The colonies from SDA plate were also subjected to
germ tube test to check for the production of germ tubes.
albicans in the
germ tube test is cheap but presents a hazard for transmission of disease [3, 6].
Identification was carried out by performing Gram stain,
germ tube test (24Fig.
Yeast isolates were further analysed through the
germ tube test and reported as candida albicans or candida non-albicans.
The Candida isolates obtained were further identified by conventional methods such as gram stain (direct microscopy),
germ tube test, Sabouraud dextrose broth, microscopic morphology on cornmeal agar, and sugar assimilation tests.
Germ tube test was performed to identify Candida albicans.
Candida species, initially identified by colony morphology, were further characterized by
germ tube test, morphology on cornmeal as well as Chromagar and sugar assimilation profiles.
Germ tube test: Small inoculum of Yeast cellswas inoculated into 0.5 mL of human serum and incubated at 37C for no longer than 3h.
Until then it had been misidentified as candida albicans if only
germ tube test was used for identification as both the species have many similarities in their microscopic morphology and ability to form germ tubes in serum.4,5
All consecutive non-duplicate Candida species isolated from March to September 2005 were identified using the
germ tube test and a commercial identification kit (Auxacolor 2, Bio-Rad, France).
In addition to variation in trehalose assimilation rates, 3-4 distinct types were apparent in the
germ tube test. Three independent inoculations ([10.sup.5] CFU/mL, mid log growth phase) of each isolate gave consistent morphologic differences.
The isolate was confirmed to be C albicans by the
germ tube test and the API 20 C AUX kit (biomerieux, Marcy-L'Etoile, France).
