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
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).