Micronucleus frequency in women with genital Chlamydia Trachomatis infection before and after therapy

The main aim of the present study was to investigate the influence of infection with the intracellular bacterium Chlamydia trachomatis, and subsequent treatments with oral doxycycline or azithromycin on the frequency of micronuclei (MN) in peripheral blood lymphocytes of adult female patients receiving standard doses of these drugs. The frequency of micronuclei was measured in the lymphocytes of 38 newly diagnosed adult women with genital C. trachomatis infection. Samples were taken before and after the therapy, and from 50 healthy control females. The therapy was taken orally during 10 days at 2 x 100 mg per day, and then for another 10 days at 1 x 100 mg per day for doxycycline, and as a single dose of 1g for azithromycin. Isolated lymphocytes from all subjects were cultured by use of the whole-blood method and blocked in metaphase with cytochalasin B (Cyt B). One thousand binucleate cells per subject were scored according to published criteria. The frequency of micronuclei was not significantly higher in samples of infected females before therapy, compared with the baseline frequency in healthy control females (p > 0.05). In patients who received doxycycline, the micronucleus frequency after the end of therapy was significantly higher than before treatment (p < 0.001). The mean frequency of micronuclei in females after the end of the therapy with azithromycin did not show an increase (p > 0.05). The application of linear regression analysis showed that the difference in micronucleus frequency before and after therapy (effect of the antibiotics) was affected by the therapy type. Age and smoking did not affect micronucleus frequency in analyzed samples of patients (p = 0.078, 0.579). We conclude that C. trachomatis infection does not induce micronuclei in peripheral blood lymphocytes of infected adult female patients. Therapy with doxycycline significantly increases the micronucleus frequency in lymphocytes of treated patients, but treatment with azithromycin does not induce micronuclei.