1. Limited usefulness of the IS6110 touchdown-PCR in blood for tuberculin skin test false-negative cattle with serological response to Mycobacterium bovis.
- Author
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Encinas, Micaela, Ferrara Muñiz, Ximena, Ayelén Sammarruco, Romina, Ruiz Menna, Victoria, Javier Garro, Carlos, Delgado, Fernando, Macías, Analía, Magnano, Gabriel, Zumárraga, Martín José, Garbaccio, Sergio Gabriel, and Eirin, María Emilia
- Subjects
TUBERCULIN test ,MYCOBACTERIUM bovis ,SKIN tests ,COW testing ,TUBERCULOSIS in cattle - Abstract
Ante-mortem diagnosis of bovine tuberculosis (bTB) is based mainly on the tuberculin skin test (TST) and the ...-IFN release assay (IGRA). Some infected animals escape screening tests, thus, limit herd sanitation. Previous reports have suggested a predominant pattern of multi-organ lesions attributable to Mycobacterium bovis (the causative agent of bTB) bacteraemia. A case--control study was conducted to investigate blood PCR as an alternative tool for improving ante-mortem detection of TST false-negative bovines. Cases comprised 70 TST false-negative bovines (cases), which were serology positive, and controls included 81 TST positive bovines; all of them confirmed as infected with M. bovis. Detection of the IS6110 target through touchdown blood-PCR (IS6110 TD-PCR) was performed. The positivity of the blood-PCR was 27.2% in the control group. This performance was similar to the 15% obtained among cases (p = 0.134). Most cases identified by the IS6110 TD-PCR exhibited focalized lesions (p = 0.002). Results demonstrated that blood-PCR could detect TST false-negative cattle, even if they are negative for IGRA. Considering that cases exhibited humoral response to M. bovis, further studies conducted in a pre-serological stage could provide evidence about the real contribution of the technique in herds. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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