CROSS-REACTIONS BETWEEN MYCOBACTERIA .2. CROSSED IMMUNOELECTROPHORETIC ANALYSIS OF SOLUBLE-ANTIGENS OF BCG AND COMPARISON WITH OTHER MYCOBACTERIA

Cross‐reactions between Mycobacterium bovis BCG and various other mycobacteria, Nacardia asteroides, Corynebacterium pyogenes and Listeria monocrtogenes were studied by incorporating antibodies against these bacteria in the ineermediate gel of a crossed immuno‐electrophoretic system with BCG antigen and anti‐BCG antibodies. In the BCG reference system forty‐four distinct antigenic components were recorded, of which thirty‐three cross‐reacted with Mycobacterium tuberculosis, twenty‐five with M. avium, twenty‐one with A, duvalii, eighteen with M. smegmatis, fifteen with M. nonchromogenicum, twelve with M. phlei, eight with N. asteroides and two wilh C. pyogenes, whereas no cross‐reaction was detected with L. monocytogenes. The value of the method for characterization of mycobacterial antigens is discussed. A taxonomic system based on this method appears particularly valuable for studies of non‐cultivable mycobacteria such as M. leprae, A majority of twenty‐one patients with lepromatous leprosy had anti‐BCG antibodies of restricted specificity, affecting only four or live BCG antigens, although one patient had twelve anti‐BCG specificities. Most of these antibodies reacted with those BCG antigens that cross‐react extensively with other mycobacteria. Copyright © 1979, Wiley Blackwell. All rights reserved