Two cases of catheter-related infection caused by Malassezia furfur and literature review

WANG Mengzhen; YU Shuying; YAN Wenjuan; DOU Hongtao; XU Yingchun

doi:10.3969/j.issn.1673-3827.2024.02.005

Abstract：Objective To report two cases of catheter-related infection caused by Malassezia furfu.Methods Two hospi-talized patients who received total parenteral nutrition developed fever.Their peripherally inserted central catheters(PICC)were collected and cultured separately.Their peripheral blood cultures were performed by BACT/ALERT 3D system and 1,3-β-D-glucan was examined.VITEK Ⅱ compact and VITEK matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF MS)were applied to identify the colonies,26S rDNA D1/D2 and rDNA ITS were sequenced bi-directionally.Antifungal agents including fluconazole,voriconazole,itraconazole,amphotericin B and caspofungin were test-ed by using E-test method.Results Colonies from the PICCs of the two patients were observed on the blood agars after 7 days,and both were identified as M.furfur by VITEK Ⅱ and MALDI-TOF MS.Sequence analysis of ITS and 26S D1/D2 confirmed the results.Both of the two patients'blood cultures were negative although they had been cultured for over 30 days.Levels of 1,3-β-D-glucan for the two patients always didn't exceed 150 pg/ml.Profiles of in vitro susceptibility test for the two M.furfur isolates were identical.The minimum inhibitory concentrations(MICs)of fluconazole,voriconazole,itraconazole,amphotericin B and caspofungin were＞256 μg/mL,＞32 μg/mL,0.38 μg/mL,＞32 μg/mL,and＞32 μg/mL respectively.Conclusions Catheter related infections caused by Malassezia are difficult to detect.Clinical suspicion of infection with Malassezia in PICC patients suggests prolonging the culture time or using specialized culture media.(1,3)-β-D-glucan is less helpful in diagnosing catheter-related infections caused by Malassezia species.Itraconazole may be a suitable choice for treating infections caused by M.furfur.