Objectives: To know the capacity of Spanish laboratories in identifying C. krusei and in performing susceptibility tests to antifungals. Methods: As a part of the Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) External Quality Control Program (QCP) in Mycology, the same yeast strain was sent to an average of 200 laboratories in two separate shipments in 1998 and 2005. Results of identification and susceptibility testing were analysed in comparison with those provided by a reference laboratory. As expected, the C. krusei strain was characterized by its intrinsic resistance to fluconazole (FLU). Results: In the first shipment (1998), the percentage of participation of laboratories was 84.2%, and 72% of them correctly identified the yeast strain at species level, 8.0% reported only genus Candida and the remaining 20% gave a discordant identification. The main methods and commercial brands used in identification were the biochemical systems API 20C AUX and API ID 32C (bioMí©rieux); the last one got the 100% of correct identifications. Susceptibility testing was performed by 40.7% of participants, and discordant results (susceptible to FLU) were reported by 47.5% of those sending data. In their commentaries, only 2.7% reported explicitly the inherent intrinsic resistance to FLU of this yeast. On the other hand, the percentage of participation was 89.9% in the 2005 control, being the correct species identification 92.1%. Only 2.8% of the centres identified the strain at genus level, and the percentage of discordant identifications dropped to 5.1%. Again, the API galleries were mostly used, and API ID 32C offered a complete agreement in the identification. The 64.5% of laboratories performed susceptibility tests to antifungals, 72.7% reported resistance to FLU, and 25.7% explicitly declared such intrinsic characteristic in their comments. Conclusion: An increased percentage of participation was observed along the study period, as well as in the correct identification of the C. krusei strain, the number or laboratories performing susceptibility tests, and in the right interpretation of their FLU results. Altogether, these results show the need for implementing training programs in Mycology in the clinical laboratories. Also, they underline the potentiality of the SEIMC QCP as a tool in the continuous education of professionals, since the analysis of the results is followed with a revised update on the subject of the control.
Full conference title:
16th European Congress of Clinical Microbiology and Infectious Diseases
- ECCMID 16th (2006)