Checklist of helminth parasites of terrestrial mammals in New Zealand

A molecular assessment of Ostertagia leptospicularis and Spiculopteragia asymmetrica among wild fallow deer in Northern Ireland and implications for false detection of livestock-associated species

BACKGROUND

Wild deer populations utilizing livestock grazing areas risk cross-species transmission of gastrointestinal nematode parasites (GINs), including GINs with anthelmintic resistance (AR) traits. Wild deer have been shown to carry problematic GIN species such as Haemonchus contortus and Trichostrongylus species in the UK, but the presence of livestock GINs in Northern Ireland deer populations is unknown. Also, is it not known whether AR traits exist among GINs of deer such as Ostertagia leptospicularis and Spiculopteragia asymmetrica in pastureland where anthelmintics are heavily used.

METHODS

Adult-stage GIN samples were retrieved from Northern Irish wild fallow deer abomasa. Individual specimens were subject to a species-specific PCR analysis for common sheep and cattle GIN species with ITS-2 sequence analysis to validate species identities. In addition, the beta-tubulin gene was subject to sequencing to identify benzimidazole (BZ) resistance markers.

RESULTS

ITS-2 sequencing revealed O. leptospicularis and S. asymmetrica, but species-specific PCR yielded false-positive hits for H. contortus, Teladorsagia circimcincta, Trichostrongylus axei, T. colubriformis, T. vitrinus and Ostertagia ostertagi. For beta-tubulin, O. leptospicularis and S. asymmetrica yielded species-specific sequences at the E198 codon, but no resistance markers were identified in either species at positions 167, 198 or 200 of the coding region.

DISCUSSION

From this report, no GIN species of significance in livestock were identified among Northern Ireland fallow deer. However, false-positive PCR hits for sheep and cattle-associated GINs is concerning as the presence of deer species in livestock areas could impact both deer and livestock diagnostics and lead to overestimation of both GIN burden in deer and the role as of deer as drivers of these pathogens. ITS-2 sequences from both O. leptospicularis and S. asymmetrica show minor sequence variations to geographically distinct isolates. AR has been noted among GINs of deer but molecular analyses are lacking for GINs of wildlife. In producing the first beta-tubulin sequences for both O. leptospicularis and S. asymmetrica, we report no BZ resistance in this cohort.

CONCLUSIONS

This work contributes to genetic resources for wildlife species and considers the implications of such species when performing livestock GIN diagnostics.

Trichostrongyloid nematodes in ruminants of northern Iran: prevalence and molecular analysis

BACKGROUND

This study was carried out to investigate the prevalence and analyze the molecular characteristics based on the internal transcribed spacer (ITS) 2 region of the ribosomal RNA (RNA) gene of trichostrongylid nematodes in different ruminants from Guilan province, northern of Iran.

METHODS

The gastrointestinal tracts of 144 ruminants including 72 cattle, 59 sheep, and 13 goats were collected from an abattoir in Guilan province during July to September 2018. After isolation the helminths, male specimens were identified based on morphological parameters. PCR and partial sequencing of the ITS2 fragment were conducted. After phylogenetic analysis, the intraspecific and interspecific differences were calculated.

RESULTS

The prevalence of total infections with the nematodes was 38.9, 74.6 and 84.6% among cattle, sheep and goats, respectively. Eleven species of trichostrongylid nematodes including Haemonchus contortus, Marshallagia marshalli, Trichostrongylus axei, T. colubriformis, T. vitrinus, Ostertagia trifurcata, Teladorsagia circumcincta, Marshallagia occidentalis, O. lyrata, O. ostertagi, and Cooperia punctate were recovered from the ruminants. The most prevalent trichostrongyloid nematodes in cattle, sheep and goats were O. ostertagi (26.4%), M. marshalli (64.4%) and T. circumcincta (69.2%), respectively. Phylogenetic tree was discriminative for Trichostrongylidae family, while phylogenetic analysis of the ITS2 gene represented low variations and no species identification of Haemonchidae and Cooperiidae families.

CONCLUSIONS

This study suggests the high prevalence and species diversity of trichostrongyloid nematodes in different ruminants, indicating the importance of implement antiparasitic strategies in north regions of Iran. As well, this study showed that the ITS2 fragment is not a discriminative marker for Haemonchidae and Cooperiidae families, and investigation of other genetic markers such as mitochondrial genes would be more valuable for better understanding of their phylogenetic relationships.

Exploiting parallels between livestock and wildlife: Predicting the impact of climate change on gastrointestinal nematodes in ruminants

Global change, including climate, policy, land use and other associated environmental changes, is likely to have a major impact on parasitic disease in wildlife, altering the spatio-temporal patterns of transmission, with wide-ranging implications for wildlife, domestic animals, humans and ecosystem health. Predicting the potential impact of climate change on parasites infecting wildlife will become increasingly important in the management of species of conservation concern and control of disease at the wildlife-livestock and wildlife-human interface, but is confounded by incomplete knowledge of host-parasite interactions, logistical difficulties, small sample sizes and limited opportunities to manipulate the system. By exploiting parallels between livestock and wildlife, existing theoretical frameworks and research on livestock and their gastrointestinal nematodes can be adapted to wildlife systems. Similarities in the gastrointestinal nematodes and the life-histories of wild and domestic ruminants, coupled with a detailed knowledge of the ecology and life-cycle of the parasites, render the ruminant-GIN host-parasite system particularly amenable to a cross-disciplinary approach.

Helminth fauna of Rattus norvegicus Berkenhout, 1769 from the Belgrade area, Serbia

The aims of this study were to provide baseline knowledge about intestinal parasites in Norway rats (Rattus norvegicus) that inhabit the Belgrade area, and to analyze the associations among helminths. Of 302 trapped rats, 52% were females and 48% males, with 39% and approx. 37% of juvenile-subadult individuals, per sex, respectively. The following parasites were detected (with their respective prevalence): Cestoda - Hymenolepis diminuta (30.46%) and Rodentolepis fraterna (12.58%); Nematoda - Heterakis spumosa (36.75%), Nippostrongylus brasiliensis (16.22%), Capillaria sp. (5.96%), Trichuris muris (5.96%), Syphacia muris (4.30%) and Strongylus sp. larvae (0.33%). Flukes (Trematoda) were not recorded. Of all examined rats, 68.54% were found to harbor at least one parasite species, with higher prevalence in male hosts and in adult individuals. There were no age-related differences in the prevalence of infection with individual helminth species. Multiple infections occurred with up to four species per rat showing different combinations of parasite infections. These are the first records of the gastrointestinal helminth fauna of Norway rats in Serbia.

Assessing the suitability of the parasitic nematode Parastrongyloides trichosuri as a vector for transmissible fertility control of brushtail possums in New Zealand - ecological and regulatory considerations

The suitability of the nematode Parastrongyloides trichosuri (Nematoda: Strongyloididae) as a genetically modified vector for transmissible fertility control of introduced brushtail possums (Trichosurus vulpecula) is being explored in New Zealand. This review of progress in assessing the ecological and epidemiological characteristics of P. trichosuri against a set of essential properties for a suitable transmissible vector indicates that the parasite appears to have all the attributes of a highly effective vector, although additional information on persistence at low host density and on the outcome of competition between existing infection and new (recombinant) strains is needed to confirm this. Concerns have been raised about risks to possums and other marsupials in Australia from a genetically modified form of P. trichosuri. An international body with responsibility for managing consultation and debate about issues arising from the proposed use of genetically modified organisms for vertebrate pest management has been suggested as a way of addressing such concerns. A key issue remains as to which agency or group of agencies would take responsibility for such a body. A joint meeting of relevant agencies and researchers is needed urgently to begin the process of moving this issue forward.

Plagiorhynchidae Meyer, 1931 (Acanthocephala) from Australasian birds and mammals, with descriptions of Plagiorhynchus (Plagiorhynchus) menurae (Johnston, 1912) and P. (P.) allisonae n. sp

New host and locality records are given for Plagiorhynchus (Plagiorhynchus) charadrii (Yamaguti, 1939) Van Cleave, 1951 and P. (Prosthorhynchus) cylindraceus (Goeze, 1782) Schmidt & Kuntz, 1966. The uncertainty of identification of a plover host of P. (P.) charadrii as well as the origins of P. (P.) cylindraceus (found in Australia but not New Zealand) and its occurrence in both bird and mammal hosts are discussed. P. (P.) menurae (Johnston, 1912) Golvan, 1956 is redescribed, including the male, and new host, Menura alberti Bonaparte, and locality records are given. P. (P.) allisonae n. sp. is described from Haematopus ostralegus finschi (Martens) and H. unicolor (Forster) from the South Island of New Zealand. P. (P.) allisonae can be differentiated from its congeners by having a proboscis armature of 18-23 rows of 14-20 hooks, thorns of hooks shorter than simple roots with short manubria, eight tubular cement glands and eggs of 134-154 x 33-36 microm in size. The presence of P. (P.) gracilis Petrochenko, 1958 in Australia is questioned. New host and locality records are given for Porrorchis hylae (Johnston, 1914) Schmidt & Kuntz, 1967 and the northern distribution of P. hydromuris (Edmonds, 1957) Schmidt & Kuntz, 1967 confirmed.

Nematodes and liver fluke in New Zealand

Abstract A general review of the epidemiology, significance and control of nematode parasitism of sheep, goats, cattle and deer in New Zealand, the emergence of anthelmintic resistance and its effects, and the search for parasite control strategies that reduce reliance on anthelmintic use, is provided. The research that has formed the basis for present levels of understanding of this complex and important topic is summarised and sources of further information are indicated. Aspects of nematode infections of horses, pigs, dogs and cats, and the history of the liver fluke, Fasciola hepatica, in New Zealand are also reviewed briefly.