title: Use of Mueller-Hinton broth and agar in the germ tube test.
abstract: 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.
authors.affiliation: Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Brazil.
authors.forename: Antonella Souza
authors.initials: AS
authors.lastname: Mattei
authors.affiliation: Departamento de Microbiologia e Parasitologia da Universidade Federal de Santa Maria (UFSM), Rio Grande do Sul, Brazil.
authors.forename: Sydney Hartz
authors.initials: SH
authors.lastname: Alves
authors.affiliation: Ciências Pneumológicas/UFRGS, Laboratório de Micologia, Santa Casa-Complexo Hospitalar, Porto Alegre, RS, Brazil.
authors.forename: Cecília Bittencourt
authors.initials: CB
authors.lastname: Severo
authors.affiliation: Ciências Pneumológicas/UFRGS, Laboratório de Micologia, Santa Casa-Complexo Hospitalar, Porto Alegre, RS, Brazil.
authors.forename: Luciana da Silva
authors.initials: Lda S
authors.lastname: Guazzelli
authors.affiliation: Ciências Pneumológicas/UFRGS, Laboratório de Micologia, Santa Casa-Complexo Hospitalar, Porto Alegre, RS, Brazil.
authors.forename: Flávio de Mattos
authors.initials: Fde M
authors.lastname: Oliveira
authors.affiliation: Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS), Brazil.
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: Severo
mesh_terms: D000362:Agar / Q000494:pharmacology*; D002175:Candida / Q000145:classification* / Q000254:growth & development; D003470:Culture Media / Q000737:chemistry*; D006801:Humans; D016533:Mycological Typing Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D013045:Species Specificity
chemical_list: D003470:Culture Media; D000362:Agar