Host specificity and species diversity of the Ostertagiinae Lopez-Neyra, 1947 in ruminants: a European perspective

Abstract

BackgroundNematodes of the subfamily Ostertagiinae appear to be rather specific to a species or family of hosts, but some are observed in a wide variety of hosts. The nematode Ostertagia leptospicularis draws special attention due to its presence or absence among the same host species in different European countries. Therefore, this paper focuses mainly on the host specificity among nematodes of the subfamily Ostertagiinae. The second aim of this study is to assess the possibility of treating O. leptospicularis as an Ostertagia species complex.MethodsData were gathered from post-mortem examinations of domestic and wild ruminants (n = 157), as well as bibliographical references (n = 96), which were pooled and discussed. The research area was limited to European countries, hence the studied ostertagiine species are limited to native ones; likewise, the host species. Special emphasis was placed on the mean abundance values that allowed a typical host or hosts for each nematode species to be specified. Correspondence analysis was performed to confirm the stated host specificity.ResultsThe analysis revealed that nematodes of this subfamily tend to use ruminants from a particular subfamily as their principal host. The results indicate that Ostertagia leptospicularis, similar to Teladorsagia circumcincta, may represent a potential species complex. This nematode, as the sole member of the subfamily Ostertagiinae, occurs in almost all representatives of the Bovidae subfamily, as well as in the Cervidae.ConclusionsDespite the stated narrow host specificity, the results obtained may suggest that O. leptospicularis is not strongly connected to any host or is comparably associated with a very wide and diverse group of hosts (Cervidae, Bovidae). The Ostertagia complex may have particular cryptic species or strains typical for any individual host or group of hosts. Such a conclusion requires further investigations on a wider scale.

Morphometric and Molecular Analyses of Ostertagia leptospicularis Assadov, 1953 from Ruminants: Species Diversity or Host Influence?

“…Furthermore, nematodes from the latter strain circulate within particular host species that can be seen in the morphological variations of specimens derived from roe deer, red deer, and fallow deer. It is also consistent with the results of our prior study where roe deer were identified to be a principal host of O. leptospicularis [ 1 ]. The aforementioned circulation may also exist among bovid host species, which requires further analyses, enriched with a wider molecular approach.…”

“…The location of the studied sequences in the presented tree at a considerable distance from each other, when isolated from the same or close phylogenetically host species, could be the basis for inferring the randomness of the formation of separate populations. Our previous study [ 1 ] showed that nematodes of the subfamily Ostertagiinae appear to be rather specific to a species or family of hosts. Thus, the presented phylogenetic tree was extended to other Ostertagiinae species and their hosts, and it showed that O. leptospicularis form separate populations specialized in colonizing one type of host.…”

“…Ostertagia leptospicularis was originally described in roe deer from Azerbaijan [ 2 ]; however, its widespread occurrence suggests an extensive historical and geographical range. This species has been treated, so far, as a typical parasite of cervids and domestic bovids in the Palearctic region [ 8 , 13 , 47 ], although it has been successfully introduced to other Holarctic regions and identified in many host species [ 1 , 17 ].…”

“…Ostertagia leptospicularis is a member of a group of ruminant stomach worms and, as the sole species of the subfamily Ostertagiinae, seems to be a generalist, capable of infecting a wide variety of hosts [ 1 ]. This nematode species was described for the first time by Assadov [ 2 ] in roe deer ( Capreolus capreolus ), and therefore, it is considered to be primarily a parasite of Cervidae (red deer ( Cervus elaphus ), sika deer ( C. nippon ), fallow deer ( Dama dama ) and moose ( Alces alces )); however, it is also able to establish in various representatives of Bovidae (cattle ( Bos taurus ), European bison ( Bison bonasus ), domestic sheep ( Ovis aries ), mouflon ( O. musimon ), domestic goat ( Capra hircus ), Alpine ibex ( C. ibex ), and chamois ( Rupicapra rupicapra )) [ 1 , 3 ].…”

Gastrointestinal Helminths of a European Moose Population in Poland

“…Further studies are needed to fully assess the changes related to extremely intensive parasitic infections in moose and to determine their impact on the health status of individual moose. It is important to note that the damage caused by endoparasites is often insidious, and the effects may only become apparent in the long term [ 51 ]. Therefore, there is a strong need to monitor parasitic infections in the unique moose population of central Europe.…”