title: Effect of drug resistance on negative conversion of sputum culture in patients with pulmonary tuberculosis.
abstract: OBJECTIVE
  Negative conversion of sputum culture is a useful marker for predicting treatment outcome and relapse of pulmonary tuberculosis (TB). The effect of drug resistance on negative conversion of sputum culture with treatment was evaluated in this study.
  
  
  METHODS
  A total of 535 patients with culture-proven pulmonary TB were classified into three groups: drug-susceptible (DS), other drug-resistant (ODR), and multidrug-resistant/extensively drug-resistant (MDR/XDR). Rates of conversion of sputum culture at 4, 8, and 12 weeks were compared.
  
  
  RESULTS
  At 4 weeks of treatment, the conversion rate in the DS group (52.7%) was higher than that in the ODR group (30.8%, p=0.003), but was not different compared with the MDR group (45.7%, p=0.427). At 8 weeks, the conversion rate in the DS group (76.3%) was higher than that in the ODR (63.5%, p=0.042) and MDR groups (60.0%, p=0.031). At 12 weeks, the conversion rate in the DS group (85.9%) tended to be higher than that in the MDR group (74.3%, p=0.062), but was not different from that in the ODR group (84.6%, p=0.796).
  
  
  CONCLUSIONS
  The pattern of resistance to anti-TB drugs affects culture conversion rates in the early phase of treatment and also prolongs the time to culture conversion.
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, Republic of Korea.
authors.forename: Joohae
authors.initials: J
authors.lastname: Kim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, Republic of Korea.
authors.forename: Nakwon
authors.initials: N
authors.lastname: Kwak
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, Republic of Korea.
authors.forename: Ha Youn
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea.
authors.forename: Taek Soo
authors.initials: TS
authors.lastname: Kim
authors.affiliation: Molecular Mycobacteriology Unit, Korean Institute of Tuberculosis, Seoul, Korea.
authors.forename: Chang-Ki
authors.initials: CK
authors.lastname: Kim
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, Republic of Korea.
authors.forename: Sung Koo
authors.initials: SK
authors.lastname: Han
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Seoul National University College of Medicine, 101 Daehak-Ro, Jongno-Gu, Seoul 110-744, Republic of Korea. Electronic address: yimjj@snu.ac.kr.
authors.forename: Jae-Joon
authors.initials: JJ
authors.lastname: Yim
mesh_terms: D000328:Adult; D000368:Aged; D000995:Antitubercular Agents / Q000627:therapeutic use*; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy* / Q000382:microbiology
chemical_list: D000995:Antitubercular Agents
keywords: Conversion time; Drug resistance; Tuberculosis