[Report of drug resistance in strains of Mycobacterium tuberculosis isolated from patients in Iran].

6,472 clinical samples of patients with tuberculosis suspicion between March, 1993 and March, 1994, were studied. Positive results were obtained in 443 patients; 238 females (53.7%) and 205 males (46.3%). The predominant age group was that between 30 and 39 years (31.5%). The cutaneous test of sensitivity to the purified protein derivate (PPD) was positive in 178 patients with a range of 10-14 mm. Abnormal radiological images were found in 222 patients (50.1%). Higher resistance frequency was detected in Mycobacterium tuberculosis strains among cases suffering from pulmonary tuberculosis. 42 (9.5%) strains were resistant to isoniazid and 31 (7.0%) to streptomycin. Resistance to one drug was observed in 25 isolations (5.4%). A few strains (1.3%) were resistant to 3 drugs, and 1 of them to 5 drugs. Clinical and epidemiological data suggest that resistance to drugs in tuberculosis is becoming an important problem in the region. The fast diagnosis of this infection and the use of antibiotics with a reduced spectrum may enable the control of this form of tuberculosis.