New Rapid Candida Test Helps Direct Treatment

Thermo Scientific Limited has launched a new rapid colorimetric test for Candida albicans. O.B.I.S. albicans (ID0700M) differentiates Candida albicans from other yeast species on standards diagnostic culture media in just one hour.

Recent trends in the incidence of invasive Candida infections have highlighted a need for the rapid differentiation of C. albicans from non-albicans Candida species. In addition to a worldwide increase in systemic Candida infections¹, some countries have found that an increasing proportion of these infections are due to non-albicans Candida species². Although C. albicans is sensitive to azoles, which are the most widely used of all antifungal agents, some non-albicans Candida species are resistant to the azole group of drugs. It is therefore important to obtain rapid, species-level identifications in order to direct appropriate antifungal treatment.

O.B.I.S. albicans is extremely easy to use and quickly indicates whether a suspect colony is C. albicans or not. The two-stage test detects the presence of two enzymes, b-galactosaminidase and L-proline aminopeptidase. Both of these enzymes are produced by C. albicans, however one or both enzymes is absent in other yeast species. If both stages of the test produce a colour reaction, the result is presumptive positive for C. albicans. The absence of a colour reaction in either or both stages of the test indicates that the suspect colonies are not C. albicans.

Unlike some biochemical tests, O.B.I.S. albicans uses safe, non-carcinogenic substrates. In addition, it is a much faster alternative to time-consuming and subjective physiological methods, such as the germ tube test.

References:
¹ Sheehan, D.J., Hitchcock, C.A. and Sibley, C.M. (1999) Clin Micro Rev 12(1):40-79
² CDR Weekly (2003) 13(42):1-5