5-Bromodeoxyuridine (BUdR) and light inactivation of proliferating Mycobacterium bovis and Mycobacterium avium sensitized bovine lymphocytes

Maximum inactivation (83-98%) of proliferating Mycobacterium bovis and/or Mycobacterium avium sensitized bovine lymphocytes was obtained when the lymphocytes were treated with 10^-4 M of 5-bromodeoxyuridine (BUdR) and light. Inactivation was specific though not total whether the cultures were first stimulated with M. bovis PPD or M. avium PPD, though slightly higher inactivation resulted when cultures were first stimulated with M. bovis PPD. There was, however, a statistically significant suppression (P < 0.05) of the counts/min of cultures initially stimulated with either M. bovis PPD or M. avium PPD and later restimulated with either of the antigens after BUdR-light treatment. Thus experiments showed that inactivation occurs only to those cells responding by proliferation to a particular stimulant. There is a potential for the use of this assay for differentiating infection due to either M. bovis or M. avium if total inactivation of proliferating lymphocytes could be achieved.