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Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anthelmintic resistant gastrointestinal helminths have become a major cause of poor health in sheep and goats. Sensitive and specific molecular markers are needed to monitor the genotypic frequency of resistance in field parasite populations. Gastrointestinal nematode resistance to benzimidazole is caused by a mutation in one of three positions within the isotype 1 β-tubulin gene. In the absence of markers for resistance to the other broad spectrum anthelmintic classes, these provide a relevant study example. Determination of the prevalence of these single nucleotide polymorphisms in field nematode populations can be impractical using conventional molecular methods to examine individual parasites; which can be laborious and lack sensitivity in determining low levels of resistance in parasite populations. Here, we report the development of a novel method based on an Illumina MiSeq deep amplicon sequencing platform to sequence the isotype 1 β-tubulin locus of the small ruminant gastrointestinal nematode, Teladorsagia circumcincta , and determine the frequency of the benzimidazole resistance mutations. We validated the method by assessing sequence representation bias, comparing the results of Illumina MiSeq and pyrosequencing, and applying the method to populations containing known proportions of resistant and susceptible larvae. We applied the method to field samples collected from ewes and lambs on over a period of one year on three farms, each highlighting different aspects of sheep management and approaches to parasite control. The results show opportunities to build hypotheses with reference to selection pressures leading to differences in resistance allele frequencies between sampling dates, farms and ewes or lambs, and to consider the impact of their genetic fixation or otherwise. This study provides proof of concept of a practical, accurate, sensitive and scalable method to determine frequency of anthelmintic resistance mutations in gastrointestinal nematodes in field studies and as a management tool for livestock farmers. Image 1 • Development and validation of Illumina Mi-Seq for the detection of anthelmintic resistance. • Assessment of the novel assay using benzimidazole resistance as a proof of concept. • Novel approach open the area of research to study the anthelmintic resistance. [ABSTRACT FROM AUTHOR]

Copyright of Parasite (1252607X) is the property of EDP Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Cientifica de la Facultade de Veterinaria is the property of Universidad del Zulia, Facultad de Ciencias Veterinarias and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Many modern-day studies require parasite samples essentially free of environmental contamination. Techniques used to prepare gastrointestinal nematode eggs from livestock are sufficient for biological studies but fall woefully short of generating pure preparations for downstream molecular, biochemical, and immunological studies. Consequently, a method to produce highly purified nematode parasite eggs free from fecal contamination is needed. The present study compared different procedures for egg isolation and attempted to improve the purity of Ostertagia osterlagi eggs isolated from cattle feces. The Wisconsin method using saturated sucrose has been used widely to enrich eggs from feces and is adequate for identification and counting. A more-recently developed method using the combination of salt and sucrose is robust and consistent and can be used to isolate eggs with much higher purity; however, residual fecal materials are still present in the egg preparations, which could account for large levels of nonspecific DNA and RNA contamination in the final samples. While large numbers of eggs can be harvested from the medium of overnight, in vitro-cultured adult worms, this method is labor intensive, involves euthanasia of animals, and requires the purification of adult worms to high purity and subsequent culturing to acquire the eggs. In addition, a large proportion of the eggs initiate development and hatch during isolation. In the current method, Ostertagia eggs free from fecal contamination were secondarily purified using lymphocyte separation medium (LSM) from eggs previously enriched by the Wisconsin method. The egg recovery following the LSM step was 100%. The results indicate that this two-step method involving sucrose and LSM was simple, rapid, nonselective, and greatly improved the purity of Ostertagia eggs. This method will have broad application for isolating eggs of the superfamily of Trichostrongyloidea, which includes the most-important nematode parasites infecting livestock. [ABSTRACT FROM AUTHOR]

The article discusses a study which explored the resistance of Garole sheep against gastrointestinal nematode infection. It offers information on the materials and methods used including examination of faecal sample, determination of species composition of third stage larvae, and grouping of animals and parameters. It indicates that Garole sheep, while susceptible to gastrointestinal nematode, possesses a high level of resilience against the disease.

The present study was carried out to know the resistance against the drug fenbendazole by in vivo and in vitro method of detection in four sheep farms located in Bangalore and Tumkur districts of Karnataka. Sheep which were not dewormed for the past 2-3 months in a herd and with minimum of 150-200 egg per gram (EPG) count before treatment were selected for the current study. The less value of lower 95% confidence limit indicated the resistance to fenbendazole detected by in vivo test and the ED50 values and LD50 values are more than 0.1 µg/ml and also percentage paralysis at different time intervals indicates the existence of higher number of resistant worms to the drug fenbendazole. [ABSTRACT FROM AUTHOR]