USE OF MUELLER-HINTON BROTH AND AGAR IN THE GERM TUBE TEST

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Antonella Souza Mattei, Sydney Hartz Alves, Cecília Bittencourt Severo, Luciana da Silva Guazzelli, Flávio de Mattos Oliveira, Luiz Carlos Severo
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2014
• Subjects: Identification; Germ tube; Mueller-Hinton; Candida albicans; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Arctic; Mueller
• Online Access: https://doi.org/10.1590/S0036-46652014000600005; https://doaj.org/article/25ed14b6137d4073a68542596a26dada

Candida albicans is often isolated from clinical samples, thus its presumptive differentiation from other species of the same genus can be based on its ability to form the germ tube in human serum. Nevertheless, there are two other species that share this characteristic: C. dubliniensis and C. africana. The aim of this study was to compare four different substrates to perform the germ tube (GT) test. The Candida spp. isolates were identified using a manual system (135 C. albicans, 24 C. tropicalis and one C. dubliniensis). The germ tube test was performed with fresh, previously frozen serum and Mueller-Hinton (MH) broth and agar. GT was observed in 96% (130/136) of the isolates through the fresh serum technique, 94% (128/136) through previously frozen serum, 92% (125/136) in MH agar, and 90% (122/136) in MH broth. The sensitivity of each test was higher than 90%, with 100% specificity. Both the MH agar and broth were able to identify the true positives, and false positives were not found. However, some C. albicans isolates were not identified. MH agar and broth may be used in laboratory for the rapid presumptive identification of C. albicans, as an alternative method for germ tube test.