Rapid Detection and Differentiation of Clinically Relevant Candida Species Simultaneously from Blood Culture by Use of a Novel Signal Amplification Approach

Abstract

Fungal bloodstream infections are a significant problem in the United States, with an attributable mortality rate of up to 40%. An early diagnosis to direct appropriate therapy has been shown to be critical to reduce mortality rates. Conventional phenotypic methods for fungal detection take several days, which is often too late to impact outcomes. Herein, we describe a cost-effective multiplex assay platform for the rapid detection and differentiation of major clinically relevant species directly from blood culture. This approach utilizes a novel biotin-labeled polymer-mediated signal amplification process combined with targeting rRNA to exploit phylogenetic differences for sensitive and unambiguous species identification; this assay detects seven pathogenic species (, ,, ,, , and) simultaneously with very high specificity to the species level in less than 80 min with the limits of detection at 1 × 10 to 10 × 10 CFU/ml or as few as 50 CFU per assay. The performance of the described assay was verified with 67 clinical samples (including mixed multiple-species infections as well), with an overall 100% agreement with matrix-assisted laser desorption ionization (MALDI) mass spectrometry-based reference results. By providing a species identity rapidly, the clinician is aided with information that may direct appropriate therapy sooner and more accurately than current approaches, including PCR-based tests.

Identification of Candida Species from Clinical Samples in a Honduran Tertiary Hospital

“…Another reason could be the presence of more than one species of yeast in a seemingly pure culture. These mixed cultures have been described frequently [21,31,43,44], and in cases in which one of the species is underrepresented, they may cause confusion in the interpretation of biochemical results. On the other hand, the use of two phenotypic methods can be considered a good practice that provides greater specificity and sensitivity in the identification of species, mainly when there are two or more species co-infecting a patient.…”

Kan Kültürlerinden İzole Edilen Mayaların Tanımlanmasında Ticari Bir Multipleks Tandem Polimeraz Zincir Reaksiyonu Yönteminin Değerlendirilmesi

“…Kandidemiler, dünyadaki en önemli hasta bakımı ile ilişkili enfeksiyonlardan biridir 1 . Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, Candida lusitaniae ve Candida guilliermondii kandidemilerin %95'inden fazlasına neden olan türlerdir 1 .…”

“…Kandidemiler, dünyadaki en önemli hasta bakımı ile ilişkili enfeksiyonlardan biridir 1 . Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, Candida lusitaniae ve Candida guilliermondii kandidemilerin %95'inden fazlasına neden olan türlerdir 1 . C.albicans, kandideminin en sık görülen nedeni olmasına rağmen son 10 yılda, azollere maruz kalmanın artması ile ilişkili olduğu düşünülen C.albicans dışı türlerin izolasyonundaki artış göze çarpmaktadır.…”

“…Candida türlerinin türe özgü antifungal duyarlılık profilleri olduğundan, enfeksiyon etkeni türün belirlenmesinin Candida kan dolaşımı enfeksiyonu olduğundan şüphelenilen hastaların uygun tedavisi için gerekli olduğu gösterilmiştir 1 . Kandidemilerde ekinokandinler ilk tedavi seçeneği iken, alternatif tedavi seçenekleri daha çok spesifik türle ilişkilidir 8 .…”