By means of fingerprinting based on detection of the insertive sequence IS6110 v DNA of M. tuberculosis predigested by the restrictive enzyme PVUII the authors proved epidemiological associations in three patients with bacillary tuberculosis. The primary source of infection was a 44-year-old man, alcoholic and homeless suffering from tuberculosis diagnosed during an episode of ethylic ebriety, discharged prematurely from hospital because of lack of discipline and drunkenness who died after 8 months with a finding of caseous pneumonia. The first contact person was a 53-year-old women suffering from diabetes and hypertension, an auxiliary worker in the laboratory where she probably was infected during manipulation of the patients infected sputum. The other patient was a 49-year-old man, alcoholic, unemployed where a symptomatic tuberculous finding was detected with general weakness, elevated temperatures and expectoration, who most probably was infected by a patient during accidental contact in his domicile. The profiles of RFLP strains of M. tuberculosis of all three patients had an identical appearance of the DF-1 clone formed by seven copies of IS6110. This profile was not found in any of the total of 98 strains of M. tuberculosis examined within the framework of the molecular epidemiological prevalence study of patients with bacillary tuberculosis notified in Prague in 1999.

        Key words: Mycobacterium tuberculosis – tuberculosis –fingerprinting DNA-RFLP.