ALTERED BACTERICIDAL ACTIVITY AGAINST STAPHYLOCOCCUS-AUREUS IN TUBERCULOUS BRONCHOALVEOLAR LAVAGE FLUIDS

We wished to evaluate the pulmonary defence capacity against common ba cterial infections in patients with pulmonary tuberculosis. Bactericid al activity against Staphylococcus aureus of bronchoalveolar lavage fl uids (cell-free supernatants) of patients with active (n=13) and inact ive pulmonary tuberculosis (n=8), and normal individuals (n=6), were s tudied. The 2 and 4 h bactericidal activities were higher than the 0 h activity in lavage fluids of healthy subjects and patients with inact ive pulmonary tuberculosis. Active tuberculous lavage fluids were equa lly competent in their bactericidal activity against S. aureus at 0 an d 2 h, but a reduced S. aureus killing was seen at 4 h of incubation. Estimation of total phospholipid levels revealed no significant differ ence between the various lavage fluids. This reduced killing of S. aur eus showed a relationship with the cellular components (lymphocytes an d macrophages) of active tuberculous lavage fluids. A reduced killing was associated with no lymphocytic alveolitis, and an increased killin g with lymphocytic alveolitis. This study suggests that alveolar linin g material of patients with active pulmonary tuberculosis has less bac tericidal activity against bacterial infections, such as S. aureus.