Performance of Short-Term Culture and Direct MALDI-TOF MS for Identification of Candida Species From Blood Cultures

Abstract

Rapid and reliable identification of Candida spp. is crucial due to changing epidemiology and increasing resistance. This study aims to compare the identification rates, average Log Score (LS) values, and three different methods: short-term culture, Sepsityper kit, and an in-house method. Simulated blood culture (BC) samples with clinical Candida isolates and human blood from healthy donors were used. Sepsityper kit was used according to manufacturers' recommendations. An in-house protocol was designed using SDS for lysis of erythrocytes. Short-term culture was performed by inoculation of BC broth on Sabouraud Dextrose Agar (SDA) and chromogenic plates and cultured for 6 h. A total of 52 clinical Candida isolates were included in the study. The identification rate was highest (71.9%) for the short-term culture method, 59.6% for the Sepsityper kit, and 57.3% for the in-house method when all types of bottles were analyzed. Higher identification rates were obtained using the BD BACTEC Mycosis-IC/F bottles: 76.7% for the short-term culture method, 100% for the in-house method, and 76.9% for the Sepsityper kit. Short-term culture has high performance in the identification of Candida species, despite a slightly longer detection time than direct MALDI-TOF MS methods.