Home | Volume 20 | Article number 127

Original article

A rare case of urinary tract infection due to Trichosporon asahii in a diabetic patient

A rare case of urinary tract infection due to Trichosporon asahii in a diabetic patient


Maryem Iken1, Ahmed Belkouch2,&, Badia Bellarj1, Hafida Naoui1, Laila Boumhil1, Anass El Bouti2, Said Jidane2, Lahcen Belyamani2, Badreddine Lmimouni1


1Parasitology and Mycology Department, Mohamed V Military Hospital of Instruction, Rabat, Morocco, 2Emergency Department, Mohamed V Military Hospital of Instruction, Rabat, Morocco



&Corresponding author
Ahmed Belkouch, Emergency Department, Mohamed V Military Hospital of Instruction, Rabat, Morocco



Trichosporonasahii is a basidiomycete yeast responsible for white piedra and onychomycosis in the immunocompetent host. In the immunocompromised patients, invasive infections are reported; their diagnosis is difficult and they are associated with high mortality rate. Urinary infection due to Trichosporon Asahi is rare but its incidence is increasing. We report the case of a 58 year old diabetic patient. The yeast was isolated from urine samples of three consecutive crops in pure form. The patient improved after antifungal therapy.




Yeasts of the genus Trichosporonsp are cosmopolitan, widespread in the environment (soil, water, organic substrates, plants). They are also part of the occasional saprophytic flora in humans at the skin, mucous membranes, and gastrointestinal tract [1,2]. Six species are considered potentially pathogenic for humans: T. asahii, T.cutaneum, T.inkin, T.asteroides, T.mucoides, T.ovoides [2-5]. These basidiomycete yeasts can be, depending on the species, responsible for benign superficial infections as white piedra of the hair in the different locations of the body, deep localized or disseminated infections especially among vulnerable patients [2,4,5]. Rare cases of systemic infections were attributed to other species such T.loubieri and T.pullulans [6]. Several cases of hypersensitivity pneumonitis T. asahii were reported exclusively in Japan in patients with high titer antibodies [7]. We report the case of a urinary tract infection with T. asahii diagnosed in the parasitology and Mycology department of the Mohamed V Military Hospital of instruction in Rabat.



Patient and observation

A 58 years old, diabetic patient treated by insulin since 10 years, he has undergone an amputation of his left foot a year ago due to gangrene. He was admitted to the emergency department for the management of a febrile urinary tract infection. Laboratory tests on admission revealed acute renal failure (urea 1,2 g/l, creatinine 68 mg/l) and C-reactive Protein was at 300 mg/l). The blood count showed leukocytosis of 17,000 per mm3, normochromic normocytic anemia with hemoglobin at 7.1 g/dl. The patient was given antibiotics (Ceftriaxone). An initial urine culture came back positive for E. coli sensitive to Ceftriaxone. A significant clinical improvement was noted but a persistent inflammatory syndrome has led us to realize another infectious analysis. Thus, three cytobacteriological urine analysis made on day 15, 17 and 20 of his hospitalization were positive. The macroscopic examination objectified colonies of white creamy yeast, rough, dry and cerebriform, with irregular contours. Microscopic examination, showed voluminous elongated yeast with arthrospores or arthroconidia, hyphae were also observed, typical of the genus Trichosporon [4,5,8,9]. The isolation of the same yeast on three consecutive urine cultures and the absence of any bacterial outbreak, has allowed us to consider T.asahii as the etiologic agent of urinary infection. The species identification was based on the study of the biochemical characteristics by Auxacolor TM 2 gallery (BIO-RAD, France) and was verified by the VITEK 2 Compact YST cards system (bioMérieux, France). The study of antifungal susceptibility on the VITEK 2 showed that the strain is susceptible to amphotericin B, fluconazole, to 5-flucytosine and voriconazole. Samples from the mouth after the occurrence of oropharyngeal candidiasis isolated Trichosporonasahii. The patient was given amphotericin B. He completely improved.




The Trichosporonsp was described as an emerging opportunistic agent. Indeed, this basidiomycete yeast is increasingly involved in deep infections. It is the second cause of invasive infections in patients with haematologic malignancies profoundly neutropenic after Candida yeast species [10,11]. In the various series reported in the literature, acute leukemia is the most frequent pathology found in 82% of cases of disseminated trichosporonosis [12]. The increased incidence of trichosporonosis is associated with other predisposing factors as immunosuppressive or corticosteroids therapy especially, a human immunodeficiency syndrome, organ transplantation or extensive burns [5,6,9,11,13]. 16 (84%) of the 19 cases of trichosporonosis described by Ruan et al, were due to Trichosporonasahii [11]. This species is recently considered as one of the causative agents of deep localized trichosporonosis. Urinary infection by T.asahii is rarely reported in the literature [9,14], but its incidence has increased in the recent years in hospital due to many factors including prolonged intravenous and bladder catheterization, cardiac prosthetic valves, peritoneal dialysis and broad-spectrum antibiotics [3,13,15]. The recent review of Sun Wei & al shows that of 23 patients with urinary tract infection with T. asahii, 14 (60.8%) had urinary catheterization [12]. Various morbidity factors were reported in the same study: hypertension, heart failure, chronic obstructive pulmonary disease, hemodialysis. Diabetes is noted in 34.7% of cases (8/23). AgenorMessias& al reported a high prevalence of T.asahii 76.66% (n = 23) isolates from urine samples and catheters, followed by T. Inkin and T. asteroides which represent a prevalence of 16.66% (n = 5) and 6.66% (n = 2) of isolates [16]. The same study describes the potential colonization of the region by perigenital six species of Trichosporonspp in normal immunocompetent population (T.asahii, T. asteroides, T. ovoid, T. mucoid, T.inkin, T. cutaneum) a rate of 11.15%. This rate confirms the one recorded by Pini G & al (12.4%) in their study [17]. Therefore, in our case, the Yeasts would probably colonized the bladder catheter from the perigenital skin flora during catheterization [3, 16,18]. In addition to their usual skin saprophytism the Trichosporon spp. have the ability to colonize other sites [5]. Virulence may be related to host defense. Indeed, the profound trichosporonosis occur in immunocompromised patients with impaired cellular immunity and macrophage functions. This virulence may also depend on the species itself. T. asahii secretes β-N-acetylhexosaminidase, the enzyme responsible for the degradation of the oligosaccharides present on the surface of macrophages and preventing recognize the fungal cells [19]. Recently, Wei Sun & al have detected two virulence factors of T. asahii: haemolytic activity and the biofilm formation capacity on polystyrene surface. These two factors give this yeast pathogenicity in urinary tract infections to Trichosporonasahii [12]. The optimal antifungal treatment of deep trichosporonosis remains controversial despite the apparent effectiveness of some antifungal in vitro [5,20]. Trichosporonspp are inconstantly sensitive to amphotericin B, the reference antifungal, and to 5-fluorocytosine [5,9,20]. Several authors report their studies of the minimum inhibitory concentration (MIC)of amphotericin B which is often elevated about 0.25 to 4mg/ml [21]. On the other hand, Wei Sun & al used the technique recommended by the Clinical and Laboratory Standards Institute using the method CLSI M27-A3 [22], to test in vitro the sensitivity of 23 strains of T. asahii to amphotericin B, 5-flucytosine and fluconazole, itraconazole, voriconazole. Their results determined low MICs for amphotericin B (0.5 mg/ml). Furthermore, voriconazole has in vitro activity higher than that of amphotericin B and fluconazole on the isolates of T. asahii [12, 23].




Trichosporonasahii is an emerging yeast responsible of deep localized infections reported mainly in the immunocompromised patients. Although rare, they are difficult to diagnose and have a guarded prognosis. The mycological study based on direct examination allows to set up the diagnosis and start rapid and effective treatment.



Competing interests

The authors declare no competing interest.



Authors’ contributions

All authors have read and agreed to the final version of this manuscript and have equally contributed to its content and to the management of the case.




  1. Miceli MH, Díaz JA, Lee SA. Emerging opportunistic yeast infections. Lancet Infect Dis. feb 2011;11(2):142 51. PubMed | Google Scholar

  2. Sellami A, Sellami H, Trabelsi H, Makni F, Néji S, Cheikhrouhou F, et al. Fongémie fatale à Trichosporonasahii: à propos des deux premiers cas à Sfax (Tunisie). Journal de Mycologie Médicale / Journal of MedicalMycology. juin 2010;20(2):133 5. PubMed | Google Scholar

  3. Sood S, Pathak D, Sharma R, Rishi S. Urinary tract infection by Trichosporonasahii. Indian J Med Microbiol. oct 2006;24(4):294 6. PubMed | Google Scholar

  4. Servonnet A, Bourgault M, Trueba F, Sarret D, Nicand E. Disseminated Trichosporonasahii infection. Ann Biol Clin (Paris). juin 2010;68(3):363 6. PubMed | Google Scholar

  5. Lacroix C, MF de C. Infections dues à Trichosporonspp et à Geotrichumspp. Emc- Maladies Infectieuses. 2005;2(2):97 104. PubMed | Google Scholar

  6. Girmenia C, Pagano L, Martino B, D?Antonio D, Fanci R, Specchia G, et al. Invasive infections caused by Trichosporon species and Geotrichumcapitatum in patients with hematological malignancies: a retrospective multicenter study from Italy and review of the literature. J Clin Microbiol. avr 2005;43(4):1818 28. PubMed | Google Scholar

  7. Hirakata Y, Katoh T, Ishii Y, Kitamura S, Sugiyama Y. Trichosporonasahii-induced asthma in a family with Japanese summer-type hypersensitivity pneumonitis. Ann Allergy AsthmaImmunol. mars 2002;88(3):335 8. PubMed | Google Scholar

  8. Guého E, Smith MT, de Hoog GS, Billon-Grand G, Christen R, Batenburg-van der Vegte WH. Contributions to a revision of the genus Trichosporon. Antonie Van Leeuwenhoek. mai 1992;61(4):289 316. PubMed | Google Scholar

  9. Guého E, Improvisi L, deHoog GS, Dupont B. Trichosporon on humans: a practical account. Mycoses. févr 1994;37(1-2):3 10. PubMed | Google Scholar

  10. Chagas-Neto TC, Chaves GM, Colombo AL. Update on the genus Trichosporon. Mycopathologia. sept 2008;166(3):121 32. PubMed | Google Scholar

  11. Ruan S-Y, Chien J-Y, Hsueh P-R. Invasive trichosporonosis caused by Trichosporonasahii and other unusual Trichosporon species at a medical center in Taiwan. Clin Infect Dis. 1 juill 2009;49(1):e11 7. PubMed | Google Scholar

  12. Sun W, Su J, Xu S, Yan D. Trichosporonasahii causing nosocomial urinary tract infections in intensive care unit patients: genotypes, virulence factors and antifungal susceptibility testing. J Med Microbiol. déc 2012;61(Pt 12):1750 7. PubMed | Google Scholar

  13. Wolf DG, Falk R, Hacham M, Theelen B, Boekhout T, Scorzetti G, et al. Multidrug-resistant Trichosporonasahii infection of nongranulocytopenic patients in three intensive care units. J Clin Microbiol. déc 2001;39(12):4420 5. PubMed | Google Scholar

  14. Silva V, Zepeda G, Alvareda D. Nosocomial urinary infection due to Trichosporonasahii,first two cases in Chile. Rev IberoamMicol. mars 2003;20(1):21 3. PubMed | Google Scholar

  15. Rastogi VL, Nirwan PS. Invasive trichosporonosis due to Trichosporonasahii in a non-immunocompromised host: a rare case report. Indian J Med Microbiol. janv 2007;25(1):59 61. PubMed | Google Scholar

  16. Messias Silvestre A, Alexandre BandeiraRampazzo Miranda M, Pires de Camargo Z. Trichosporon Species Isolated from the Perigenital Region, Urine and Catheters of a Brazilian Population. Braz J Microbiol. 2010;41(3):628 34. PubMed | Google Scholar

  17. Pini G, Faggi E, Donato R, Fanci R. Isolation of Trichosporon in a hematology ward. Mycoses. janv 2005;48(1):45 9. PubMed | Google Scholar

  18. Kucukates E, Balkan I, Hondur N, Gultekin N. A rare case of urinary tract infection due to Trichosporonasahii .J Pak Med Assoc. 2013; 63: 1041-43. PubMed | Google Scholar

  19. Ichikawa T, Sugita T, Wang L, Yokoyama K, Nishimura K, Nishikawa A. Phenotypic switching and beta-N-acetylhexosaminidase activity of the pathogenic yeast Trichosporonasahii. MicrobiolImmunol. 2004;48(4):237 42. PubMed | Google Scholar

  20. Paphitou NI, Ostrosky-Zeichner L, Paetznick VL, Rodriguez JR, Chen E, Rex JH. In vitro antifungal susceptibilities of Trichosporon species. Antimicrob Agents Chemother. avr 2002;46(4):1144 6. PubMed | Google Scholar

  21. Chagas-Neto TC, Chaves GM, Melo ASA, Colombo AL. Bloodstream infections due to Trichosporon spp: species distribution, Trichosporonasahii genotypes determined on the basis of ribosomal DNA intergenic spacer 1 sequencing, and antifungal susceptibility testing. J Clin Microbiol. avr 2009;47(4):1074 81. PubMed | Google Scholar

  22. Clinical and Laboratory Standards Institute (CLSI) Reference Method for Broth Dilution Antifungal Susceptibility Testing of Yeasts; Approved Standard-Third Edition. CLSI Document M27-A3. Wayne, Penn, USA: Clinical and Laboratory Standards Institute; 2008. Google Scholar

  23. Rodriguez-Tudela JL, Diaz-Guerra TM, Mellado E, Cano V, Tapia C, Perkins A, et al. Susceptibility patterns and molecular identification of Trichosporon species. Antimicrob Agents Chemother. oct 2005;49(10):4026 34. PubMed | Google Scholar