A Neutrophil-based Test as an Auxiliary Tool for Substantiating the Diagnosis of Bovine Tuberculosis

Abstract

Background: Bovine tuberculosis (bTB) is still a prominent threat to animal health; lacking an efficient vaccine, other than BCG to get rid of tuberculosis, the most effective way for this is culling and slaughtering the infected animals. There are several cellular, serological, and molecular tests for the diagnosis of the disease but the most practical one at the field level is the double skin testing with bovine and aviary tuberculins. This is not a very specific test but is sensitive enough to identify most diseased animals; adjunct practical tests are desirable to strengthen the utility of skin tests. All lymphoid and myeloid cells participate, in diverse grades, in the immune response to tuberculosis with neutrophils playing an unintended pathologic role. The study aimed to investigate the response of neutrophils to agents present in the sera of tuberculous cows. Methods: We have developed a neutrophil-based test (N BT) to identify diseased cows within a herd suspected of having tuberculosis; a positive N BT correlates with a positive double skin test. In this test, healthy neutrophils are incubated with the sera of healthy or tuberculous cows for 3 and 6 h, and the nuclear morphologic changes are recorded and analyzed. Results: Sera from tuberculous but not from healthy cows induce nuclear alterations including pyknosis, swelling, apoptosis, and sometimes NETosis, in healthy neutrophils, and CFP 10 and ESAT 6 participate in the phenomenon. Conclusion: We propose the N BT as an auxiliary tool for substantiating the diagnosis of bTB reinforcing the PPD test outcome to help decide whether or not a cow should be sacrificed.

Mycobacterium marinum MMAR_0267-regulated copper utilization facilitates bacterial escape from phagolysosome

“…6D). CFP-10 associates with secreted proteins, including ESAT-6 and CAML (calcium-modulator and cyclophilin ligand), forming a complex on the host cell membrane, facilitating its entry of the bacterium into the host cell and triggers apoptosis and in ammatory responses, thereby exhibiting its virulence 42 . Our results indicate that copper ions may enhance the transcription of the CFP-10 virulence factor in M. marinum.…”

Application of Flow Cytometry in the Diagnosis of Bovine Epidemic Disease

“…The most effective way to control the disease is to kill infected animals. Therefore, detection technology has become an important factor in the control of bovine tuberculosis [ 53 ]. Currently, the main methods used to detect BTB are the IFN-γ in vitro release test, the tuberculin intradermal hypersensitivity test (TST), and the antibody detection method.…”