scholarly journals A 4 year observation of gastrointestinal nematode egg counts, nemabiomes and the benzimidazole resistance genotypes of Teladorsagia circumcincta on a Scottish sheep farm

2021 ◽  
Author(s):  
M.J. Evans ◽  
U.N. Chaudhry ◽  
L.M. Costa-Júnior ◽  
K. Hamer ◽  
S.R. Leeson ◽  
...  
Keyword(s):  
Gastrointestinal Nematode ◽  
Teladorsagia Circumcincta ◽  
Sheep Farm ◽  
Benzimidazole Resistance

scholarly journals Some larval morphological characteristics of Camelostrongylus mentulatus and Nematodirus spathiger

2020 ◽  
Vol 3 (2) ◽  
pp. 7-11
Author(s):  
A. Saidi ◽  
R. Mimouni ◽  
F. Hamadi ◽  
W. Oubrou
Keyword(s):  
Morphological Characteristics ◽  
Gastrointestinal Nematode ◽  
Parasitic Nematodes ◽  
Morphological Identification ◽  
Morphological Pattern ◽  
Wild Ruminants ◽  
Nematode Parasites ◽  
Domestic Ruminants ◽  
Teladorsagia Circumcincta ◽  
Camelostrongylus Mentulatus

Monitoring of gastrointestinal nematode parasites in ruminants (domestic and wild) is often based on fecal examination techniques, looking for excreted eggs and larval forms using morphological keys. These, are more available in domestic ruminants, in which helminths are widely studied, than in wild ruminants.  This study tried to provide certain morphological elements that will help to recognize the L3 larvae of Camelostrongylus mentulatus and Nematodirus spathiger that could parasite either domestic or wild ruminants. For that, we resorted first to the culture of L3 larvae from fecal samples taken from African antelopes, and second by the microscopic characterization of each isolated larval morphological pattern previously identified by sequencing of its internal transcribed spacer (ITS-2) regions of the ribosomal DNA. The results of different microscopic captured images showed that Camelostrongylus mentulatus larva is 16 intestinal cells that measuring approximately 820 µm length, ‎≈ 25 µm wide, and ‎≈ 47 µm for its sheath tail extension and by this be closer to Teladorsagia circumcincta characteristics.  For Nematodirus spathiger, it possesses 8 gut cells and measuring about 1020 µm long, ‎≈ 25 µm wide, and‎ ≈ 143 µm for its sheath tail extension with specific tail appendages. Have done this, we were able to get some clarifications on the morphology of the studied larvae, and we believe thus that this study will contribute to the establishment of morphological identification keys especially for parasitic nematodes of wild ruminants.

Multi-species Grazing for Control of Gastrointestinal Nematodes – a Review

2021 ◽  
Vol 99 (Supplement_2) ◽  
pp. 36-37
Author(s):  
Joan M Burke ◽  
James E Miller
Keyword(s):  
Anthelmintic Resistance ◽  
Small Ruminants ◽  
Gastrointestinal Nematode ◽  
Gastrointestinal Nematodes ◽  
Copper Tolerance ◽  
Resistant Species ◽  
Complex Interactions ◽  
Teladorsagia Circumcincta ◽  
Management Scheme ◽  
Time Required

Abstract Multi-species grazing, alternate grazing of cattle with sheep or goats, offers benefits to gastrointestinal nematode (GIN) control as GIN species differ between hosts. In the Southeastern United States, common GIN species of cattle include Cooperia spp., Ostertagia ostertagi, Haemonchus spp., whereas species of sheep and goats are Haemonchus contortus, Teladorsagia circumcincta, Trichostrongylus spp., Cooperia curticei, and Oesophagostomum spp. Anthelmintic resistance is widely prevalent in small ruminants, and is an increasing problem in cattle, but remains less prevalent. Thus, it is recommended to farmers to use a multi-faceted approach of GIN control, including multi-species grazing. Because management differs between cattle and small ruminants in regard to copper tolerance in minerals, predator control and fencing, alternate grazing of species has most commonly been used. Other considerations include age or susceptibility to GIN, as young calves may be vulnerable to GIN, but mature cows often have negligible GIN infection. Similarly, weanling lambs and kids are susceptible, and depending on breed, adults range from highly resistant to susceptible. Research indicates that GIN burden of more resistant animals is less influenced by multi-species grazing, and highly susceptible animals will likely need additional measures of control. The more resistant species used in the multi-species grazing may lend more control to the more susceptible. Some research showed reductions in O. ostertagi, but not C. oncophora in cattle during extended grazing of cattle and sheep, and reductions of H. contortus and T. colubriformis in sheep. However, other research reported similar worm burdens. Weight gains were improved in lambs grazed alternately with cattle in some studies, and most studies showed little benefit to cattle. Little has been published on alternate grazing with cattle and goats. The complex interactions, larger plot sizes needed, and time required to complete experiments limits published studies of this important management scheme.

Moisture and temperature requirements in faeces for the development of free-living stages of gastrointestinal nematodes of sheep, cattle and deer

1995 ◽  
Vol 69 (4) ◽  
pp. 357-362 ◽  
Author(s):  
C.E. Rossanigo ◽  
L. Gruner
Keyword(s):  
Haemonchus Contortus ◽  
Gastrointestinal Nematode ◽  
Nematode Species ◽  
Gastrointestinal Nematodes ◽  
Free Living ◽  
Moisture Contents ◽  
Cooperia Oncophora ◽  
Teladorsagia Circumcincta ◽  
Temperature Requirements ◽  
Different Temperatures

AbstractIsolates from eight gastrointestinal nematode species parasitic in sheep, cattle and deer were maintained in sheep, to provide eggs in similar faecal environments and to compare temperature and moisture requirements for their development. Faecal cultures were processed at different temperatures (for four species) and moisture contents (for eight species). At 60% of faecal moisture content (FMC), maximal rates of development (expressed as L3/100 hatchable eggs estimated by an extraction technique from the faeves) were observed at 20, 23 and 28°C respectively for Ostertagia leptospicularis, O. ostertagi, Teladorsagia circumcinctaand Trichostrongylus colunriformis. For the eight species, the curves of development rates as functions of FMC were Gaussian, without modification between 18 and 28°C. Optimal developments were when the FMC ranged from 57 to 68%; low development of 1L3/100eggs were observed when the FMC ranged from 85 to 95% and from 25 to 55%. The main differences between species were in the ability of the eggs of Teladorsagia circumcincta, Trichostrongylus colubriformis, T. vitrinusand Chabertia ovina to develop at lower FMC than Haemonchus contortus, O. ostertagi, O. legptospicularis and Cooperia oncophora.

scholarly journals High frequency of benzimidazole resistance alleles in Haemonchus contortus, Teladorsagia circumcincta and Trichostrongylus colubriformis from Austrian sheep flocks in an alpine transhumance management system

2019 ◽  
Author(s):  
Barbara Hinney ◽  
Julia Schoiswohl ◽  
Lynsey Melville ◽  
Vahel J. Ameen ◽  
Walpurga Wille-Piazzai ◽  
...  
Keyword(s):  
Management System ◽  
Anthelmintic Resistance ◽  
Treatment Strategies ◽  
Small Ruminants ◽  
Nucleotide Polymorphisms ◽  
Sheep Population ◽  
Teladorsagia Circumcincta ◽  
Benzimidazole Resistance ◽  
Drug Classes ◽  
New Treatment

Abstract Infections of small ruminants with trichostrongyloid nematodes often result in reduced productivity and may be detrimental to the host. Anthelmintic resistance (AR) against most anthelmintic drug classes is now widespread amongst the trichostrongyloids. Baseline establishment, followed by regular monitoring of the level of AR, is necessary for farmers and veterinarians to make informed decisions about parasite management. The detection of single nucleotide polymorphisms (SNPs) is a sensitive method to detect AR against benzimidazoles (BZs), one of the most widely used anthelmintic classes. Alpine transhumance constitutes a special type of pasturing of sheep from many different farms, the aim of this study was to investigate the prevalence of benzimidazole resistance alleles in this particular management system. Sixteen sheep flocks in Styria and Salzburg in Austria were examined by pyrosequencing for SNPs at codons 167, 198 and 200 of the isotype-1 β-tubulin gene. The frequency of the resistance-associated mutation F200Y was 87–100% for H. contortus, 77–100% for T. colubriformis and <5–66% for T. circumcincta. Additionally, the F167Y polymorphism was detected in T. colubriformis from two farms at a frequency of 19% and 23% respectively. The high resistance allele frequency in H. contortus and T. colubriformis in the examined sheep population urgently calls for the development of new treatment strategies to sustainably control trichostrongyloid infections for this kind of pasturing, since the frequent mixing of flocks during the alpine summer grazing must be considered an important risk factor for the spread of resistant nematodes to a large number of farms.

scholarly journals Multitrait indices to predict worm length and number in sheep with natural, mixed predominantly Teladorsagia circumcincta infection

Parasitology ◽  
2015 ◽  
Vol 142 (6) ◽  
pp. 773-782 ◽  
Author(s):  
COLETTE MAIR ◽  
LOUISE MATTHEWS ◽  
JOAQUIN PRADA J. DE CISNEROS ◽  
THORSTEN STEFAN ◽  
MICHAEL J. STEAR
Keyword(s):  
Gastrointestinal Nematode ◽  
Linear Combinations ◽  
Teladorsagia Circumcincta ◽  
Pathogenic Effects

SUMMARYAccurately identifying resistance to gastrointestinal nematode infections requires the ability to identify animals with low and high intensities of infection. The pathogenic effects of nematodes depend upon both the length and number of worms, neither of which can be measured in live animals. Indices that predict these quantities are urgently needed. Monthly fecal egg counts, bodyweights, IgA concentrations and pepsinogen concentrations were measured on Scottish Blackface sheep naturally infected with a mixture of nematodes, predominantly Teladorsagia circumcincta. Worm number and average worm length were available on over 500 necropsied lambs. We derived predictive indices for worm length and number using linear combinations of traits measured in live animals. The correlations between the prediction values and the observed values were 0·55 for worm length and 0·51 for worm number. These indices can be used to identify the most resistance and susceptible lambs.

scholarly journals Infection with the sheep gastrointestinal nematode Teladorsagia circumcincta increases luminal pathobionts

2019 ◽  
Author(s):  
Alba Cortes ◽  
John Wills ◽  
Xiaopei Su ◽  
Rachel Hewitt ◽  
Jack Robertson ◽  
...  
Keyword(s):  
T Cells ◽  
Control Strategies ◽  
Parasitic Infection ◽  
Gastrointestinal Nematode ◽  
Parasite Infection ◽  
Helminth Parasites ◽  
Gastrointestinal Helminths ◽  
Microbial Composition ◽  
Teladorsagia Circumcincta ◽  
The Impact

Abstract Background The multifaceted interactions between gastrointestinal (GI) helminth parasites, vertebrate host gut microbiota and the immune system are emerging as a key area of research within the field of host-parasite relationships. In spite of the plethora of data available on the impact that GI helminths exert on the composition of the gut microflora, whether alterations of microbial profiles are caused by direct parasite-bacteria interactions or, indirectly, by alterations of the GI environment (e.g. mucosal immunity), remains to be determined. Furthermore, no data is thus far available on the downstream roles that qualitative and quantitative changes in gut microbial composition play in the overall pathophysiology of parasite infection and disease. Results In this study, we investigated the fluctuations in microbiota composition and local immune microenvironment of sheep vaccinated against, and experimentally infected with, the ‘brown stomach worm’ Teladorsagia circumcincta, a parasite of worldwide socio-economic significance. We compared gut microbial profiles with those obtained from groups of unvaccinated/infected and unvaccinated/uninfected animals. We show that alterations to the gut microbial composition are associated mainly with parasite infection, and that this involves the expansion of populations of bacteria with known pro-inflammatory roles that may contribute to the immunopathology of helminth disease. Using novel quantitative approaches for the analysis of confocal microscopy-derived images we also show that gastric tissue infiltration of T cells is driven by parasitic infection rather than anti-helminth vaccination. Conclusions Teladorsagia circumcincta infection leads to an expansion of potentially pro-inflammatory gut microbial species and abomasal T cells. This data paves the way for future experiments aimed at determining the contribution of the gut flora to the pathophysiology of parasitic disease, with the ultimate aim to design and develop novel treatment/control strategies focused on preventing and/or restricting bacterial-mediated inflammation upon infection by gastrointestinal helminths.

scholarly journals Teladorsagia Circumcincta Beta Tubulin: The Presence of the E198L Polymorphism on Its Own is Associated with Benzimidazole Resistance

2020 ◽  
Author(s):  
María Martínez Valladares ◽  
Elora Valderas-García ◽  
Javier Gandasegui ◽  
Philip Skuce ◽  
Alison Morrison ◽  
...  
Keyword(s):  
Phenotypic Variability ◽  
Linear Regression Analysis ◽  
Significant Variable ◽  
Multivariate Linear Regression Analysis ◽  
Tubulin Gene ◽  
Phenotypic Resistance ◽  
Pyrosequencing Assay ◽  
Teladorsagia Circumcincta ◽  
Benzimidazole Resistance ◽  
Β Tubulin

Abstract Background: Benzimidazole resistance is associated with isotype-1 β-tubulin gene F200Y, E198A and F167Y SNPs. In this study, the recently described polymorphism E198L was reported and analysed in Teladorsagia circumcincta.Methods: The benzimidazole phenotypic resistance was measured by the Faecal Egg Count Reduction Test (FECRT) and the Egg Hatch Test (EHT) using a discriminating dose in 39 sheep flocks. Around 1,000 larvae collected before and after treatment were used for DNA extraction. The resistant species identified in all flocks was T. circumcincta . The resistance alleles frequencies were measured for F200Y and E198A. A 371 bp fragment of the isotype-1 β-tubulin gene was analysed, including the three codons of interest, and a new pyrosequencing assay was designed for testing E198L. Results: The percentage of resistant flocks was 32% by FECRT or 26% by EHT, however F200Y and E198A SNPs were absent in T. circumcincta . The amplification a 371 bp fragment confirmed the absence of F167Y and F200Y in 6 resistant flocks. Regarding codon 198, all samples after treatment carried a leucine (CTA). A pyrosequencing assay analysed the allele frequencies for the first two bases at codon 198 independently, G/C and A/T. The correlation between C and T frequencies was almost 1 (r = 0.929; p = 0.000) and the mean value of both was calculated to measure the leucine frequency; this value ranged between 10.4 and 80.7% before treatment, and from 82.3 to 92.8% after treatment. Very high and similar correlations were reported between the genotypic variables (C frequency, T frequency or mean of both frequencies) and phenotypic resistance (r > 0.720; p = 0.000), although negatively associated with the FECRT and positively with the EHT. According to multivariate linear regression analysis, the T frequency was the most significant variable influencing the phenotypic resistance (FECRT or EHT; p = 0.000). In the EHT, 67.1% of the phenotypic variability is associated with the T frequency but in the FECRT only 33.4%; therefore, the EHT using a DD seems to detect the genotypic resistance more accurately than the FECRT. Conclusions: The E198L polymorphism can confer BZ resistance on its own in T. circumcincta .

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