Comparison of Mycosis IC/F and Plus Aerobic/F media for diagnosis of fungemia by the Bactec 9240 system

Fungemia is associated with a high mortality rate. We compared the performance of the Mycosis IC/F selective fungal medium and the Plus Aerobic/F standard bacteriological medium for the diagnosis of fungemia on the Bactec 9240 automatic system. We retrospectively analyzed 550 blood culture pairs composed of one Mycosis IC/F vial and one Plus Aerobic/F vial, drawn in 187 patients with fungemia. The positivity rate by vial was significantly higher on Mycosis IC/F medium than on Plus Aerobic/F medium (88.0% versus 74.9%, P < 0.0001). The positivity rate for fungus detection on Plus Aerobic/F medium fell to 26.9% when bacteria were present in the same vial. The positivity rate by patient was also significantly higher on Mycosis IC/F medium than on Plus Aerobic/F medium (92.5% versus 75.9%, P < 0.0001). A marked superiority of Mycosis IC/F medium was demonstrated for diagnosis of Candida glabrata fungemia (31 of 31, 100%, versus 18 of 31, 58.1%, P < 0.0001). The mean detection time was significantly shorter on Mycosis IC/F medium than on Plus Aerobic/F medium (28.9 +/- 22.2 h versus 36.5 +/- 24.6 h, P < 0.0001). The mean time saving was 8.8 h for Candida albicans and 43.7 h for C. glabrata. Mycosis IC/F medium enabled more sensitive and earlier diagnosis, particularly for the two strains most frequently responsible for fungemia, C. albicans and C. glabrata, and also in the event of the concomitant presence of both yeasts and bacteria. In patients with risk factors, it would thus appear to be sensible to draw a Mycosis IC/F vial in addition to the standard bacteriological vials.