Improved Integral System YEASTS Plus for Simultaneous ID and AST of Yeasts
The Liofilchem® Integral System YEASTS Plus (ref. 71822) is a 24 reaction well panel containing biochemical substrata and antimycotics for the identification and Antifungal Susceptibility Testing of the most clinically important yeasts. The panel is inoculated with the cell suspension. The ID and AST results are delivered after incubating at 36°C for 48 hours.
PRINCIPLE OF THE METHOD:
Identification
Identification of the yeast is based on assimilation of various sugars and the consequent pH change in the well; which leads to a color change. The tests are interpreted by examining the color change of wells 1-GLU to 12-DUL.
From the combination of positive and negative reactions a numerical code can be calculated and the identification of the yeast under examination is made by consulting the codebook or using a convenient software system. The software is available on-line on the Liofilchem® website or can be installed on a PC.
- The red to yellow color change in the identification wells indicates growth of the yeast under examination.
- The red to orange color change in the identification wells indicates slow growth of the yeast under examination.
- No color change in the identification well indicates no growth of the yeast under examination.
The new Integral Systems YEASTS Plus also includes a chromogenic well (no. 13-CHR) directly derived from Liofilchem® Chromatic technology, for improving the fungi identification. The well no. 13-CHR delivers a color based distinction: green colour for Candida albicans, purple colour for Candida tropicalis.
Antifungal Susceptibility Testing
The tests are evaluated according to growth or inhibition of yeasts in media containing antimycotics, in wells 14-NY to 23-FLU.
- The red to yellow color change in the AST wells indicates resistance to the concentration of antimycotic in the well.
- The red to orange color change in the AST wells indicates an intermediate sensitivity to the concentration of antimycotic in the well.
- No color change in the AST well indicates sensitivity to the concentration of antimycotic in the well.
The range of the Liofilchem® Integral Systems is completed by I.S. Enteorobacteria, I.S. Staphylococci, I.S. Streptococci and I.S. Gardenerella, which conveniently combine ID and AST in one single panel.
References
- Murray, Baron, Pfaller, Tenorev and Yolken. Manual of Clinical Microbiology 8th Edition (2003)
- Bayley and Scott's. Diagnostic Microbiology 7thEdition (1986).
- Davise H. Larone. "Medically important fungi: a guide to identification". 2ThEdition. Elsevier (1987).
- J.P. Van der Walt, L.Rodrigues De Miranda, S.A.Meyer. "The Yeasts ". 3ThEdition. Elsevier (1984).
- Barchiesi, F., A.M. Tortorano, l.F. Di Francesco, M. Cogliati, G.scalise, and M.A.Viviani. In vitro activity of five antifungal agents against uncommon clinical isolates of Candida spp. J.Antimicrob.Chemother. 43.295-299 (1999).
- NCCLS. Reference method for broth dilution antifungal susceptibility testing of yeasts. M27-A2.(2002).