RESUMO
The impact of Haemonchus contortus infections on nitrogen retention (NR) of hair sheep lambs is unknown. This study estimated the feed intake, digestibility, NR, haematocrit (HT), and their relationship with the gradient of H. contortus infection in hair sheep lambs. Twenty-four hair sheep lambs, 3-4 months old, reared parasite-free were used (live weight (LW) 16.7 ± 1.7 kg). Six lambs were kept parasite-free, nine lambs received a dose of 300 H. contortus infective larvae (L3)/kg LW, and the remaining nine lambs received 500 H. contortus L3/kg LW. Infection doses ranged from 3870 to 9,500 L3. Lambs were individually fed for an average daily gain (ADG) of 100 g. On days 1 (P < 0.01) and 7 (P < 0.001) post-infection (PI), the L3 doses were positively associated with HT, possibly due to platelet recruitment. On week 1 PI, the infection (L3) reduced the crude protein (CP) intake (g/kg metabolic LW) (P < 0.05). A reduction of 1% HT corresponded to 1200 eggs per gram of faeces (EPG) for day 21 PI (P < 0.05), 2300 EPG for day 28 PI (P < 0.001), 2400 EPG for day 35 (P < 0.001), and 1300 EPG for day 41 PI (P < 0.001). However, the HT levels were never lower than 21 %. A lower CP digestibility was associated with EPG only on week 5 PI (P < 0.05). There was no significant association between EPG, Total egg in faeces, or worm burden (WB) with intake, dry matter digestibility (DMD), ADG or NR. The NR of lambs was positive along the different weeks of study irrespective of infection level. The WB was negatively associated only with HT on day 41 PI (P < 0.001), where a 1 % HT reduction was estimated for every 257 worms hosted. In conclusion, no relationship was found between H. contortus infection and DMD, ADG or NR in hair sheep lambs. The cost of H. contortus infection resulted only from the HT reduction and depended on the gradient and stage of the infection.
Assuntos
Hemoncose , Nitrogênio , Doenças dos Ovinos , Ração Animal/análise , Animais , Fezes/química , Hemoncose/fisiopatologia , Hemoncose/veterinária , Haemonchus/fisiologia , Nitrogênio/metabolismo , Óvulo , Contagem de Ovos de Parasitas/veterinária , Ovinos , Doenças dos Ovinos/fisiopatologiaRESUMO
Gastrointestinal nematode infection of small ruminants causes losses in livestock production. Plant compounds show promises as alternatives to commercial anthelmintics that have been exerting selective pressures that lead to the development of drug-resistant parasites. Soybean (Glycine max) is an economical value crop, with a higher protein content compared to other legumes. The objective of this study was to evaluate whether the protease inhibitors exuded from the G. max mature seeds have anthelmintic activity against Haemonchus contortus. To obtain the soybean exudates (SEX), mature seeds were immersed in 100 mM sodium acetate buffer, pH 5.0, at 10 C, for 24 hr. Then the naturally released substances present in SEX were collected and exhaustively dialyzed (cutoff 12 kDa) against distilled water. The dialyzed seed exudates (SEXD) were heated at 100 C for 10 min and centrifuged (12,000 g, at 4 C for 15 min). The supernatant obtained was recovered and designated as the heat-treated exudate fraction (SEXDH). The protein content, protease inhibitor activity, and the effect of each fraction on H. contortus egg hatch rate were evaluated. The inhibition extent of SEX, SEXD, and SEXDH on H. contortus egg proteases was 31.1, 42.9, and 63.8%, respectively. Moreover, SEX, SEXD, and SEXDH inhibited the egg hatching with EC50 of 0.175, 0.175, and 0.241 mg ml-1, respectively. Among the commercial protease inhibitors tested, only EDTA and E-64 inhibited the H. contortus hatch rate (79.0 and 28.9%, respectively). We present evidence demonstrating that soybean exudate proteins can effectively inhibit H. contortus egg hatching. This bioactivity is displayed by thermostable proteins and provides evidence that protease inhibitors are a potential candidate for anthelmintic use.
Assuntos
Exsudatos e Transudatos/química , Glycine max/química , Haemonchus/efeitos dos fármacos , Extratos Vegetais/farmacologia , Inibidores de Proteases/farmacologia , Sementes/química , Animais , Hemoncose/parasitologia , Hemoncose/veterinária , Haemonchus/enzimologia , Haemonchus/fisiologia , Concentração de Íons de Hidrogênio , Peptídeo Hidrolases/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Inibidores de Proteases/isolamento & purificação , Ovinos , Doenças dos Ovinos/parasitologia , Proteínas de Soja/químicaRESUMO
The aim of the present study was to investigate the occurrence of Haemonchus contortus and Haemonchus placei in beef cattle and the frequency of single nucleotide polymorphisms associated with benzimidazole (BZ)-resistance in Haemonchus spp. in Brazil. For such, fecal samples were collected from 61 beef cattle ranches in 11 Brazilian states. Third-stage larvae (L3) were produced for morphological species identification and DNA extraction. PCR was performed for the analysis of the isotype 1 ß-tubulin gene and the products were sequenced to confirm the presence of H. placei and H. contortus. For each field population, pyrosequencing assays were performed to quantify the frequency of the F167Y, E198A and F200Y polymorphisms in the isotype-1 ß-tubulin gene. The results of the morphometric analysis of 2345 larvae showed that H. placei was present on all ranches. The analysis of the isotype 1 ß-tubulin gene confirmed 100% prevalence for H. placei and 23.7% for H. contortus. Pyrosequencing assays demonstrated single-nucleotide polymorphisms (SNPs) associated with BZ-resistance in all three codons (F167Y, E198A and F200Y) of the isotype 1 ß-tubulin gene in H. placei field populations. Frequencies of resistance-associated alleles above background (≥ 15%) were found for at least one codon in 11.4% of the field isolates and maximum frequencies of 30, 21 and 29% were found for codons 167, 198 and 200, respectively, on individual ranches. This study confirms the presence of H. contortus in beef cattle in the major livestock farming states in Brazil and demonstrates that genotypes associated with BZ resistance are present in field populations of Haemonchus spp..
Assuntos
Anti-Helmínticos/farmacologia , Benzimidazóis/farmacologia , Doenças dos Bovinos/epidemiologia , Resistência a Medicamentos/genética , Hemoncose/veterinária , Haemonchus/fisiologia , Polimorfismo de Nucleotídeo Único/genética , Alelos , Animais , Biodiversidade , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Hemoncose/epidemiologia , Hemoncose/parasitologia , Haemonchus/genética , Masculino , PrevalênciaRESUMO
The objective of this trial was to evaluate the period of spelling necessary for a pasture to become free of contamination by infective larvae of gastrointestinal nematodes (GIN) of sheep, in different seasons of the year, as well as to determine when the greatest pasture contamination occurs and how long it lasts. An area was divided into four paddocks, one for each season (spring, summer, autumn, and winter). In order to contaminate the paddocks with free living stages of GIN, eight ewes, naturally infected, grazed on each paddock for 14 consecutive days, starting on the following dates: autumn, on April 4, 2017; winter, on July 4, 2017; spring, on September 26, 2017; summer, on January 2, 2019. At the beginning and end of the grazing period, faecal samples were taken directly from the rectums of the ewes to count eggs per gram of faeces (EPG) and for faecal cultures. Every 14 days pasture samples were collected to assess the number of infective larvae (L3) per kilogram of dry matter. At the end of the 14 day ewe grazing period, 21 stakes were placed where there were faeces on the paddock. Subsequently, every 14 days, the faeces located at three of the stakes were collected and the L3 were recovered. After the exit of the ewes, monthly, two tracer lambs, free of helminth infection, were allocated into the paddock for 14 days. At the end of this period they were housed in covered stalls for 28 days. Faeces from the lambs were collected for individual EPG counting and faecal culture at 21 and 28 days after grazing. Infective larvae recuperation was observed from faeces and pasture in all seasons. In the autumn, spring, and summer, high EPG counts were observed in the first tracer lambs (8521, 4800, and 8064 EPG, respectively), while in winter, high infection (14132 EPG) of the animals was observed only from the second pair of tracer lambs. For a pasture to become "clean", 322 days, 350 days, 294 days, and 182 days following contamination were necessary, respectively, in the autumn, winter, spring, and summer. In autumn, spring, and summer, massive contamination of the pasture with L3 occurred soon after an area had been grazed by infected sheep, while in winter this took a little longer. The contamination persisted, approximately, from a minimum of six months post contamination in summer to up to almost one year post contamination in winter.
Assuntos
Criação de Animais Domésticos , Hemoncose/veterinária , Haemonchus/fisiologia , Doenças dos Ovinos/prevenção & controle , Animais , Brasil , Fazendas , Fezes , Pradaria , Hemoncose/parasitologia , Hemoncose/prevenção & controle , Haemonchus/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Estações do Ano , Ovinos , Doenças dos Ovinos/parasitologia , Fatores de TempoRESUMO
This study aimed to evaluate the dynamics of Haemonchus contortus and Haemonchus placei infections and hybridization between these species in grazing sheep without contact with cattle. On January 14, 2014, sixteen young sheep were infected with 4000 infective H. placei third-stage larvae L3; 11 days later, another group n = 16 was infected with 4000 H. contortus L3. The establishment rates of H. contortus and H. placei L3 were, on average, 61.6 % and 56.8 %, respectively, in the permanent sheep. After the establishment of patent infections, all permanent sheep were allocated together in the same clean pasture where they grazed for the next 12 months. Euthanasia of a sample of the permanent sheep was performed every three months: in May, August, November and February. Two weeks before the sheep were removed for euthanasia, 2 worm-free tracer sheep were introduced to the pasture to evaluate the larval population in the field. The tracer sheep grazed alongside the permanent sheep for 2 weeks. Then, they were housed indoors for 20 days; at the end of this period, they were euthanized. Parasites were recovered from the permanent and tracer sheep and identified using morphological and molecular techniques. A total of 432 worms (from permanent and tracer animals) were analyzed by PCR using species-specific primer pairs. Of these specimens, only two (0.46 %) male worms were identified as hybrids: one was recovered from a permanent animal euthanized in August and the other from a tracer sheep that grazed in May. The last detection of adult H. placei worms occurred in sheep euthanized in May (approximately 3.5 months after the beginning of the grazing period). The morphological evaluation of the L3 produced in fecal cultures showed that H. placei were progressively replaced by H. contortus populations starting in March. The last trace of H. placei L3 was found in August, when a small percentage (0.5 %) of infective larvae with H. placei morphology was identified in a fecal culture. In conclusion, hybridization between H. contortus and H. placei can occur in the field during coinfection. It was demonstrated that H. placei established successfully in artificially infected worm-free sheep; however, with concomitant natural reinfection with H. contortus, the H. placei population showed a rapid decrease and was eliminated within a few months in an environment without cattle.
Assuntos
Coinfecção/veterinária , Hemoncose/veterinária , Haemonchus/fisiologia , Doenças dos Ovinos/epidemiologia , Animais , Coinfecção/epidemiologia , Coinfecção/parasitologia , Fazendas , Feminino , Hemoncose/epidemiologia , Hemoncose/parasitologia , Haemonchus/genética , Haemonchus/crescimento & desenvolvimento , Herbivoria , Hibridização Genética , Larva/crescimento & desenvolvimento , Larva/fisiologia , Masculino , Ovinos , Doenças dos Ovinos/parasitologia , Especificidade da EspécieRESUMO
Abstract This study aimed to evaluate the anthelmintic and ultrastructural effects of Calotropis procera latex on Haemonchus contortus. C. procera latex was twice centrifuged at 10,000×g and dialyzed to obtain a fraction rich in proteins, named LP (latex protein), and at 3,000 rpm to obtain a fraction rich in secondary metabolites, named LNP (latex non-protein). Specimens of H. contortus exposed to LNP, LP and PBS in the Adult Worm Motility Test (AWMT) were submitted to scanning (SEM) and transmission (TEM) electron microscopy to verify changes in their ultrastructure. Phytochemical tests in the LNP indicated the presence of phenols, steroids, alkaloids and cardenolides. High-Performance Liquid Chromatography (HPLC) characterized the presence of the compounds gallic acid and quercetin in the LNP. The protein content in the LP was 43.1 ± 1.1 mg/mL and 7.7 ± 0.3 mg/mL in LNP. In AWMT, LNP and LP inhibited the motility of 100% of the nematodes, with LNP being more effective than LP and ivermectin more effective than both (p <0.05). Cuticle changes were observed by SEM and TEM in nematodes treated with LP and LNP. Calotropis procera latex has anthelmintic effects against H. contortus, causing damage to its cuticle and other alterations in its ultrastructure.
Resumo Este estudo objetivou avaliar os efeitos anti-helmínticos e ultraestruturais do látex de Calotropis procera sobre Haemonchus contortus. Látex de C. procera foi centrifugado duas vezes à a 10.000xg e dialisado para obter uma fração rica em proteínas, denominada proteínas do látex (LP). E centrifugado e centrifugado a 3.000 rpm, para obter uma fração rica em metabólitos secundários, denominada LNP (látex não proteico). Espécimes de H. contortus expostos à LNP, LP e PBS no Teste de Motilidade dos Nematoides Adultos (TMNA) foram submetidos a microscopia eletrônica de varredura (MEV) e de transmissão (MET), para verificar alterações em sua ultraestrutura. Testes fitoquímicos em LNP indicaram a presença de fenóis, esteroides, alcaloides e cardenolídeos. A presença dos compostos ácido gálico e quercetina em LNP foi caracterizada por Cromatografia Líquida de Alta Eficiência (CLAE). O conteúdo de proteínas em LP foi de 43,1 ± 1,1 mg/mL e de 7,7 ± 0,3 mg/mL em LNP. No TMNA, LNP e LP inibiram a motilidade de 100% dos nematoides, sendo LNP mais eficaz que LP, e a ivermectina mais eficaz que ambos (p <0,05). Alterações na cutícula de nematoides tratados com LP e LNP foram observadas por MEV e MET. O látex de C. procera apresenta efeito anti-helmíntico sobre H. contortus, causando danos à sua cutícula e outras alterações em sua ultraestrutura.
Assuntos
Animais , Calotropis/química , Haemonchus/efeitos dos fármacos , Haemonchus/ultraestrutura , Látex/química , Anti-Helmínticos/farmacologia , Fenóis/química , Fitosteróis/química , Saponinas/química , Doenças dos Ovinos/parasitologia , Taninos/química , Triterpenos/química , Técnicas In Vitro , Brasil , Resistência a Medicamentos , Ovinos/parasitologia , Microscopia Eletrônica de Varredura , Cardenolídeos/química , Cromatografia Líquida de Alta Pressão , Alcaloides/química , Hemoncose/veterinária , Haemonchus/isolamento & purificação , Haemonchus/fisiologia , Látex/isolamento & purificação , Antocianinas/químicaRESUMO
Understanding the immunological basis of resistance to gastrointestinal nematode infections in livestock is important in order to develop novel methods of parasite control such as vaccination or genetic selection for parasite resistance. The present study aimed to investigate differences in immune response between parasite resistant Santa Ines and susceptible Ile de France sheep breeds to natural Haemonchus contortus infection. Parasitological parameters, humoral immunity, local and circulating cellular immune responses were evaluated in 19 Santa Ines and 19 Ile de France lambs undergoing different anthelmintic treatments regimens: suppressive treatments (SUP) or targeted selective treatments (TST) over a 5-month grazing period. Santa Ines lambs had significantly lower Haemonchus faecal egg count and worm burden compared to Ile de France regardless of treatment regime. In addition, circulating blood eosinophils count and parasite-specific IgG levels were significantly higher and more rapidly induced in Santa Ines lambs. Abomasal immune responses were generally greater in the resistant breed, which had significantly higher levels of parasite-specific IgA in mucus, and elevated number of globule leukocytes and CD3+ T cells within the abomasal mucosal. Furthermore, numbers of POU2F3+ epithelial cells, a tuft-cell specific transcription factor, were also elevated in the Santa Ines breed, suggesting that this breed is better able to initiate T-helper type 2 immune responses within the abomasum. In conclusion, the differential immunological responses detailed here are relevant to understanding resistance to gastrointestinal nematodes in other host breeds, as well as to resistance breeding as a sustainable control approach for parasitic infections.
Assuntos
Imunidade Adaptativa , Suscetibilidade a Doenças/veterinária , Gastroenteropatias/veterinária , Hemoncose/veterinária , Haemonchus/fisiologia , Imunidade Inata , Doenças dos Ovinos/imunologia , Animais , Brasil , Gastroenteropatias/imunologia , Gastroenteropatias/parasitologia , Hemoncose/imunologia , Hemoncose/parasitologia , Imunidade Celular , Imunidade Humoral , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro DomésticoRESUMO
Infection with Haemonchus contortus is the most economically important gastrointestinal nematode parasitosis and the most important cause of mortality in sheep production. The aim of this study was to estimate variance components of gastrointestinal parasite resistance traits, maternal efficiency (ME) and ewe adult weight (AW) in Santa Inês breed in tropical conditions. The phenotypic records were collected from 700 animals, belonging to four flocks located south-east and north-east in Brazil. The evaluated traits were as follows: degree of anaemia assessed using the FAMACHA chart (FMC), haematocrit (HCT), white blood cell (WBC), red blood cell (RBC), haemoglobin (HGB), platelets (PLT), faecal egg count (EPGlog ), ME, metabolic maternal efficiency (MME), AW and metabolic ewe adult weight (MAW). From the 700 animals, 576 (82% of the evaluated population) were genotyped with the Ovine SNP12k BeadChip (Illumina, Inc.). Markers with unknown genomic position, located on sex chromosomes, monomorphic, with minor allele frequency <0.05, call rate <90% and with excess heterozygosity were excluded. The variance components were estimated using a single-trait animal model with ssGBLUP procedure. The correlation between the parasite's resistance indicators and the ME suggested that selecting animals with both higher adult weight and ME will also favour the selection of animals with better resistance to gastrointestinal nematodes parasites, specially H. contortus. Therefore, since there are few or no studies with Santa Inês breed in this area, it is important to study those traits to better manage selection programs.
Assuntos
Trato Gastrointestinal/fisiologia , Trato Gastrointestinal/parasitologia , Haemonchus/fisiologia , Ovinos/genética , Ovinos/parasitologia , Animais , Feminino , Trato Gastrointestinal/metabolismo , Genótipo , Masculino , Fenótipo , Ovinos/fisiologiaRESUMO
Nematophagous fungi from the feces of water buffalo and soil from southeastern Mexico were isolated, and their in vitro predatory activity against Haemonchus contortus infective larvae (L3) (HcL3) was assessed. The fungi were isolated by sprinkling soil or feces on water agar plates. Six series of 10 Petri dishes containing a 7-day-old culture of each fungus and a series without fungi as the control were prepared. Five hundred HcL3 were added to each plate. The plates were incubated at room temperature. The average of recovered HcL3 was considered to estimate the larval reduction rate. Four nematophagous fungi isolates corresponding to Arthrobotrys oligospora, var microspora (strains 4-276, 269 and 50-80) and one identified as A. oligospora,var. oligospora (isolates 48-80) were obtained from water buffalo feces. From the soil, five isolates were isolated; three corresponded to A. musiformis (Bajío, Yumca and Macuspana isolates), and two isolates were identified as A. oligospora (Comalcalco and Jalapa de Méndez isolates). The predatory activity of isolates from water buffalo feces ranged between 85.9 and 100%. Meanwhile, the fungi from the soil ranged between 55.5 and 100% (p≤0.05). The nematophagous fungi obtained could have important implications in the control of parasites of importance in the livestock industry.
Assuntos
Búfalos/parasitologia , Fezes/parasitologia , Haemonchus/fisiologia , Solo/parasitologia , Animais , Feminino , Haemonchus/classificação , Haemonchus/isolamento & purificação , Masculino , MéxicoRESUMO
Abstract Nematophagous fungi from the feces of water buffalo and soil from southeastern Mexico were isolated, and their in vitro predatory activity against Haemonchus contortus infective larvae (L3) (HcL3) was assessed. The fungi were isolated by sprinkling soil or feces on water agar plates. Six series of 10 Petri dishes containing a 7-day-old culture of each fungus and a series without fungi as the control were prepared. Five hundred HcL3 were added to each plate. The plates were incubated at room temperature. The average of recovered HcL3 was considered to estimate the larval reduction rate. Four nematophagous fungi isolates corresponding to Arthrobotrys oligospora, var microspora (strains 4-276, 269 and 50-80) and one identified as A. oligospora,var. oligospora (isolates 48-80) were obtained from water buffalo feces. From the soil, five isolates were isolated; three corresponded to A. musiformis (Bajío, Yumca and Macuspana isolates), and two isolates were identified as A. oligospora (Comalcalco and Jalapa de Méndez isolates). The predatory activity of isolates from water buffalo feces ranged between 85.9 and 100%. Meanwhile, the fungi from the soil ranged between 55.5 and 100% (p≤0.05). The nematophagous fungi obtained could have important implications in the control of parasites of importance in the livestock industry.
Resumo Fungos nematófagos das fezes de búfalo de água e do solo no sudeste do México foram isolados, e a atividade predatória in vitro contra larvas infectantes de Haemonchus contortus (L3) (HcL3) foi avaliada.Os fungos foram isolados por aspersão de solo e de fezes em placas de agar água. Foram preparadas seis séries de 10 placas de Petri contendo uma cultura de 7 dias de idade de cada fungo e uma série sem fungos como controle. Quinhentos HcL3 foram adicionadas a cada placa. As placas foram incubadas à temperatura ambiente. O número médio de HcL3 recuperadas foi considerado para estimar a taxa de redução larval. Quatro isolados de fungos nematófagos corresponderam a Arthrobotrys oligospora, var microspora (estirpes 4-276, 269 e 50-80) e um isolado identificado como A. oligospora, var. oligospora (isolados 48-80 de fezes de búfalo de água. Do solo, dos cinco isolados três corresponderam a A. musiformis (Bajío, Yumca e Macuspana isolados), e dois isolados foram identificados como A. oligospora (isolados de Comalcalco e Jalapa de Méndez). A atividade predatória de isolados de fezes de búfalo de água variou entre 85,9 e 100%. Enquanto isso, os fungos do solo variaram entre 55,5 e 100% (p≤0,05). Os fungos nematófagos obtidos podem ter importantes implicações nesse controle de parasitos de importância na indústria pecuária.
Assuntos
Animais , Masculino , Feminino , Solo/parasitologia , Búfalos/parasitologia , Fezes/parasitologia , Haemonchus/fisiologia , Haemonchus/isolamento & purificação , Haemonchus/classificação , MéxicoRESUMO
This study aimed to evaluate the simultaneous infections of Haemonchus contortus and Haemonchus placei in sheep, as well as the production of hybrids. A parental group of lambs (n = 6) were mix-infected with 2000 infective larvae (L3) of H. placei and 2000 L3 of H. contortus. Faecal samples were taken from each of these six lambs to produce the first generation of L3 (F1-L3) in individual cultures. These F1-L3 were used to infect 12 lambs; six of them were euthanized at 42 days (Group F1-42) and six at 84 days (Group F1-84) post infection. Polymerase chain reaction (PCR) analysis, using species-specific primer pairs, was the gold standard method for identification of Haemonchus adult species and hybrids. The establishment rate of both species was similar in the parental group: 51.7% H. contortus and 48.3% H. placei. Of the 219 adult specimens from groups F1-42 and F1-84 analysed by PCR, eight (3.65%) were hybrids, 111 were H. contortus and 100 were H. placei. The morphological evaluation of the F1-L3 from the parental group showed a predominance of larvae with H. contortus size (51.5%) in comparison with H. placei (42.8%). In the second generation of L3 (F2-L3) produced by the F1-lambs, larvae with H. contortus morphology predominated, with 81.5% in the F1-42 group and 84.0% in the F1-84 group. In conclusion, an artificial mixed infection by H. contortus and H. placei was established in lambs and resulted in the production of a small number of hybrids among their offspring.
Assuntos
Hemoncose/veterinária , Haemonchus/genética , Hibridização Genética , Doenças dos Ovinos/parasitologia , Animais , Coinfecção/parasitologia , Fezes/parasitologia , Feminino , Hemoncose/parasitologia , Haemonchus/fisiologia , Larva/genética , Larva/fisiologia , Masculino , OvinosRESUMO
The mechanisms responsible for the imbalance between oxidants and antioxidants in sheep infected with Haemonchus contortus are not well established. This study aimed to prove the hypothesis that oxidative stress occurring during infection by H. contortus varies according to breed, and that the parasite burden correlates with hypoalbuminaemia and anaemia. Thus, after deworming and confirming the absence of infection, two different sheep breeds, Suffolk (n = 15) and Santa Ines (n = 22), were orally inoculated with a single dose of 5,000 L3 of H. contortus. The egg counts per gram of faeces (EPG), packed cell volume (PCV) and concentrations of several plasma markers of oxidative stress (lipid peroxidation, albumin, uric acid, total bilirubin, total antioxidant capacity [TAC], total oxidant concentration [TOC] and the oxidative stress index [OSI]) were quantified before (control group) and during the experimental infection (28, 34 and 42 days post-inoculation). In both breeds, TOC increased at 28 days and TAC increased at 42 days. In Suffolk sheep, there was a positive correlation of EPG with oxidant components (28 days) and a negative correlation of EPG with PCV (42 days). In Santa Ines sheep, there was a positive correlation of EPG with bilirubin (r = 0.492; p = 0.020). H. contortus infection caused oxidative stress, which varied according to the breed. Parasite burden was not associated with hypoalbuminaemia, whereas there was a negative correlation with PCV. This research provides the first evidence that the antioxidant status contributes more to the resilience to H. contortus in Santa Ines sheep compared to Suffolk sheep.
Assuntos
Anemia/veterinária , Hemoncose/veterinária , Haemonchus/fisiologia , Hipoalbuminemia/veterinária , Estresse Oxidativo , Doenças dos Ovinos/parasitologia , Anemia/parasitologia , Animais , Fezes/parasitologia , Feminino , Gastroenteropatias/parasitologia , Hemoncose/parasitologia , Hematócrito/veterinária , Hipoalbuminemia/parasitologia , Larva , Peroxidação de Lipídeos , Masculino , Contagem de Ovos de Parasitas/veterinária , OvinosRESUMO
BACKGROUND: Infections of sheep with gastrointestinal parasites, especially Haemonchus contortus, have caused serious losses in livestock production, particularly after the emergence of resistance to conventional anthelmintics. The search for new anthelmintic agents, especially those of botanical origin, has grown substantially due to the perspective of less contamination of meat and milk, as well as other advantages related to their cost and accessibility in less developed countries. The aim of this study was to evaluate the in vitro anthelmintic activity of essential oils of the plant species Citrus aurantifolia, Anthemis nobile and Lavandula officinalis against the main developmental stages of the parasite H. contortus. RESULTS: Plant species were selected based on substantial ethnopharmacological information. Analysis of the composition of each oil by gas chromatography coupled to mass spectrometry (GC-MS) demonstrated the presence of limonene (56.37%), isobutyl angelate (29.26%) and linalool acetate (35.97%) as the major constituents in C. aurantifolia, A. nobile and L. officinalis, respectively. Different concentrations of each oil were tested in vitro for their capacity to inhibit egg hatching (EHT), larval development (LDT) and adult worm motility (AWMT) using a multidrug-resistant strain of H. contortus (Embrapa 2010). The IC50 values obtained for the oils of C. aurantifolia, A. nobile and L. officinalis were 0.694, 0.842 and 0.316 mg/ml in the EHT and 0.044, 0.117 and 0.280 mg/ml in the LDT, respectively. The three oils were able to inhibit adult worm motility completely within the first 8-12 h of observation in the AWMT. CONCLUSIONS: The present results demonstrate significant anthelmintic activity of the three oils against the different developmental stages of H. contortus. Furthermore, this study is of ethnopharmacological importance by validating the anthelmintic activity of the oils studied. Although new experiments are necessary, these data contribute to the development of pharmaceutical-veterinary products for sheep farming by opening up new therapeutic possibilities against gastrointestinal infections caused by H. contortus.
Assuntos
Anti-Helmínticos/farmacologia , Anthemis/química , Citrus/química , Haemonchus/efeitos dos fármacos , Lavandula/química , Óleos Voláteis/farmacologia , Animais , Anti-Helmínticos/isolamento & purificação , Bioensaio , Cromatografia Gasosa-Espectrometria de Massas , Haemonchus/fisiologia , Concentração Inibidora 50 , Larva/efeitos dos fármacos , Larva/fisiologia , Locomoção/efeitos dos fármacos , Óleos Voláteis/química , Óleos Voláteis/isolamento & purificação , Ovinos , Análise de SobrevidaRESUMO
The aim of this study was to evaluate the effect of copper edetate on biochemical parameters, oxidative profile, cholinesterase's activities, as well as its capacity to control gastrointestinal parasites in infected sheep. Thus, Lacaune sheep (n = 18) infected by Haemonchus contortus were used and divided into three groups of six animal each: the group A was composed of untreated animals (the control group), the group B was formed by animals treated with 0.3 mg/kg of copper edetate, and the group C was composed of animals treated with 0.5 mg/kg of copper edetate. Blood collection was performed on days 0, 10, 20 and 30 after mineral supplementation and different variables were measured. Cholinergic system was evaluated to determine the acetylcholinesterase (AChE) activity in total blood and butyrylcholinesterase (BChE) activity in serum. Eggs per gram of feces (EPG) were evaluated. There were no significant differences (P > 0.05) between groups regarding total protein, albumin, globulin and urea levels, GGT activity, as well as the hematocrit, and EPG. ALT activity decreased (P < 0.05) on groups B and C on day 30 compared to the control group (the group A). AChE activity decreased (P < 0.05) in the group C on days 10 and 30 compared to the control group, such decrease (P < 0.05) was also observed for BChE activity in the group C on day 10. ROS levels increased in the group C compared to groups A and B on day 10, while the SOD activity increased in the group C on days 20 and 30 compared to the control group (P < 0.05). CAT activity did not differ between groups (P > 0.05). In summary, the copper edetate was not efficient to control gastrointestinal parasites, but efficiently activated SOD, an important antioxidant enzyme. In addition, copper edetate was able to partially inhibit cholinesterase's activities when supplementated at its highest dose.
Assuntos
Colinesterases/sangue , Ácido Edético/administração & dosagem , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Doenças dos Ovinos/parasitologia , Superóxido Dismutase/sangue , Acetilcolinesterase/sangue , Animais , Butirilcolinesterase/sangue , Inibidores da Colinesterase/farmacologia , Ácido Edético/farmacologia , Ativação Enzimática , Fezes/parasitologia , Hemoncose/metabolismo , Hemoncose/parasitologia , Haemonchus/fisiologia , Oviposição/efeitos dos fármacos , Contagem de Ovos de Parasitas , Espécies Reativas de Oxigênio/metabolismo , Ovinos , Doenças dos Ovinos/metabolismoRESUMO
Calotropis procera is among the species of medicinal plants that have traditionally been used for the treatment of parasites in small ruminants, stimulating the scientific validation of anthelmintic effects. This study aimed to investigate the chemical composition of ethyl acetate extract of Calotropis procera latex (EAECPL), assess the in vitro effect against Haemonchus contortus and the structural changes caused in the adult worm. The latex was collected, lyophilized and subjected to washing with the ethyl acetate solvent to obtain EAECPL. The constituents of the extract were isolated by column chromatography and identified by (13)C and (1)H nuclear magnetic resonance spectroscopy. The egg hatching test (EHT), larval development test (LDT) and adult worms motility test (WMT) were conducted to evaluate the effectiveness of EAECPL on eggs, larvae and adult of H. contortus, respectively. The worms obtained from the WMT, after 24h exposure to EAECPL or controls were observed on a scanning electron microscope (SEM). The results were analysed by variance analysis and compared with Tukey's test (P<0.05). Three compounds were isolated from EAECPL and identified as urs-19(29)-en-3-yl acetate, (3ß)-Urs-19(29)-en-3-ol, and 1-(2',5'-dimethoxyphenyl)-glycerol. In the EHT, EAECPL inhibited larval hatching by 91.8% at dose of 4mg/ml. In the LDT 1mg/ml inhibited 99.8% larval development. In the WMT, EAECPL in the concentration of 100µg/ml inhibited 100% motility of worms, 12h post-exposition. In the SEM, obvious differences were not detected between the negative control worms and the worms treated with EAECPL. In this study, EAECPL showed an effect on inhibition egg hatching, larval development and motility of the adult worms of H. contortus. This should be related both to the identified compounds, as well as the other compounds present in the EAECPL, acting alone or synergistically.
Assuntos
Calotropis/química , Hemoncose/veterinária , Haemonchus/efeitos dos fármacos , Látex/química , Látex/farmacologia , Abomaso/parasitologia , Acetatos , Animais , Fezes/parasitologia , Liofilização/veterinária , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/crescimento & desenvolvimento , Haemonchus/fisiologia , Haemonchus/ultraestrutura , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura/veterinária , Contagem de Ovos de Parasitas/veterinária , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologiaRESUMO
This study evaluated four models based on the number of eggs per gram of faeces (EPG) to segregate Pelibuey or Katahdin ewes during the lactation period into resistant or susceptible to gastrointestinal nematodes (GIN) in tropical Mexico. Nine hundred and thirty EPG counts of Pelibuey ewes and 710 of Katahdin ewes were obtained during 10 weeks of lactation. Ewes were segregated into resistant, intermediate and susceptible, using their individual EPG every week. Then, data of every ewe was used to provide a reference classification, which included all the EPG values of each animal. Then, four models were evaluated against such reference. Model 1 was based on the 10-week mean EPG count ± 2 SE. Models 2, 3 and 4 were based on the mean EPG count of 10, 5 and 2 weeks of lactation. The cutoff points for the segregation of ewe in those three models were the quartiles ≤Q1 (low elimination) and ≥Q3 (high elimination). In all the models evaluated, the ewes classified as resistant had lower EPG than intermediates and susceptible (P < 0.001) while ewes classified as susceptible had higher EPG than intermediate and resistant (P < 0.001). According to J Youden test, models presented concordance with the reference group (>70 %). Model 3 tended to show higher sensitivity and specificity with the reference data, but no difference was found with other models. The present study showed that the phenotypic marker EPG might serve to identify and segregate populations of adult ewes during the lactation period. All models used served to segregate Pelibuey and Katahdin ewes into resistant, intermediate and susceptible. The model 3 (mean of 5 weeks) could be used because it required less sampling effort without losing sensitivity or specificity in the segregation of animals. However, model 2 (mean of 2 weeks) was less labour-intensive.
Assuntos
Criação de Animais Domésticos , Suscetibilidade a Doenças/veterinária , Hemoncose/veterinária , Lactação , Doenças dos Ovinos/diagnóstico , Animais , Suscetibilidade a Doenças/diagnóstico , Suscetibilidade a Doenças/parasitologia , Fezes/parasitologia , Feminino , Hemoncose/diagnóstico , Hemoncose/parasitologia , Haemonchus/fisiologia , México , Modelos Biológicos , Contagem de Ovos de Parasitas , Ovinos , Doenças dos Ovinos/parasitologia , Clima TropicalRESUMO
Effective control of gastrointestinal parasites is necessary in sheep production. The development of anthelmintics resistance is causing the available chemically based anthelmintics to become less effective. Biological control strategies present an alternative to this problem. In the current study, we tested the larvicidal effects of Bacillus thuringiensis var. israelensis Cry11Aa toxin against Haemonchus contortus larvae. Bacterial suspensions [2 × 108 colony-forming units (CFU) g-1 of the feces] of B. thuringiensis var. israelensis and recombinant Escherichia coli expressing Cry11Aa toxin were added to naturally H. contortus egg-contaminated feces. The larvae were quantified, and significant reductions of 62 and 81% (P < 0·001) were, respectively observed, compared with the control group. A 30 mL bacterial suspension (1 × 108 CFU mL-1) of B. thuringiensis var. israelensis and recombinant E. coli expressing Cry11Aa toxin were then orally administered to lambs naturally infected with H. contortus. Twelve hours after administration, feces were collected and submitted to coprocultures. Significant larvae reductions (P < 0·001) of 79 and 90% were observed respectively compared with the control group. The results suggest that the Cry11Aa toxin of B. thuringiensis var. israelensis is a promising new class of biological anthelmintics for treating sheep against H. contortus.
Assuntos
Proteínas de Bactérias/toxicidade , Endotoxinas/toxicidade , Haemonchus/efeitos dos fármacos , Proteínas Hemolisinas/toxicidade , Inseticidas/toxicidade , Animais , Toxinas de Bacillus thuringiensis , Proteínas de Bactérias/genética , Bioensaio , Terapia Biológica/métodos , Modelos Animais de Doenças , Endotoxinas/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Hemoncose/parasitologia , Hemoncose/terapia , Haemonchus/fisiologia , Proteínas Hemolisinas/genética , Larva/efeitos dos fármacos , Larva/fisiologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/toxicidade , Ovinos , Análise de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
With the aim of validating the FAMACHA(©) as a method for phenotypic selection of sheep resistant/resilient to gastrointestinal nematodes, 27 Suffolk ewes with known FAMACHA(©) score histories were experimentally infected with 25,000 larvae of Haemonchus contortus. From the day of infection (day 0) to 60 days post-infection, at intervals of 7-15 days, ewes were evaluated for packed cell volume (PCV) and fecal egg counts (FEC). A statistically significant increase (p<0.05) in FEC occurred between day 0 and day 60. PCV values showed a decrease (p<0.05) starting from day 21, compared to day 0. Based on the changes in FEC and PCV values from day 0 to day 60, 15 ewes (55.56%) were classified as susceptible (S) and 12 ewes (44.44%) as resistant/resilient (RR). A comparison of the average FEC after infection between susceptible (4487.6 eggs per gram-epg) and resistant/resilient (1317.9epg) ewes showed a significant difference (p<0.05) between the two groups. The difference in average PCV values after infection (24.8% and 30.3% for S and RR, respectively) was also significant (p<0.05). Data from 980 previous evaluations of FAMACHA(©) scores from the 27 ewes showed that 58.33% of the ewes classified as RR and 46.67% of the S group had a history of only F1 and F2 scores. In the RR group, only one animal (8.33%) had an F4 score, occurring one time out of the 61 evaluations of this ewe. In contrast, 40.0% of S group ewes had F4 and/or F5 scores. During the period of FAMACHA(©) score history that was evaluated, 69.56% of the total number of anthelmintic treatments in the flock were administered to ewes from group S. Since ewes with F4 and/or F5 scores during the FAMACHA(©) score time period were classified as susceptible during the experimental infection (with the exception of one ewe), we conclude that the FAMACHA(©) score history is a useful tool for the selection of ewes that are resistant/resilient, as well as for the identification of susceptible animals that should be culled.
Assuntos
Criação de Animais Domésticos/métodos , Suscetibilidade a Doenças/veterinária , Hemoncose/veterinária , Doenças dos Ovinos/parasitologia , Animais , Suscetibilidade a Doenças/diagnóstico , Fezes/parasitologia , Feminino , Hemoncose/diagnóstico , Hemoncose/parasitologia , Haemonchus/fisiologia , Hematócrito/veterinária , Contagem de Ovos de Parasitas/veterinária , OvinosRESUMO
Efficient control of gastrointestinal parasites is necessary in sheep breeding. However, the available chemically based anthelmintics are becoming less effective due to the development of parasite resistance. An alternative to this problem is biological control. In the present study, we tested the larvicidal effect of Bacillus circulans by administering a spore suspension (2 × 109 colony forming units/ml) orally to lambs naturally infected with Haemonchus contortus. The number of faecal larvae was quantified daily and a significant reduction (~87%, P< 0.05) of larval development was observed after administration of B. circulans. Using a transformed B. circulans with green fluorescent protein, we were able to detect B. circulans in the faeces at 4 h post-administration and 72 h after cessation of its administration. These results suggest the use of B. circulans as a promising biological alternative for parasite control.
Assuntos
Antibiose , Bacillus/fisiologia , Hemoncose/veterinária , Haemonchus/microbiologia , Larva/microbiologia , Doenças dos Ovinos/terapia , Animais , Fezes/parasitologia , Hemoncose/parasitologia , Hemoncose/terapia , Haemonchus/fisiologia , Larva/fisiologia , Controle Biológico de Vetores , Ovinos , Doenças dos Ovinos/parasitologia , Esporos Bacterianos/fisiologiaRESUMO
The objective of this study was to assess antagonism of nematophagous fungi and species producers metabolites and their effectiveness on Haemonchus contortus infective larvae (L3). Assay A assesses the synergistic, additive, or antagonistic effect on the production of spores of fungal isolates of the species Duddingtonia flagrans, Clonostachys rosea, Trichoderma esau, and Arthrobotrys musiformis; Assay B evaluates in vitro the effect of intercropping of these isolates grown in 2% water-agar (2% WA) on L3 of H. contortus. D. flagrans (Assay A) produced 5.3 × 10(6) spores and associated with T. esau, A. musiformis, or C. rosea reduced its production by 60.37, 45.28, and 49.05%, respectively. T. esau produced 7.9 × 10(7) conidia and associated with D. flagrans, A. musiformis, or C. rosea reduced its production by 39.24, 82.27, and 96.96%, respectively. A. musiformis produced 7.3 × 10(9) spores and associated with D. flagrans, T. esau, or C. rosea reduced its production by 99.98, 99.99, and 99.98%, respectively. C. rosea produced 7.3 × 10(8) conidia and associated with D. flagrans, T. esau, or A. musiformis reduced its production by 95.20, 96.84, and 93.56%, respectively. These results show evidence of antagonism in the production of spores between predators fungi.