Utility of the Germ Tube Test for the Identification of Candida 1 albicans Directly from Positive Blood Culture

We compared the germ tube test for the identification of C. albicans directly from positive 2 blood culture bottles, with results obtained from subcultured colonies. The direct germ tube test was 3 87.1% sensitive and 100% specific for the identification of C. albicans when compared results obtained 4 from fungal colonies. 5 Introduction. Recent evidence has suggested that early institution of appropriate antifungal therapy is 6 a critical factor in improving outcomes during bloodstream infections with Candida species (2, 4, 5). 7 Given that most bloodstream isolates of C. albicans remain susceptible to azoles such as fluconazole (7, 8 9), the rapid identification of C. albicans is a key step in the diagnostic and treatment algorithm for 9 bloodstream Candida infection to guide targeted and cost effective antifungal strategy (6). 10 Traditionally, the preliminary identification of C. albicans is made through the use of a germ 11 tube test (GTT) performed from a subcultured colony grown on solid agar. Although the test itself is 12 rapid, growth of sufficient colonies on solid agar requires a delay of a minimum of 24, and up to 72 13 hours before identification can be performed. In a preliminary report, Terlecka and colleagues 14 performed the germ tube test directly from 31 BacTAlert blood culture bottles positive for yeast on 15 gram stain , thirteen of which were C. albicans (11). Although the numbers were limited, they observed 16 100% concordance between the direct GTT and the GTT performed from the subcultured organisms 17 grown on solid media. We report here a 2 year prospective study from two sites investigating the 18 possibility that the GTT could be performed directly from blood culture bottles that had been flagged 19 positive. In addition, to extend these results, 67 yeast isolates previously recovered from candidemic 20 patients were tested in blood culture bottles inoculated with human blood. 21 AC CE PT ED on N ovem er 5, 2017 by gest ht://jcm .sm .rg/ D ow nladed fom