Environmental DNA: A Promising Factor for Tuberculosis Risk Assessment in Multi-Host Settings
PLoS ONE publish this investigation article
May 29th, 2020
Attaining and maintaining the Official Tuberculosis Free status continues to be a challenge when several domestic and wild hosts contribute to the maintenance of the Mycobacterium tuberculosis complex (MTC). Local tuberculosis hotspots are sometimes identified in cattle in low-prevalence regions. We have, therefore, studied one such hotspot in depth in order to produce an epidemiological diagnosis. Host population size and MTC prevalence were estimated in selected wildlife and in livestock, while on-cattle environmental DNA detection was additionally used as a proxy for risk of exposure at the farm (herd) level. Positive skin test reactors were found on16 of the 24 cattle farms studied in the period 2012-2016. Although all goats tested negative to the skin test during this period, MTC was confirmed in four sheep at slaughter, thus indicating an unknown prevalence of infection in this host species. With regard to wildlife, the prevalence of MTC infection based on culture was 8.8% in the case of wild boar (Sus scrofa), and the only road-killed badger (Meles meles) submitted for culture tested positive. Two criteria were employed to divide the cattle farms into higher or lower risk: tuberculosis testing results and environmental DNA detection. Environmental MTC DNA detection yielded significant differences regarding "use of regional pastures" and "proximity to woodland". This study suggests that on-animal environmental DNA sampling may help when assessing contact risk as regards MTC in livestock at the herd level. This tool opens up new avenues of epidemiological research in complex multi-host settings
Martinez-Guijosa J., Romero B., Infantes-Lorenzo JA., Diez E., Boadella M., Balseiro A., Veiga M., Navarro D., Moreno I., Ferreres J., Dominguez M., Fernandez C., Dominguez L. and Gortazar C.
 | Sanidad y Biotecnología (SaBio). Instituto de Investigación en Recursos Cinegéticos (IREC). Consejo Superior de Investigaciones Científicas (CSIC). Universidad de Castilla La Mancha (UCLM). Gobierno de Castilla-La Mancha (JCCM). |
 | Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
| Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
 | Servicio de Ganadería. Departamento de Desarrollo Rural. Medio ambiente y Administración Local. Gobierno de Navarra. |
 | Sabiotec. |
 | Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA). Gobierno del Principado de Asturias. |
 | Servicio de Inmunología. Centro Nacional de Microbiología (CNM). Instituto de Salud Carlos III (ISCIII). |
