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12. Direct correlation between potentiometric and impedance biosensing of antibody-antigen interactions using an integrated system

Author

Tsai, Meng-Yen, primary, Creedon, Niamh, additional, Brightbill, Eleanor, additional, Pavlidis, Spyridon, additional, Brown, Billyde, additional, Gray, Darren W., additional, Shields, Niall, additional, Sayers, Ríona, additional, Mooney, Mark H., additional, O'Riordan, Alan, additional, and Vogel, Eric M., additional

Published
2017
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13. Biosecurity, bovine viral diarrhoea virus (BVDv), and bovine herpesvirus-1 (BoHV-1): epidemiological investigations in Irish dairy herds

Author

Sayers, Ríona (Regina) Geraldine, Arkins, Sean, and Dillon, Paul

Subjects
disease control, health planning, animal diseases, Irish dairy herds
Abstract

peer-reviewed The fundamental basis of herd health planning and disease control is a science-based risk analysis. A disease risk analysis involves examining the probability of a disease occurring and the impact of that disease should it occur. Epidemiological investigations are required to provide the necessary data on biosecurity, disease prevalence, vaccination, and production losses associated with a particular infectious agent for the purposes of a comprehensive risk analysis. BVDv and BoHV-1 are highly contagious cattle viruses, exhibit a worldwide distribution and are listed as notifiable diseases by the OIE (Office International des Epizooties). A national eradication scheme is currently underway in Ireland for BVDv but no co-ordinated programme exists for the control or eradication of BoHV-1. Relatively little published data are available on the prevalence or production losses associated with BVDv and BoHV-1 infection in Ireland. Neither are data available relating to current biosecurity and vaccination practices on Irish dairy farms. The research programme outlined in this thesis aimed to provide relevant Irish stakeholders, such as AHI (Animal Health Ireland) and DAFM (Department of Agriculture, Food and the Marine), the necessary data to conduct an informed risk analysis on BVDv and BoHV-1. Results show that biosecurity practices, in general, were poorly implemented on dairy farms with lack of information cited as the primary cause. The concept of biosecurity was not well understood, a 20% discrepancy highlighted between self-declared and truly ‘closed’ herds. Additionally, inconsistencies in biosecurity practices and opinions across veterinarians, dairy advisors, and farmers were highlighted emphasising the need for improved communication amongst these stakeholders. Poor implementation of biosecurity is reflected in the prevalence of exposure to BVDv and BoHV-1 recorded in the current study. From a geographically representative population of 312 dairy herds, an apparent prevalence of 88% and 80% was recorded for BVDv and BoHV-1, respectively. Additionally, approximately one third of participating herds were spot test (youngstock screen used to indicate recent viral circulation) positive for BVDv antibodies indicating extensive BVDv circulation in 2009. Over 60% of study herds vaccinated against BVDv and 12% against BoHV-1. Such extensive use of BVDv vaccine necessitated examination of the impact of vaccine administration on BVDv bulk milk testing as bulk milk analysis is likely to be an important tool in on-going national BVD surveillance. One commercially available inactivated BVD vaccine was shown not to interfere with BVD p80 bulk milk antibody interpretation making it a useful tool in BVD control during eradication. BVDv and BoHV-1 antibody positive herds were found to record inferior production performance than antibody negative herds. Herds with evidence of recent BVDv circulation and herds bulk milk antibody positive for BoHV-1 recorded the most significant production losses. These losses will act as important motivators in engaging farmers in national eradication and control programmes for both BVDv and BoHV-1. The baseline data documented in this thesis will form the basis for more detailed sociological, economic, and epidemiological research to facilitate targeting of future training of, and risk communication with, the dairy farming community in Ireland.

Published
2014

16. Determining the Prevalence and Seasonality of Fasciola hepatica in Pasture-based Dairy herds in Ireland using a Bulk Tank Milk ELISA.

Author

Bloemhoff, Yris, Forbes, Andrew, Danaher, Martin, Good, Barbara, Morgan, Eric, Mulcahy, Grace, Sekiya, Mary, and Sayers, Ríona

Subjects
DISEASE prevalence, ANIMAL herds
Abstract

Background: Fasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact. However information on F. hepatica infections in Irish pasture-based dairy herds is limited. Therefore this study was conducted in order to determine the prevalence, seasonality and management factors associated with F. hepatica. A total of 319 Irish dairy herds were selected for this study. Bulk tank milk (BTM) samples were collected from 290 dairy farms on a quarter year basis, while from a further 29 dairy farms BTM samples were collected on a monthly basis to provide a more detailed pattern of F. hepatica exposure in Irish herds. BTM samples were analysed using a commercially available F. hepatica antibody detection ELISA. Furthermore, within-herd prevalence of F. hepatica was assessed in a subset of these 29 herds (n = 17); both individual serum samples and bulk tank milk samples were collected. Results: A within-herd prevalence of ≤ 50 % was found for herds with negative bulk tank milk samples. The mean prevalence of the 290 study herds was 75.4 % (Range 52 %-75.1 %), with the highest prevalence being observed in November (75.1 %). The seasonal pattern of F. hepatica shows elevated antibodies as the grazing season progressed, reaching a peak in January. A significant association was found between F. hepatica and age at first calving. Conclusion: This study demonstrates that F. hepatica is present in a large proportion of Irish dairy herds and provides a basis on which control practices, particularly in adult dairy cows, can be reviewed. [ABSTRACT FROM AUTHOR]

Published
2017
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17. Direct correlation between potentiometric and impedance biosensing of antibody-antigen interactions using an integrated system.

Author

Meng-Yen Tsai, Creedon, Niamh, Brightbill, Eleanor, Pavlidis, Spyridon, Brown, Billyde, Gray, Darren W., Shields, Niall, Sayers, Ríona, Mooney, Mark H., O'Riordan, Alan, and Vogel, Eric M.

Subjects
POTENTIOMETRY, BIOSENSORS, IMPEDANCE spectroscopy, BLOOD plasma, CHARGE transfer, BIOMOLECULES
Abstract

A fully integrated system that combines extended gate field-effect transistor (EGFET)-based potentiometric biosensors and electrochemical impedance spectroscopy (EIS)-based biosensors has been demonstrated. This integrated configuration enables the sequential measurement of the same immunological binding event on the same sensing surface and consequently sheds light on the fundamental origins of sensing signals produced by FET and EIS biosensors, as well as the correlation between the two. Detection of both the bovine serum albumin (BSA)/anti-BSA model system in buffer solution and bovine parainfluenza antibodies in complex blood plasma samples was demonstrated using the integrated biosensors. Comparison of the EGFET and EIS sensor responses reveals similar dynamic ranges, while equivalent circuit modeling of the EIS response shows that the commonly reported total impedance change (DZtotal) is dominated by the change in charge transfer resistance (Rct) rather than surface capacitance (Csurface). Using electrochemical kinetics and the Butler-Volmer equation, we unveil that the surface potential and charge transfer resistance, measured by potentiometric and impedance biosensors, respectively, are, in fact, intrinsically linked. This observation suggests that there is no significant gain in using the FET/EIS integrated system and leads to the demonstration that low-cost EGFET biosensors are sufficient as a detection tool to resolve the charge information of biomolecules for practical sensing applications. [ABSTRACT FROM AUTHOR]

Published
2017
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20. Response letter

Author

Bloemhoff, Yris, Forbes, Andrew, Good, Barbara, Morgan, Eric, Mulcahy, Grace, Strube, Christina, and Sayers, Riona

Published
2015
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21. Determining the Prevalence and Seasonality of Fasciola hepaticain Pasture-based Dairy herds in Ireland using a Bulk Tank Milk ELISA

Author

Bloemhoff, Yris, Forbes, Andrew, Danaher, Martin, Good, Barbara, Morgan, Eric, Mulcahy, Grace, Sekiya, Mary, and Sayers, Ríona

Abstract

Fasciola hepaticais a helminth parasite of global importance in livestock, with major economic impact. However information on F. hepaticainfections in Irish pasture-based dairy herds is limited. Therefore this study was conducted in order to determine the prevalence, seasonality and management factors associated with F. hepatica. A total of 319 Irish dairy herds were selected for this study. Bulk tank milk (BTM) samples were collected from 290 dairy farms on a quarter year basis, while from a further 29 dairy farms BTM samples were collected on a monthly basis to provide a more detailed pattern of F. hepaticaexposure in Irish herds. BTM samples were analysed using a commercially available F. hepaticaantibody detection ELISA. Furthermore, within-herd prevalence of F. hepaticawas assessed in a subset of these 29 herds (n = 17); both individual serum samples and bulk tank milk samples were collected. A within-herd prevalence of ≤ 50 % was found for herds with negative bulk tank milk samples. The mean prevalence of the 290 study herds was 75.4 % (Range 52 %–75.1 %), with the highest prevalence being observed in November (75.1 %). The seasonal pattern of F. hepaticashows elevated antibodies as the grazing season progressed, reaching a peak in January. A significant association was found between F. hepaticaand age at first calving. This study demonstrates that F. hepaticais present in a large proportion of Irish dairy herds and provides a basis on which control practices, particularly in adult dairy cows, can be reviewed.

Published
2016
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22. Biosecurity, bovine viral diarrhoea virus (BVDv), and bovine herpesvirus-1 (BoHV-1): epidemiological investigations in Irish dairy herds

Author

Arkins, Sean, Dillon, Paul, Sayers, Ríona (Regina) Geraldine, Arkins, Sean, Dillon, Paul, and Sayers, Ríona (Regina) Geraldine

Abstract

peer-reviewed, The fundamental basis of herd health planning and disease control is a science-based risk analysis. A disease risk analysis involves examining the probability of a disease occurring and the impact of that disease should it occur. Epidemiological investigations are required to provide the necessary data on biosecurity, disease prevalence, vaccination, and production losses associated with a particular infectious agent for the purposes of a comprehensive risk analysis. BVDv and BoHV-1 are highly contagious cattle viruses, exhibit a worldwide distribution and are listed as notifiable diseases by the OIE (Office International des Epizooties). A national eradication scheme is currently underway in Ireland for BVDv but no co-ordinated programme exists for the control or eradication of BoHV-1. Relatively little published data are available on the prevalence or production losses associated with BVDv and BoHV-1 infection in Ireland. Neither are data available relating to current biosecurity and vaccination practices on Irish dairy farms. The research programme outlined in this thesis aimed to provide relevant Irish stakeholders, such as AHI (Animal Health Ireland) and DAFM (Department of Agriculture, Food and the Marine), the necessary data to conduct an informed risk analysis on BVDv and BoHV-1. Results show that biosecurity practices, in general, were poorly implemented on dairy farms with lack of information cited as the primary cause. The concept of biosecurity was not well understood, a 20% discrepancy highlighted between self-declared and truly ‘closed’ herds. Additionally, inconsistencies in biosecurity practices and opinions across veterinarians, dairy advisors, and farmers were highlighted emphasising the need for improved communication amongst these stakeholders. Poor implementation of biosecurity is reflected in the prevalence of exposure to BVDv and BoHV-1 recorded in the current study. From a geographically representative population of 312 dairy herds, an appare

23. Biosecurity, bovine viral diarrhoea virus (BVDv), and bovine herpesvirus-1 (BoHV-1): epidemiological investigations in Irish dairy herds

Author

Arkins, Sean, Dillon, Paul, Sayers, Ríona (Regina) Geraldine, Arkins, Sean, Dillon, Paul, and Sayers, Ríona (Regina) Geraldine

Abstract

peer-reviewed, The fundamental basis of herd health planning and disease control is a science-based risk analysis. A disease risk analysis involves examining the probability of a disease occurring and the impact of that disease should it occur. Epidemiological investigations are required to provide the necessary data on biosecurity, disease prevalence, vaccination, and production losses associated with a particular infectious agent for the purposes of a comprehensive risk analysis. BVDv and BoHV-1 are highly contagious cattle viruses, exhibit a worldwide distribution and are listed as notifiable diseases by the OIE (Office International des Epizooties). A national eradication scheme is currently underway in Ireland for BVDv but no co-ordinated programme exists for the control or eradication of BoHV-1. Relatively little published data are available on the prevalence or production losses associated with BVDv and BoHV-1 infection in Ireland. Neither are data available relating to current biosecurity and vaccination practices on Irish dairy farms. The research programme outlined in this thesis aimed to provide relevant Irish stakeholders, such as AHI (Animal Health Ireland) and DAFM (Department of Agriculture, Food and the Marine), the necessary data to conduct an informed risk analysis on BVDv and BoHV-1. Results show that biosecurity practices, in general, were poorly implemented on dairy farms with lack of information cited as the primary cause. The concept of biosecurity was not well understood, a 20% discrepancy highlighted between self-declared and truly ‘closed’ herds. Additionally, inconsistencies in biosecurity practices and opinions across veterinarians, dairy advisors, and farmers were highlighted emphasising the need for improved communication amongst these stakeholders. Poor implementation of biosecurity is reflected in the prevalence of exposure to BVDv and BoHV-1 recorded in the current study. From a geographically representative population of 312 dairy herds, an appare

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