title: Primary and acquired pyrazinamide resistance in patients with pulmonary tuberculosis treated at a referral hospital in the city of Recife, Brazil.
abstract: OBJECTIVE
  To determine primary and acquired resistance to pyrazinamide in Mycobacterium tuberculosis strains isolated in sputum samples from patients with pulmonary tuberculosis.
  
  
  METHODS
  This was a prospective, descriptive study conducted between April and November of 2011 at a referral hospital for tuberculosis in the city of Recife, Brazil. Cultures, drug sensitivity tests, and tests of pyrazinamidase activity were conducted in a private laboratory in Recife.
  
  
  RESULTS
  Of the 71 patients included in the study, 37 were treatment-naïve and 34 represented cases of retreatment. Pyrazinamide-resistant strains were isolated in 14 (41.2%) of the 34 patients who had previously been treated for tuberculosis and in none of the 37 treatment-naïve patients. Of the 14 isolates, 10 (90.9%) tested negative for pyrazinamidase activity. A total of 60 isolates tested positive for pyrazinamidase activity. Of those, 56 (93.3%) were found to be sensitive to pyrazinamide.
  
  
  CONCLUSIONS
  The high frequency of pyrazinamide-resistant strains (41.2%) in patients previously treated for tuberculosis highlights the need for drug susceptibility testing prior to the adoption of a new treatment regimen.
authors.affiliation: Residência Médica de Clínica Médica, Hospital Getúlio Vargas, Recife, Brazil. lianyribeiro@gmail.com
authors.forename: Liany Barros
authors.initials: LB
authors.lastname: Ribeiro
authors.forename: Vera
authors.initials: V
authors.lastname: Magalhães
authors.forename: Marcelo
authors.initials: M
authors.lastname: Magalhães
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000581:Amidohydrolases / Q000378:metabolism; D000995:Antitubercular Agents / Q000627:therapeutic use*; D001938:Brazil; D024881:Drug Resistance, Bacterial; D057075:Enzyme Assays; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology; D011446:Prospective Studies; D011718:Pyrazinamide / Q000627:therapeutic use*; D019233:Retreatment; D013183:Sputum / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*; D055815:Young Adult
chemical_list: D000995:Antitubercular Agents; D011718:Pyrazinamide; D000581:Amidohydrolases; C022490:pyrazinamide deamidase