A comparative study for production of germ tube in Candida albicans of various pulmonary samples, by different methods in a tertiary care hospital of south west Rajasthan

Abstract

Background: Systemic candidiasis is associated with a high crude mortality rate, even with first line antifungal therapy. C. albicans is the predominant cause of invasive fungal diseases which is a serious public health issue. The main objective was to assess the reliability of different media for germ tube production in Candida albicans isolated from various clinically diagnosed pulmonary samples.Methods: All Candida isolates were identified and speciated by conventional methods such as Gram’s staining, germ tube test, chlamydospore formation on corn meal agar, sugar fermentation test, sugar assimilation test, and growth on Hi-chrome candida agar.Results: Out of 108 clinical isolates of Candida albicans, 5 different methods were used for germ tube production. Pooled human sera showed 93/108 (86.1%) was the most sensitive method wherein YEPD (yeast extract peptone dextrose) broth 91/108 (84.7%) was the reliable and easy method for detection of germ tube, followed by trypticase soy broth 81/108 (81.4%); peptone water 80/108 (74.7%) and 2% sucrose 71/108 (65.7%).Conclusions: YPED broth is found to be a better serum free substrate and subsequently for the presumptive differentiation of C. albicans from non-albicans candida (NAC), without the extensive time required for the preparation and testing of pooled human serum. Furthermore, this medium is commercially available, more stable, effective, and is not bio hazardous.

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

“…Our study highlights that around 92.79% of positivity were seen with YEPD ( Yeast Extract Peptone Dextrose) which correlates with a study conducted by KIM et al, 18 where demonstration of Germ tubes were seen within 30 minutes in YEPD at 39 0 C but after 60 min in serum at 37 0 C. Whereas study conducted by Bhumla et al, 19 showed 81.25% production of germ tube production with YEPD and another study carried out by Abiroo Jan et al, 20 showed 89.30% germ tube production but only in Candida albicans and no germ tube formation in candida dubliniensis.…”

Comparison of Several Types of Plasma as Media in the Germ Tube Test for Identification of Candida Albicans

“…Unlike plasma, such as CPDA, Citrate or EDTA plasma in this study which can be found easier in laboratories or blood bank units. Researches on several commercial media that is particularly available in the laboratory also showed that the average times of germ tube formation on those media were longer compared to serum [21,22]. Another research succeeded in proving that the germ tube test had the same effectiveness as phenotypic methods, such as PCR.…”