Phage type of tubercle bacilli isolated from patients with two or more sites of organ involvement

To evaluate the possibility of separate pulmonary infections in human beings by different strains of Mycobacterium tuberculosis, a search for multiple phage types within a single host was under-taken. Culture isolates from 2 or more distinct anatomic sites of infection in the same patient were obtained from 87 persons. In 3 subjects, 2 distinct phage types were found. The possible explanations for 2 types in the same patient and the epidemiologic implications are discussed.