Understanding the pathogenic mechanisms and therapeutic effects in neurocysticercosis.

Despite being a leading cause of acquired seizures in endemic regions, the pathological mechanisms of neurocysticercosis are still poorly understood. This study aims to investigate the impact of anthelmintic treatment on neuropathological features in a rat model of neurocysticercosis. Rats were intracranially infected with Taenia solium oncospheres and treated with albendazole + praziquantel (ABZ), oxfendazole + praziquantel (OXF), or untreated placebo (UT) for 7 days. Following the last dose of treatment, brain tissues were evaluated at 24 h and 2 months. We performed neuropathological assessment for cyst damage, perilesional brain inflammation, presence of axonal spheroids, and spongy changes. Both treatments showed comparable efficacy in cyst damage and inflammation. The presence of spongy change correlated with spheroids counts and were not affected by anthelmintic treatment. Compared to white matter, gray matter showed greater spongy change (91.7% vs. 21.4%, p < 0.0001), higher spheroids count (45.2 vs. 0.2, p = 0.0001), and increased inflammation (72.0% vs. 21.4%, p = 0.003). In this rat model, anthelmintic treatment destroyed brain parasitic cysts at the cost of local inflammation similar to what is described in human neurocysticercosis. Axonal spheroids and spongy changes as markers of damage were topographically correlated, and not affected by anthelmintic treatment.

PRESCRIBING PATTERNS AND THE USE OF ANTHELMINTIC DRUGS IN COLOMBIAN PATIENTS: A CROSS-SECTIONAL STUDY.

Intestinal parasites continue to be a public health problem in low- and middle-income countries. Broad use of anthelmintics during deworming programs is still necessary in many regions. However, description of the usage of these medications in general medical practice has been limited. The objective of this study was to determine the use of anthelmintic drugs and their indications in a group of Colombian patients. This was a descriptive study from a drug-dispensing database, identifying patients with prescriptions for anthelmintic drugs. A total of 381 cases were randomly selected, and their medical records were reviewed, analyzing sociodemographic, clinical, and pharmacological variables (indication of use). The lack of diagnosis registration or clinical manifestations of parasites was determined as a prescription without indication. In total, 50.9% (n = 194) of patients were female, and 67.4% of all patients were under 18 yr of age. The diagnosis of helminthiases was clearly stated in 114 (29.9%) patients, and only 4.2% (n = 16) of these had microbiological confirmation. The most commonly used anthelmintic drug was albendazole (70.4% of all prescriptions). The use of anthelmintics was not indicated in 266 cases (69.8%). Nutritional supplements or vitamin prescriptions were associated with using anthelmintics without indication (odds ratio: 2.25; 95% confidence interval: 1.26-4.03). A high proportion of patients lacked symptoms or diagnoses in their clinical records that supported the use of anthelmintic drugs.

Fasciola hepatica and rumen flukes - in vitro evaluation of main commercial anthelmintics

Background: Trematode infections are of great importance as they affect the health of many species of mammals as cattle, sheep and goat. Fasciola hepatica represents the main trematode zoonosis and risks to human and cattle and paramphistomosis is one emerging parasitic diseases of ruminants widely distributed in the world. The economic expenses are incurred by the use of ineffective anthelmintics for trematode control. Besides to faecal egg count reduction test (FECRT) to determine the anthelmintic efficacy, can be used in vitro assays, by this the aim of the study was to determine the lethal doses (LD) with hatching egg test (EHT) of the main commercial anthelmintics used for the control of trematodes in cattle. Materials, Methods & Results: Liver and rumen were examined from cattle slaughtered in Tabasco, Chiapas and Campeche states from Mexico. F. hepatica eggs were recovered from gallbladder and rumen fluke eggs collected from adult parasites in saline solution. Subsequently, the hatching egg assays were performed placing 100 trematode eggs in distilled water in each one of 96 wells of polystyrene plates. After making the appropriate dilutions, several concentrations of commercial anthelmintics were evaluated, ranging from 0.04 to 80.63 mM for triclabendazole + 0.046 to 96.87 mM febendazole (TC+FBZ), from 0.04 to 91 mM for rafoxanide (RAFOX), from 0.02 to 43.74 mM for closantel (CLOS), from 0.036 to 76.18 mM for clorsulon + 0.002 to 3.31 mM ivermectin (CLORS+ IVM) and from 0.163 to 334.47 mM for nitroxynil (NITROX). A control group (water) was included in each plate. Lethal doses were obtained using the Probit procedure and analysis of the means with a one-way statistical design. Most drugs used against rumen fluke eggs presented a high LD50 and therefore were ineffective to cause egg mortality, such was the case of RAFOX that presented LD50 from 4,580 to 10,790 µg/mL (7 to 17 mM). CLOS presented the lowest LD50 (80 µg/mL or 0.12 mM) on rumen fluke eggs. TC+FBZ was found to be effective drug against the development of F. hepatica eggs in many samples. In the same way NITROX showed a low LD50 (37 to 63 µg/mL or 0.13 to 0.22 mM), but RAFOX presented a highest LD50 (1,450 µg/mL or 2.32 mM). Discussion: The present study focused on screen the ovicidal activity and determining in vitro lethal doses 50 of main commercial anthelmintics used to control F. hepatica and rumen fluke as rapid tests in a tropical region from Mexico. The FECRT is the main method to detect effectiveness of anthelmintic and other method is the coproantigen reduction test (CRT) by ELISA. Both tests require many infected animals depending the number of treatments and by this the egg hatch assay (EHA) represent a complementary diagnosis of effectiveness of anthelmintic products to compare between regions and even between farms, because few animals are required from the farm to collect trematode eggs, and it is possible to know the effectiveness against various anthelmintics at the same time. Efficacy studies on trematodes using egg hatching tests are scarce, although they have the advantage that they can be applied to both F. hepatica and rumen fluke. TC+FBZ was one of the most effective products in inhibiting the development of F. hepatica eggs. However, RAFOX showed low effectiveness against trematode eggs, with very high lethal doses. These results agree with a study that show low efficacy against the development of Paramphistomum cervi eggs and with the FECRT test reductions of 75% and 80.58% were obtained, in times from 7 to 84 days after treatment with RAFOX. NITROX and CLORS were drugs that had good efficacy on the development of F. hepatica eggs. A differential response between liver and rumen fluke was observed. The anthelmintics used against rumen fluke eggs show low ovicidal activity and in Fasciola hepatica TC+FBZ show the best activity

Susceptibility of Angiostrongylus cantonensis Larvae to Anthelmintic Drugs.

Human helminthiasis affects approximately one in five people in the world and disproportionally affects the poorest and most deprived communities. Human angiostrongyliasis, caused by nematode Angiostrongylus cantonensis, is a neglected emerging disease with escalating importance worldwide. Chemotherapy is the main control method for helminthiasis, but the therapeutic arsenal is limited. This study aimed to evaluate the antiparasitic and molecular properties of the major available anthelmintic drugs against A. cantonensis in vitro. The first-stage larvae (L1), isolated from feces of an A. cantonensis-infected rat, were exposed to a set of 12 anthelmintic drugs in vitro. The larvae were monitored, and the concentration- and time-dependent viability alterations were determined. From 12 anthelmintic drugs, six (ivermectin, salamectin, moxidectin, pyrantel pamoate, albendazole and levamisole) were identified to affect the viability of A. cantonensis. The macrocyclic lactones (ivermectin, salamectin, moxidectin) and the imidazothiazole levamisole, were the most effective drugs, with IC50 ranging from 2.2 to 2.9 µM and a rapid onset of action. Albendazole, the most widely used anthelmintic in humans, had a slower onset of action, but an IC50 of 11.3 µM was achieved within 24 h. Molecular properties studies suggest that a less lipophilic character and low molecular weight could be favorable for the biological activity of the non-macrocyclic molecules. Collectively, our study revealed that macrocyclic lactones, levamisole, pyrantel pamoate, and albendazole are important anthelmintic agents against A. cantonensis. The results of this in vitro study also suggest that A. cantonensis L1 may be a particularly sensitive and useful model for anthelmintic studies.

Sensitivity of Haemonchus contortus to anthelmintics using different in vitro screening assays: a comparative study.

BACKGROUND: Helminthiasis and resistance to commercial anthelmintic compounds are major causes of economic losses for livestock producers, resulting in an urgent need for new drugs and reliable in vitro screening tests capable of detecting potentially active products. Considering this, a series of novel benzimidazole derivatives (5-methylbenzimidazole 1,2-disubstituted, 5-carboxybenzimidazole, 5-methylbenzimidazole 2-one) was screened on exsheathed L3 (xL3) and on the adult stage of Haemonchus contortus (Kirby anthelmintic-susceptible McMaster isolate). METHODS: This work presents the set-up of an automated motility assay on the xL3 stage of H. contortus using an infrared tracking device (WMicrotracker One) together with a larval development test (xL3 to L4) and a motility assay on the adult stage of H. contortus. A comparative study of the sensitivity of these in vitro assays using commercial anthelmintics with different mechanisms of action was carried out, also evaluating anthelmintic activity of a series of novel benzimidazole derivatives. RESULTS: The automated xL3 assay had the great advantage of being able to analyze many compounds simultaneously, but it showed the limitation of having lower sensitivity, requiring higher concentrations of the commercial anthelmintics tested compared to those needed for the adult motility or development assays. Although none of the novel 1,2,5-tri-substituted benzimidazole derivatives could significantly decrease the motility of xL3s, one of them (1e) significantly affected the development of xL3s to L4, and five new compounds (1b, 1d, 1e, 2a and 2c) reduced the motility of H. contortus adult stage. CONCLUSIONS: The analysis of the results strongly suggests that the in vitro xL3 to L4 development test, particularly for the L4 stage, could be closer to the pharmacological sensitivity of the adult stage of H. contortus (target of interest) for commercial anthelmintic selected, with different mechanisms of action, and for the series of benzimidazole derivatives assayed. Therefore, an automated motility assay on L4 using the infrared tracking device is being set up. Further studies will be conducted to evaluate the in vivo anthelmintic activity of the most active novel benzimidazole derivatives.

Mortality caused by gastrointestinal nematodes in beef cattle submitted to an inadequate sanitary protocol / Mortalidade causada por nematódeos gastrintestinais em bovinos de corte submetidos a protocolo sanitário inadequado

The aim of this study was to describe the epidemiological, clinical, and pathological findings of two outbreaks of gastrointestinal nematode infections in beef cattle kept under an inadequate sanitary protocol. An outbreak of trichostrongylosis occurred in Amambai, Mato Grosso do Sul (MS), from May to July 2016. The herd consisted of 3,000 Nellore cows, and of these, fifteen died after showing emaciation and diarrhea and remaining in recumbency. At necropsy, the abomasum showed edema in the folds, white, raised areas, multifocal to coalescent, and small ulcers. Histopathology showed larvae compatible with trichostrongylid nematodes were present inside the abomasum glands. Trichostrongylus axei was identify in the abomasum. The hemonchosis outbreak began in October 2018, in a breeding and finishing property in Santa Rita do Pardo, MS. Of 4,000 cattle aged 8 to 18 months, 673 became ill and 117 died. Clinical signs were emaciation, weakness, dehydration, submandibular edema, and soft stools. At necropsy, large numbers of nematodes were found in the abomasum; they were morphologically classified as Haemonchus placei. Both outbreaks were caused by failures in the parasite control protocol. However, in Outbreak I, frost and immune stress caused by lack of food may have contributed to the deaths. In Outbreak I, the main failure in the devermination protocol was the use of anthelmintics without carrying out an efficacy test. In Outbreak II, there was no parasite control protocol in the rearing and finishing property, and in the breeding property, there was resistance to the anthelmintic used (ivermectin). The two outbreaks highlight the importance of gastrointestinal nematode control protocols in cattle and demonstrate that infections by T. axei and H. placei can be lethal for this species.

O objetivo deste trabalho foi descrever os achados epidemiológicos, clínicos e patológicos de dois surtos de verminose em bovinos de corte mantidos sob protocolo sanitário inadequado. Um surto de tricostrongilose ocorreu em Amambai, Mato Grosso do Sul (MS), de maio a julho de 2016. O rebanho de cria era composto por 3.000 vacas Nelore, das quais, quinze vacas adultas morreram após apresentarem emagrecimento, diarreia e permanecerem em decúbito. Na necropsia, o abomaso apresentava edema das pregas, áreas brancacentas, elevadas, multifocais a coalescentes e pequenas úlceras. Na histopatologia, larvas compatíveis com nematódeos tricostrongilídeos estavam presentes no interior das glândulas do abomaso. A recuperação de helmintos do abomaso demonstrou que Trichostrongylus axei foi o principal agente etiológico. O surto de hemoncose iniciou-se em outubro de 2018, em uma propriedade de recria e terminação em Santa Rita do Pardo, MS. Do total de 4 mil bovinos com 8 a 18 meses, 673 adoeceram e 117 morreram. Os sinais clínicos foram emagrecimento, fraqueza, desidratação, edema submandibular e fezes pastosas. Na necropsia, havia grande quantidade de nematódeos no abomaso, que foram classificados morfologicamente como Haemonchus placei. Ambos os surtos foram causados por falhas no protocolo de controle parasitário, porém, no Surto I, geadas e estresse imunológico causado pela falta de alimento podem ter contribuído para as mortes. No Surto I, a principal falha no protocolo de desverminação foi o uso de anti-helmínticos sem a realização de teste de eficácia. No Surto II, não havia protocolo de controle parasitário na propriedade de recria e terminação, e na propriedade de cria, havia resistência ao anti-helmíntico utilizado (ivermectina). Os dois surtos ressaltam a importância dos protocolos de controle de nematódeos gastrintestinais em bovinos e demonstram que infecções por T. axei e H. placei podem ser letais para esta espécie.

Survey of anthelmintic use in South American camelids in the UK.

BACKGROUND: Gastrointestinal helminths are common in South American camelids in the UK. However, there are no anthelmintics currently licenced for camelids, leading to a limited evidence base for treatment. The aim of this study was to assess the usage of anthelmintics among UK camelid farmers. METHODS: An online questionnaire focusing on the use of anthelmintics in camelids was distributed to UK camelid owners in Spring 2019. RESULTS: Forty-nine of the 51 respondents treated their camelids with anthelmintics, while 21 (42.0%) reported a previous gastrointestinal helminth diagnosis on their farms. A wide variety of anthelmintics were employed and there was striking variation in treatment frequency, dosage and source of information used to select anthelmintic dosing regimen. CONCLUSION: This work highlights the need for quality efficacy studies of anthelmintics in camelids to provide an appropriate evidence base for treatment, as well as the need for better education for camelid owners on anthelmintics and anthelmintic resistance.

Percepción universitaria sobre el cuidado responsable de animales de compañía en Costa Rica / College Student Perception on the Companion Animal Responsible Care in Costa Rica

Resumen El estudio tuvo como objetivo analizar el conocimiento que tienen los universitarios sobre el manejo responsable de mascotas en sus hogares. Se realizó un estudio transversal a la población universitaria, cuyo tamaño muestral fue estimado en 369 personas, aunque se encuestaron a 393 estudiantes. El 99 % de los sujetos reporto tener mascotas, y el perro fue el animal más común dentro de los hogares. El método de desparasitación más comúnmente utilizado fue el de uso interno 59,6 %. Las mascotas son desparasitadas más comúnmente cada 3 meses. Se encontró que es más probable que los hombres en posesión de una mascota la lleven al veterinario con respecto a las mujeres y el 65,3 % de los encuestados reporta que sus mascotas duermen dentro del hogar. Este es el primer estudio en Costa Rica que muestra la forma en que los poseedores de mascotas conviven y cuidan de ellas. La mayoría de los sujetos no conoce el desparasitante que aplica en sus mascotas. Es necesario reforzar la educación en los propietarios para que conozcan más sobre los productos que utilizan en sus mascotas y quién los está recomendando, así como las implicaciones de una correcta higiene en ellas.

Abstract This study aims to analyze the knowledge by college students on the responsible management of pets at home. A cross-sectional study was conducted on the college population with an estimated sample of 369 persons, even though 393 were surveyed. Out of them, 99% reported to have a pet and the dog was the most common in their homes. The home de-worming was the most commonly used method (59.6%) to that end. Pets are de-wormed quarterly in most cases. It was found that men are more likely to bring the pet to the doctor as compared to women and 65.3% of the surveyed sample states that their pets sleep inside the house. This is the first studied conducted in Costa Rica showing how pet owners live with and care them. Most of the subjects do not know the de-worming drug being administered to their pets. There is a need to strengthen the education among pet owners so that they got to know more about the products being used in their pets, who recommends the product, and the implications of the correct hygiene.

Toxocariosis / Toxocariosis

RESUMEN La toxocariosis humana es una helmintozoonosis por invasión de las larvas de la especie Toxocara al organismo humano. Se adquiere al ingerir los huevos de larvas por falta de higiene de las manos, consumo de vegetales y carnes crudas, geofagía y aguas no tratadas. El serodiagnóstico se realiza por Elisa o Western Blot. Es una enfermedad altamente prevalente, en especial en países tropicales, en vía de desarrollo y sobre todo en áreas rurales. Hay diferentes formas de presentación clínica y entre ellas la del compromiso del sistema nervioso central. Su tratamiento es con antihelminticos.

SUMMARY Human toxocariasis is a helminthic zoonosis caused by the invasion of the larvae of the species Toxocara to the human organism. It is acquired by ingesting the eggs of larvae due to lack of hand hygiene, consumption of vegetables and raw meats, geophagy, and untreated water. The serodiagnosis is performed by ELISA or western blot. It is a highly prevalent disease especially in countries tropical, developing and especially in rural areas. There are different ways to clinical presentation and among them that of central nervous system involvement. Its treatment is with anthelmintics.

In Vitro Antischistosomal Activity of the Argemone mexicana Methanolic Extract and Its Main Component Berberine.

BACKGROUND: Schistosomiasis has been identified as a major public health problem in tropical countries. The present study aimed to investigate the schistosomicidal effects of the methanolic extract of Argemone mexicana L. and its active component, berberine against Schistosoma mansoni on in-vitro experiments. METHODS: S. mansoni adults were used. Various concentrations of the methanolic extract (10 - 200 µg/ml) and berberine (2.5 - 50 µM) were tested from 24 to 72 h. The viability of S. mansoni was confirmed with an invertoscope-microscope. Furthermore, cytotoxic (Hemolysis test), and antioxidant (DPPH radical scavenging assay) capacities were determined. RESULTS: The viability tests on S. mansoni showed that A. mexicana at 50 µg/mL is lethal at 48 h and berberine at 10 µM is lethal at 24 h. The hemolytic activity at 1,000 µg/mL was 2.9% for A. mexicana and 90.2% for berberine. The antioxidant capacities shown by A. mexicana and berberine, were EC50 156.3 and 84.1 µg/mL, respectively. CONCLUSION: The extract of A. mexicana and berberine demonstrated high antischistosomal activities in low concentration and short exposure time on the in-vitro model.

Profile of endoparasites in dairy cattle in the microregion of São João del-Rei, state of Minas Gerais, Brazil / [Perfil de endoparasitas em bovinos leiteiros na microrregião de São João del-Rei, Minas Gerais, Brasil]

The present study provides the first evaluation of the endoparasite profile in dairy cattle from the microregion of São João del-Rei, Minas Gerais, Brazil, including seasonal variations in parasitic infections. Fecal samples were collected directly from rectum of 123 dairy cows and 160 calves on 15 farms. These were kept in insulated boxes and sent for immediate analysis. Using eggs per gram of feces (EPG) we found the following prevalences: Strongyloidea 43.5%, Moniezia sp. 7.6% and both Strongyloides sp. and Trichuris spp. 2.2%, in dairy cows. In calves, the prevalence was Strongyloidea 50.9%, Moniezia sp. 5.6% and Strongyloides sp. 1.9%. The third-stage larvae recovered from coprocultures from cows and calves consisted mainly of Cooperia spp., Haemonchus spp. and Ostertagia spp. EPG counts were significantly higher in calves. Regarding seasonality, the EPG counts and prevalence of Moniezia sp. tended to be higher in the dry period, whereas those of Strongyloidea were higher in the rainy season. Evidence suggests that parasite control and prophylaxis were inadequately managed on the farms studied here. The present parasitological profile correlates with those found by other similar studies, indicating that the main problem is still the inadequate management of parasite control and prophylaxis by farmers.(AU)

O presente estudo representa a primeira avaliação do perfil de endoparasitos em bovinos leiteiros da microrregião de São João del-Rei, Minas Gerais, Brasil, e das variações sazonais das infecções parasitárias. Foram avaliadas amostras fecais de 123 vacas e 160 bezerros de 15 propriedades rurais, coletadas diretamente do reto, mantidas em caixas térmicas isoladas e analisadas imediatamente. A contagem de ovos por grama de fezes (OPG) revelou prevalências de 43,5% de Strongyloidea, 7,6% de Moniezia sp. e 2,2% de Strongyloides sp. e Trichuris spp. em vacas leiteiras. As prevalências de OPG em bezerros foram 50,9% de Strongyloidea, 5,6% de Moniezia sp. e 1,9% de Strongyloides sp. As larvas do terceiro estádio recuperadas de coproculturas de vacas e bezerros foram principalmente de Cooperia spp., Haemonchus spp. e Ostertagia spp. OPG dos parasitos foram significativamente maiores em bezerros. Em relação à sazonalidade, OPG e a prevalência de Moniezia sp. tenderam a ser maiores durante a estação seca, enquanto OPG de Strongyloidea foram maiores na estação chuvosa. Com base nos resultados, é possível concluir que o manejo antiparasitário nas propriedades estudadas não é realizado de maneira plenamente satisfatória. O presente perfil parasitológico se assemelha a outros encontrados em estudos semelhantes, indicando que o maior problema ainda é o manejo antiparasitário inadequado realizado nas propriedades de bovinos leiteiros.(AU)

Evaluation of anthelmintic drugs against egg development of rumen flukes recovered from cattle raised in the humid tropics of Mexico.

Paramphistomosis is a parasitic disease endemic in ruminants nearly worldwide. In the present study, an in vitro screening of the main anthelmintics used in Mexico was carried out to determine the mean lethal dose for rumen fluke eggs from cattle in a humid, warm region. Rumen flukes were obtained from cattle slaughtered in the states of Tabasco and Chiapas in Mexico. Eggs were collected using a 37-µm sieve and quantified. Then, an in vitro incubation study was performed: 100 eggs were placed into the wells of polystyrene microtiter plates. Anthelmintic products were tested on the eggs at concentrations ranging from 0.0015 to 3.0 mg/ml for rafoxanide, 0.0025 to 10.20 mg/ml for nitroxinil and 0.0015 to 3 mg/ml for closantel to determine the median lethal dose (LD50) and maximum lethal dose (LD99). A control group (water) was included in each plate. Three different species of rumen flukes (Calicophoron brothriophoron, Calicophoron clavula and Paramphistomum cervi) belonging to five isolates were identified. Nitroxinil had the highest efficacy against rumen fluke eggs, with an LD50 of 0.11 to 65 µg/ml, whereas rafoxanide showed the lowest efficacy with an LD50 ranging from 500 to 1713 µg/ml. Closantel showed high variability in the LD50 among the different analysed isolates (17 to 122 µg/ml). The evaluated flukicidal drugs presented differential efficacy against the development of rumen fluke eggs. The efficacy of the drugs will vary depending on the geographical area of origin of the animals.

Efecto de antiparasitarios de uso común en granjas ovinas ubicadas en valledupar, cesar

Introducción: Las enfermedades parasitarias se encuentran entre las causas más frecuentes e importantes que ocasionan repercusiones sanitarias y económicas en las producciones ovinas del país. Objetivo: Determinar la efectividad de los antihelmínticos de uso común en parásitos gastrointestinales de granjas ovinas en Valledupar, Cesar. Métodos: Estudio realizado con 340 ovinos, divididos en 4 granjas (Control, Albendazol, Fenbendazol y Levamisol). Se seleccionaron ovinos con carga parasitaria moderada; se les aplicó tratamiento antihelmíntico y un muestreo postratamiento (15 días). Se evidenciaron los nematodos en estadío infectante (L3) mediante coprocultivo. Resultados: En los grupos tratados Febendazol, Albendazol y Levamisol se pudo obtener una efectividad de 44 %, 65 % y 84 %, con un límite inferior (95 %conf) de 60 %, 70 % y 86 %, respectivamente. No obstante, se evidenciaron diferencias significativas (P<0,05) en cada grupo y entre los grupos tratados. Se recuperaron larvas de Cooperia curticei, Haemonchus contortus, Strongyloides papillosus, Trichostrongylus sp. y Ostertagia sp.

Introduction: Parasitic disease are the most important and frequent cause of sanitary and economic problems in the national sheep farms. Objective: To determine the effectiveness of anthelmintics commonly used in gastrointestinal parasites from sheep farms in Valledupar, Cesar. Method: The study was realized with 340 sheep, divided into 4 farms (control, albendazole, fenbendazole, and levamisole). Sheep with a moderate parasite load were selected and treatment with an-thelmintic, post-treatment sampling was applied (15 days). Nemato-des in the infective stage (L3) were evidenced by stool culture. Results: Groups treated with fenbendazole, albendazole and levamisole had an effectivity of 44%, 65% y 84% with an inferior limit (95% conf.) of 60%, 70%, and 86%, respectively. Nevertheless, significant differences were evidenced (p < 0,05) in each group and between the treated groups. Cooperia curticei, Haemonchus contortus, Strongyloides papillosus, Trichostrongylus sp., and Ostertagia sp. larvae were found.

Susceptibility of entomopathogenic nematodes to ivermectin and thiabendazole.

The objective of the present study was to determine the susceptibility of entomopathogenic nematodes to ivermectin and thiabendazole. Soil samples collected from the municipalities of Irapuato and León, Guanajuato, Mexico, were obtained, from which the entomopathogenic nematodes (EPNs) of the Steinernematidae and Heterorhabditidae families were isolated. The samples were classified from livestock and nonlivestock soils, and the susceptibility of EPNs to anthelmintics was determined with the larval motility assay (LMA, 24 h) and the larval migration inhibition assay (LMI assay, 48 h). Sterile distilled water (T1) and treatments with 1% ivermectin diluted in 5% DMSO (dimethyl sulfoxide) (T2) and 5% thiabendazole diluted in 5% DMSO (T3) were applied to infective juvenile larvae. Analysis of variance was performed with a factorial design and Tukey's test at 0.05 probability. In addition, different concentrations of ivermectin (0.1, 0.5, 1, 1.2, 1.5, and 2 µg) and thiabendazole (1, 5, 10, 12, 15, and 20 mg) were evaluated to perform a Probit analysis to determine their LC50. All strains of EPNs were susceptible to ivermectin in both the LMA and LMI assay. The results show that EPNs are susceptible to ivermectin and thiabendazole, and the degree depends on the type of test performed, the chemical product used, and the origin of the strain of EPN.

Fitoterapia no controle de parasitos gastrintestinais de ruminantes: ênfase no gênero Mentha e seus componentes bioativos / Phytotherapy in the control of gastrointestinal parasites of ruminants: emphasis on the genus Metha and its bioactive components

Essa revisão apresenta considerações acerca da relevância das infecções de parasitos gastrintestinais (PGI) em ruminantes, abordando a importância de fármacos antiparasitários no controle das helmintoses e demais alternativas. Foi realizada uma abordagem conceitual e histórica sobre o controle de PGI e o processo de desenvolvimento da resistência parasitária. Como alternativa da baixa eficácia de medicamentos, foi feita uma descrição detalhada sobre o uso de óleos essenciais (OE) e de componentes bioativos no controle das PGI em ruminantes. A produção de OE de plantas, passa pela composição química, técnicas de extração dos componentes, mecanismo de ação e ensaios para validação da sua atividade terapêutica, incluindo sua ação anti-helmíntica. Este artigo traz, na sua segunda parte, uma descrição detalhada de duas espécies do gênero Mentha, com foco em sua biologia, composição química e mecanismos de ação de seus OE. Dentro desse tópico, as espécies Mentha vilosa e M. piperita são as mais estudadas, bem como os seus componentes majoritários e bioativos; carvone e limoneno. Ao final do documento, discutimos sobre a técnica de cromatografia gasosa e espectrometria de massas, que se faz obrigatória para a identificação de compostos presentes em OE. Incluímos ainda, o detalhamento sobre tecnologias de nanoemulsão e suas vantagens na confecção de formulações mais estáveis, menos tóxicas aos hospedeiros e com potencial de aumentar a eficácia de fármacos contra as PGI, para o desenvolvimento de novos compostos fitoterápicos ecosustentáveis.(AU)

This review presents considerations about the relevance of gastrointestinal parasite (GIP) infections in ruminants, covering also the importance of antiparasitic drugs in the control of helminth infections and some other alternatives. This document describes a conceptual and historical view of the development of routine GIP control and the process of development of drug resistance. As an alternative to the low efficacy of some products, a detailed description was made of the use of essential oils (EO) and their bioactive compounds in the control of GIP in ruminants. The production of EO from plants, goes through the chemical composition, techniques of extraction of components, mechanism of action and assays for the validation of their activity, including the anthelmintic activity. The present document brings, in its second part, a more detailed description of two species of the genus Mentha, focusing on their biology, chemical composition and the mechanism of action of their EO. Within this topic, the species of Mentha vilosa and M. piperita are better studied, as well as their chemical composition and bioactive components carvone and limonene. At the end, it is discussed the gas chromatography and mass spectrometry techniques that are useful to identify compounds present in EO. It was also included the details about nanoemulsion technologies and their advantages in obtaining a more stable formulation, less toxic to the host, with a great potential to increase anthelmintic efficacy against GIP, for the development of new herbal bioactive and ecofriendly compounds.(AU)

Fitoterapia no controle de parasitos gastrintestinais de ruminantes: ênfase no gênero Mentha e seus componentes bioativos / Phytotherapy in the control of gastrointestinal parasites of ruminants: emphasis on the genus Metha and its bioactive components

Essa revisão apresenta considerações acerca da relevância das infecções de parasitos gastrintestinais (PGI) em ruminantes, abordando a importância de fármacos antiparasitários no controle das helmintoses e demais alternativas. Foi realizada uma abordagem conceitual e histórica sobre o controle de PGI e o processo de desenvolvimento da resistência parasitária. Como alternativa da baixa eficácia de medicamentos, foi feita uma descrição detalhada sobre o uso de óleos essenciais (OE) e de componentes bioativos no controle das PGI em ruminantes. A produção de OE de plantas, passa pela composição química, técnicas de extração dos componentes, mecanismo de ação e ensaios para validação da sua atividade terapêutica, incluindo sua ação anti-helmíntica. Este artigo traz, na sua segunda parte, uma descrição detalhada de duas espécies do gênero Mentha, com foco em sua biologia, composição química e mecanismos de ação de seus OE. Dentro desse tópico, as espécies Mentha vilosa e M. piperita são as mais estudadas, bem como os seus componentes majoritários e bioativos; carvone e limoneno. Ao final do documento, discutimos sobre a técnica de cromatografia gasosa e espectrometria de massas, que se faz obrigatória para a identificação de compostos presentes em OE. Incluímos ainda, o detalhamento sobre tecnologias de nanoemulsão e suas vantagens na confecção de formulações mais estáveis, menos tóxicas aos hospedeiros e com potencial de aumentar a eficácia de fármacos contra as PGI, para o desenvolvimento de novos compostos fitoterápicos ecosustentáveis.

This review presents considerations about the relevance of gastrointestinal parasite (GIP) infections in ruminants, covering also the importance of antiparasitic drugs in the control of helminth infections and some other alternatives. This document describes a conceptual and historical view of the development of routine GIP control and the process of development of drug resistance. As an alternative to the low efficacy of some products, a detailed description was made of the use of essential oils (EO) and their bioactive compounds in the control of GIP in ruminants. The production of EO from plants, goes through the chemical composition, techniques of extraction of components, mechanism of action and assays for the validation of their activity, including the anthelmintic activity. The present document brings, in its second part, a more detailed description of two species of the genus Mentha, focusing on their biology, chemical composition and the mechanism of action of their EO. Within this topic, the species of Mentha vilosa and M. piperita are better studied, as well as their chemical composition and bioactive components carvone and limonene. At the end, it is discussed the gas chromatography and mass spectrometry techniques that are useful to identify compounds present in EO. It was also included the details about nanoemulsion technologies and their advantages in obtaining a more stable formulation, less toxic to the host, with a great potential to increase anthelmintic efficacy against GIP, for the development of new herbal bioactive and ecofriendly compounds.

Effect of cooking on the stability of veterinary drug residues in chicken eggs.

The available information on drug residue stability in chicken egg is scarce. The objective of this study was to evaluate the stability of drug residues in egg under different traditional cooking procedures. Fresh eggs were spiked with different drug concentrations of albendazole (ABZ) and its albendazole sulphoxide (ABZSO) and albendazole sulphone (ABZSO2) metabolites; flubendazole (FLBZ) and its reduced flubendazole (R-FLBZ) and hydrolyzed flubendazole (H-FLBZ) metabolites; amoxicillin (AMX); and enrofloxacin (EFX) and its ciprofloxacin (CFX) metabolite. The egg samples were cooked in different ways, namely, boiling, microwaving, and omelette making. Drug residue concentrations in egg were quantified by HPLC with UV or fluorescence detectors. ABZ and ABZSO concentrations in egg were not affected by boiling and microwaving, while the omelette processing significantly reduced these molecules. Residues of ABZSO2 in egg were stable or increased after all cooking procedures. In contrast, FLBZ and its metabolites FLBZ-H and FLBZ-R residues in egg decreased after all treatments. The residue concentration quantified for EFX and CFX did not show significant changes after any cooking method. AMX residues were unstable, with extremely significant drug reduction after all cooking processes. Conventional methods of egg cooking cannot be considered a tool to eliminate all veterinary drug residues.

[Strongyloides hyperinfection in patient from Patagonia with HTLV-1 co-infection]. / Hiperinfección por Strongyloides en paciente de la Patagonia con co-infección por HTLV-1.

Strongylodiasis is an unattended condition caused by the parasite Strongyloides stercoralis. The Strongyloides hyperinfection syndrome can develop in immunosuppressed hosts, mainly in those with depression of cellular immunity. Co-infection with human T-cell lymphotropic virus (HTLV) is a risk factor for the development of severe forms of strongyloidiasis. We present the case of a 50-year-old man with Strongyloides hyperinfection and coinfection with HTLV. The diagnosis was delayed owing to its unusual epidemiology and an initial suspicion of inflammatory bowel disease. Identification of the parasite in bronchioalveolar lavage and duodenal and colonic mucosa biopsies confirmed the diagnosis. Subcutaneous ivermectin was used as an anthelmintic treatment with an adequate therapeutic response.

La estrongiloidiasis es una afección desatendida causada por el parásito Strongyloides stercoralis. En los individuos inmunosuprimidos, fundamentalmente en los que tienen depresión de la inmunidad celular, puede desarrollarse el síndrome de hiperinfección por Strongyloides. La coinfección con virus linfotrópico de células T humanas (HTLV) es un factor de riesgo para el desarrollo de formas graves de estrongiloidiasis. Presentamos el caso de un hombre de 50 años con hiperinfección por Strongyloides y coinfección con HTLV. Se demoró el diagnóstico debido a su epidemiología inusual y a la sospecha inicial de enfermedad inflamatoria intestinal. El diagnóstico se confirmó mediante la identificación del parásito en muestras de lavado bronquio-alveolar y biopsias de mucosa duodenal y colónica. Se utilizó ivermectina subcutánea como tratamiento antihelmíntico con adecuada respuesta terapéutica.

Hiperinfección por Strongyloides en paciente de la Patagonia con co-infección por HTLV-1 / Strongyloides hyperinfection in patient from Patagonia with HTLV-1 co-infection

La estrongiloidiasis es una afección desatendida causada por el parásito Strongyloides stercoralis. En los individuos inmunosuprimidos, fundamentalmente en los que tienen depresión de la inmunidad celular, puede desarrollarse el síndrome de hiperinfección por Strongyloides. La coinfección con virus linfotrópico de células T humanas (HTLV) es un factor de riesgo para el desarrollo de formas graves de estrongiloidiasis. Presentamos el caso de un hombre de 50 años con hiperinfección por Strongyloides y coinfección con HTLV. Se demoró el diagnóstico debido a su epidemiología inusual y a la sospecha inicial de enfermedad inflamatoria intestinal. El diagnóstico se confirmó mediante la identificación del parásito en muestras de lavado bronquio-alveolar y biopsias de mucosa duodenal y colónica. Se utilizó ivermectina subcutánea como tratamiento antihelmíntico con adecuada respuesta terapéutica.

Strongylodiasis is an unattended condition caused by the parasite Strongyloides stercoralis. The Strongyloides hyperinfection syndrome can develop in immunosuppressed hosts, mainly in those with depression of cellular immunity. Co-infection with human T-cell lymphotropic virus (HTLV) is a risk factor for the development of severe forms of strongyloidiasis. We present the case of a 50-year-old man with Strongyloides hyperinfection and coinfection with HTLV. The diagnosis was delayed owing to its unusual epidemiology and an initial suspicion of inflammatory bowel disease. Identification of the parasite in bronchioalveolar lavage and duodenal and colonic mucosa biopsies confirmed the diagnosis. Subcutaneous ivermectin was used as an anthelmintic treatment with an adequate therapeutic response.

Essential oils of Citrus aurantifolia, Anthemis nobile and Lavandula officinalis: in vitro anthelmintic activities against Haemonchus contortus.

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.