Pericardial Effusion Due to Trichosporon japonicum: A Case Report and Review of the Literature

Invasive infections due to Trichosporon spp. are life-threatening opportunistic fungal infections that may affect a wide array of organs. Here, we described a case of pericardial effusion due to Trichosporon japonicum in a 42-year-old female after a heart transplantation. T. japonicum was isolated from the pericardial fluid, pericardial drain hole and the swab of the sternal surgery scar wound. The late mycological diagnosis due to blood culture negative, the ineffective control of pulmonary bacterial infection and the late start antifungal therapy were the contributing factors in the patient’s death.


Introduction
Trichosporon are emerging opportunistic basidiomycetous yeast-like organisms. Ubiquitous in the environment, they are occasionally involved in invasive fungal diseases [1]. Patients with hematological malignancies, persistent neutropenia, intravenous and urinary catheters, those who have had thoracic or abdominal surgery, and those who are immunosuppressed or pre-exposed to antifungal therapy, especially to echinocandins, are at risk of invasive trichosporonosis [2]. The most common species involved in clinical infections are Trichosporon asahii, followed by T. inkin, T. faecale, and T. asteroides [3].
In this report, we present a rare case of a Trichosporon japonicum infection in a 42 years old female following heart transplantation. We discussed the value of the different diagnostic tools available and performed a review of the literature on T. japonicum infections.

Patient History
A 42-year-old female was admitted at La Timone hospital (Marseille, France) to undergo a heart transplantation. She had a history of congenital cardiopathy (single ventricle) with multiple cardiac decompensation episodes, severe left ventricular dysfunction (LVEF 25%) and New York Heart Association class III dyspnea. The patient was on mechanical ventilation throughout the duration of the hospitalization, and did not develop any fever. At day 6 post transplantation, a routine trans-thoracic echography showed a 1 cm pericardial effusion (Figure 1). The pericardial effusion progressively increased to 1.2 cm at day 10, and 1.5 cm at day 17. At day 13, the patient developed an acute respiratory distress syndrome, and HSV-1 PCR was positive (in blood and bronchoalveolar lavage fluid); the patient was treated with acyclovir. The following bacteria were repeatedly cultured from respiratory samples from day 6 post transplant: Pseudomonas aeruginosa (one bronchial aspirate and Pathogens 2022, 11, 598 2 of 7 one bronchoalveolar lavage fluid), Stenotrophomonas maltophilia (three bronchial aspirate, one bronchoalveolar lavage fluid and one sputum) and Citrobacter freundii (one bronchial aspirate and one bronchoalveolar lavage fluid). Following that, the patient was treated with an adapted antibiotic therapy, which unfortunately does not enable the control of the infection. From the first day post transplant, the patient had a supranormal white blood cell count with an average of 28 × 10 9 /L (range: 18 × 10 9 -43 × 10 9 ).
Pathogens 2022, 11, x FOR PEER REVIEW fluid); the patient was treated with acyclovir. The following bacteria were repeatedl tured from respiratory samples from day 6 post transplant: Pseudomonas aeruginosa bronchial aspirate and one bronchoalveolar lavage fluid), Stenotrophomonas malto (three bronchial aspirate, one bronchoalveolar lavage fluid and one sputum) and Cit ter freundii (one bronchial aspirate and one bronchoalveolar lavage fluid). Following the patient was treated with an adapted antibiotic therapy, which unfortunately doe enable the control of the infection. From the first day post transplant, the patient supranormal white blood cell count with an average of 28 × 10 9 /L (range:18 × 10 9 -43 ×

Diagnostic Assessment and Therapeutic Intervention
At day 23, the pericardial effusion became circumferential and measured 2.4 cm patient underwent a surgical drainage. The pericardial aspirate was purulent and cream-colored dry wrinkled colonies with irregular margins after 3 days (Figure 2A) terial culture was negative. Fresh microscopic examination of the colonies revealed r yeast cells with blastoconidia and arthroconidia ( Figure 2B,C). Trichosporon japonicum identified by MALDI-TOF mass spectrometry (MicroflexLT, Bruker Daltonics GmbH men, Germany) with a Logscore value at 2.02 obtained from the standard manufac library, and it was deposited (strain number: IHEM 28563). DNA sequence-based id fication was performed as previously described [4]. The 100% identity with the rRN tergenic spacer IGS1 sequence (GenBank AB066426.1) of JCM8357, the type strain japonicum, confirmed this identification. The other genomic regions rRNA Internal scribed Spacer 1 and 2, the D1/D2 domains of the rRNA large-subunit were less info tive but in agreement with this identification. All nucleotide sequences of the presen late were submitted to GenBank (Acc. No OM865139, OM865141 and OM897590) NCBI BLASTn results are detailed in Supplementary Table S1. The same yeast wa lated from the swab of sternal surgery scar wound (day 23 and day 30) and perica drain hole (day 29). Blood culture (BacT/ALERT system, bioMerieux, Craponne, Fr remain negative for the duration of the stay. Aspergillus galactomannan antigena (Bio-Rad Laboratories, Marnes-La-Coquette, France) was negative, at day 17 and da Cryptococcal serum antigen (CrAg ® LFA kit, IMMY, Norman, OK, USA) was negat day 20 but positive (1:80 titer) at day 30. fluid); the patient was treated with acyclovir. The following bacteria were repeatedly cultured from respiratory samples from day 6 post transplant: Pseudomonas aeruginosa (one bronchial aspirate and one bronchoalveolar lavage fluid), Stenotrophomonas maltophilia (three bronchial aspirate, one bronchoalveolar lavage fluid and one sputum) and Citrobacter freundii (one bronchial aspirate and one bronchoalveolar lavage fluid). Following that, the patient was treated with an adapted antibiotic therapy, which unfortunately does not enable the control of the infection. From the first day post transplant, the patient had a supranormal white blood cell count with an average of 28 × 10 9 /L (range:18 × 10 9 -43 × 10 9 ).

Diagnostic Assessment and Therapeutic Intervention
At day 23, the pericardial effusion became circumferential and measured 2.4 cm. The patient underwent a surgical drainage. The pericardial aspirate was purulent and grew cream-colored dry wrinkled colonies with irregular margins after 3 days ( Figure 2A). Bacterial culture was negative. Fresh microscopic examination of the colonies revealed round yeast cells with blastoconidia and arthroconidia ( Figure 2B,C). Trichosporon japonicum was identified by MALDI-TOF mass spectrometry (MicroflexLT, Bruker Daltonics GmbH, Bremen, Germany) with a Logscore value at 2.02 obtained from the standard manufacturer library, and it was deposited (strain number: IHEM 28563). DNA sequence-based identification was performed as previously described [4]. The 100% identity with the rRNA intergenic spacer IGS1 sequence (GenBank AB066426.1) of JCM8357, the type strain of T. japonicum, confirmed this identification. The other genomic regions rRNA Internal Transcribed Spacer 1 and 2, the D1/D2 domains of the rRNA large-subunit were less informative but in agreement with this identification. All nucleotide sequences of the present isolate were submitted to GenBank (Acc. No OM865139, OM865141 and OM897590). The NCBI BLASTn results are detailed in Supplementary Table S1. The same yeast was isolated from the swab of sternal surgery scar wound (day 23 and day 30) and pericardial drain hole (day 29). Blood culture (BacT/ALERT system, bioMerieux, Craponne, France) remain negative for the duration of the stay. Aspergillus galactomannan antigenaemia (Bio-Rad Laboratories, Marnes-La-Coquette, France) was negative, at day 17 and day 30. Cryptococcal serum antigen (CrAg ® LFA kit, IMMY, Norman, OK, USA) was negative at day 20 but positive (1:80 titer) at day 30.
: positive Trichosporon japonicum culture; Pathogens 2022, 11, x FOR PEER REVIEW 2 of 7 fluid); the patient was treated with acyclovir. The following bacteria were repeatedly cultured from respiratory samples from day 6 post transplant: Pseudomonas aeruginosa (one bronchial aspirate and one bronchoalveolar lavage fluid), Stenotrophomonas maltophilia (three bronchial aspirate, one bronchoalveolar lavage fluid and one sputum) and Citrobacter freundii (one bronchial aspirate and one bronchoalveolar lavage fluid). Following that, the patient was treated with an adapted antibiotic therapy, which unfortunately does not enable the control of the infection. From the first day post transplant, the patient had a supranormal white blood cell count with an average of 28 × 10 9 /L (range:18 × 10 9 -43 × 10 9 ).

Diagnostic Assessment and Therapeutic Intervention
At day 23, the pericardial effusion became circumferential and measured 2.4 cm. The patient underwent a surgical drainage. The pericardial aspirate was purulent and grew cream-colored dry wrinkled colonies with irregular margins after 3 days (Figure 2A). Bacterial culture was negative. Fresh microscopic examination of the colonies revealed round yeast cells with blastoconidia and arthroconidia ( Figure 2B,C). Trichosporon japonicum was identified by MALDI-TOF mass spectrometry (MicroflexLT, Bruker Daltonics GmbH, Bremen, Germany) with a Logscore value at 2.02 obtained from the standard manufacturer library, and it was deposited (strain number: IHEM 28563). DNA sequence-based identification was performed as previously described [4]. The 100% identity with the rRNA intergenic spacer IGS1 sequence (GenBank AB066426.1) of JCM8357, the type strain of T. japonicum, confirmed this identification. The other genomic regions rRNA Internal Transcribed Spacer 1 and 2, the D1/D2 domains of the rRNA large-subunit were less informative but in agreement with this identification. All nucleotide sequences of the present isolate were submitted to GenBank (Acc. No OM865139, OM865141 and OM897590). The NCBI BLASTn results are detailed in Supplementary Table S1. The same yeast was isolated from the swab of sternal surgery scar wound (day 23 and day 30) and pericardial drain hole (day 29). Blood culture (BacT/ALERT system, bioMerieux, Craponne, France) remain negative for the duration of the stay. Aspergillus galactomannan antigenaemia (Bio-Rad Laboratories, Marnes-La-Coquette, France) was negative, at day 17 and day 30. Cryptococcal serum antigen (CrAg ® LFA kit, IMMY, Norman, OK, USA) was negative at day 20 but positive (1:80 titer) at day 30.

Diagnostic Assessment and Therapeutic Intervention
At day 23, the pericardial effusion became circumferential and measured 2.4 cm. The patient underwent a surgical drainage. The pericardial aspirate was purulent and grew cream-colored dry wrinkled colonies with irregular margins after 3 days (Figure 2A). Bacterial culture was negative. Fresh microscopic examination of the colonies revealed round yeast cells with blastoconidia and arthroconidia ( Figure 2B,C). Trichosporon japonicum was identified by MALDI-TOF mass spectrometry (MicroflexLT, Bruker Daltonics GmbH, Bremen, Germany) with a Logscore value at 2.02 obtained from the standard manufacturer library, and it was deposited (strain number: IHEM 28563). DNA sequence-based identification was performed as previously described [4]. The 100% identity with the rRNA intergenic spacer IGS1 sequence (GenBank AB066426.1) of JCM8357, the type strain of T. japonicum, confirmed this identification. The other genomic regions rRNA Internal Transcribed Spacer 1 and 2, the D1/D2 domains of the rRNA large-subunit were less informative but in agreement with this identification. All nucleotide sequences of the present isolate were submitted to GenBank (Acc. No OM865139, OM865141 and OM897590). The NCBI BLASTn results are detailed in Supplementary Table S1. The same yeast was isolated from the swab of sternal surgery scar wound (day 23 and day 30) and pericardial drain hole (day 29). Blood culture (BacT/ALERT system, bioMerieux, Craponne, France) remain negative for the duration of the stay. Aspergillus galactomannan antigenaemia (Bio-Rad Laboratories, Marnes-La-Coquette, France) was negative, at day 17 and day 30. Cryptococcal serum antigen (CrAg ® LFA kit, IMMY, Norman, OK, USA) was negative at day 20 but positive (1:80 titer) at day 30.
The patient was treated with liposomal amphotericin B (1.5 mg/kg/D) starting from day 27. The patient developed a multiple organ failure and died at day 33. Pathogens 2022, 11, x FOR PEER REVIEW 3 of 7

Discussion
Trichosporon japonicum was first isolated in 1998 from air collected in the house of a patient with summer-type hypersensitivity pneumonitis in Japan [5]. So far, T. japonicum infections have been scarcely reported in the literature. A review of the English language literature in Medline by using the following keywords: "Trichosporon japonicum" AND "Human" (Table 1) found only five references reporting a total of six human cases of T. japonicum infections. These infections were documented in blood (n = 2) [6,7], urinary tract (n = 2) [8] and respiratory tract (n = 2) from respiratory samples [9,10]. The mean age of reported cases was 24 years (range:8-50), the sex ratio was 1.5 and three patients died. Regarding the patients' risk factors, two patients were kidney transplant recipients, two patients had a hematologic malignancy (AML, ALL), and similarly to our patient, one underwent cardiac surgery. No data was provided about the remaining case in whom Trichosporon japonicum DNA was detected in lower respiratory specimens [10]. In the present case, our patient developed a pericardial effusion following heart transplantation. The heart preservation fluid culture remained sterile, which should rule out transmission by the graft. Finally, our patient is the second case described following heart surgery and the third after solid organ transplantation.

Discussion
Trichosporon japonicum was first isolated in 1998 from air collected in the house of a patient with summer-type hypersensitivity pneumonitis in Japan [5]. So far, T. japonicum infections have been scarcely reported in the literature. A review of the English language literature in Medline by using the following keywords: "Trichosporon japonicum" AND "Human" (Table 1) found only five references reporting a total of six human cases of T. japonicum infections. These infections were documented in blood (n = 2) [6,7], urinary tract (n = 2) [8] and respiratory tract (n = 2) from respiratory samples [9,10]. The mean age of reported cases was 24 years (range: 8-50), the sex ratio was 1.5 and three patients died. Regarding the patients' risk factors, two patients were kidney transplant recipients, two patients had a hematologic malignancy (AML, ALL), and similarly to our patient, one underwent cardiac surgery. No data was provided about the remaining case in whom Trichosporon japonicum DNA was detected in lower respiratory specimens [10]. In the present case, our patient developed a pericardial effusion following heart transplantation. The heart preservation fluid culture remained sterile, which should rule out transmission by the graft. Finally, our patient is the second case described following heart surgery and the third after solid organ transplantation.
Prompt diagnosis and timely management of trichosporonosis are essential. The gold standard diagnosis is the culture with growth between 48 and 72 h on Sabouraud medium [11] and their ability to grow on non-specific media. In the present case, the repetitive blood cultures remained negative, but the samples grew rapidly (within 72 h). T. japonicum was identified by the MALDI TOF MS and DNA sequencing confirmed the identification. Whereas the ITS and D1/D2 domains of rDNA are considered as the gold standard for medically important yeasts identification [12], in this present case, they could not differentiate T. japonicum, T. asahii and T. asteroides. The IGS region is more discriminating and has confirmed the species (Table S1). Our results confirm previous reports that the rRNA IGS1 region nucleotide sequence is the most discriminating and relevant for the precise species identification within the Trichosporon genus [1,11,[13][14][15].  Like Cryptococcus spp., Trichosporon spp. are Basidiomycota, and cross-reactions between cryptococcal polysaccharide antigen detection and Trichosporon species are known [16,17]. Until now, the reported cases of cross-reactions concerned the following species: Trichosporon cutaneum [18,19], Trichosporon beigelii [16,[20][21][22][23], Trichosporon asahii [24,25] and Trichosporon dermatis [26]. We present the first case of a positive cryptococcal antigen detection during a Trichosporon japonicum infection. Interestingly, in the literature, only Bogomin et al. [6] performed a cryptococcal antigen detection in a T. japonicum fungemia in a patient with a transcutaneous biventricular assist device. The latex agglutination cryptococcal capsular polysaccharide antigen test returned negative, although performed concomitantly with positive blood cultures. In our patient, the serum cryptococcal antigen using CrAg ® LFA kit (IMMY, Norman, OK, USA) was negative 3 days before the pericardial fluid puncture and positive 7 days after. Three situations have been reported regarding the time to serum cryptococcal antigen positivity in patients infected with the other Trichosporon species. Karigane et al. reported Trichosporon asahii fungemia in an AML patient with positive cryptococcal antigenemia 5 days before the isolation of the fungus [25], while others reported a positive cryptococcal antigen concomitantly [16] or after the yeast isolation [20,26]. Interestingly, in our patient, the cryptococcal antigen was positive in several biological fluids, such as urine or cerebrospinal fluid, all confirmed by a subsequent Trichosporon positive culture [19,22].
Cross-reaction between Aspergillus galactomannan detection and Trichosporon spp. have been reported [27,28]. A dual positivity of cryptococcal antigen and Aspergillus galactomannan has been described in case of disseminated Trichosporon dermatis infection [26]. In our patient, Aspergillus galactomannan assay in the serum at day 17 and day 30 was negative. We tested cryptococcal antigen (IMMY, Norman, OK, USA) and Platelia Aspergillus galactomanan (Bio-Rad Laboratories, Marnes-La-Coquette, France) in the supernatant from a T. japonicum culture. Both returned positive, suggesting that T. japonicum share common epitopes with Cryptococcus and Aspergillus cell wall components. As recommended in the ESCMID and ECMM joint clinical guidelines [28], in case of suspected invasive Trichosporon infection, the diagnosis should include the combined use of culture, Aspergillus galactomannan and cryptococcal antigen determination. It would be interesting to extend the use of these tools to the first-line diagnostic approach of invasive fungal infections.
There is no consensus on the treatment of trichosporonosis and data concerning MIC interpretation for all antifungal drugs are scarce [3]. Like in most basidiomycetes, the use of echinocandins is not recommended due to natural resistance [29]. Consistently, in our case, the isolates of T. japonicum showed high MIC for echinocandins and low MIC for azoles except for fluconazole. Despite data suggesting a discrepancy between in vitro and in vivo activity, susceptibility testing is still recommended for epidemiological knowledge [3,8]. Recent guidelines moderately recommend voriconazole for initial antifungal therapy, exhibiting excellent in vitro and in vivo activity against Trichosporon spp. [3,8]. In the present case, treatment with amphotericin B was initiated following sensitivity testing and late in the course of the disease. Therapeutic failure is thus difficult to assess.

Conclusions
Trichosporon japonicum infection is rare. In case of suspected invasive Trichosporon infection, prompt diagnosis, including the combined use of culture, Aspergillus galactomannan and cryptococcal antigen determination and the rapid initiation of antifungal treatment are essential.
Supplementary Materials: The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/pathogens11050598/s1, Table S1: Molecular identification of Trichosporon japonicum sequencing ITS, D1/D2 and IGS genetic regions.  Informed Consent Statement: Patient consent was waived due to her inability to sign a written consent (hospitalization in intensive care unit then death). This case, completely anonymized, reports the history of the patient with her management in accordance with ethical respect. No further analysis was performed.
Data Availability Statement: Not applicable.