RESUMO
Fasciolosis is a food and waterborne disease caused by Fasciola spp., representing a global health burden to various hosts, including humans and other animals. This study investigates the in vitro activity of tellurium- and selenium-containing diaryl dichalcogenides: diacetal ditelluride (LQ07), diacetal diselenide (LQ62), and diacetyl diselenide (LQ68) alone and in combination with ivermectin (IVM) against eggs of Fasciola hepatica. The eggs were exposed for 12 h with each organochalcogen (OC) (0.1 - 2 mmol l-1) and IVM (0.01 - 2 mmol l-1) following an incubation of 15 days, allowing embryonation. The inhibitory concentration of 50 % (IC50) of each OC or IVM was tested with the IC10, IC30, and IC50 of IVM or each OC, respectively. LQ07, LQ62, and LQ68, as well as IVM, demonstrated a concentration-dependent ovicidal activity. The peak ovicidal activity of 99.74 % was achieved when IVM was tested at 2.0 mmol l-1. LQ62 and LQ68 demonstrated greater ovicidal activity, having an IC50 < 0.32 mmol l-1 being 6.25-fold more toxic than IVM alone. The percentage of dead eggs was significantly higher in the IVM group (early mortality), as Se-containing OCs led to the (miracidia) embryonation of the eggs with no hatching (late mortality). Blending Se-containing OCs and IVM showed an additive effect of up to 27 % against F. hepatica eggs. The present data contribute to the potential use of blending-based therapeutic strategies to combat F. hepatica infections in eradication programs worldwide. The combinations may also act against multidrug-resistant strains, reinstating drug-based parasite control.
Assuntos
Fasciola hepatica , Ivermectina , Animais , Fasciola hepatica/efeitos dos fármacos , Ivermectina/farmacologia , Anti-Helmínticos/farmacologia , Concentração Inibidora 50 , Óvulo/efeitos dos fármacos , Calcogênios/farmacologia , Calcogênios/química , Fasciolíase/tratamento farmacológico , Fasciolíase/parasitologia , Fasciolíase/veterináriaRESUMO
Fasciolosis, a globally re-emerging zoonotic disease, is mostly caused by the parasitic infection with Fasciola hepatica, often known as the liver fluke. This disease has a considerable impact on livestock productivity. This study aimed to evaluate the fluke burdens and faecal egg counts in goats that were administered phage clones of cathepsin L mimotopes and then infected with F. hepatica metacercariae. Additionally, the impact of vaccination on the histology of the reproductive system, specifically related to egg generation in adult parasites, was examined. A total of twenty-four goats, which were raised in sheds, were divided into four groups consisting of six animals each. These groups were randomly assigned. The goats were then subjected to two rounds of vaccination. Each vaccination involved the administration of 1 × 1013 phage particles containing specific mimotopes for cathepsin L2 (group 1: PPIRNGK), cathepsin L1 (group 2: DPWWLKQ), and cathepsin L1 (group 3: SGTFLFS). The immunisations were carried out on weeks 0 and 4, and the Quil A adjuvant was used in combination with the mimotopes. The control group was administered phosphate-buffered saline (PBS) (group 4). At week 6, all groups were orally infected with 200 metacercariae of F. hepatica. At week 22 following the initial immunisation, the subjects were euthanised, and adult F. hepatica specimens were retrieved from the bile ducts and liver tissue, and subsequently quantified. The specimens underwent whole-mount histology for the examination of the reproductive system, including the testis, ovary, vitellaria, Mehlis' gland, and uterus. The mean fluke burdens following the challenge were seen to decrease by 50.4%, 62.2%, and 75.3% (p < 0.05) in goats that received vaccinations containing cathepsin L2 PPIRNGK, cathepsin L1 DPWWLKQ, and cathepsin L1 SGTFLFS, respectively. Animals that received vaccination exhibited a significant reduction in the production of parasite eggs. The levels of IgG1 and IgG2 isotypes in vaccinated goats were significantly higher than in the control group, indicating that protection is associated with the induction of a mixed Th1/Th2 immune response. The administration of cathepsin L to goats exhibits a modest level of efficacy in inducing histological impairment in the reproductive organs of liver flukes, resulting in a reduction in egg output.
Assuntos
Catepsina L , Fasciola hepatica , Fasciolíase , Cabras , Vacinação , Animais , Fasciola hepatica/imunologia , Catepsina L/metabolismo , Fasciolíase/veterinária , Fasciolíase/prevenção & controle , Fasciolíase/imunologia , Fasciolíase/parasitologia , Vacinação/métodos , Feminino , Masculino , Doenças das Cabras/parasitologia , Doenças das Cabras/prevenção & controle , Doenças das Cabras/imunologia , Contagem de Ovos de Parasitas , Bacteriófagos/imunologiaRESUMO
Fascioliasis is a parasitic disease that affects both people and a wide variety of animals, primarily herbivores. In Latin America and the Caribbean, it is caused by the trematode Fasciola hepatica. Fascioliasis is classified by the World Health Organization (WHO) as one of the neglected tropical diseases. The Pan American Health Organization (PAHO), as part of its commitment to achieving the goals of the 2030 Agenda for Sustainable Development and the Sustainable Health Agenda for the Americas 2018-2030, has launched an initiative to eliminate communicable diseases in the Region of the Americas, which includes among its objectives the elimination of fascioliasis as a public health problem in the Americas by 2030. These operational guidelines have been developed to provide information and guidance to support endemic countries in advancing towards and achieving that goal. They have been prepared with the support of technicians from the countries as well as expert professionals from the Region and the WHO Collaborating Centre on fascioliasis and its vector snails, attempting to incorporate current practices and considering the challenges and particularities of endemic areas. While fasciolosis in animals is a problem in many countries of the Region, leading to economic losses, human fascioliasis is limited to environments where the ethnographic characteristics and socio-economic determinants necessary for human infection are present. These operational guidelines focus on such areas, typically associated with small-scale farmers and rural communities, and are framed within the "One Health" approach, integrating different sectors involved, working together and synergistically to make interventions more effective and sustainable.
Assuntos
Fasciolíase , Fasciola hepatica , Zoonoses , Saúde Pública Veterinária , Doenças TransmissíveisRESUMO
The transmission of Fasciola hepatica occurs only where there are -or recently were- aquatic or amphibious snails of the Lymnaeidae family, the intermediate host of this parasite. Direct detection of these snails is time-consuming and imprecise, hindering accurate and detailed mapping of transmission risk. To identify which microenvironmental factors could be used as proxies for the occurrence of the lymnaeid snail Galba viator, a major intermediate host in South America, a total of 183 1-m2 quadrants across diverse water bodies in an endemic area in Andean Patagonia were manually timed-searched for snails and microenvironmental variables were registered. Data was analyzed using a Bayesian hierarchical occupancy model that assessed the effects of the microenvironmental variables on the presence of snails while considering imperfect snail detection. The model estimated that G. viator predominantly inhabits shallow aquatic environments, in the presence of grasses, where snails of the genus Biomphalaria are also detected, and with scarce tree canopy cover. Physical factors affecting occupancy presumably act as proxies for the average water temperature, while the temperature at the time of sampling was found to affect snail detectability. The identified variables are easy, fast, and inexpensive to measure, and can complement management decisions and risk maps based on coarser remote-sensing data, particularly relevant in a context of growing resistance to anthelminthic drugs.
Assuntos
Fasciola hepatica , Caramujos , Temperatura , Água , Animais , Fasciola hepatica/fisiologia , Caramujos/parasitologia , Água/parasitologia , Água/química , Argentina/epidemiologia , Fasciolíase/veterinária , Fasciolíase/epidemiologia , Fasciolíase/parasitologia , Teorema de BayesRESUMO
Fascioliasis is a trematodiasis that affects domestic and wild animals as well as humans worldwide. It is a well-recognized disease in livestock, were it produces serious economic losses. Yet in cattle, there is limited information about the burden of liver flukes and its relation to the eggs per gram shed to the environment. There is also lack of knowledge on the effect of parasite load in blood parameters of infected animals, which is important to evaluate the severity and progression of the disease. The objective of this work was to gain insight in these aspects. Cattle from Mendoza province, Argentina, were inspected at a farm and at the abattoir determining the presence or absence of Fasciola hepatica. Each animal was sampled for blood and feces and in the slaughterhouse the livers were inspected. Hematology and blood chemistry parameters were determined, feces were examined for F. hepatica eggs by a quantitative sedimentation technique and livers were thoroughly inspected to determine the number of flukes. Infected cattle presented a mild burden of liver flukes per animal, strongly correlated (r = 0.72) to the number of eggs per gram of feces. The total number of eggs (XÌ=35,100) shed per animal to the environment and the type of livestock management techniques in the region exacerbate the role of cattle as efficient reservoirs of this disease. Statistically significant lower red blood cell, lymphocyte and neutrophil counts were observed in infected compared to uninfected animals. All hepatic parameters tested showed highly statistically significant differences (p < 0.001) as well as proteins by cause of rise of globulins in infected cattle. The correlation between the amount of flukes in the liver and the number of eggs per gram of faces indicates coprology as a reliable and cost-effective method to infer parasite burden. The impact of fascioliasis on blood parameters can be of aid for the veterinary practitioner on the assessment of this disease on cattle.
Assuntos
Doenças dos Bovinos , Fasciola hepatica , Fasciolíase , Fezes , Carga Parasitária , Animais , Fasciolíase/veterinária , Fasciolíase/sangue , Fasciolíase/parasitologia , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/sangue , Doenças dos Bovinos/epidemiologia , Fezes/parasitologia , Fasciola hepatica/isolamento & purificação , Argentina/epidemiologia , Contagem de Ovos de Parasitas , Fígado/parasitologia , Análise Química do Sangue , Doença Crônica , MatadourosRESUMO
There are various diagnostic techniques available for chronic fasciolosis in ruminants. However, many of them exhibit low specificity and sensitivity, making them impractical for field use and in low-resource laboratories. The present study evaluates the usefulness of the Natural Sedimentation technique in diagnosing chronic fasciolosis in three domestic species conducted at the Laboratorio de Parasitología y Enfermedades Parasitarias, Facultad de Ciencias Veterinas, Universidad Nacional de Cajamarca. Fecal samples were collected from n = 323 cattle, n = 362 sheep, and n = 231 swine for Fasciola hepatica fecal egg counts. The visualization of adult parasites in animal livers post-mortem was considered the gold standard. Additionally, the sensitivity of the technique was evaluated using five different amounts of feces. In cattle, a sensitivity of 0.93 ± 0.03, specificity of 0.91 ± 0.06, positive predictive value of 0.96 ± 0.03, and negative predictive value of 0.86 ± 0.07 were obtained. In sheep, a sensitivity of 0.79 ± 0.05, specificity of 0.83 ± 0.07, positive predictive value of 0.90 ± 0.04, and negative predictive value of 0.66 ± 0.08 were observed. In swine, a sensitivity of 0.92 ± 0.06, specificity of 1.00 ± 0.00, positive predictive value of 1.00 ± 0.00, and negative predictive value of 0.96 ± 0.03 were found. There was no statistical difference in egg counts when using 1, 2, 3, 4, and 5 g of feces (p = 0.907). Furthermore, 1 to 688 fecal eggs of F. hepatica were counted in 1 g of feces. The Natural Sedimentation technique has both qualitative and quantitative applications with satisfactory results when using 1 g of feces in the diagnosis of chronic fasciolosis in domestic animals. Due to its simplicity, it can be implemented in field conditions and low-resource laboratories.
Assuntos
Doenças dos Bovinos , Fasciola hepatica , Fasciolíase , Fezes , Contagem de Ovos de Parasitas , Sensibilidade e Especificidade , Doenças dos Ovinos , Doenças dos Suínos , Animais , Fasciolíase/diagnóstico , Fasciolíase/veterinária , Fasciolíase/parasitologia , Fezes/parasitologia , Ovinos , Doenças dos Ovinos/parasitologia , Doenças dos Ovinos/diagnóstico , Bovinos , Fasciola hepatica/isolamento & purificação , Contagem de Ovos de Parasitas/métodos , Contagem de Ovos de Parasitas/veterinária , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/parasitologia , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/parasitologia , Doença CrônicaRESUMO
Bovine fasciolosis is a parasitic disease with a global reach. Coprological based on egg detection in fecal samples and liver inspection to evaluate the presence of the parasite is currently the gold standard for diagnosing chronic fasciolosis in cattle. However, these techniques are labor-intensive and ineffective during the acute phase of the disease. Serodiagnosis using native and recombinant antigens has become an interesting alternative in efforts to identify cattle fasciolosis. We evaluated cattle from abattoir (n = 139) and farms (n = 500) through liver inspection and coprological examination, respectively. Our laboratory team optimized and validated enzyme-linked immunosorbent assay tests based on somatic antigen, excretory/secretory proteins, and the recombinant antigen cathepsin L-1 to detect serum antibodies against fasciolosis in cattle. For animals from abattoir, 10 were positive for fasciolosis according to liver inspection. Both FhES and FhrCL-1 presented an area under the receiver operating characteristic (AUROC) curve of 0.80, with a sensitivity of 0.80 (95% CI: 0.46-0.95) and 0.70 (95% CI: 0.38-0.90) and specificity of 0.81 (95% CI: 0.73-0.87) and 0.87 (95% CI: 0.80-0.92), respectively. For those cattle from farms, 28 were positive only for fasciolosis according to coprological examination. In this scenario, FhES gave the best performance, with an AUROC of 0.84, sensitivity of 0.79 (95% CI: 0.60-0.90), and specificity of 0.86 (95% CI: 0.82-0.89). In conclusion, our study highlights the potential of serodiagnosis for accurately screening cattle fasciolosis. The promising sensitivity and specificity values of FhES when compared to liver inspection or coprological examination enhance its importance for cattle fasciolosis diagnosis. IMPORTANCE: The aim of this article was to identify antibodies against fasciolosis in cattle in Brazil. The methodology was reproduced in our laboratory and applied for the first time to the Brazilian cattle herd. The antigens tested can be used as a screening test and thus speed up the diagnosis of bovine fascioliasis.
Assuntos
Anticorpos Anti-Helmínticos , Antígenos de Helmintos , Doenças dos Bovinos , Ensaio de Imunoadsorção Enzimática , Fasciolíase , Sensibilidade e Especificidade , Animais , Bovinos , Fasciolíase/diagnóstico , Fasciolíase/veterinária , Fasciolíase/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/parasitologia , Antígenos de Helmintos/imunologia , Brasil , Anticorpos Anti-Helmínticos/sangue , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/genética , Fezes/parasitologia , Testes Sorológicos/métodos , Testes Sorológicos/veterinária , Fasciola hepatica/imunologia , Matadouros , Curva ROC , Fígado/parasitologiaRESUMO
Despite the importance of fish-borne trematodes of the family Opisthorchiidae as causative agents of human liver fluke disease, studies on these parasites outside Asia are relativally scarce. In South America, human focus of amphimerosis is known in Ecuador since the mid-20th century, and Amphimerus spp. have also been reported in wild and domestic mammals. Nevertheless, the knowledge on the snails that act as the first intermediate host of these potentially zoonotic parasites are scarce. Herein, a new cercaria of the pleurolophocercous morphotype found in the freshwater snail Idiopyrgus souleyetianus from Brazil was subjected to morphological and molecular studies. Multigene phylogenetic analyses based on 28S, 5.8S-ITS-2 and Cox-1 sequences enabled the identification of Amphimerus sp., a species distinct from that reported in humans from Ecuador. This cercariae was morphologically compared with other opisthorchiid cercariae known. The possible occurrence of human amphimerosis in Brazil is discussed.
Assuntos
Fasciola hepatica , Opisthorchidae , Trematódeos , Infecções por Trematódeos , Animais , Humanos , Brasil , Filogenia , Caramujos/parasitologia , Cercárias/genética , Cercárias/anatomia & histologia , Infecções por Trematódeos/epidemiologia , Infecções por Trematódeos/veterinária , Infecções por Trematódeos/parasitologia , MamíferosRESUMO
In this study, we present the preparation, stability, and in vivo fasciolicidal activity of three new intramuscular formulations in sheep of a prodrug based on triclabendazole, named fosfatriclaben. The new formulations were ready-to-use aqueous solutions with volumes recommended for intramuscular administration in sheep. The use of poloxamers (P-407 and P-188) and polysorbates (PS-20 and PS-80) in the new formulations improved the aqueous solubility of fosfatriclaben by 8-fold at pH 7.4. High-performance liquid chromatography with UV detection was used to evaluate the stability of fosfatriclaben in the three formulations. High recovery (> 90%) of fosfatriclaben was found for all formulations after exposure at 57 ± 2 °C for 50 h. The three intramuscular formulations showed high fasciolicidal activity at a dose of 6 mg/kg, which was equivalent to the triclabendazole content. The fasciolicidal activity of fosfatriclaben was similar to commercial oral (Fasimec®) and intramuscular (Endovet®) triclabendazole formulations at a dose of 12 mg/kg. In the in vivo experiments, all formulations administered intramuscularly reduced egg excretion by 100%, and formulations F1, F2, and F3 presented fasciolicidal activities of 100%, 100%, and 99.6%, respectively.
Assuntos
Anti-Helmínticos , Fasciola hepatica , Fasciolíase , Pró-Fármacos , Doenças dos Ovinos , Animais , Ovinos , Triclabendazol , Fasciolíase/veterinária , Anti-Helmínticos/uso terapêutico , Pró-Fármacos/química , Benzimidazóis/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Água/químicaRESUMO
Fasciola hepatica, a worldwide distributed helminth, has a robust immunoregulatory effect in the host, increasing the susceptibility to secondary infections. Foot and mouth disease (FMD) is a highly contagious acute vesicular viral disease effectively controlled by vaccination in endemic regions. Despite the evidence of immunoregulatory effects, the impact of fasciolosis on the immune response induced by FMD vaccination in cattle has never been assessed. Our objective was to evaluate whether the infection by F. hepatica in cattle influences the long-term immunity elicited by the currently used commercial FMD-inactivated vaccines. Aberdeen Angus steers negative for F. hepatica were vaccinated twice against FMD virus (FMDV) during the first 6 months of age using a commercial oil vaccine formulated with A24/Cruzeiro and O1/Campos strains. When maternal antibodies against F. hepatica were weaned (18--20 months of age) animals were divided into groups of 12 and infected or mock-infected with 500 metacercariae/animal. Individual serum samples were collected at 0-, 28-, 59-, 87- and 157-days post-infection (dpi). Indirect ELISAs were used to detect A24/Cruzeiro specific bovine IgG and IgG subtypes. The total IgG antibody levels and avidity against FMDV did not show significant differences between all the groups. The commercial vaccine induced higher IgG2 than IgG1 titers in vaccinated animals. Anti-FMDV IgG1 levels significantly decreased in the infected group at 28 dpi. In addition, the avidity of IgG1 FMDV-specific antibodies at day 28 in the infected group was reduced compared to the control. These results show that F. hepatica infection modified anamnestic responses against FMDV, reducing serum IgG1 titers and avidity. To our knowledge, this is the first report of immune-regulation of F. hepatica altering the immune response of FMD vaccines, one of the most globally used animal vaccines.