title: Potential for erroneous results indicating resistance when using the Bactec MGIT 960 system for testing susceptibility of Mycobacterium tuberculosis to pyrazinamide.
abstract: During susceptibility testing of 743 isolates of Mycobacterium tuberculosis to pyrazinamide (PZA) using the Bactec 960 system, 57 (7.7%) isolates showed PZA resistance. Repeat testing of resistant isolates with the Bactec 460 reference method confirmed 33 (4.4%) of these isolates as resistant, and 24 (3.2%) were susceptible. Erroneous results for resistance with the Bactec 960 were confirmed by testing the 24 discordant isolates for pyrazinamidase and mutations in the pncA gene.
authors.affiliation: Public Health Laboratory-Toronto, Ontario Agency for Health Protection and Promotion, 81 Resources Road, Toronto, Ontario M9P 3T1, Canada. Pam.Chedore@oahpp.ca
authors.forename: Pamela
authors.initials: P
authors.lastname: Chedore
authors.forename: Lina
authors.initials: L
authors.lastname: Bertucci
authors.forename: Joyce
authors.initials: J
authors.lastname: Wolfe
authors.forename: Meenu
authors.initials: M
authors.lastname: Sharma
authors.forename: Frances
authors.initials: F
authors.lastname: Jamieson
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology*; D003951:Diagnostic Errors; D024881:Drug Resistance, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods*; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D011718:Pyrazinamide / Q000494:pharmacology*
chemical_list: D000995:Antitubercular Agents; D011718:Pyrazinamide