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En esta revisión se presenta un panorama general de las nematodosis en pequeños rumiantes en México; así como los principales problemas que enfrentan los productores para mantener su actividad productiva. Del mismo modo, se muestra información general sobre las nematodosis gastrointestinales y sus efectos en la salud animal y en la productividad. Por otra parte, se analizan los principales retos o desafíos que se enfrenta el sector pecuario para contrarrestar estas importantes enfermedades, haciendo énfasis en las distintas estrategias de control y prevención incluyendo la quimioterapia, resistencia antihelmíntica, manejo del pastoreo, desparasitación selectiva, estrategia nutricional proteica, vacunación, selección de animales genéticamente resistentes a los nematodos, el uso de plantas y compuestos con actividad nematicida; así como los resultados más recientes en cuanto al uso de hongos nematófagos como agentes de control biológico, entre otras herramientas de control. En este trabajo se hace mención a importantes resultados obtenidos en la investigación generada en el Área de Helmintología del CENID-SAI del INIFAP y se plantea como perspectiva el establecimiento de un método integral de control de estas enfermedades a las distintas fases de desarrollo de los parásitos como “blancos” de ataque hacia dónde dirigir las estrategias de control, a los diferentes estadios evolutivos de estos parásitos, con lo que se esperan los mejores resultados contra este grupo de parásitos que tanto afectan a la salud de los rebaños y a la economía de los productores.

The excretory/secretory (E/S) products released by infective transitory larvae (xL

The analysis of the immune gene expression was performed in Zebu × Holstein calves with resistant and susceptible phenotypes naturally infected with Cooperia punctata. Fourteen calves of 4 months old were grazed for 11 weeks under a tropical climate. The parasitic infection showed an average epg value of 1055 ± 1155 and an IgG optical density of 0.814 ± 0.0.037 with statistic differences among the different weeks (p0.05), and a pcv value of 24 ± 2.0 % (p0.05). High variation in epg value was observed, between 7 ± 7.14 and 4657 ± 1886, and, based on these differences; the infected hosts were classified as five resistant calves with epg ≤ 200 and nine susceptible calves with epg ≥ 300. Moreover, IgG levels displayed statistical differences between resistance and susceptible calves to C. punctata infection. The immune gene expression was analysed in three resistant and susceptible calves, respectively. Nine cytokine genes and the FCεR1A receptor were analysed at the 3rd and 11th weeks post-infection. In the first period upregulation was found, from 2.19- to 9.45-fold, (p 0.05) for IL-2, -5, - 6, -10, TGF-β and FCεR1A in the resistant group; the expression was decreased at the 11th week with low level of IgG. In contrast, downregulation for susceptible calves was found for nine immune genes and upregulation for INF-γ in both periods together with increased IgG levels. In conclusion, immune gene expression was regulated at the begging infection of C. punctata in resistant grazing calves. In contrast, suppression of important genes was involved in calves susceptible to C. punctata.

The objective of this study was to analyze the mRNA transcription levels of ten functional genes of P-glycoproteins (P-gp) in free life stages, eggs and infective larvae (L3) and in endoparasitic stages, fourth larval stage (L4) and adult males of two native isolates of Haemonchus contortus: resistant and susceptible to IVM. The IVM resistant isolate was obtained from sheep naturally infected with H. contortus, and the susceptible isolate (with no pressure to IVM) conserved since 1990. The lethal effect of IVM was evaluated under in vitro conditions, which showed significant differences between susceptible and resistant H. contortus L3 isolates (P < 0.01). The IVM susceptible isolate revealed a lethal effect of 79.22% at 11.42 mM, whereas that resistant isolate showed no lethal effect at any of the four assessed concentrations (1.43, 2.85, 5.71 and 11.42 mM) of IVM. The expression levels of ten Hco-pgp genes (1, 2, 3, 4, 9, 10, 11, 12, 14, and 16) were evaluated in the resistant isolate of H. contortus and compared to the susceptible isolate (as control), using two constitutive genes (GAPDH and β-tubulin). Up-regulation at two statistical significant values (P ≤ 0.05, 0.1) was the criterion to associate IVM resistance with the free life and endoparasitic stages of H. contortus. The expression levels in H. contortus adult nematodes showed 5.64 to 127.56-fold increase for Hco-pgp genes 1, 9, 12, 14, and 16, followed by an increase for Hco-pgp-2 (49.75-fold) and Hco-pgp-10 (106.40-fold) in L4, and for Hco-pgp-16 (2.90-fold) in eggs (P ≤ 0.05). In addition, high expression levels with P < 0.1 were detected in H. contortus L3, L4, and adults for Hco-pgp genes 1, 4, 11, 12, and 16, with changes ranging from 2.17 to 29.72-fold. In conclusion, the highest expression was observed in the adult stage of H. contortus, and the most frequent gene with a significant P-value was Hco-pgp-16, revealing it plays an important role in IVM resistance.

This research assessed the dose/response to Duddingtonia flagrans chlamydospores (Df-C) administered to calves naturally infected with gastrointestinal nematodes (GINs), and its effect in reducing the infective larvae (L3) population in faeces in a farm in the Mexican tropics. Forty zebu calves, between 6 and 12 months of age, were randomly distributed into four groups of 10 calves. One control and three groups treated with different oral doses of Df-C based on their body weight (BW) were established as follows: group 1 (control); group 2, 0.250 × 106 Df-C per kg/BW; group 3, 0.5 × 106 Df-C per kg/BW and group 4, 1 × 106 Df-C per kg/BW. The fungal doses were administered daily for 10 days. Every group was confined to individual pens, and they received a nutritional regime based on Buffel grass, concentrated supplement and water ad libitum. Every third day, starting one week before treatments, faeces were taken from the rectum of each animal to determine the number of eggs per g of faeces (epg) through the McMaster technique. Four coprocultures of 20 g each from each individual faecal sample were prepared and incubated for 14 days. The efficacy of the treatments was based on the mean of the GIN L3 recovered from coprocultures of the different groups. Data were analysed using a completely randomized design through an ANOVA analysis, followed by a Duncan multiple range test. The efficacy of treatments was expressed as the larval reduction rate. High variation in the epg in the different groups along the experiment was recorded. The reduction in the GIN L3 population was observed from the 4 to 11 day post-treatment in the three assessed doses. Results in group 2 (lowest fungal dose), showed 88.5, 57.6, 55.9 and 30% (58% overall reductions) in the GIN L3 in the faeces of animals 4, 7, 9 and 11 days post-treatment, respectively. In group 3 (medium fungal dose), 95.8, 80.4, 63.4 and 52.7% GIN L3 reductions (73% overall reduction) were recorded, respectively. At the highest Df-C dose used (1 × 106 per kg/BW), the results were 88.9, 78.0, 59.3 and 67.3% (73.5% overall reduction), respectively (p

The excretory/secretory (E/S) products released by infective transitory larvae (xL3) of Haemonchus placei have an important biological function in stimulating immune mechanisms during the invasive process. Our objective was to analyse the modulatory activity of 15 and 70 kDa E/S products from H. placei xL3. Both E/S products were collected from xL3 in vitro cultures at 24 and 72 h. Proteins were confirmed by SDS-PAGE, and the corresponding spots were elicited by gel isoelectrofocusing (IEF) and characterised by mass spectrometry. Additionally, flow cytometry of CD4+/γδ+ T cells and immune gene expression were performed by proliferation assays using each E/S product to stimulate lymphocyte and peripheral blood mononuclear cells (PBMCs) from non-infected calves. The IEF results displayed two spots of 7.0 and 5.7 pI for the 15 and 70 kDa products, respectively. Additionally, 29 and 17 peptides from the 15 and 70 kDa E/S products, respectively, were identified with the hypothetical neurotransmitter and enzymatic functions necessary for larval development. The relative expression displayed upregulation of IL4, 5, 6, 8, 10, 13, IFNγ, and FCeR1A genes (from 2.0- to 17.6-fold, p 0.05), the 15-kDa protein reduced the levels of both T cells, and the 70-kDa proteins increased the γδ+ cells slightly. Additionally, there was increased PBMCs proliferation by the 70 kDa proteins (p

Summary This study determined the efficacies of four classes of anthelmintics (AH) in a goat flock where anthelmintic resistance (AR) to ivermectin was suspected. We selected and randomly distributed 105 animals with >500 eggs per gram of feces into seven groups of 15 animals: an untreated control group and groups treated with ivermectin, eprinomectin, albendazole sulfoxide, albendazole, levamisole, and closantel. The goats were individually weighed and treated with the recommended dose. Fecal samples were collected 14 days post-treatment to determine the fecal egg counts and for a fecal egg count reduction test (FECRT). Coprocultures were also performed for identifying any resistant genera. A molecular assay (polymerase chain reaction, PCR) was used to confirm benzimidazole resistance. The FECRTs for the ivermectin, eprinomectin, albendazole sulfoxide, and albendazole treatments were Haemonchus spp. Levamisole had a FECRT confidence interval

One metabolite against lamb gastrointestinal nematodes (GIN) was identified from extracts of Lysiloma acapulcensis leaves. Firstly, an aqueous extract of L. acapulcensis leaves and two fractions, organic and aqueous, were evaluated at different concentrations against Haemonchus contortus eggs and histotrophic larvae. In other experiment, 35 Pelibuey GIN-infected lambs were randomly divided into five groups, as follows: (1) ivermectin (0.2 mg/kg BW); (2) control (untreated); (3) rutin (10 mg/kg BW, as a flavonoid comparison control); (4) L. acapulcensis leaves ethyl acetate fraction (EtAc-F, 25 mg/kg BW); and (5) L. acapulcensis leaves (dried and grinded, 5 g/kg BW). The EtAc-F fraction caused 94.8% egg-hatching inhibition (P

Ethnopharmacology relevance Acacia cochliacantha is a small tree whose foliage is traditionally used in Mexico for treatment of kidney pain, gastrointestinal illnesses and to kill intestinal parasites. In recent decades, the study of vegetal extracts has offered other possible alternatives for the control of Haemonchus contortus . Considering that this nematode affects dramatically the health and productivity of small ruminants, the aim of this study was to identify the anthelmintic compounds from A. cochliacantha hydro-alcoholic extract (HA-E) through an ovicidal test. Material and methods In vitro egg hatch assay was conducted to determinate the anthelmintic effects of a HA-E (60 g). Liquid-liquid ethyl acetate/water extraction gave two fractions (EtOAc-F, 1.92 g; Aq-F; 58.1 g). The less polar compounds from ethyl acetate fraction were extracted by addition of dichloromethane offering a precipitate phase (Mt-F, 1.25 g) and a soluble mixture (DCMt-F 1.15 g). All fractions were evaluated for ovicidal activity obtaining the egg hatching inhibition (EHI, 0.07–25 mg/mL). Ivermectin (0.5 mg/mL) was used as a reference drug (positive control), and distilled water, 2.5% DMSO and 2% methanol were used as negative controls. The isolated compounds from the most active fractions were subjected to spectroscopic ( 1 H NMR) Spectrometric (MS) and UV HPLC analysis in order to identify the bioactive compounds. Results The less polar treatments (AcOEt-F, DCMt-F, DCMt-P) showed the highest ovicidal activities (98–100% EHI; at 0.62–1.56 mg/mL) and the major compounds found in these fractions were identified as caffeoyl and coumaroyl derivatives, including caffeic acid ( 1 ), p -coumaric acid ( 2 ), ferulic acid ( 3), methyl caffeate ( 4 ), methyl- p -coumarate ( 5 ), methyl ferulate ( 6 ) and quercetin. In case of the less active fractions (Aq-F, Mt-F) were constituted principally by glycosylated flavonoids. Conclusion These results show that caffeoyl and coumaroyl derivatives from Acacia cochliacantha leaves had promising anthelmintic activity against Haemonchus contortus . This leguminous may offer an alternative source for the control of gastrointestinal nematodes of small ruminants.

We analysed the immune response involved in sheep naturally infected with gastrointestinal (GI) nematodes. Fifteen Pelibuey lambs were grazed in paddocks contaminated with GI nematodes for 13 weeks. To assess the infection, the number of eggs per gram (epg) and the percentage of packed cell volume (pcv) were evaluated. Blood and abomasal tissue samples were collected at week 8 post-infection to analyse the expression levels of IL-4, IL-5, IL-6, IL-8, IL-13, TGF-β and FCεR1A genes. The nematode Haemonchus contortus was the main species identified. In addition, two groups of lambs were classified based on the x ± SE of epg and pcv values: G-1, with 151 ± 28 and 29 ± 0.33%, respectively, and G-2, with 475 ± 59.5 and 26 ± 0.38%, respectively. For G-1, upregulation of IL-4, IL-8, IL-13, TGF-β and FCεR1A genes from 2.42- to 14.99-fold was observed in blood and abomasal tissue samples (p .05), and IL-5, IL-8 and TGF-β genes had significant gene expression levels in blood (p .05). For G-2, moderate gene expression levels, ranging from 1.22- to 3.45-fold, were observed in abomasal tissue (p .05), and the IL-5 gene presented significant gene expression in blood (p .05). Strong positively correlated values (r) between pcv and IL-4, IL-8 and TGF-β genes were observed in G-1. In contrast, significant negative correlations between epg and IL-4, IL-5 and FCεR1A genes indicate acute infection for G-2. Our results suggest that IL-4, IL-5, IL-13, TGF-β and FCεR1A genes are important modulators of GI nematode infections of Pelibuey lambs.

The aim of the present study was to assess the expression of cytokines and FCeR1A receptor stimulated by Haemonchus placei larval excretory and secretory (ES) products associated with the pathogenesis in calves. Bovine peripheral blood mononuclear cells (PBMC) were stimulated in in vitro assays with H. placei L4 ES product at 8, 12, 16 and 24 h. ES products were collected in in vitro assays at 48 h with molecular weight of 72/60 kDa and isoelectric point of 7.2 pI. Specific IgG for infected and control calves, positive and negative, were employed to recognise H. placei larval ES products by indirect ELISA, showing a mean of 1.8, 0.83 and 0.28 OD, respectively, (p ≤ 0.001). The quantification of relative gene expression was performed using a set of cytokines (IL-2, IFNγ, TGFβ, IL-4, IL-5, IL-6, IL-8, IL-10 and IL-13), FCeR1A receptor and housekeeping (GAPDH, β-actin and β-2-microglobulin) by RT-qPCR. An early increased expression, 2.2- to 3.4-fold change, of IL-2 (p ≤ 0.001), IL-5 and TGFβ (p ≥ 0.05) was determined, followed by TGFβ (30.7 and 14.14), IL-8 (102.8 and 1504.4) and IL-10 (60.4 and 1.7) (p ≤ 0.05) after 12 and 16 h, respectively, and reducing the expression level at 24 h. In addition, IL-6, IL-13 and FCeR1A receptor also displayed mild expression level, 2.1 – to 7.60-fold change, at 24 h (p ≥ 0.05). We conclude that ES products of 72/60 kDa collected in vitro from H. placei larvae are recognised by infected hosts and have the ability to induce diverse immune factors to modulate the nematode damage.

Gastrointestinal parasite infections represent a major welfare problem in small ruminants reared in extensive systems, which may be exacerbated by anthelmintic resistance. Therefore, we aimed to study the efficacy of albendazole and ivermectin in sheep. Eighty-six animals were selected from commercial farms in the temperate area of the State of Mexico at the age of seven months. These animals were randomly distributed into three groups: Group A, treated with albendazole, Group I, treated with ivermectin and Group C, left untreated. Faecal samples were collected before the anthelmintic was administered and 15 days post-treatment. Both Group A and Group I displayed a significant decrease of faecal egg counts when pre- and post-treatment values were compared (p = 0.003 and p = 0.049, respectively), and a significantly lower faecal egg count when compared with Group C after the treatment (p &lt, 0.05). However, the faecal egg count reduction test showed that gastrointestinal nematodes (GIN) developed anthelmintic resistance to both albendazole and ivermectin. The results of the polymerase chain reaction (PCR) allowed the identification of Cooperia spp., and Trichostrongylus colubriformis. The allele-specific PCR results confirmed that T. colubriformis was resistant to albendazole. In conclusion, this study showed the presence of resistant GIN to albendazole and ivermectin in sheep reared in Mexican temperate zones. Therefore, nematode infections should be systematically monitored in order to implement integrated management strategies to prevent the spread of anthelmintic resistance.

The expression profiles of cytokines and antioxidant genes were determined from an experimental infection with H. contortus in Pelibuey lambs. The infection was followed for 34 days (d) to determine the number of eggs per gram (epg) and the packed cell volume (PCV). Differential white cell counts and expression profile estimations of IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, FCεR1A, GPX and SOD1 were determined at 0 hour, 4 hours, 2 days and 14 days post-infection (PI) in infected and control groups. Comparison of the fold change between 0 and 4-hours, 4-hours and 2-days and 2- and 14-days periods was performed. Significant differences (P.05) between epg (2000) and PCV (30%) were determined after 21 days and were also observed with regard to monocyte and lymphocyte cells after 2 and 7 days PI. At 0 hour and 14 days PI, the GPX and IL-2 genes showed a 0.37- and 0.49-fold decrease in expression, respectively. In contrast, upregulation was observed at 4 hours of IL-8 (2.58) and FCεR1A (2.71), at 2 days for IL-4 (2.14) and IL-8 (4.02) and at 14 days for IL-2 (0.41), IL-10 (2.35) and FCεR1A (2.28). The comparison between the intervals of infection showed high expression values against H. contortus infection in Pelibuey sheep after the 2nd period of PI involving a dichotomy T cells.