Occurrence of gastrointestinal nematodes in lambs in Norway, as assessed by copromicroscopy and droplet digital polymerase chain reaction.

Bibliographic Details
Title: Occurrence of gastrointestinal nematodes in lambs in Norway, as assessed by copromicroscopy and droplet digital polymerase chain reaction.
Authors: Gravdal, Maiken1 (AUTHOR) maiken.gravdal@nmbu.no, Woolsey, Ian David2 (AUTHOR), Robertson, Lucy Jane2 (AUTHOR), Höglund, Johan3 (AUTHOR), Chartier, Christophe4 (AUTHOR), Stuen, Snorre1 (AUTHOR)
Source: Acta Veterinaria Scandinavica. 5/25/2024, Vol. 66 Issue 1, p1-11. 11p.
Subject Terms: *HAEMONCHUS contortus, *POLYMERASE chain reaction, *FECAL egg count, *LAMBS, *NEMATODES, *AUTUMN
Geographic Terms: NORWAY
Abstract: Background: Gastrointestinal nematodes (GINs) have a major impact on sheep production, health, and welfare worldwide. Norway is no exception, but there are only a few studies on the prevalence of GINs in Norwegian sheep. The aim of this study was to investigate the current occurrence of the most important nematodes in sheep flocks in Norway. Faecal samples were collected from flocks in 2021/2022, mainly from three geographical regions in Norway, i.e., northern, eastern, and western. In each of 134 flocks included, individual samples from 10 lambs (autumn) were pooled. Third stage larvae (L3) were cultivated and harvested (Baermann method) from the pooled samples. The DNA was then extracted and further analysed using droplet digital PCR (ddPCR). This enables assessment of the proportions of the three most important nematode species/genera, i.e., H. contortus, T. circumcincta, and Trichostrongylus. The fractional abundance/relative proportion of each species/genus was assessed by performing duplex assays with universal strongyle and species/genus-specific primers and probe sets. In addition, the occurrence of Nematodirus eggs was assessed by standard faecal egg counts (i.e., McMaster method). Results: Of the 134 flocks sampled, 24 were from the northern region, 31 from eastern, and 71 from western Norway. In addition, some flocks from central (n = 7), and southern (n = 1) Norway were included. Among the sampled flocks, T. circumcincta occurred most commonly (94%), followed by H. contortus (60%) and Trichostrongylus (55%), and Nematodirus (51%). In general, mixed infections were observed, with 38% and 18% of flocks infected with three or all four genera, respectively. Conclusions: The results of this study indicate that GINs are widespread in Norway. Teladorsagia circumcincta seems to be present in most flocks based on this screening. Moreover, the results show that Nematodirus spp. infect lambs throughout the country, predominantly N. battus, and indicate that this nematode has become more abundant, which could lead to an increase in nematodirosis. [ABSTRACT FROM AUTHOR]
Copyright of Acta Veterinaria Scandinavica is the property of BioMed Central 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.)
Database: Academic Search Complete
Full text is not displayed to guests.
More Details
ISSN:0044605X
DOI:10.1186/s13028-024-00743-z
Published in:Acta Veterinaria Scandinavica
Language:English