Abstract:

Objective To analyze the characteristics of drug resistance of Mycobacterium tuberculosis complex（MTBC）in patients with pulmonary tuberculosis in Yunfu city so as to guide individualized treatment. Methods A total of 1 517 sputum culture-positive strains were selected from newly visit tuberculosis patients in Yunfu urban area and 4 counties. MTBC was identified by P-nitrobenzoic acid（PNB）culture medium. Meanwhile,anti-tuberculosis drug sensitivity test of 9 drugs（4 first-line drugs and 5 second-line drugs）were conducted by proportional method. Results Of the 1 571 strains, 1 514（96.4%）were identified as MTBC,and 57（3.6%）were identified as Nontuberculous mycobacterium（NTM）. There was 237 strains（15.7%）of drug-resistance MTBC. The drug-resistance pattern was dominated by monoresistance（9.6%）,followed by polyresistance（3.8%）,multidrug resistance（2.2%）,and extensive resistance（0.07%）. The drug resistance rates of the 4 first-line drugs were streptomycin（11.2%）,isoniazid（7.5%）,rifampicin（3.7%）and ethambutol（3.4%）. The drug resistance rates of the 5 second-line drugs were ofloxacin（1.8%）,aminosalicylic acid（1.5%）,capreomycin（0.5%）,protionamide（0.5%）,and kanamycin（0.3%）. In the 4 first-line drugs,ethambutol had the highest drug resistance（67.6%）to multidrug resistance tuberculosis,followed by streptomycin（52.9%）. In the 5 second-line drugs,ofloxacin had the highest drug resistance（23.5%）to multidrug resistance tuberculosis,and the drug resistance rate of Kanamycin was zero. The drug resistance rate of the first-line combination of isoniazid+rifampicin+streptomycin+ethambutol,isoniazid+rifampicin+ethambutol,and isoniazid+rifampicin were 41.2%,26.4% and 20.6%. The most common combination of multidrug resistance tuberculosis second-line drugs was isoniazid+rifampicin+streptomycin+ethambutol+ofloxacin,and its drug resistance rate was 14.7%. The extensively drug-resistant strain was found in one patient, and it was resistant to all tested drugs. Conclusion The drug resistance of tuberculosis was well controlled in Yunfu city. However, it is necessary to plan personalized treatment based on drug sensitivity test results in vitro,standardize the use of second-line anti-tuberculosis drugs,and prevent drug resistance,especially multidrug resistance and extensively drug resistance.

Key words: Pulmonary tuberculosis, Mycobacterium tuberculosis complex, Drug sensitivity test, Drug resistance