Limited usefulness of the IS6110 touchdown-PCR in blood for tuberculin skin test false-negative cattle with serological response to Mycobacterium bovis

• DOI: 10.3389/fvets.2024.1359205
• Publication Date: 2024-05-20T04:30:25Z
• Authors: Micaela Encinas; Ximena Ferrara Muñiz; Romina Ayelén Sam...; Victoria Ruiz Menna; Carlos Javier Garro; Fernando Delgado; Analía Macías; Gabriel Magnano; Martín José Zumár...; Sergio Gabriel Ga...; María Emilia Eirin
• Keywords: 0301 basic medicine; 03 medical and health sciences; diagnosis; blood; false-negative; Veterinary medicine; SF600-1100; Veterinary Science; bovine tuberculosis; anergy; IS6110 touchdown-PCR

Ante-mortem diagnosis of bovine tuberculosis (bTB) is based mainly on the tuberculin skin test (TST) and ɣ-IFN release assay (IGRA). Some infected animals escape screening tests, thus, limit herd sanitation. Previous reports have suggested a predominant pattern multi-organ lesions attributable to Mycobacterium bovis (the causative agent bTB) bacteraemia. A case–control study was conducted investigate blood PCR as an alternative tool for improving ante-mortem detection TST false-negative bovines. Cases comprised 70 bovines (cases), which were serology positive, controls included 81 positive bovines; all them confirmed with M. . Detection IS 6110 target through touchdown blood-PCR (IS TD-PCR) performed. The positivity 27.2% in control group. This performance similar 15% obtained among cases ( p = 0.134). Most identified by TD-PCR exhibited focalized 0.002). Results demonstrated that could detect cattle, even if they are negative IGRA. Considering humoral response , further studies pre-serological stage provide evidence about real contribution technique herds.