| Objective FGs has been widely used as second-line anti-TB drugs in China since 1980s, mainly for drug-resistant TB, especially MDR-TB, retreatment and initial treatment patience who can't tolerate the first-line antituberculosis drugs. However, because of the widely application in clinical therapy, the status of resistance to fluoroquinolone of MTB is not optimistic. To investigate the resistant situation of FGs to MTB isolated from the sputum of patients with pulmonary tuberculosis and to provide scientificreference for utilizing FGs in antit uberculosis regimen, we select 119 strains isolated from 119 patients hospitalized in Tianjin Haihe Hospital, and conducted to strain identification and drug susceptibility tests with OFLX, LVFX.Methods (1) drug susceptibility tests:All strains isolated from 119 patients hospit-alized in Tianjin Haihe Hospital from March 2008 to March 2009 were conducted to strain identification and drug susceptibility tests with OFLX, LVFX. MTB in this study were the second transfer of culture strains, including the quality control and standard strains, and all the strains were Human type MTB. The interview adopts pure powder formulations of OFLX, LVFX, both of them were offerd by the reference laboratories of Beijing Tuberculosis and Thoracic Tumor Research Institute. Concentration set by 2-fold dilution method in vitro, was divided into 5μg/ml, 10μg/ml,20μg/ml,50μg/ml,100μg/ml, and set 0μg/ml as control. Colony formation was found in vitro and the number of colonies≥20 was sentenced for the drug resistant if the drug concentration≥5μg/ml. (2) group:①male and female group divided by sex;②young, middle, older group divided by age;③initial treatment and retreated group divided by history with chemotherapy;④By first-line anti-TB drug sensitivity tests dividing into first-line drug-sensitive and first-line drug resistance group, and later group including monoresistance tuberculosis,polyresistance tuberculosis,multidrug resistant tuberculosis,extensive drug resistant tuberculosis;⑤by history of FQs before specimens were collected, dividing into not used, unknown, used group; the last group divided into≤2 weeks,2 weeks-1 month,1 month-3 month,3 months-6 months,≥6 month group by the time of FQs using.Results (1) 40 patients exhibited resistance to ofloxacin while 25 patients were resistant to levofloxacin with a ratio of 33.6% and 21% respectively among the 119 clinical resistant tuberculosis strains. (2)29 male and 11 female patients exhibited resistance to ofloxacin with a ratio of 34.9% and 30.6% while 19 male and 6 female patients were resistant to levofloxacin at rates of 22.9% and 16.7% respectively. (3) On one hand,9 youth,22 middle-aged and 9 aged patients diaplayed resistance to ofloxacin with a ratio of 26.5%,45.8% and 24.3% respectively. On the other hand, the resistance to levofloxacin occurred to 3 youth,17 middle-aged and 5 aged at rates of 8.8%,35.4% and 13.5% respectively. (4) It happened that 10 initial treatment cases and 30 retreatment cases exhibited resistant to ofloxacin with a ratio of 14.5% and 60% respectively. Meanwhile,3 initial treatment cases and 22 retreatment cases displayed resistant to levofloxacin at rates of 4.3% and 21.0% respectively.(5)In the drug-sensitive group,8 and 2 initial treatment patients,8 and 6 retreatment patients were resistant to ofloxacin and levofloxacin, with a ratio of 12.7%,3.2%,38.1% and 28.6%, respectively. Meanwhile, in the drug-resistant group,2 and 1 initial treatment patients,22 and 16 retreatment patients were resistant to ofloxacin and levofloxacin, with a ratio of 33.3%,16.7%,75.9% and 55.2%, respectively. Besides,2 monoresistance,10 polyresistance,7 multidrug resistances and 5 extensive drug resistances displayed resistant to ofloxacin with a ratio of 40.0%,66.7%,77.8% and 88.3% respectively. Meanwhile,2 monoresistance,6 polyresistance,5 multidrug resistances and 4 extensive drug resistances displayed resistant to levofloxacin with a ratio of 40.0%,40.0%,55.6% and 66.7% respectively. (6) OFLX resistant rates in the used, unknown, used group were 8 patients (14%),5patients (29.6%),27 patients (60%),LVFX resistant rates were 4 patients(7%),1 patients(5.9%),20 patients(44%); When FGs were used for 2 weeks,2 weeks -1 month,1 mo nth-3 months,3 months-6 months,≥6 months, the OFLX resistant rates were 2 patients(33.3%),4 patients (36.4%),7 patients (50.0%),9 patients (100%),5 patients(100%), LVFX resistant rates were 1 patients (16.7%),2 patients(18.2%),6 patients(42.9%),6 patients(66.7% ),5 patients (100%); (7) There were 25 strains of MTB were resistant to botn OFLX and LVFX, resistant to OFLX but sensitive to LVFX was 15 strains; there was no resistant to LVFX but sensitive to LVFX; (8) The resistance rates in 2000 were OFLX 26 patients (25.7%), LVFX 12 patients(11.9%); in 2005 were OFLX 28 patients(45.2%), LVFX 21 patients(33.9%); in 2009 were OFLX 40 patients(33.6%), LVFX 25 patients(21%).Conclusion The FGs resistance rate was highest in 2005.And the resistance rate in the retreatment group, resistant strains group especially extensive drug resistant tuberculosis and multidrug resistant tuberculosis were much higher than that in the other groups. Vitro drug concentr ation was negatively correlated with drug resistance. LVFX is better than OFLX in chemotherapy. |
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