AUTHOR=Liu Lingli , Du Lijun , He Shuquan , Sun Tianshu , Kong Fanrong , Liu Yali , Xu Yingchun 

TITLE=Subculturing and Gram staining of blood cultures flagged negative by the BACTEC™ FX system: Optimizing the workflow for detection of Cryptococcus neoformans in clinical specimens

JOURNAL=Frontiers in Microbiology

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2023.1113817

DOI=10.3389/fmicb.2023.1113817

ISSN=1664-302X

ABSTRACT=<sec><title>Objective</title><p>To investigate whether an incubation time of 5 days (Aerobic/F, Anaerobic/F) and 14 days (Myco/F) blood culture bottles is sufficient to prevent false-negative results.</p></sec><sec><title>Methods</title><p>We evaluated 1,244 blood bottles (344 patients) defined as negative by the BACTEC™ FX system. We also reviewed published cases and our own cases of bloodstream infection caused by <italic>Cryptococcus neoformans</italic> and simulated different scenarios, including different inoculation concentrations, bottle types, and clinical isolates.</p></sec><sec><title>Results</title><p>Two bottles (0.16%) were found to contain <italic>C. neoformans</italic> when subcultured and Gram stained. A 5-day protocol with Aerobic/F bottles was insufficient for the growth of <italic>C. neoformans</italic> in some cases, and <italic>C. neoformans</italic> grew better in Myco/F bottles than in Aerobic/F bottles.</p></sec><sec><title>Conclusion</title><p>Subculturing and Gram staining after a 5-day protocol were important for the detection of <italic>C. neoformans</italic>, and Myco/F bottles should be collected for the blood culture of <italic>C. neoformans</italic>.</p></sec>