Trichosporon montevideense isolated from descending colon of Crohn disease patient: case report

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Trichosporon montevideense isolated from the descending colon of a patient with active severe Crohn disease: a case report

Crohn’s disease (CD), a chronic inflammatory bowel disease (IBD) causing abdominal pain, diarrhea, and rectal bleeding, affects millions worldwide—and new research suggests gut fungi (the mycobiota) may worsen symptoms in severe cases. A 2020 study from Peking University First Hospital highlights how one fungal species, Trichosporon montevideense, exacerbated illness in a teen with severe CD—and how targeted antifungal treatment saved her life.

The Case: A Teen’s Battle with Severe CD and Fungal Infection

In April 2013, a 13-year-old girl from Shandong Province was admitted to Peking University First Hospital’s IBD center. Three months earlier, she’d developed hematochezia (blood in stool) and fever that didn’t improve with antibiotics. A colonoscopy revealed classic CD signs: segmental lesions, “cobblestoning” (thickened intestinal lining), and strictures (narrowed areas). Tests ruled out other causes—cytomegalovirus (CMV), Clostridium difficile, amoebae, Behçet’s disease, or vasculitis—and she was diagnosed with active severe CD (Vienna type A1L3B2).

Initial treatment with glucocorticoids (to reduce inflammation) and antituberculosis drugs (to exclude intestinal TB) failed. She switched to infliximab, a biologic drug for CD, but after three doses, a follow-up colonoscopy showed no improvement. A biopsy uncovered a surprise: a fungus later identified as Trichosporon montevideense via genetic sequencing (internal transcriber spacers and intergenic spacer regions). At first, doctors thought it was harmless—Trichosporon is common in healthy guts.

Three months later, her condition collapsed: she needed emergency surgery for intestinal bleeding (total colectomy and ileostomy) and developed a life-threatening post-op fever (39°C). Broad-spectrum antibiotics (meropenem, teicoplanin) and an antifungal (caspofungin acetate) did nothing. Blood and peritoneal fluid cultures were negative, and fungal tests (1,3-β-D glucan, galactomannan) came back clear.

The Breakthrough: Targeting Trichosporon Resistance

The team recalled two critical facts:

  1. Trichosporon is naturally resistant to caspofungin, the antifungal they’d used.
  2. The girl had previously tested positive for T. montevideense in her colon.

Trichosporon is the second most common basidiomycetous yeast (a type of fungus) that causes human infections—and gut translocation (fungi moving from the gut to the bloodstream) is a major source of illness. They switched to voriconazole, an antifungal effective against Trichosporon. Within 24 hours, her fever dropped; three days later, it was nearly normal. She was discharged home three months later. Follow-up immunofluorescence testing confirmed yeast in her colon tissue—proving Trichosporon was the likely cause of her fever.

Mouse Study Confirms: T. montevideense Worsens Colitis

To validate their findings, the team used a dextran sodium sulfate (DSS) mouse model—DSS damages the intestinal lining, mimicking human colitis. They gave mice daily oral doses (gavage) of 10⁸ T. montevideense cells. The results were clear:

  • T. montevideense had no effect on healthy mice.
  • In DSS-treated mice (with colitis), T. montevideense worsened symptoms: more weight loss, shorter colons (a sign of inflammation), higher disease activity scores, and worse tissue damage than mice given DSS alone.

Genetic testing confirmed T. montevideense was present in the colon mucosa of yeast-treated mice—linking fungal colonization directly to worse colitis.

What This Means for Patients and Clinicians

Led by researchers from Peking University First Hospital’s Departments of Gastroenterology, Dermatology and Venereology, and Research Center for Medical Mycology, the study adds to growing evidence that gut fungi play a role in IBD. While the exact role of T. montevideense in CD is still emerging, the findings suggest:

  • Fungal colonization matters: Clinicians should test for Trichosporon in CD patients with fever, rectal bleeding, or positive biopsy cultures—especially if standard treatments fail.
  • Targeted antifungals save lives: Trichosporon resistance to caspofungin means voriconazole is the better choice for treatment.

References

  1. Colombo AL, Padovan ACB, Chaves GM. Current knowledge of Trichosporon spp. and Trichosporonosis. Clin Microbiol Rev 2011;24:682–700. doi:10.1128/CMR.00003-11.
  2. Richard ML, Lamas B, Liguori G, Hoffmann TW, Sokol H. Gut fungal microbiota: the Yin and Yang of inflammatory bowel disease. Inflamm Bowel Dis 2015;21:656–665. doi:10.1097/mib.0000000000000261.
  3. Limon JJ, Tang J, Li D, Wolf AJ, Michelsen KS, Funari V, et al. Malassezia is associated with Crohn’s disease and exacerbates colitis in mouse models. Cell Host Microbe 2019;25:377–388. doi:10.1016/j.chom.2019.01.007.
  4. Ott SJ, Kuhbacher T, Musfeldt M, Rosenstiel P, Hellmig S, Rehman A, et al. Fungi and inflammatory bowel diseases: alterations of composition and diversity. Scand J Gastroenterol 2008;43:831–841. doi:10.1080/00365520801935434.
  5. Iliev ID, Funari VA, Taylor KD, Nguyen Q, Reyes CN, Strom SP, et al. Interactions between commensal fungi and the C-type lectin receptor Dectin-1 influence colitis. Science 2012;336:1314–1317. doi:10.1126/science.1221789.

He SD, Li RY, Chi Y, Wan Z, Wang HH. Trichosporon montevideense isolated from the descending colon of a patient with active severe Crohn’s disease: a case report. Chin Med J 2020;133:1245–1247. doi:doi.org/10.1097/CM9.0000000000000793

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