New Approaches to Control Parasites

Parasite Control DRL

Over the past 18 months, the NZDFA and AgMardt have been co-funding a research project through the Otago Innovation company Otago University’s Disease Research Laboratory (DRL) (now based at Invermay) in a $150,000 project research area “New approaches to control parasites (in deer)”.

This project set out to identify and measure the natural resistance or susceptibility to parasitic infection in livestock populations through identifying biomarkers that may indicate genetic based resilience or susceptibility.

The concept is a further development of the earlier DFA/DEEResearch and DRL research co funded through the $500,000 Callaghan Innovation project looking to identify Resilience (R) and susceptibility (S) Biomarkers to Johne’s disease.

The Final report to AgMardt was approved recently.

As part of the reporting a short Press Release was required and is copied below. The full final report has been distributed to the funding branches and is available on request (via e copy).

In terms of outcomes, Research Leader Dr Rory O’Brien advises the current state of the play is:

“As a direct result of AgMardt and NZDFA support received, we now have in place DNA based diagnostic assays for gut parasites (Ostertagia spp.) and bovine and cervine lungworm (Dictyocaulus spp.).”

Having demonstrated necessary proof of principle of a DNA based diagnostic for parasites shed in faeces, we are now working towards calibration of the assay against conventional methodologies (faecal egg and larval counts) using a cohort of young red deer exposed to naturally acquired parasite infection and monitored routinely at the AgResearch Invermay agricultural campus.

The disease status of each of these animals will be confirmed retrospectively, following necropsy of animals experimentally infected with Ostertagia parasites.

The NZDFA would like to thank all those involved to date at the research end through Dr Rory O’Brien and Simon Liggett, the AgResearch Deer Research Group and for the leadership of Prof Frank Griffin and wider team and particularly those in the DFA who nationally and at Branch level supported the programme financially and assured its success. We look forward to future developments in the further definition Biomarkers for disease resilience especially in Johne’s disease and parasitism, and emerging areas (as part of the Tomorrows deer DEEResearch programme).
– Tony Pearse. Producer Manager DINZ

AGMARDT Agribusiness Innovation Grant A16027. Otago Innovation Ltd Disease Research Laboratory
MEDIA Release August 2017
New Approaches to Control Parasites; Final Report.

For New Zealand to meet the Government’s target of doubling agricultural exports by 2025, new technologies to control infectious diseases are needed.

Parasitic infections are the most important infectious disease in NZ ruminants. They are poorly understood and therapeutic control has changed little since the development of anthelminthic drenches 40 years ago.  Diagnosis remains largely unchanged, relying on manually performed faecal egg and larval counts to estimated degree of worm burden.

The research aims of the current study were twofold.

1. Firstly when an animal is scouring or losing weight we wanted to be able to better diagnose why. To this end we have augmented our (existing) Johne’s disease faecal test technology to concurrently detect endoparasite species commonly affecting red deer.
   The goal has been to develop a composite diagnostic test for animals presenting with generalised, nonspecific clinical indicators of enteric disease such as scouring or progressive weight loss.
   Distinguishing between Johne’s and parasitic disease remains a continuing challenge in disease control and early differentiation will expedite informed and appropriately targeted treatment and management.
   With this funding assistance from AgMardt and the key NZ Deer Farmers’ Association Branches,  we have developed rapid, quantitative and species-specific DNA tests for parasite eggs and larvae shed in the dung of affected hosts as an alternative to conventional faecal egg counts and as an adjunct to routine Johne’s testing.
2. Secondly, we have begun to investigate the emergence of natural resistance or susceptibility to parasitic infection evident in naturally exposed livestock populations.
   To this end we have utilised methods we developed to monitor ruminant (cervine) immune responses to Johne’s disease to monitor immune responses to parasitic infection.
   Improved diagnostics will allow us to differentiate between diseased, susceptible animals, and resilient/resistant animals with protective immunity for further study. These studies are exploratory and a logical prelude to future research to develop immunodiagnostics that identify diseased/susceptible animals for targeted anthelminthic treatment.
   By contrast the identification of markers of immune protection/resilience will inform future vaccine development and support genetic selection of animals with superior resistance or resilience to parasites.

Parasitism ranks as the most costly type of infectious disease affecting NZ livestock, with losses >$700M pa.

Currently the strategy to control parasitic disease involves repeated drenching of young animals with anthelminthics using protocols that have changed little in 40 years. Repeat drenching is expensive, produces chemical residues and results in the development of drug resistance, limiting long term utility.

In a world of ever increasing parasite resistance to chemical drenches, with consumer opinion signalling disapproval of resultant residues and with ever tighter margins on production systems, it is time to consider alternative approaches to the problem of parasitism. This work addresses key issues that could enhance the production of residue-free food products in an ever discriminating International marketplace.

Research publications from DRL –

• Thomas, R. R., H. J. Brooks, and R. O’Brien. 2017. Prevalence of Shiga toxin-producing and enteropathogenic Escherichia coli marker genes in diarrhoeic stools in a New Zealand catchment area. J. Clin. Pathol. 2017 Jan;70(1):81-84.
• Mackintosh, C. G., J. F. Griffin, I. C. Scott, R. O’Brien, J. L. Stanton, P. MacLean, and R. Brauning. 2016. SOLiD SAGE sequencing shows differential gene expression in jejunal lymph node samples of resistant and susceptible red deer (Cervus elaphus) challenged with Mycobacterium avium subsp. paratuberculosis. Vet. Immunol. Immunopathol. 169:102-110.
• O’Brien, R., Hughes, A., Liggett, S and Griffin, F. 2013. Composite Diagnostic Testing to Achieve Optimal Ante-Mortem Diagnosis of Johne’s Disease in Farmed New Zealand Deer: Correlations Between Bacteriological Culture, Histopathology, Serological Reactivity and Faecal Shedding as Determined by Quantitative PCR., BMC Veterinary Research, 9, 72.
• Marfell BJ, O’Brien R, Griffin JF. 2013. Global gene expression profiling of monocyte-derived macrophages from red deer (Cervus elaphus) genotypically resistant or susceptible to Mycobacterium avium subspecies paratuberculosis infection. Dev. Comp. Immunol. 2013 Feb 20.
• Dobson B, Liggett S, O’Brien R, Griffin JF. 2013. Innate immune markers that distinguish red deer (Cervus elaphus) selected for resistant or susceptible genotypes for Johne’s disease. Vet Res. 2013 Jan 24;44(1):5
• Robinson MW, O’Brien R, Mackintosh CG, Clark RG, Griffin JF. 2011. Immunoregulatory cytokines are associated with protection from immunopathology following Mycobacterium avium subspecies paratuberculosis infection in red deer. Infect. Immun. 79(5): 2089-97.
• Robinson M, O’Brien R, Mackintosh C, Griffin F. 2010. Peripheral blood mononuclear cell population chan ges associated with age and Mycobacterium avium subspecies paratuberculosis infection in red deer (Cervus elaphus). Vet. Immunol. Immunopathol. 136 (3-4): 211-8.
• Gillan S, Hughes, AD, O’Brien R, Griffin JF. 2010. Ovine immune parameters following immunisation against Mycobacterium avium ssp. paratuberculosis using a lipid-based live-cell vaccine. Vet. Immunol. Immunopathol. 137 (1-2):109-19.
• Gillan S, O’Brien R, Hughes AD, Griffin JF. 2009. Identification of immune parameters to differentiate disease states among sheep infected with Mycobacterium avium subsp paratuberculosis. Clin. Vacc. Immunol. 17 (1): 108-17.
• Robinson M, O’Brien R, Mackintosh C, Griffin F. 2008. Differential immune responses of red deer (Cervus elaphus) following experimental challenge with Mycobacterium avium subsp. paratuberculosis. Clinical and Vaccine Immunology, 15 (6): 963–969.
• O’Brien, R., Mackintosh, C. G., Bakker, D., Kopecna, M. Pavlik, I., Griffin., J.F.T. 2006. Immunological and molecular characterisation of susceptibility in relation to bacterial strain differences in Mycobacterium avium subsp. paratuberculosis infection in red deer (Cervus elaphus). Infection and Immunity. 74: 3530-3537.
• Begg, D. J., O’Brien, R., Mackintosh, C. G., and Griffin, J. F. T. 2005. Experimental Infection Model for Johne’s disease in Sheep. Infection and Immunity. 73:5603-5611.

Conference proceedings –

• O’Brien, R., Liggett, S., Bates, A. and Griffin, F. 2016. Johne’s disease diagnosis in New Zealand: An update. Proceedings of the Society of Dairy Cattle Veterinarians of the NZVA Annual Conference; Hamilton, New Zealand: NZVA; 2016: 41-50.
• Bates, A., O’Brien, R., Liggett, S. and Griffin, F. Diagnosis of sub-clinical infection with Mycobacterium avium subsp. paratuberculosis and its effect on milk production. Proceedings of the Society of Dairy Cattle Veterinarians of the NZVA Annual Conference; Hamilton, New Zealand: NZVA; 2016: 51-53.
• Bates, A., R. O’Brien, S. Liggett, and F. Griffin. 2016. Diagnosis of sub-clinical infection with Mycobacterium avium subsp. paratuberculosis and its effect on milk production. in Proc. Of the World Buiatrics Congress, Dublin, Ireland.
• O’Brien, R. 2015. A model for the heritability of susceptibility or tolerance to Johne’s Disease. Combined proceedings of the Society of Sheep and Beef Veterinarians of the NZVA and Cervetec Conference 3–5 June 2015, Queenstown.
• O’Brien, R. 2014 A model for the heritability of susceptibility or tolerance to Johne’s Disease. Cervetec Conference, Queenstown, New Zealand.
• O’Brien, R., Liggett, S., and Griffin. F. 2014 Serological assay followed up by quantitative PCR; a synergistic combo for antemortem diagnosis of Johne’s Disease in farmed New Zealand deer. Proceedings of the 12th International Colloquium on Paratuberculosis (p. 93).
• Brennan, L., O’Brien, R., & Griffin, F. (2013). Genetic markers for resilience and susceptibility to Johne’s disease in red deer (Cervus elaphus). Proceedings of the 43rd Australasian Society for Immunology (ASI) Annual Scientific Meeting., (pp. 143).
• Griffin, F., O’Brien, R., Liggett, S., Marfell, B., Brennan, L., & Mackintosh, C. (2013). A deer model: Using a systems biology approach to study pathways of resilience or susceptibility to Johne’s disease. Proceedings of the 43rd Australasian Society for Immunology (ASI) Annual Scientific Meeting., (pp. 80).
• Dobson, B., O’Brien, R., & Griffin, J. F. T. (2012). The search for candidate genes that characterise susceptibility or resistance to pathogenic mycobacteria. Immunology, 137 (Suppl. s1), (pp. 666).
• O’Brien R., Hughes, A and Griffin, F. 2011. Quantitative PCR as an ancillary, ante-mortem diagnostic test for Johne’s Disease in deer: a comparison between bacteriologic culture, serological reactivity and faecal shedding.  In P. Wilson (Ed.), Proceedings of a Deer Course for Veterinarians No. 28, (pp. 121-127). Wellington, New Zealand: Deer Branch, New Zealand Veterinary Association.
• O’Brien R., Hughes, A and Griffin, F. 2010. Quantitative PCR as an Ancillary, Ante-Mortem Diagnostic test for Johne’s Disease in Deer.  In P. Wilson (Ed.),Proceedings of a Deer Course for Veterinarians No. 27, (pp. 45-51). Wellington, New Zealand: Deer Branch, New Zealand Veterinary Association.
• O’Brien, R., Hughes, A and Griffin, F. 2009. Quantitative PCR as an Ancillary, Ante-Mortem Diagnostic test for Johne’s Disease in Deer. In P. Wilson (Ed.),Proceedingsof a Deer Course for Veterinarians No. 26, (pp. 62-66). Wellington, New Zealand: Deer Branch, New Zealand Veterinary Association.
• Griffin, J. F. T., O’Brien, R. P., Spittle, E., Liggett, S., Cooper, M., Crosbie, P., and Rodgers, C. 2003. Immunodiagnostic tests in the management of Johne’s disease in deer herds. Proceedings of the Deer Branch New Zealand Veterinary Association 20, pp. 99-102)
• O’Brien. R., Rodgers. C., Liggett. S., Spittle. E., Crosbie. P. and Griffin. F. 2004. Immunodiagnosis of TB and Johne’s disease in deer. Proceedings of the 1st World Deer Veterinary Congress. Queenstown, New Zealand.
• O’Brien. R., Chinn. N., Rodgers. C., Liggett. S., Spittle. E., Crosbie. P., Mackintosh. C., Beatson. N., and Griffin. F. 2003. Johne’s disease: an emerging problem in farmed deer. Proceedings of the Seventh International Colloquium on Paratuberculosis (pp. 353-357).