Journal name: Infection and Drug Resistance Article Designation: Original Research Year: 2018 Volume: 11 Infection and Drug Resistance Dovepress Running head verso: Yu et al Running head recto: Invasive infections caused by Trichosporon dohaense open access to scientific and medical research DOI: http://dx.doi.org/10.2147/IDR.S174301 Open Access Full Text Article O RIg I nal ReseaR ch Trichosporon dohaense, a rare pathogen of human invasive infections, and literature review shu-Ying Yu,1–3 li-na guo,1,3 Background: Trichosporon dohaense is a rare fungal species that has not been described in Meng Xiao,1,3 Timothy human invasive infections. Kudinha,4,5 Fanrong Kong,4 he Patients and methods: In this study, we investigated two T. dohaense isolates from patients with Wang,1,3 Jing-Wei cheng,1–3 invasive infections in two hospitals in China, as part of the China Hospital Invasive Fungal Sur- Meng-lan Zhou,1–3 hui Xu,6 veillance Net (CHIF-NET) program. Both patients were under immunocompromised conditions. Ying-chun Xu1–3 Results: On chromogenic agar, T. dohaense isolates were dark blue, similar to the color of 1Department of clinical laboratory, Candida. tropicalis, but the characteristic moist colony appearance was quite different from that Peking Union Medical college of T. asahii. The two isolates were misidentified as T. asahii and T. inkin by the VITEK 2 YST hospital, chinese academy of Medical system. The rDNA internal transcribed spacer (ITS) region and the D1/D2 domain sequences sciences, Beijing, china; 2graduate T For personal use only. school, Peking Union Medical college, of the two T. dohaense isolates were 100% identical to T. dohaense type strain CBS10761 . The chinese academy of Medical sciences, sequence of the intergenic spacer region-1 also clearly distinguished the species. Of the three 3 Beijing, china; Beijing Key laboratory matrix-assisted laser desorption/ionization time-of-flight mass spectrometry systems, Bruker for Mechanisms Research and Precision Diagnosis of Invasive Fungal Biotyper and Autobio MS correctly identified the two isolates to species level, whereas Vitek Diseases, Beijing, china; 4centre for MS systems misidentified them as T. ovoides or T. asteroides. Echinocandins exhibited no in vitro Infectious Diseases and Microbiology laboratory services, IcPMR – activities against the two T. dohaense isolates. In addition, the isolates exhibited intermediate Pathology West, University of sydney, susceptibility to fluconazole (with minimal inhibitory concentrations [MICs] of 8 and 16 µg/ Westmead hospital, Westmead, mL) and itraconazole, voriconazole, and posaconazole (MICs of 0.25–1 µg/mL). T. dohaense nsW, australia; 5centre for Infectious Diseases and Microbiology demonstrated susceptibility to amphotericin B with MIC of 1 µg/mL. The MICs of fluconazole laboratory services, Westmead and voriconazole in our study were higher than the MIC50 of 62 for T. asahii isolates (4 and 0.064 hospital, Westmead, nsW, australia; µg/mL) in the CHIF-NET program. 6Department of clinical laboratory, Infection and Drug Resistance downloaded from https://www.dovepress.com/ by 42.228.4.34 on 21-Sep-2018 First affiliated hospital of Zhengzhou Conclusion: This case study points to a possible emergence of T. dohaense as an opportunistic University, Zhengzhou, henan, china human invasive fungal pathogen, and the reduced susceptibility should be noted. Keywords: Trichosporon dohaense, invasive infection, emerging pathogen, identification, reduced susceptibility correspondence: Ying-chun Xu Department of clinical laboratory, Peking Union Medical college hospital, Introduction chinese academy of Medical sciences, no. 1, shuaifuyuan Wangfujing, Trichosporon species are yeast-like fungi distributed widely in the environment; they Dongcheng District, Beijing 100730, commonly colonize the human skin and the respiratory or gastrointestinal tract but can china 1–5 Tel +86 106 915 9766 cause lethal infections. Trichosporonosis basically occurs in immunocompromised Fax +86 106 915 9766 hosts, with the infection most commonly associated with broad-spectrum antibiotic email [email protected] therapy, chemotherapy, organ transplantation, surgical operation, as well as long-term hui Xu Department of clinical laboratory, The intravascular device implantation, especially in the setting of hematological malignancy First Affliated Hospital of Zhengzhou patients.1–4,6 Furthermore, due to delayed diagnosis and the lack of an optimal treatment University, no. 1, east Jianshe Road, strategy, mortality due to trichosporonosis remains high (50%–80%) in malignant Zhengzhou, henan 450000, china email [email protected] hematological patients despite treatment with antifungal drugs.7,8 submit your manuscript | www.dovepress.com Infection and Drug Resistance 2018:11 1537–1547 1537 Dovepress © 2018 Yu et al. This work is published and licensed by Dove Medical Press Limited. 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Powered by TCPDF (www.tcpdf.org) 1 / 1 Yu et al Dovepress The development of modern molecular identification from Day 1 through to Day 8 of admission, as well as broad- methods has helped greatly in the classification of the genus spectrum antibiotics daily from Day 5 to Day 8, but he never Trichosporon, and to date, 16 species considered potential had any exposure to antifungals during the hospitalization. causative agents of human infections have been described, He had a fever of up to 38.6°C on Day 5. A yeast isolate, including T. asahii, T. asteroides, T. cutaneum, T. inkin, T. identified as T. asahii by chromogenic agar (CHROMagar japonicum, T. jirovecii, T. mucoides, T. dermatis, T. montevi- Candida; CHROMagar Company, Paris, France), was recov- deense, T. coremiiforme, T. domesticum, T. faecale, T. loubieri, ered on Day 11 from the blood culture taken on Day 7. The T. ovoides, T. dohaense, and T. mycotoxinivorans.4,7,9–11 Of isolate was subsequently identified by rRNA gene sequencing these, T. dohaense was first described as causing superficial as T. dohaense (see the following text). The patient was dis- infections in immunocompromised patients in Qatar in 2009.6 charged against medical advice on Day 10 before the fungal Two cases of invasive infections caused by T. dohaense isolate was identified and thus did not receive any antifungal in two hospitals were identified under the China Hospital therapy, although he was in a serious condition. The patient Invasive Fungal Surveillance Net (CHIF-NET) program. was subsequently lost to follow-up (Table 1). Here, we describe these two case studies, including the clinical and molecular characteristics of the two T. dohaense Patient 2 isolates, as well as their notably reduced susceptibility to An 81-year-old female presented to the First Affiliated Hospi- azoles, especially fluconazole. tal of Zhengzhou University on 10 March 2013 for treatment of rectovaginal fistula and incisional hernia after abdominal case review fistulation; she had continuous abdominal pain, nausea, and Patient 1 vomiting. She received broad-spectrum antibiotics from A 56-year-old male, presenting with non-Hodgkin’s lym- Day 0 through to Day 38 of admission. She was transferred phoma with rectal or bladder involvement, was admitted to to the ICU, where she was inserted with a right subclavian the intensive care unit (ICU) of Peking Union Medical Col- vein catheter and intrathoracic drain on Day 8 and received For personal use only. lege Hospital, Beijing, China, on 30 September 2010. The red blood cell transfusion. Blood (1,3)-β-D-glucan level was patient suffered from acute renal failure and acute myocardial significantly raised on Day 25. The patient had a fever of up infarction. He received chemotherapy and hemodialysis daily to 39.2°C on Day 29. Intravenous fluconazole was started Table 1 clinical features of two patients with invasive infection caused by Trichosporon dohaense Clinical feature Patient 1 Patient 2 Isolate ID number 10PU193 12ZZ130 age 56 81 gender Male Female Reason for hospital admission non-hodgkin’s lymphoma colorectal cancer Infection and Drug Resistance downloaded from https://www.dovepress.com/ by 42.228.4.34 on 21-Sep-2018 Underlying disease acute renal failure, acute myocardial infarction hypertension, coronary heart disease, diabetes First isolation of T. dohaense (datea) 6/10/2010 (7) 17/04/2013 (37) clinical status at time of positive culture Immunosuppressive state Yes Yes neutropenia (<109/l) no no Presence of cVc no Yes Broad-spectrum antibiotics Yes Yes Parenteral nutrition no Yes surgery within 30 days no Yes Intensive care Yes Yes Previous antifungal agents within 30 days no Yes Indwelling urinary catheter Yes no Therapy cVc removal (datea) not applicable Yes (37) antifungal therapy after culture no no Outcome of patient Discharge without medical advice Discharge without medical advice Note: anumbers in parentheses indicate the days from the beginning of hospitalization. Abbreviation: cVc, central venous catheter. 1538 submit your manuscript | www.dovepress.com Infection and Drug Resistance 2018:11 Dovepress Powered by TCPDF (www.tcpdf.org) 1 / 1 Dovepress Invasive infections caused by Trichosporon dohaense (400 mg daily) on Day 28, then her temperature went down USA). Species identification was performed by querying the to about 38.0°C. On Day 37, the central venous catheter obtained ITS, D1/D2, and IGS1 sequences against those in (CVC) was removed and sent for culture; meanwhile, central the GenBank database, with nucleotide Basic Local Align- and peripheral blood cultures were also taken. An organism ment Search Tool (BLASTn, http://blast.ncbi.nlm.nih.gov). initially identified as Candida albicans/C.