Investigation article published in Scientific reports

February 20^th, 2023

The single and comparative intradermal tuberculin tests (SITT and CITT) are official in vivo tests for bovine tuberculosis (TB) diagnosis using bovine and avian purified protein derivatives (PPD-B and PPD-A). Infection with bacteria other than Mycobacterium tuberculosis complex (MTC) can result in nonspecific reactions to these tests. We evaluated the performance of the skin test with PPDs and new defined antigens in the guinea pig model. A standard dose (SD) of Rhodococcus equi, Nocardia sp., M. nonchromogenicum, M. monacense, M. intracellulare, M. avium subsp. paratuberculosis, M. avium subsp. avium, M. avium subsp. hominissuis, M. scrofulaceum, M. persicum, M. microti, M. caprae and M. bovis, and a higher dose (HD) of M. nonchromogenicum, M. monacense, M. intracellulare, M. avium subsp. paratuberculosis were tested using PPD-B, PPD-A, P22, ESAT-6-CFP-10-Rv3615c peptide cocktail long (PCL) and fusion protein (FP). The SD of R. equi, Nocardia sp., M. nonchromogenicum, M. monacense, M. intracellulare and M. avium subsp. paratuberculosis did not cause any reactions. The HD of M. nonchromogenicum, M. monacense, M. intracellulare, and M. avium subsp. paratuberculosis and the SD of M. avium subsp. hominissuis, M. scrofulaceum and M. persicum, caused nonspecific reactions (SIT). A CITT interpretation would have considered M. avium complex and M. scrofulaceum groups negative, but not all individuals from M. nonchromogenicum HD, M. monacense HD and M. persicum SD groups. Only animals exposed to M. bovis and M. caprae reacted to PCL and FP. These results support the advantage of complementing or replacing PPD-B to improve specificity without losing sensitivity

Fernandez-Veiga L., Fuertes M., Geijo M., Perez del Val B., Vidal E., Michelet L., Boschiroli ML., Gómez-Buendía A., Bezos J., Jones GJ., Vordermeier M., Juste RA., Garrido JM. and Sevilla AI.

Differences in skin test reactions to official and defined antigens in guinea pigs exposed to non-tuberculous and tuberculous bacteria

Differences in skin test reactions to official and defined antigens in guinea pigs exposed to non-tuberculous and tuberculous bacteria

	Animal Health Department. Instituto Vasco de Investigación y Desarrollo Agrario (NEIKER). Gobierno Vasco.
	Basque Research and Technology Alliance (BRTA).
	Centre de Recerca en Sanitat Animal (CReSA). Universitat Autònoma de Barcelona (UAB). Instituto de Investigación y Tecnología Agroalimentarias (IRTA). Generalitat de Catalunya.
	Universitat Autònoma de Barcelona (UAB).
	Unité Zoonoses Bactériennes. Laboratoire de Santé Animale, Maisons-Alfort. Agence Nationale de Sécurité Sanitaire de l´alimentation, de l´environnement et du travail (ANSES).
	Université Paris-Est.
	Servicio de Micobacterias (MYC). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM).
	Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM).
	Department of Bacteriology. Animal and Plant Health Agency (APHA).