Drug resistance study of Mycobacterium tuberculosis strains and mycobacteria other than tubercle bacilli strains to ofloxacin and ciprofloxacin isolated from patients admitted to research center for TB and pulmonary diseases of Tabriz

Study and evaluation of effectiveness of second line drugs against mycobacterial strains has become more important in the past few years, particularly due to the outbreak caused by multi-drug resistant (MDR) strains of Mycobacterium tuberculosis (MT). The aim of this study was to evaluate the in-vitro susceptibility of M. tuberculosis (MT) and mycobacteria other than tubercle bacilli (MOTT) strains to the two main second line anti-mycobacterial agents (ciprofloxacin and ofloxacin). In this study, in-vitro activities of ofloxacin and ciprofloxacin against totally 100 mycobacterial strains including 90 Mycobacterium tuberculosis strains (40 strains resistant and 50 strains sensitive to the first line drugs) and 10 mycobacteria other than tubercle bacilli strains (all strains resistant to the first line drugs) were investigated by proportional method on Lowenstein-Jensen (LJ) medium. Out of 90 M. tuberculosis strains, 50 strains that were sensitive to the first line drugs were diagnosed as susceptible to ofloxacin and ciprofloxacin. Of other 40 strains which were resistant to the first line drugs, only one strain was resistant to ofloxacin and 2 strains were found to be resistant to ciprofloxacin. Of 10 mycobacteria other than tubercle bacilli strains, 4 strains were resistant to ofloxacin and 3 strains were found to be resistant to ciprofloxacin. The findings of this study showed that ofloxacin and ciprofloxacin could be effectively used against Mycobacterium tuberculosis strains and mycobacteria other than tubercle bacilli strains.