii and N. caninum in the sheep herds of Paraná state.

Resumo O objetivo deste estudo foi avaliar a soroprevalência e os fatores de risco associados à presença de anticorpos contra Toxoplasma gondii e Neospora caninum em ovinos do Paraná. A detecção dos anticorpos para T. gondii e N. caninum foi realizada, usando-se testes de ELISA indireto caseiro e comercial, respectivamente. A análise de regressão logística múltipla foi usada para verificar os fatores de risco associados à soroprevalência. Anticorpos anti-T. gondii e anti-N. caninum foram observados em 42,7% e em 17,6% dos animais, respectivamente. Os fatores de proteção associados à soropositividade foram "algum nível de confinamento (confinamento ou semiextensivo)" (OR=0,53) para T. gondii e "presença de mão de obra especializada" para N. caminum (OR=0,64). Os fatores de risco foram "presença de gatos" para T. gondii (OR=1,75) e "alimentação de cães com resíduos placentários" (OR=1,79) para N. caninum. Além de apresentar uma significante e simultânea soroprevalência para ambos os agentes (9,9% dos animais), os resultados também indicam que as deficiências em gestão e saneamento ambiental, a presença de reservatórios e os tipos de exploração favorecem a soropositividade. Dessa forma, estudos como estes podem auxiliar em programas sanitários e políticas públicas para a prevenção de T. gondii e N. caninum nos rebanhos ovinos do Paraná.

Anthelmintic resistance of Haemonchus contortus from sheep flocks in Brazil: concordance of in vivo and in vitro (RESISTA-Test©) methods / Resistência anti-helmíntica de Haemonchus contortus em rebanhos ovinos no Brasil: concordância de métodos in vivo e in vitro (RESISTA-Test©)

Abstract This study evaluated the resistance status of Haemonchus contortus from sheep flocks in the state of São Paulo, Brazil, through comparison between the fecal egg count reduction test (FECRT) and the larval development test (LDT). For the FECRT, 35 sheep were selected in each of five flocks and divided into groups treated with: benzimidazole, levamisole, ivermectin, monepantel and control. Feces were collected for EPG and fecal cultures. The LDT was performed using thiabendazole (TBZ), levamisole (LEV), ivermectin aglycone (IVM-A) and Zolvix (ZLV). Resistance to all drugs was detected using FECRT in 100% of the flocks, except in relation to ZLV (40% resistant and 20% suspected of resistance). LDT indicated resistance to TBZ and IVM-A in all flocks, to LEV in 80% of flocks and to ZLV in 10%. Total agreement was obtained between the two tests for TBZ and IVM (k = 1.0), while for LEV (k = 0.8) and ZLV (k = 0.9), substantial and almost perfect agreement were obtained, respectively. The concordance between the tests was significant, thus showing that it is possible to use the outcome of the LDT to predict the FECRT, and hence validating the former as a fast diagnostic test for use by sheep farmers in Brazil.

Resumo Este estudo avaliou o status de resistência de Haemonchus contortus em rebanhos ovinos do estado de São Paulo, Brasil, através de um estudo comparativo entre o teste de redução da contagem de ovos nas fezes (TRCOF) e o teste de desenvolvimento larvar (TDL). Para o TRCOF, 35 ovinos foram selecionados em cada um dos cinco rebanhos e divididos em grupos tratados com: benzimidazol, levamisol, ivermectina, monepantel e controle. Fezes foram coletadas para OPG e coproculturas. O TDL foi realizado com tiabendazol-TBZ, levamisol-LEV, ivermectina aglicona-IVM-A e Zolvix-ZLV. Resistência a todos os fármacos foi detectada por meio do TRCOF em 100% dos rebanhos, exceto para ZLV (40% resistentes e 20% suspeitos de resistência). O LDT indicou resistência ao TBZ e IVM-A em todos os rebanhos; em 80% dos rebanhos ao LEV e 10% ao ZLV. Foi obtida concordância total entre os dois testes para TBZ e IVM (k = 1,0), enquanto para LEV (k = 0,8) e ZLV (k = 0,9) foram obtidas concordância substancial e quase perfeita, respectivamente. A concordância entre os testes foi significante, sendo possível usar o resultado do LDT para prever o do TRCOF, validando-se o primeiro como um teste diagnóstico rápido para criadores de ovinos no Brasil.

Toxoplasma gondii and Neospora caninum infections and factors associated in goats in the Parana state, Southern Brazil.

The aim of this study was to determine the occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and their associated factors among goats in farms from the Paraná state, South Brazil. The serological analysis was performed by indirect ELISA on 629 goat serum samples collected from 32 farms distributed in five mesorregions from the state. Seropositivity was observed in 30.7% of the animals for T. gondii, 6.3% for N. caninum, and 3.0% for both agents. Final multiple regression models showed that the use of assisted reproduction decreased the chance of seropositivity for T. gondii (PR=0.70) and the slaughtering site on the farm (PR=2.03) increased it. To N. caninum, the supplying concentrated feed to animals (OR=4.80) and animal pre-weaning death (OR=9.96) increased the chance of seropositivity. The variables associated with these seropositivities suggest deficiencies in sanitation and reproductive management. In addition, it recognizes critical points of infection for animal production management.

Seroepidemiology of ovine toxoplasmosis and neosporosis in breeding rams from Rio Grande do Sul, Brazil.

This study determined the prevalence of ovine toxoplasmosis and neosporosis and the risk factors associated with the development of these diseases in breeding rams from the State of Rio Grande do Sul (RS), Southern Brazil. Serum samples (n = 1,800) from breeding rams maintained on 705 sheep farms from seven mesoregions were evaluated serologically to detect anti-IgG Toxoplasma gondii by indirect ELISA and anti-IgG Neospora caninum by the indirect immunofluorescence assay (IFA). The prevalence of T. gondii was 33.05% (595/1,800); seropositivity to N. caninum was 18.44% (332/1,800). Additionally, there was simultaneous seropositivity (8.94%;161/1,800) to N. caninum and T. gondii. The variables size of the property (<500 ha) (Prevalence Ratio, PR = 1.36); breeding system (semi-intensive/intensive) (PR = 1.23); and natural mounting without control (PR = 1.50) were considered as risk factors for the occurrence of T. gondii. Size of the property (<500 ha) (PR = 1.58) and natural mounting without control (PR = 2.32) were risk factors associated with the prevalence of N. caninum in rams. Additionally, separation of ewes prior to parturition was considered as a protective factor for the occurrence of T. gondii (PR = 0.82) and N. caninum (PR = 0.74). These results demonstrated that these two parasitic disease agents are endemic in rams throughout all regions of RS.

Toxoplasma gondii and Neospora caninum infections and factors associated in goats in the Parana state, Southern Brazil / Infecções por Toxoplasma gondii e Neospora caninum e fatores associados em caprinos no estado do Paraná, Sul do Brasil

Abstract The aim of this study was to determine the occurrence of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and their associated factors among goats in farms from the Paraná state, South Brazil. The serological analysis was performed by indirect ELISA on 629 goat serum samples collected from 32 farms distributed in five mesorregions from the state. Seropositivity was observed in 30.7% of the animals for T. gondii, 6.3% for N. caninum, and 3.0% for both agents. Final multiple regression models showed that the use of assisted reproduction decreased the chance of seropositivity for T. gondii (PR=0.70) and the slaughtering site on the farm (PR=2.03) increased it. To N. caninum, the supplying concentrated feed to animals (OR=4.80) and animal pre-weaning death (OR=9.96) increased the chance of seropositivity. The variables associated with these seropositivities suggest deficiencies in sanitation and reproductive management. In addition, it recognizes critical points of infection for animal production management.

Resumo O objetivo desse estudo foi avaliar a ocorrência de anticorpos anti-Toxoplasma gondii e anti-Neospora caninum e seus fatores associados em caprinos de propriedades do Estado do Paraná, Sul do Brasil. A análise sorológica foi realizada, utilizando-se ELISA indireto em 629 amostras de soro caprino, coletadas em 32 propriedades distribuídas em cinco mesorregiões do Estado. A soropositividade foi observada em 30,7% dos animais para T. gondii, 6,3% para N. caninum e 3,0% para ambos. Os modelos finais de regressão múltipla mostraram que o uso de reprodução assistida reduziu a chance de soropositividade para T. gondii (PR=0,70), enquanto a presença no local de abate na fazenda (PR=2,03) aumentou. Para N. caninum, o fornecimento de ração concentrada (OR=4,80) e a morte dos animais no pré-desmame (OR=9,96) aumentaram a chance de soropositividade. O estudo das variáveis associadas às soropositividades sugere deficiências no saneamento e no manejo reprodutivo dos Animais. Além disso, reconhece pontos críticos para a infecção no manejo da produção animal.

Assessment of anthelmintic activity and bio-guided chemical analysis of Persea americana seed extracts.

The aim of this study was to characterize the extracts and fractions of Persea americana Mill. (Avocado) seeds and to determine the composition and the in vitro anthelmintic activity against third-stage larvae (L3) of Haemonchus contortus. The fresh (F) and dried (H) avocado seeds (PA) were subjected to extraction with hot water (W-PAF, W-PAH), ethanol (E-PAF, E-PAH) or methanol 70% (v/v), and partition with solvents of increasing polarity [n-hexane (H-PAF, H-PAH), chloroform (C-PAF, C-PAH), ethyl acetate (Ea-PAF, Ea-PAH), and n-butanol (B-PAF, B-PAH)], yielding a total of 14 extracts/fractions. After considering the yield, water solubility, and the preliminary results of the larval migration test (LMT), the E-PAF, E-PAH, H-PAF, and H-PAH were selected for further experiments. E-PAH presented an efficiency concentration of 50% (EC50) of 36 µg/mL on the LMT. E-PAH showed the greatest efficiency when its EC50 was compared to the other fractions (E-PAF = 147 µg/mL; H-PAF = 801 µg/mL; H-PAH = 77 µg/mL). After that, the E-PAH was chemically characterized, considering its quantitative polyphenolic and flavonoid contents by colorimetric and chromatographic techniques. E-PAH presented 50, 38, and 24 mg/g of dry matter of total phenol, condensed tannins (CT), and flavonoid contents, respectively. Using high performance liquid chromatography (HPLC) analysis, E-PAH had shown to have epicatechin (4.7 µg/mL), rutin (2.8 µg/mL), and chlorogenic acid (1.4 µg/mL) as its main constituents besides quercetin. These isolated compounds were evaluated using the LMT in order to relate the composition to the anthelmintic activity observed for E-PAH. Quercetin (EC50 = 7.8 µg/mL) and epicatechin (EC50 = 10 µg/mL) presented a higher efficiency than rutin (EC50 = 30 µg/mL). Chlorogenic acid was also tested with the LMT but did not present a significant efficiency. According to the results, the phenolic composition of E-PAH and the EC50 values obtained for the isolated phenols, it can be suggested that, besides the CT content, the presence of epicatechin and rutin contributed to the larvicidal activity of E-PAH. In conclusion, avocado seeds may be used as a source of polyphenols with promising anthelmintic applications.

Efficacy of condensed tannin presents in acacia extract on the control of Trichostrongylus colubriformis in sheep / Eficácia dos taninos condensados presentes no extrato de acácia no controle de Trichostrongylus colubriformis em ovinos

The aim of this study was to evaluate the potential uses of acacia extract (AE) on Trichostrongylus colubriformis control in sheep. The lambs were allocated in three groups of six animals. Two groups were experimentally infected with third-stage larvae of T. colubriformis and one was remained as non-infected control. Thirty days post-infection, the infected animals from treated group were supplemented with AE. During and after the treatment, the values of faecal eggs counts (FEC), number of third-stage larvae recovered per gram of faeces (LPG), number of FEC accumulated per animal during the treatment period, nematode egg viability, and worm burden were determined. Animals from non-infected group did not presented FEC values, during the experimental period. The average of total accumulated amount of FEC output per group, during the 10 days of the treatment was lower in AE treated lambs (P<0.05). The values of egg viability were statistically reduced (P<0.05) on days 4, 7 and 10 post treatment (p.t.). The number of LPG was lower (P<0.05), at the days 10 and 14p.t., in treated animals. AE showed potential to be used on the prophylaxis of gastrointestinal nematode infections in sheep.

O objetivo deste trabalho foi avaliar o potencial do extrato de acácia (EA) para o controle de T. colubriformis em ovinos. Os cordeiros foram alocados em três grupos de seis animais. Dois grupos foram experimentalmente infectados com larvas infectantes de T. colubriformis, sendo um grupo mantido como controle não infectado. Trinta dias pós-infecção, os animais infectados do grupo tratado foram suplementados com EA. Durante e após o tratamento os valores de contagem de ovos por grama de fezes (OPG), número de larvas de terceiro estágio por grama de fezes (LPG), número de OPG eliminado por animal durante o período de tratamento, viabilidade dos ovos e carga parasitária foram determinados. Os animais do grupo não infectado permaneceram com número de OPG igual a zero durante todo o período experimental. A média do número de OPG total eliminado por grupo, somatória durante os 10 dias de tratamento, foi menor nos cordeiros tratados com EA (P<0,05). Os valores de viabilidade dos ovos de helmintos foram menores (P<0,05) nos dias 4, 7 e 10 pós-tratamento (p.t.). O número de LPG foi menor (P<0,05), nos dias 10 e 14p.t., no grupo tratado. O EA demonstrou potencial para sua utilização no controle de T. colubriformis em ovinos.

Use of biotherapic in the control of the natural infestation by Boophilus microplus: pilot study / Uso do bioterapico no controle da infestação natural por Boophilus microplus: estudo piloto

In the control of tick-borne disease (TBD), resistance to chemical products has been reported and a concern with the preservation of the environment requires alternative procedures to control infestation by Boophilus microplus worldwide. The use of biotherapic preparations is one of such alternatives. The aim of this study was to evaluate the effects of a biotherapic mixture including B. microplus in naturally infested cattle. 27 animals were divided in 3 groups (n=9): I – control, received no treatment; II- treated with amitraz dip; III- treated with a standard commercial mixture of biotherapic 12cH, p.o. Group III presented a statistically significant decrease of ticks when compared to the control group (p < 0.05). There was no statistically significant difference between groups II (amitraz) and III (biotherapic) (p < 0.05). These results suggest that biotherapic preparations might be effective in the control of B. microplus in cattle.

No controle de enfermidades transmitidas por carrapatos tem sido notada a resistência a produtos químicos. A preocupação com a conservação do meio ambiente tem exigido procedimentos alternativos para controlar a infestação por Boophilus microplus, em todo o mundo. O uso de bioterápicos representa uma dessas alternativas. O objetivo deste estudo foi avaliar o efeito de uma mistura de bioterápicos incluindo B. microplus, em gado bovino infestado naturalmente. 27 animais foram divididos em 3 grupos (n=9): I) controle sem tratamento; II) tratado com banho de amitraz; III) tratado com mistura comercial de bioterápicos 12 cH, via oral. O grupo III apresentou uma diminuição estatísticamente significativa de carrapatos, em comparação com grupo controle (p < 0,05). Não houve diferença significativa entre os grupo II e III (p < 0,05). Estes resultados sugerem que os preparados de bioterápicos podem ser eficazes para o controle de B. microplus em bovinos.

Use of biotherapic in the control of the natural infestation by Boophilus microplus: pilot study / Uso do bioterapico no controle da infestação natural por Boophilus microplus: estudo piloto

In the control of tick-borne disease (TBD), resistance to chemical products has been reported and a concern with the preservation of the environment requires alternative procedures to control infestation by Boophilus microplus worldwide. The use of biotherapic preparations is one of such alternatives. The aim of this study was to evaluate the effects of a biotherapic mixture including B. microplus in naturally infested cattle. 27 animals were divided in 3 groups (n=9): I – control, received no treatment; II- treated with amitraz dip; III- treated with a standard commercial mixture of biotherapic 12cH, p.o. Group III presented a statistically significant decrease of ticks when compared to the control group (p < 0.05). There was no statistically significant difference between groups II (amitraz) and III (biotherapic) (p < 0.05). These results suggest that biotherapic preparations might be effective in the control of B. microplus in cattle.(AU)

No controle de enfermidades transmitidas por carrapatos tem sido notada a resistência a produtos químicos. A preocupação com a conservação do meio ambiente tem exigido procedimentos alternativos para controlar a infestação por Boophilus microplus, em todo o mundo. O uso de bioterápicos representa uma dessas alternativas. O objetivo deste estudo foi avaliar o efeito de uma mistura de bioterápicos incluindo B. microplus, em gado bovino infestado naturalmente. 27 animais foram divididos em 3 grupos (n=9): I) controle sem tratamento; II) tratado com banho de amitraz; III) tratado com mistura comercial de bioterápicos 12 cH, via oral. O grupo III apresentou uma diminuição estatísticamente significativa de carrapatos, em comparação com grupo controle (p < 0,05). Não houve diferença significativa entre os grupo II e III (p < 0,05). Estes resultados sugerem que os preparados de bioterápicos podem ser eficazes para o controle de B. microplus em bovinos.(AU)

Evaluation of the indirect fluorescent antibody test and modified agglutination test for detection of antibodies against Toxoplasma gondii in experimentally infected pigs

No presente trabalho determinaram-se a sensibilidade e especificidade das técnicas de imunofluorescência indireta (IFAT) e aglutinação modificada (MAT) para a detecção de anticorpos anti-Toxoplasma gondii, analisando-se soros de 46 suínos experimentalmente infectados. O valor de sensibilidade foi de 95,7% (intervalo de confiança de 95%: 84,0-99,2%), de especificidade foi de 97,8% (intervalo de confiança de 95%: 87,0-99,9%), em ambas as provas. Houve ótima concordância de resultados entre IFAT e MAT evidenciado pelo teste de Kappa = 0,86. Estes resultados validam estas provas para a detecção da infecção toxoplásmica em suínos. IFAT e MAT apesar de possuírem metodologias com características e leituras diferentes apresentaram a mesma acurácia nas amostras analisadas.