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In the present study, we evaluated and compared the in vitro biological parameters of the evolutionary stages of R. microplus (female, eggs, and larva) from two extreme regions of Brazil: Santa Rita (SR) northeast region and Bagé (BG) southern region. For this, all stages were maintained at 23, 27, and 32°C with a relative humidity (RH) of 65, 80, and 100%. The mean incubation period was 43.7 to 53.7 days (SR population) and 59.0 to 56.1 days (BG population) at 23°C and 18.0 to 19.3 days (SR population) and 16.8 to 21.2 days (BG population) at 32°C. Eggs incubated at 23°C (65, 80, and 100% RH) of SR and BG populations showed a similar egg hatching percentage (P > 0.05). The egg hatching percentage of the SR population (30.5 to 98.0%) was always higher than that of the BG population (8.7 to 85.5%; P < 0.05) when incubated at 32°C and 65, 80, or 100% RH. Deleterious effects on the larval survival period from SR and BG were observed under all experimental conditions (temperature and RH), especially at 23 and 32°C. However, they were more intense on larvae at 32°C (all RH). Under 80 and 100% RH, the mean period of larval survival did not exceed 65 days, being shortest for the BG population (mean: 42.7 days [80% RH] and 55.1 days [100% RH]) compared with the SR population.

Gastrointestinal nematodes affect the animal's health and cause economic losses in meat, milk, and wool production. Essential oils and their terpenoids have been shown to effectively control gastrointestinal nematodes and may be an alternative to control gastrointestinal nematodes. The great advantage of terpenoids is the possibility of acting on the parasite in a multidirectional way on the neuromuscular system and body structures of nematodes. The current chapter describes the pharmacological basis of the combination of terpenes and synthetic anthelmintics as an alternative for increasing antiparasitic efficacy. It is necessary to evaluate if these combinations show antagonist, additive or synergic effects at the pharmacokinetic and pharmacodynamic levels. The physicochemical properties, pharmacokinetic features and potential drug drug interactions at the metabolism or transport level of monoterpenes may be relevant for obtaining effective concentrations against different nematodes. In this context, the prediction of absorption, distribution, metabolism and excretion (ADME) is essential to optimize the anthelmintic action of these compounds. The rapid absorption and elimination of monoterpenes after their oral administration may directly influence the drug concentration level attained at the target parasites and the resultant pharmacological effect. Therefore, investigations on the dose schedule, administration route and type of pharmaceutical formulation are necessary. The integration of in vitro assays, in silico analysis, and in vivo pharmaco-parasitological studies are relevant to corroborate the kinetic/metabolic interactions and the efficacy of bioactive natural products combined with synthetic anthelmintics

Citrus fruits are consumed all over the world and their by-products are used for animal feed and essential oils production. This study aimed to evaluate the in vitro and in vivo activity of Citrus aurantium var. Dulcis essential oil (CaEO) combined with ABZ against benzimidazole resistant Haemonchus contortus. In vitro egg hatching assays (EHA) were performed using CaEO and ABZ to estimate the effective concentration to achieve 50% egg death (EC50) values and calculate the test essential oil and drug combinations using a simplex-centroid mixture design. These concentrations were used for a second round of EHAs. Sixteen sheep were randomly allocated into two groups and treated with ABZ and the combination of CaEO and ABZ, and faecal egg count reduction tests were performed. In the first round of EHA, CaEO and ABZ showed EC50 values of 0.57 and 0.0048 mg mL-1, respectively. The H. contortus strain used in the study was shown to be highly benzimidazole resistant, with only 1.5% of parasites having susceptible ß-tubulin SNP genotypes. The ABZ reduced the shedding of nematode eggs by 78%, however, its combination with CaEO reduced faecal egg counts by only 9%. The present study is important to highlight the interferences of natural products in anthelmintic metabolism and consequently in drug efficacy.

Previous studies have illustrated that different bioactive legume fodders containing condensed tannins might represent one of the options for integrated sustainable control of gastrointestinal nematodes (GIN) in ruminants, which may help address the worldwide development of resistance to synthetic anthelmintics. More recently, impetus has been given to assess the potential antiparasitic activity of less conventional resources, represented by different agro-industrial by-products (AIBPs). This review presents in vitro and in vivo results obtained with a range of tannin-containing AIBPs of various geographical and botanical origins, namely AIBP of nuts, temperate and tropical barks, carob, coffee and cocoa. They tend to confirm the "proof of concept" for their antiparasitic effects and also for other aspects of ruminant production in an agro-ecological context. Socio-economic aspects of the exploitation of such non-conventional resources are also discussed as potential models of the circular economy, by using waste. The different modes of use of these resources are presented in this review, as well as strengths, weaknesses, opportunities, and threats (SWOT) analyses to illustrate the advantages and limitations of on-farm use.Utilisation de sous-produits agro-industriels contenant des tanins pour le contrôle intégré des nématodes gastro-intestinaux chez les ruminants.Plusieurs études antérieures ont illustré le fait que des légumineuses bioactives contenant des tannins condensés peuvent représenter une des alternatives à intégrer avec d’autres options pour une maitrise durable des nématodes gastro-intestinaux en réponse au développement constant et à l’expansion continue à l’échelle mondiale des résistances aux anthelminthiques de synthèse. Des recherches plus récentes se sont intéressées au potentiel d’application de ressources moins conventionnelles que représentent des coproduits agroindustriels (CPAI). Cette revue vise à présenter des résultats in vitro et in vivo obtenus avec une gamme de CPAI d’origines géographiques et botaniques diversifiées (coproduits de l’industrie des noix, du bois (en régions tempérées et tropicales), du caroubier, du café et du cacao). Ces résultats ont confirmé la preuve de concept pour les effets antiparasitaires, et aussi pour d’autres volets de la production des ruminants dans un contexte agro écologique de l’élevage. Par ailleurs, les aspects socio-économiques d’exploitation de ces ressources, considérées jusqu’à présent comme des déchets, dans un modèle de circuits courts sont aussi évoqués. Les avantages et inconvénients des différentes modalités d’exploitation des CPAI sont aussi discutés dans le cadre d’une analyse SWOT.

Our current understanding of differences in the epidemiology of gastrointestinalnematode (GIN) species in co-grazed sheep and goats is inadequate with reference to the development of sustainable control strategies. The next-generation metabarcoded sequencing method referred to as the ‘nemabiome’ allows some of these differences to be explored to describe the intensity of co-infecting GIN species. We applied this platform to study sheep and goats that were co-grazed on Guinea grass pasture in northeastern Brazil. Co-grazed goats and sheep were treated with a monepantel anthelmintic, then exposed to the same gastrointestinal nematode species. Overall, there were differences in the prevalence of GIN species identified in the sheep and goats;Trichostrongylus colubriformis and Teladorsagia circumcincta predominated in goat kids, while Haemonchus contortus predominated in adult does, ewes and lambs once burdens became re-established after anthelmintic treatment. Description of the pattern of re-infection following anthelmintic treatment was prevented by the unpredicted poor efficacy of 2.5 mg/kg and 5 mg/kg, respectively, of monepantel against O. columbianum and T. circumcincta in lambs, and T. circumcincta adult does. Differences in drug efficacy between host age and species groups may be important when considering sustainable GIN control strategies for co-grazed animals. The aggregated FECs of the adult does and goat kids representing re-established GIN burdens, were higher than those of the co-grazedadult ewes and lambs. This implies that there are inherent differences in GIN species adaptation to the two naïve small ruminant host species, and shows the need for better understanding of the factors giving rise to this situation associated with exposure to infective larvae and host responses. At the start of the study, the adult does were coinfected with several GIN species, with the highest intensity of T. circumcincta, contrasting with the situation in the adult ewes, in which H. contortus predominated.However, once burdens became re-established after treatment, H. contortus predominated in both adult does and ewes. This demonstrates the potential for host burdens of H. contortus to establish and predominate after anthelmintic treatment when burdens of coinfecting GIN species are low.

Los anfibios hospedan una amplia variedad de parásitos, sea de forma temporal (hospedero paraténico), intermediaria o definitiva. Solamente un 8% de los anfibios en Brasil han sido investigados con relación a sus helmintos asociados, por lo que en este trabajo analizamos 20 especímenes de Rhinella jimi Stevaux, 2002 colectados en los estados de Ceará y Rio Grande do Norte, en la región Nordeste de Brasil. Siete taxones de nematodos se encontraron infectando individuos de R. jimi (Oswaldocruzia lopesi Travassos, 1938, Raillietnema spectans Gomes, 1964, Physaloptera sp., Parapharyngodon sp., Rhabdias sp., Cosmocercidae, y una larva no identificada). Todas las especies encontradas representan nuevos registros de parásitos para R. jimi, resultado que amplía los registros de nematodos para esta especie, así como aumentan el conocimiento de la diversidad de parásitos en anuros para América del Sur.

Made available in DSpace on 2020-12-12T01:36:15Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-01-01 Ornithonyssus bursa: is a haematophagous mite of veterinary and public health concern. The association between O. bursa and humans in Brazil has been known for several decades, but most of the information is limited and confusing. Herein, we present an overview of the cases of gamasoidosis in Brazil based on published and new records. Wild birds are common sources for human infestation, especially omnivorous and insectivorous birds that live in urban and rural environments. Species of the Columbidae are the most common birds associated with O. bursa in Brazil. Program in Biotechnology Department of Pathology Veterinary Parasitology State University of Maranhão Department of Preventive Veterinary Medicine and Animal Health Faculty of Veterinary Medicine University of São Paulo Department of Microbiology and Parasitology Center for Health Sciences UFSM Department of Animal Parasitology Federal Rural University of Rio de Janeiro UFRRJ Department of Veterinary Pathology Faculty of Agrarian and Veterinary Sciences Paulista State University -UNESP Department of Chemical Engineering UFMA Department of Veterinary Pathology Faculty of Agrarian and Veterinary Sciences Paulista State University -UNESP