Objectives: Traditionally, for mycobacterial culture both solid and broth media are used and routinely held for 6 weeks minimum to optimize yield. We retrospectively reviewed all positive mycobacterial cultures over a 12-month period to assess growth kinetics of clinically relevant isolates. Methods: From January to December 2015, 658 positive mycobacteria cultures by solid (7H11 and 7H10 plates) and/or broth (BACTEC MGIT) media were identified and reviewed. Results: In broth-only cultures, 21 of 153 (13.7%) from 21 patients were positive after 28 days' incubation. Subsequent chart review revealed the following species: 11 Mycobacterium avium intracellulare complex (MAI), five Mycobacterium tuberculosis (MTB), and five other non-MTB/MAI mycobacteria. Two of the cases of MTB were first-time isolates, and 11.4% of MTB-positive cultures became positive after 4 weeks' incubation. Conclusions: These data provide strong evidence reaffirming that clinically meaningful results are frequently detected after extended incubation times by broth-only methods, including several MTB isolates.
Objectives: Traditionally, for mycobacterial culture both solid and broth media are used and routinely held for 6 weeks minimum to optimize yield. We retrospectively reviewed all positive mycobacterial cultures over a 12-month period to assess growth kinetics of clinically relevant isolates. Methods: From January to December 2015, 658 positive mycobacteria cultures by solid (7H11 and 7H10 plates) and/or broth (BACTEC MGIT) media were identified and reviewed. Results: In broth-only cultures, 21 of 153 (13.7%) from 21 patients were positive after 28 days' incubation. Subsequent chart review revealed the following species: 11 Mycobacterium avium intracellulare complex (MAI), five Mycobacterium tuberculosis (MTB), and five other non-MTB/MAI mycobacteria. Two of the cases of MTB were first-time isolates, and 11.4% of MTB-positive cultures became positive after 4 weeks' incubation. Conclusions: These data provide strong evidence reaffirming that clinically meaningful results are frequently detected after extended incubation times by broth-only methods, including several MTB isolates.
Authors: Wei Gu; Xianding Deng; Marco Lee; Yasemin D Sucu; Shaun Arevalo; Doug Stryke; Scot Federman; Allan Gopez; Kevin Reyes; Kelsey Zorn; Hannah Sample; Guixia Yu; Gurpreet Ishpuniani; Benjamin Briggs; Eric D Chow; Amy Berger; Michael R Wilson; Candace Wang; Elaine Hsu; Steve Miller; Joseph L DeRisi; Charles Y Chiu Journal: Nat Med Date: 2020-11-09 Impact factor: 87.241