Didier Hocquet1, Marlène Sauget2, Sandrine Roussel3, Caroline Malugani4, Fabienne Pouthier5, Pascal Morel5, Houssein Gbaguidi-Haore2, Xavier Bertrand2, Frédéric Grenouillet3. 1. Service d'Hygiène Hospitalière, Centre Hospitalier Universitaire Régional Besançon, Besançon, France; UMR 6249 Chrono-environnement, Université de Franche-Comté, Besançon, France. Electronic address: dhocquet@chu-besancon.fr. 2. Service d'Hygiène Hospitalière, Centre Hospitalier Universitaire Régional Besançon, Besançon, France; UMR 6249 Chrono-environnement, Université de Franche-Comté, Besançon, France. 3. UMR 6249 Chrono-environnement, Université de Franche-Comté, Besançon, France; Service de Parasitologie-Mycologie, Centre Hospitalier Universitaire Régional Besançon, Besançon, France. 4. Etablissement Français du Sang, Besançon, France. 5. UMR 1098 Interaction Hôte-Greffon-Tumeur et Ingénierie Cellulaire et Génique, Université de Franche-Comté, Besançon, France; Etablissement Français du Sang, Besançon, France.
Abstract
BACKGROUND AIMS: Automated blood culture systems are widely used for the detection of microorganisms in cell therapy products. However, they are not validated by the manufacturers for this purpose. The aim of this study was to assess the ability of the Bactec system (Becton-Dickinson, Le Pont-De-Claix, France) to detect the microorganisms that could contaminate cell therapy products. METHODS: Three types of vials and conditions were tested: Plus Aerobic/F and Anaerobic/F media incubated at 35°C and Mycosis IC/F medium incubated at 30°C. All vials were incubated 10 days. We tested 18 microorganisms, including slow growers and some with fastidious nutritional requirements (10 bacteria, four yeasts, four filamentous fungi), each with four inocula (10-10(4) colony-forming units) performed in quintuplicate. RESULTS: The combination of Plus Aerobic/F and Plus Anaerobic/F vials detected all the tested pathogenic bacteria, all the tested Gram-positive skin commensal or environmental bacteria, all the tested yeasts, and three of four tested filamentous fungi. The addition of the Mycosis IC/F vial extended the range of detected microorganisms to one fungal environmental contaminant. Two bacterial environmental contaminants were not detected by our method. Low inocula of the skin contaminant Propionibacterium acnes were detected only after 7 days of incubation. CONCLUSIONS: These data suggest that (i) the prolongation of the incubation time of Plus Aerobic/F and Plus Anaerobic/F vials from 7 to 10 days and (ii) the use of Mycosis IC/F medium make minor contributions in the sterility testing of cell therapy products. We have validated the Bactec method using aerobic and anaerobic vials incubated 7 days at 35°C.
BACKGROUND AIMS: Automated blood culture systems are widely used for the detection of microorganisms in cell therapy products. However, they are not validated by the manufacturers for this purpose. The aim of this study was to assess the ability of the Bactec system (Becton-Dickinson, Le Pont-De-Claix, France) to detect the microorganisms that could contaminate cell therapy products. METHODS: Three types of vials and conditions were tested: Plus Aerobic/F and Anaerobic/F media incubated at 35°C and Mycosis IC/F medium incubated at 30°C. All vials were incubated 10 days. We tested 18 microorganisms, including slow growers and some with fastidious nutritional requirements (10 bacteria, four yeasts, four filamentous fungi), each with four inocula (10-10(4) colony-forming units) performed in quintuplicate. RESULTS: The combination of Plus Aerobic/F and Plus Anaerobic/F vials detected all the tested pathogenic bacteria, all the tested Gram-positive skin commensal or environmental bacteria, all the tested yeasts, and three of four tested filamentous fungi. The addition of the Mycosis IC/F vial extended the range of detected microorganisms to one fungal environmental contaminant. Two bacterial environmental contaminants were not detected by our method. Low inocula of the skin contaminant Propionibacterium acnes were detected only after 7 days of incubation. CONCLUSIONS: These data suggest that (i) the prolongation of the incubation time of Plus Aerobic/F and Plus Anaerobic/F vials from 7 to 10 days and (ii) the use of Mycosis IC/F medium make minor contributions in the sterility testing of cell therapy products. We have validated the Bactec method using aerobic and anaerobic vials incubated 7 days at 35°C.