Genomic-Bioinformatic Analysis of Transcripts Enriched in the Third-Stage Larva of the Parasitic Nematode Ascaris suum

Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3) of A. suum was constructed by suppressive-subtractive hybridization (SSH), and a subset of cDNAs from 3075 clones subjected to microarray analysis using cDNA probes derived from RNA from different developmental stages of A. suum. The cDNAs (n = 498) shown by microarray analysis to be enriched in the L3 were sequenced and subjected to bioinformatic analyses using a semi-automated pipeline (ESTExplorer). Using gene ontology (GO), 235 of these molecules were assigned to ‘biological process’ (n = 68), ‘cellular component’ (n = 50), or ‘molecular function’ (n = 117). Of the 91 clusters assembled, 56 molecules (61.5%) had homologues/orthologues in the free-living nematodes Caenorhabditis elegans and C. briggsae and/or other organisms, whereas 35 (38.5%) had no significant similarity to any sequences available in current gene databases. Transcripts encoding protein kinases, protein phosphatases (and their precursors), and enolases were abundantly represented in the L3 of A. suum, as were molecules involved in cellular processes, such as ubiquitination and proteasome function, gene transcription, protein–protein interactions, and function. In silico analyses inferred the C. elegans orthologues/homologues (n = 50) to be involved in apoptosis and insulin signaling (2%), ATP synthesis (2%), carbon metabolism (6%), fatty acid biosynthesis (2%), gap junction (2%), glucose metabolism (6%), or porphyrin metabolism (2%), although 34 (68%) of them could not be mapped to a specific metabolic pathway. Small numbers of these 50 molecules were predicted to be secreted (10%), anchored (2%), and/or transmembrane (12%) proteins. Functionally, 17 (34%) of them were predicted to be associated with (non-wild-type) RNAi phenotypes in C. elegans, the majority being embryonic lethality (Emb) (13 types; 58.8%), larval arrest (Lva) (23.5%) and larval lethality (Lvl) (47%). A genetic interaction network was predicted for these 17 C. elegans orthologues, revealing highly significant interactions for nine molecules associated with embryonic and larval development (66.9%), information storage and processing (5.1%), cellular processing and signaling (15.2%), metabolism (6.1%), and unknown function (6.7%). The potential roles of these molecules in development are discussed in relation to the known roles of their homologues/orthologues in C. elegans and some other nematodes. The results of the present study provide a basis for future functional genomic studies to elucidate molecular aspects governing larval developmental processes in A. suum and/or the transition to parasitism

A Field Evaluation of the LuciTrap and the Western Australian Trap with Three Different Baits Types for Monitoring Lucilia cuprina and Lucilia sericata in New Zealand

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Prevalence of liver fluke on the West Coast

A study of all herds (n=430) supplying Westland Milk Co-op were tested with an IDEXX Bulk Milk Elisa (BME) (IDEXX Fasciolosis Verification, IDEXX Europe BV, Hoofdorp, The Netherlands) which characterises herds into intensities of infection (Nil, Low, Medium, Strong). These equate to liver fluke infection prevalence of 0%, 50% within the sampled herd. Overall, the distribution of herds as analysed in the autumn of 2017 was Nil=31%, Low=11%, Medium=14%, Strong=43%. It was notable that some regions had much higher levels of infection than others.fals

Effects of Forage Chicory (\u3cem\u3eCichorium Intybus\u3c/em\u3e) On Farmed Deer Growth and Internal Parasitism

Internal parasitism (particularly lungworm - Dictyocaulus sp) significantly limits post-weaning growth of deer. Endoparasite control using anthelmintics may be unsustainable, due to the increasing risk of anthelmintic resistance and the risk or perception of chemical residues in animal products. Chicory has a high feeding value and contains sesquiterpene lactones and low levels of condensed tannins, both with anti-parasitic activity (Molan et al., 2003). Grazing chicory during autumn may reduce the requirement for anthelmintic treatment of young deer compared with grazing ryegrass-based pasture (Hoskin et al., 1999). The objective of this study was to investigate the effect of withholding anthelmintic treatment of young deer grazing grass-based pasture or chicory on autumn growth and internal parasitism

CHANGES IN THE LEVELS OF THEILERIA ORIENTALIS IKEDA TYPE INFECTION IN HAEMAPHYSALIS LONGICORNIS NYMPHS OVER A SIX-MONTH PERIOD

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Predicting the potential distribution of \u3ci\u3eAmblyomma americanum\u3c/i\u3e (Acari: Ixodidae) infestation in New Zealand, using maximum entropy‑based ecological niche modelling

Although currently exotic to New Zealand, the potential geographic distribution of Amblyomma americanum (L.), the lone star tick, was modelled using maximum entropy (Max- Ent). The MaxEnt model was calibrated across the native range of A. americanum in North America using present-day climatic conditions and occurrence data from museum collections. The resulting model was then projected onto New Zealand using both present-day and future climates modelled under two greenhouse gas emission scenarios, representative concentration pathways (RCP) 4.5 (low) and RCP 8.5 (high). Three sets of WorldClim bioclimatic variables were chosen using the jackknife method and tested in MaxEnt using different combinations of model feature class functions and regularization multiplier values. The preferred model was selected based on partial receiver operating characteristic tests, the omission rate and the lowest Akaike information criterion. The final model had four bioclimatic variables, Annual Mean Temperature ( BIO1), Annual Precipitation ( BIO12), Precipitation Seasonality ( BIO15) and Precipitation of Driest Quarter ( BIO17), and the projected New Zealand distribution was broadly similar to that of Haemaphysalis longicornis Neumann, New Zealand’s only livestock tick, but with a more extensive predicted suitability. The climate change predictions for the year 2050 under both low and high RCP scenarios projected only moderate increases in habitat suitability along the mountain valleys in the South Island. In conclusion, this analysis shows that given the opportunity and license A. americanum could and would successfully establish in New Zealand and could provide another vector for theileriosis organisms

Predicting the potential distribution of Amblyomma americanum (Acari: Ixodidae) infestation in New Zealand, using maximum entropy-based ecological niche modelling

Although currently exotic to New Zealand, the potential geographic distribution of Amblyomma americanum (L.), the lone star tick, was modelled using maximum entropy (MaxEnt). The MaxEnt model was calibrated across the native range of A. americanum in North America using present-day climatic conditions and occurrence data from museum collections. The resulting model was then projected onto New Zealand using both present-day and future climates modelled under two greenhouse gas emission scenarios, representative concentration pathways (RCP) 4.5 (low) and RCP 8.5 (high). Three sets of WorldClim bioclimatic variables were chosen using the jackknife method and tested in MaxEnt using different combinations of model feature class functions and regularization multiplier values. The preferred model was selected based on partial receiver operating characteristic tests, the omission rate and the lowest Akaike information criterion. The final model had four bioclimatic variables, Annual Mean Temperature (BIO1), Annual Precipitation (BIO12), Precipitation Seasonality (BIO15) and Precipitation of Driest Quarter (BIO17), and the projected New Zealand distribution was broadly similar to that of Haemaphysalis longicornis Neumann, New Zealand’s only livestock tick, but with a more extensive predicted suitability. The climate change predictions for the year 2050 under both low and high RCP scenarios projected only moderate increases in habitat suitability along the mountain valleys in the South Island. In conclusion, this analysis shows that given the opportunity and license A. americanum could and would successfully establish in New Zealand and could provide another vector for theileriosis organisms

Genetic susceptibility to Theileria orientalis (Ikeda) in Angus- and Hereford-sired yearling cattle born to dairy cattle on an endemically infected farm in New Zealand

fals

The milk production impacts of liver fluke (Fasciola hepatica) infection in dairy cows on the West Coast of the South Island, New Zealand

The impact of fasciolosis has been estimated on many occasions and can vary from mild to severe effects on animal productivity. The aim of the current study was to utilise observations on seroconversion of dairy cattle to Fasciola hepatica over the course of a lactation and compare their milk production with other cattle who remained serologically negative throughout the same lactation. Four spring-calving dairy herds on the West Coast of the South Island of New Zealand were selected based on prior knowledge of endemic liver fluke infection. Over the four herds, a total of 485 cows were blood sampled twice during one lactation, in early November (spring) and early March (autumn). The F. hepatica antibody titre of F. hepatica antibody was quantified using a commercial ELISA test (IDEXX Fasciolosis Verification, IDEXX Europe BV, Hoofdorp, The Netherlands). Milk production was estimated by a series of 3–4 herd tests over the lactation where each cow is individually measured during the morning and evening milking on the same day with samples analysed for milk yield, milk fat (MF), protein (MP), lactose (ML) and total milk solids (MS). Energy corrected milk (ECM) was then calculated using the formula: ECM (kg/d) = 12.55 × MF (kg/d) + 7.39 × MP (kg/d) + 0.2595 × milk yield (kg/d). At the spring sampling, 52 % of cows had antibodies detected which increased to 63 % in autumn. For the sampled cows, those that were in the negative IDEXX test category in autumn and spring were categorised as ‘uninfected’ while those which were negative in spring and seroconverted to the strong positive category in autumn were categorised as ‘infected’. Those in the intermediate categories were ignored. A total of 235 cows were categorised as ‘uninfected’ at the spring testing, being in the negative IDEXX diagnostic category. Of those 235, at the autumn testing, 152 remained in the negative diagnostic category and 50 were in the strong positive IDEXX diagnostic category and were categorised as ‘infected’. A model was fitted which described the lactation curve of each milk component (MF, ML, MP, ECM), a variable describing the infection status of the cow was then tested in the model. The only significant change detected was mean Milk Fat (MF) % being 0.24 MF% points (95 % CI 0.04–0.44 %) lower for ‘infected’ compared to ‘uninfected’ cows. Using a value of6.044/kg MF New Zealand dollars (NZD) this represents an economic loss of NZD 60.2 per ‘infected’ cow in a West Coast herd. Although small, such an effect will still have an appreciable impact on the economic return to a dairy farmer.fals