RESUMEN

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.

Asunto(s)

Fasciola hepatica , Ivermectina , Animales , Fasciola hepatica/efectos de los fármacos , Ivermectina/farmacología , Antihelmínticos/farmacología , Concentración 50 Inhibidora , Óvulo/efectos de los fármacos , Calcógenos/farmacología , Calcógenos/química , Fascioliasis/tratamiento farmacológico , Fascioliasis/parasitología , Fascioliasis/veterinaria

RESUMEN

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.

Asunto(s)

Catepsina L , Fasciola hepatica , Fascioliasis , Cabras , Vacunación , Animales , Fasciola hepatica/inmunología , Catepsina L/metabolismo , Fascioliasis/veterinaria , Fascioliasis/prevención & control , Fascioliasis/inmunología , Fascioliasis/parasitología , Vacunación/métodos , Femenino , Masculino , Enfermedades de las Cabras/parasitología , Enfermedades de las Cabras/prevención & control , Enfermedades de las Cabras/inmunología , Recuento de Huevos de Parásitos , Bacteriófagos/inmunología

RESUMEN

Fasciola hepatica is a parasitic trematode that infects livestock animals and humans, causing significant health and economic burdens worldwide. The extensive use of anthelmintic drugs has led to the emergence of resistant parasite strains, posing a threat to treatment success. The complex life cycle of the liver fluke, coupled with limited funding and research interest, have hindered progress in drug discovery. Our group has been working in drug development against this parasite using cathepsin proteases as molecular targets, finding promising compound candidates with in vitro and in vivo efficacy. Here, we evaluated hybrid molecules that combine two chemotypes, chalcones and quinoxaline 1,4-di- N-oxides, previously found to inhibit F. hepatica cathepsin Ls and tested their in vitro activity with the isolated targets and the parasites in culture. These molecules proved to be good cathepsin inhibitors and to kill the juvenile parasites at micromolar concentrations. Also, we performed molecular docking studies to analyze the compounds-cathepsins interface, finding that the best inhibitors interact at the active site cleft and contact the catalytic dyad and residues belonging to the substrate binding pockets. We conclude that the hybrid compounds constitute promising scaffolds for the further development of new fasciolicidal compounds.

Asunto(s)

Catepsinas , Fasciola hepatica , Simulación del Acoplamiento Molecular , Quinoxalinas , Quinoxalinas/farmacología , Quinoxalinas/química , Quinoxalinas/síntesis química , Animales , Fasciola hepatica/efectos de los fármacos , Fasciola hepatica/enzimología , Relación Estructura-Actividad , Catepsinas/antagonistas & inhibidores , Catepsinas/metabolismo , Estructura Molecular , Flavonoides/farmacología , Flavonoides/química , Flavonoides/síntesis química , Relación Dosis-Respuesta a Droga , Fascioliasis/tratamiento farmacológico , Pruebas de Sensibilidad Parasitaria , Antihelmínticos/farmacología , Antihelmínticos/síntesis química , Antihelmínticos/química , Humanos

RESUMEN

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.

Asunto(s)

Fasciola hepatica , Caracoles , Temperatura , Agua , Animales , Fasciola hepatica/fisiología , Caracoles/parasitología , Agua/parasitología , Agua/química , Argentina/epidemiología , Fascioliasis/veterinaria , Fascioliasis/epidemiología , Fascioliasis/parasitología , Teorema de Bayes

RESUMEN

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.

Asunto(s)

Fascioliasis , Fasciola hepatica , Zoonosis , Salud Pública Veterinaria , Enfermedades Transmisibles

RESUMEN

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 (X̄=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.

Asunto(s)

Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Heces , Carga de Parásitos , Animales , Fascioliasis/veterinaria , Fascioliasis/sangre , Fascioliasis/parasitología , Bovinos , Enfermedades de los Bovinos/parasitología , Enfermedades de los Bovinos/sangre , Enfermedades de los Bovinos/epidemiología , Heces/parasitología , Fasciola hepatica/aislamiento & purificación , Argentina/epidemiología , Recuento de Huevos de Parásitos , Hígado/parasitología , Análisis Químico de la Sangre , Enfermedad Crónica , Mataderos

RESUMEN

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.

Asunto(s)

Anticuerpos Antihelmínticos , Antígenos Helmínticos , Enfermedades de los Bovinos , Ensayo de Inmunoadsorción Enzimática , Fascioliasis , Sensibilidad y Especificidad , Animales , Bovinos , Fascioliasis/diagnóstico , Fascioliasis/veterinaria , Fascioliasis/inmunología , Ensayo de Inmunoadsorción Enzimática/métodos , Ensayo de Inmunoadsorción Enzimática/veterinaria , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/parasitología , Antígenos Helmínticos/inmunología , Brasil , Anticuerpos Antihelmínticos/sangre , Proteínas Recombinantes/inmunología , Proteínas Recombinantes/genética , Heces/parasitología , Pruebas Serológicas/métodos , Pruebas Serológicas/veterinaria , Fasciola hepatica/inmunología , Mataderos , Curva ROC , Hígado/parasitología

RESUMEN

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.

Asunto(s)

Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Heces , Recuento de Huevos de Parásitos , Sensibilidad y Especificidad , Enfermedades de las Ovejas , Enfermedades de los Porcinos , Animales , Fascioliasis/diagnóstico , Fascioliasis/veterinaria , Fascioliasis/parasitología , Heces/parasitología , Ovinos , Enfermedades de las Ovejas/parasitología , Enfermedades de las Ovejas/diagnóstico , Bovinos , Fasciola hepatica/aislamiento & purificación , Recuento de Huevos de Parásitos/métodos , Recuento de Huevos de Parásitos/veterinaria , Enfermedades de los Bovinos/diagnóstico , Enfermedades de los Bovinos/parasitología , Porcinos , Enfermedades de los Porcinos/diagnóstico , Enfermedades de los Porcinos/parasitología , Enfermedad Crónica

RESUMEN

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.

Asunto(s)

Antihelmínticos , Fasciola hepatica , Fascioliasis , Profármacos , Enfermedades de las Ovejas , Animales , Ovinos , Triclabendazol , Fascioliasis/veterinaria , Antihelmínticos/uso terapéutico , Profármacos/química , Bencimidazoles/uso terapéutico , Enfermedades de las Ovejas/tratamiento farmacológico , Agua/química

RESUMEN

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.

Asunto(s)

Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Virus de la Fiebre Aftosa , Fiebre Aftosa , Vacunas Virales , Animales , Bovinos , Inmunoglobulina G , Anticuerpos Antivirales , Fiebre Aftosa/prevención & control , Fascioliasis/prevención & control , Fascioliasis/veterinaria , Vacunación/veterinaria , Inmunidad

RESUMEN

Fasciolosis is caused by parasites of the genus Fasciola, affecting animals and humans worldwide. In South America, the disease is a result of infection with Fasciola hepatica and although animal infections are more frequently reported, the full extent of the impact on human health due to underdiagnosis remains uncertain. This study analyzed changes in land use and the distribution of F. hepatica in bovine livers in Brazil over 18 years. Data on land use and land cover were collected from the Mapbiomas Project. Data on 414,481,963 slaughtered cattle and condemned livers due to F. hepatica infection were obtained from 4,433 municipalities. Joinpoint analysis was used to study the time series, and the Susceptible-Infected-Recovered (SIR) model was utilized to explore the behavior of F. hepatica infection. In the North, pasture areas significantly increased (P = 0.000001), while forested areas decreased (P = 0.000001). The midwestern and northern regions concentrated the highest number (>290 million) of cattle slaughtered in Brazil. More than 2 million bovine livers were infected by F. hepatica. The infected cattle originated from 194 municipalities in 2002, increasing to 747 in 2020. We consider that the changes in land use and intense cattle transportation may have caused the expansion of F. hepatica. The SIR model analyzed the spread of the disease looking at all six biomes: Caatinga, Amazon Forest, Cerrado, Pantanal, Atlantic Forest, and Pampa. Moreover, this infection not only threatens the health of animals but is also a major concern to biodiversity and vulnerable human communities in South America. Emblematic biomes such as the Amazon basin already face challenges with logging, desertification, and loss of biodiversity. Therefore, strategies for mitigating infection should include controlling illegal pasture areas, establishing health inspections of animal transport, quarantine of newly arrived animals, and livestock zoning, as well as clear One Health policies.

Asunto(s)

Enfermedades de los Bovinos , Fasciola hepatica , Fasciola , Fascioliasis , Animales , Bovinos , Humanos , Brasil/epidemiología , Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/parasitología , Fascioliasis/epidemiología , Fascioliasis/veterinaria , Fascioliasis/parasitología

RESUMEN

Fasciola hepatica is a parasite with a worldwide distribution that affects several mammals, including humans, and is considered a public health problem. Therefore, the aim of this study was to determine the prevalence of Fasciola hepatica in humans, cattle and sheep, as well as to evaluate factors associated with the prevalence. A total of 185 serum samples from sheep, 290 from cattle, and 114 from humans were collected and processed using an in-house developed ELISA to detect IgG antibodies against F. hepatica. Additionally, 185 stool samples from sheep and 290 from cattle were examined using a Dennis sedimentation technique. Risk factors were analyzed using epidemiological surveys. The overall seroprevalence was 46.5% (86/185) in sheep, 32.5% (94/289) in cattle, and no humans tested positive for the infection. The coprological prevalence was 47.7% (86/180) in sheep and 33.7% (98/290) in cattle. Female gender and cattle living with alternate grazing management showed 2.5 and 6.5 times higher probability of infection, respectively. Bovines coexisting with sheep exhibited a higher risk of infection (odds ratio [OR]=4.3) compared to those without sheep. We concluded that F. hepatica in cattle and sheep has an endemic behavior, and therefore represents a problem of public health for rural communities.

Asunto(s)

Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Enfermedades de las Ovejas , Humanos , Bovinos , Ovinos , Femenino , Animales , Fascioliasis/epidemiología , Fascioliasis/veterinaria , Fascioliasis/diagnóstico , Estudios Seroepidemiológicos , Prevalencia , Colombia/epidemiología , Enfermedades de las Ovejas/parasitología , Enfermedades de los Bovinos/diagnóstico , Mamíferos

RESUMEN

The objective of this work was to evaluate the effect of the ethyl acetate extract from A. ludoviciana (EALM) and artemisinin against adult parasites and eggs of F. hepatica. For the ovicidal assay, cell culture plates with 24 wells were used, and 90 to 110 F. hepatica eggs were placed in each well. The eggs were exposed to concentrations of 100, 200, 300, 400, and 500 mg/L EALM and incubated for 16 days. Additionally, triclabendazole (TCBZ) was used as a reference drug at concentrations of 10 and 50 mg, and the response of artemisinin at concentrations of 10 and 20 mg was simultaneously assessed. Adult flukes were exposed to concentrations of 125, 250, 375, and 500 mg/L EALM. The results of the ovicidal action of EALM on the eggs showed that concentrations greater than 300 mg/L were significant, with ovicidal percentages greater than 60% observed on day 16 of incubation (p < 0.05). The maximum efficiency of EALM on adult flukes was reached 72 h post-exposure at a concentration of 125 mg/L (p < 0.05).

Asunto(s)

Antihelmínticos , Artemisia , Artemisininas , Fasciola hepatica , Fascioliasis , Parásitos , Animales , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Bencimidazoles/farmacología , Artemisininas/farmacología , Artemisininas/uso terapéutico , Fascioliasis/parasitología , Resistencia a Medicamentos

RESUMEN

Fasciolosis is an important zoonotic disease caused by the trematode Fasciola hepatica, and it causes great losses in bovine production. The anthelmintic resistance is a major problem in the control of fasciolosis. In this study, the F. hepatica egg development and hatching test (EDHT) was used for the evaluation of the ovicidal activity of commercial drugs, commonly used for treating infected cattle, which reflects F. hepatica anthelminthic resistance in infected bovines, according to recent literature. Bile samples from F. hepatica naturally parasitized cattle were obtained from slaughterhouses in the cities of Lages and Otacílio Costa, Santa Catarina State, Brazil. The bile was washed, the eggs were recovered, quantified, and distributed in universal collectors, with a minimum of 1,000 eggs per vial. Four commercial drugs were used in this study, containing albendazole sulfoxide (ABDZ), closantel (CSTL), nitroxynil (NTXL), and triclabendazole with fenbendazole (TBZF). The drugs were diluted according to the manufacturer instructions. All drugs, and the respective control, were tested in triplicates, with the quantity of recovered eggs determining the number of drugs to be tested. The vials were incubated for 28 days at 27 °C, and the eggs were classified according to their degree of development under a stereomicroscope. In total, 121 egg samples were analyzed. Two samples were identified as resistant to TBZF. Undetermined resistance/susceptibility has been found in two isolates treated with ABDZ, one treated with NTXL and six treated with TBZF. CSTL did not present ovicidal activity and cannot be used in EDHT. This is the first time that commercial drugs were used in F. hepatica EDHT.

Asunto(s)

Antihelmínticos , Enfermedades de los Bovinos , Fasciola hepatica , Fascioliasis , Bovinos , Animales , Resistencia a Medicamentos , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Triclabendazol , Fascioliasis/tratamiento farmacológico , Fascioliasis/veterinaria , Nitroxinilo/uso terapéutico , Fenbendazol/uso terapéutico , Enfermedades de los Bovinos/tratamiento farmacológico , Heces

RESUMEN

Hepatosplenic schistosomiasis (HSS) is a serious complication of chronic schistosomiasis that can result in portal hypertension and variceal bleeding. ß-blockers, a class of medications commonly used to treat hypertension and other cardiovascular conditions, have been investigated for their potential use in preventing variceal bleeding in HSS. Several studies have shown that ß-blockers can reduce portal pressure and prevent variceal bleeding effectively in these patients. However, there are limited data on the long-term efficacy and safety of ß-blockers in this setting, and further research is needed to determine the optimal use of these medications. This review summarizes the evidence supporting current recommendations of ß-blocker use in patients with HSS.

Asunto(s)

Várices Esofágicas y Gástricas , Fascioliasis , Hepatitis , Hipertensión Portal , Esquistosomiasis , Enfermedades del Bazo , Humanos , Várices Esofágicas y Gástricas/complicaciones , Hemorragia Gastrointestinal/etiología , Esquistosomiasis/complicaciones , Esquistosomiasis/tratamiento farmacológico , Hipertensión Portal/complicaciones , Hipertensión Portal/tratamiento farmacológico , Enfermedades del Bazo/tratamiento farmacológico , Fascioliasis/complicaciones

RESUMEN

Many studies about fasciolosis control have been carried out, whether acting on the adult parasite or in Pseudosuccinea columella, compromising the development of the larval stages. The present study aimed to evaluate, under laboratory conditions, the susceptibility of P. columella to Heterorhabditis bacteriophora HP88, during for 24 and 48 hours of exposure. The snails were evaluated for 21 days for accumulated mortality; number of eggs laid; hatchability rate; biochemical changes; and histopathological analysis. We found that exposure induced a reduction in glucose and glycogen levels, characterizing a negative energy balance, due to the depletion of energy reserves as a result of the direct competition established by the nematode/endosymbiont bacteria complex in such substrates. A mortality rate of 48.25% and 65.52% was observed in the group exposed for 24 h and 48 h, respectively, along with significant impairment of reproductive biology in both exposed groups in relation to the respective controls. The results presented here show that P. columella is susceptible to the nematode H. bacteriophora, with the potential to be used as an alternative bioagent in the control of this mollusk, especially in areas considered endemic for fascioliasis, in line with the position expressed by the World Health Organization Health.

Asunto(s)

Fascioliasis , Rabdítidos , Animales , Control Biológico de Vectores/métodos , Caracoles/parasitología , Fascioliasis/veterinaria

RESUMEN

In the fall of 2022, decreased triclabendazole (TCBZ) efficacy against F. hepatica was suspected in a sheep farm located in the Santa Cruz province, Argentinian Patagonia. Since TCBZ-resistance in F. hepatica has never been reported in this province, this study aimed to confirm potential TCBZ-resistance in F. hepatica and to evaluate the efficacy of closantel (CLO) and nitroxinil (NTX), through faecal egg count reduction test (FECRT), and the efficacy of albendazole (ABZ) through the in vitro egg hatch test (EHT) in sheep. Sixty-eight (68) animals were selected from a herd of eighty (80) female Merino naturally infected with F. hepatica based on eggs per gram of F. hepatica (EPGFh) counts and assigned into four (4) groups (n = 17 per group): Group Control, animals did not receive anthelmintic treatment; Group TCBZ, animals were orally treated with TCBZ (12 mg/kg); Group CLO, animals were orally treated with CLO (10 mg/kg); and Group NTX, animals were subcutaneously treated with NTX (10 mg/kg). The fluke egg output was monitored on days 0 and 21 post-treatment. For the EHT, liver fluke eggs were isolated from faecal samples (approx. 50 g) collected from animals of the control group. TCBZ efficacy against liver fluke was 53.4%, confirming the presence of TCBZ-resistant isolates on the farm. CLO and NTX were highly effective (100%) for the treatment of F. hepatica on this farm. The EHT was carried out in two different laboratories, in which was observed an ABZ efficacy of 95.8 (Bariloche) and 96.5% (Tandil). These results indicate the ABZ susceptibility of this F. hepatica isolate and the inter-laboratory precision of the test.

Asunto(s)

Fasciola hepatica , Fascioliasis , Enfermedades de las Ovejas , Femenino , Ovinos , Animales , Triclabendazol/uso terapéutico , Fascioliasis/tratamiento farmacológico , Fascioliasis/veterinaria , Bencimidazoles/farmacología , Bencimidazoles/uso terapéutico , Resistencia a Medicamentos , Enfermedades de las Ovejas/tratamiento farmacológico , Albendazol/farmacología , Albendazol/uso terapéutico , Nitroxinilo , Oveja Doméstica

RESUMEN

About a third of the world population is infected by helminth parasites implicated in foodborne trematodiasis. Fascioliasis is a worldwide disease caused by trematodes of the genus Fasciola spp. It generates huge economic losses to the agri-food industry and is currently considered an emerging zoonosis by the World Health Organization (WHO). The only available treatment relies on anthelmintic drugs, being triclabendazole (TCBZ) the drug of choice to control human infections. The emergence of TCBZ resistance in several countries and the lack of an effective vaccine to prevent infection highlights the need to develop new drugs to control this parasitosis. We have previously identified a group of benzochalcones as inhibitors of cathepsins, which have fasciolicidal activity in vitro and are potential new drugs for the control of fascioliasis. We selected the four most active compounds of this group to perform further preclinical studies. The compound's stability was determined against a liver microsomal enzyme fraction, obtaining half-lives of 34-169 min and low intrinsic clearance values (<13 µL/min/mg), as desirable for potential new drugs. None of the compounds were mutagenic or genotoxic and no in vitro cytotoxic effects were seen. Compounds C31 and C34 showed the highest selectivity index against liver fluke cathepsins when compared to human cathepsin L. They were selected for in vivo efficacy studies observing a protective effect, similar to TCBZ, in a mouse model of infection. Our findings strongly encourage us to continue the drug development pipeline for these molecules.

Asunto(s)

Antihelmínticos , Chalconas , Fasciola hepatica , Fascioliasis , Animales , Ratones , Humanos , Fascioliasis/tratamiento farmacológico , Fascioliasis/parasitología , Chalconas/farmacología , Chalconas/uso terapéutico , Triclabendazol/farmacología , Triclabendazol/uso terapéutico , Antihelmínticos/farmacología , Antihelmínticos/uso terapéutico , Catepsinas

RESUMEN

Sheep husbandry in Patagonia, Argentina, started at the beginning of the 20th century from European settlers. Sanitary management is minimal, which has serious implications for the sheep health. Sheep can be infested by diverse parasites, with well over 150 species of internal and external parasites reported worldwide. Gastrointestinal parasitism is one of the most common and important infections in sheep concerning the health status, and is the cause of significant morbidity and mortality, which generates considerable production losses. The present work is the first paleoparasitological study of sheep coprolites from Patagonia throughout historical times. Fifty-seven coprolites from the 'Cueva Peligro' archaeological site (Patagonia, Argentina) were analyzed using the Lutz spontaneous sedimentation technique and the modified Faust flotation technique. Ancient DNA (aDNA) study was carried out in order to identify the zoological origin of coprolites. The results obtained from Cytb analysis confirmed the identity of the host as Ovis aries (domestic sheep). A total of 39 coprolites examined were positive for parasites by at least one of the studied methods. Thirty eight samples were positive by spontaneous sedimentation and 10 samples were positive by the modified Faust technique. The parasitic fauna found was Trichuris sp. (Trichinellida: Trichuridae), Nematodirus sp., Nematodirus spathiger (Strongylida, Trichostrongyloidea), two unidentified Strongylida-type egg morphotypes, Fasciola hepatica (Trematoda: Digenea) and coccidia oocysts of Eimeria spp. (Apicomplexa: Eimeriidae). The modified Faust technique provided satisfactory results in terms of sensitivity for the detection of Eimeria spp. The use of this methodology as a routine procedure enables the processing of ancient samples, in order to increase recoveries. These results show the importance of integrating different diagnostic approaches in order to optimize parasitic findings. The recorded parasite diversity appears to have not changed over the last 120 years. The study displayed the presence of different parasitic species which suggests potential exposure to parasitic diseases through the historical times, both for sheep and for other domestic and wild mammals from Patagonia. Also, suggests the presence of fasciolosis, a zoonotic disease that implies a potential risk for Patagonian populations in the past.

Asunto(s)

Eimeria , Fascioliasis , Parasitosis Intestinales , Nematodirus , Parásitos , Enfermedades de las Ovejas , Animales , Ovinos , Oveja Doméstica , Parasitosis Intestinales/veterinaria , Fascioliasis/veterinaria , Argentina/epidemiología

RESUMEN

Lymnaeid snails serve as intermediate hosts for Fasciola hepatica (Linnaeus, 1758), the etiological agent of fasciolosis, which is a widespread livestock disease in Argentina. Determining their geographic distribution and identifying the snail species involved in the transmission of fasciolosis can provide crucial information for designing strategic control programs. In this context, this work aimed at genetically characterizing the species of lymnaeid snails collected in different water bodies of northern Patagonia, Argentina. To this end, 689 snails were collected in 12 sites in the provinces of Neuquén, Río Negro and Chubut, in areas where fasciolosis is endemic. According to the morphological characteristics of their valves, they were identified as Galba spp. Twenty-three of these specimens were further identified using the nuclear sequences of the internal transcribed spacers ITS-1 and ITS-2 and 18S rRNA. The results confirmed the identity of all the analyzed snails as Galba viatrix and provided evidence that studying the variable region V2 of the 18S rRNA gene is not enough to differentiate closely related species, as observed in lymnaeid snails. Both the fact that G. viatrix was the only species identified in the endemic area surveyed and previous evidence of the high prevalence of F. hepatica infestation in grazing animals in the region suggest that this species is the main intermediate host of F. hepatica. The correct identification of lymnaeid snail species has great importance to determine risk zones and develop appropriate control measures to reduce transmission, according to the different ecological characteristics of each species.

Asunto(s)

Fasciola hepatica , Fascioliasis , Animales , Argentina/epidemiología , Fascioliasis/veterinaria , Ganado , ARN Ribosómico 18S , Caracoles