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 BACTECâ„¢ 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=ObjectiveTo 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.
MethodsWe evaluated 1,244 blood bottles (344 patients) defined as negative by the BACTECâ„¢ FX system. We also reviewed published cases and our own cases of bloodstream infection caused by Cryptococcus neoformans and simulated different scenarios, including different inoculation concentrations, bottle types, and clinical isolates.
ResultsTwo bottles (0.16%) were found to contain C. neoformans when subcultured and Gram stained. A 5-day protocol with Aerobic/F bottles was insufficient for the growth of C. neoformans in some cases, and C. neoformans grew better in Myco/F bottles than in Aerobic/F bottles.
ConclusionSubculturing and Gram staining after a 5-day protocol were important for the detection of C. neoformans, and Myco/F bottles should be collected for the blood culture of C. neoformans.