Use of various substrate/ media for germ tube test (GTT) detection in Candida albicans and Candida dubliniensis from a tertiary care hospital

Abstract

In recent years, non-judicious use of broad spectrum antibiotics, corticosteroids, antineoplastic agents, immune suppressive drugs, widespread increased use of bone marrow and organ transplant, and unreasonable use of indwelling catheters have led to an increased incidence invasive candidiasis (IC). The germ tube test (GTT) is a well established, inexpensive, rapid and easy to dispense test used to identify . So the present study was conducted to assess the reliableness of different media for GTT production in and . A total of 102 and 09 strains were obtained from various clinical samples received at Department of Microbiology from a teaching institute and hospital located at west- central part of Maharashtra for a period of nine months. Medium that were employed for production of germ tube in and C.dubliniensis in the present study were trypticase soy broth, YEPD (Yeast Extract Peptone Dextrose) broth, Muller-Hinton agar/broth and peptone water which were assessed and compared with pooled human sera routinely used for detection of germ tube. For both the isolates human pooled serum showed 96.39% positivity followed by YEPD (yeast extract peptone dextrose) broth with 92.79% positivity, Trypticase soy broth showed 80.18% positivity, whereas Muller Hinton broth produced 67.56% positivity and least positivity was seen with Peptone water where only 45.04% of germ tube induction was observed. So our study clearly highlights that YEPD broth is better serum free media for germ tube production. Moreover, this medium is available commercially, is more stable, reliable, effective, is non biohazardous, convenient and cost effective alternative.