Oral communication in 33rd Annual Congress of the European Society of Mycobacteriology

July 4^th, 2012

Casal C., Bezos J., Diez A., Alvarez J., Romero B., de Juan L., Rodriguez-Campos S., Fernandez de Mera IG., Vordermeier M., Whelan A., Hewinson G., Mateos A., Dominguez L. and Aranaz A.

The intradermal tuberculin test (single and comparative interpretation) is the principal technique based on the cell-mediated immune response used worldwide for the ante-mortem diagnosis of bovine tuberculosis. Several factors may affect the performance and the outcome of intradermal tests compromising the detection of infected animals. Conventional reagents currently in use are Purified Protein Derivative (PPDs) obtained from Mycobacterium bovis and M. avium culture, their composition is poorly characterized and difficult to standardize. The biological potency of the PPDs has to fulfil some criteria according to the European Pharmacopoeia and the OIE. As the components of the PPDs are common to all mycobacteria, cross reactions with non pathogenic mycobacteria have been described. To solve it, specific antigens located in the RD1 region of mycobacteria causative of tuberculosis such as ESAT-6, CFP-10, Rv3615c (or a combination of them) are being studied. The objectives of this study were: 1, to assess the biological potency and storage conditions of the PPDs employed in the intradermal tests; 2, to evaluate the use of new specific antigens in the diagnostic tests, and finally, 3, to determine the effect of the practitioner experience on the diagnostic test outcome. Regarding objective 1, variability between manufacturers and batches were reported, and occasionally PPDs with no suitable biological potency were found. The use of these PPDs in eradication campaigns would compromise the sensitivity of the diagnostic tests. Concerning objective 2, this preliminary study showed no significant differences (p>0.05) when the intradermal test was performed with standard PPDs or with the specific antigens therefore, these antigens could be potentially used for in vivo diagnosis. Considering objective 3, percentage of disagreement ranged between 20,84% and 70,83% when intradermal test was performed by different veterinarians in the same animals

	Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).