QUANTITATIVE STUDIES OF MYCOBACTERIAL POPULATIONS IN SPUTUM AND SALIVA

Abstract

Populations of culturable tubercle bacilli in sputum and saliva were enumerated serially in patients with chronic pulmonary tuberculosis, selected on the basis of a positive result on microscopy. These patients were followed during chemotherapy through the point of sputum "conversion." Pretreatment sputum bacillary counts typically were in the range of 106 to 107 organisms per ml. Bacilli declined steadily from cultures during chemotherapy. At the time sputum became negative by microscopy a mean of 9,500 organisms per ml was obtained from colony counts. In patients with primary drug-resistant Mycobacterium tuberculosis, and mixed M. tuberculosis-M. kansasii infections, organisms declined after chemotherapy at about the same rate as in patients with drug-susceptible M. tuberculosis. Organisms were cultured from saliva before chemotherapy in nearly all patients studied. The degree of initial salivary loading was variable. Bacillary populations in the mouth declined in less regular fashion than was observed for sputum populations. Salivary "conversion" often occurred just prior to sputum "conversion.".