ABSTRACT
BACKGROUND: While fluoroquinolone-resistant Chlamydia trachomatis strains have not been clinically isolated, they were isolated in an in vitro study recently. METHODS: To determine whether C. trachomatis strains develop resistance under sub-MIC antibacterial exposure in a clinical therapeutic term, C. trachomatis strains were exposed to sub-MIC levofloxacin (LVFX) for about 2 weeks. The MIC of LVFX was measured and DNA fingerprinting was performed every 72 h by PCR using random primers. RESULTS: There was almost no change in the MIC under exposure to 0.125 microg/ml LVFX. However, some mutational changes in DNA fingerprints developed. CONCLUSIONS: In clinical therapeutic terms, resistant strains of C. trachomatis will probably not develop, even if sub-MIC LVFX is employed.
