title: Reduction of contamination of mycobacterial growth indicator tubes using increased PANTA concentration.
abstract: We assessed the effect of a double concentration of supplemental polymyxin B, amphotericin B, nalidixic acid, trimethoprim and azlocillin (PANTA) added to the Mycobacterial Growth Indicator Tube (MGIT) on contamination and positivity rates in 216 sputum cultures. Contamination rates were respectively 12.9% and 5.5% for samples processed using standard and double PANTA concentrations (P = 0.0001, McNemar's test). Thirty-five per cent of cultures performed using standard PANTA and 36.5% of those performed using two-fold PANTA concentrations were positive for Mycobacterium tuberculosis, compared to 25.9% of cultures inoculated on Ogawa medium. These results suggest that the use of MGIT with 2× PANTA may be useful in reducing culture contamination without reducing the diagnostic yield.
authors.affiliation: Center for Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil.
authors.forename: R L
authors.initials: RL
authors.lastname: Peres
authors.forename: M
authors.initials: M
authors.lastname: Palaci
authors.forename: R B
authors.initials: RB
authors.lastname: Loureiro
authors.forename: R
authors.initials: R
authors.lastname: Dietze
authors.forename: J L
authors.initials: JL
authors.lastname: Johnson
authors.forename: E L
authors.initials: EL
authors.lastname: Maciel
mesh_terms: D000666:Amphotericin B / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001390:Azlocillin / Q000494:pharmacology; D001431:Bacteriological Techniques / Q000295:instrumentation*; D003470:Culture Media; D004209:Disposable Equipment / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D004866:Equipment Contamination / Q000517:prevention & control*; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000254:growth & development / Q000302:isolation & purification*; D009268:Nalidixic Acid / Q000494:pharmacology; D011112:Polymyxin B / Q000494:pharmacology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D013183:Sputum / Q000382:microbiology*; D014295:Trimethoprim / Q000494:pharmacology; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D009268:Nalidixic Acid; D000666:Amphotericin B; D014295:Trimethoprim; D001390:Azlocillin; D011112:Polymyxin B