Isolation of Trichoderma atroviride from a liver transplant

Isolation of Trichoderma atroviride from a liver transplant

Journal de Mycologie Médicale (2008) 18, 234—236 CASE REPORT/CAS CLINIQUE Isolation of Trichoderma atroviride from a liver transplant Isolement de T...

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Journal de Mycologie Médicale (2008) 18, 234—236

CASE REPORT/CAS CLINIQUE

Isolation of Trichoderma atroviride from a liver transplant Isolement de Trichoderma atroviride à partir d’un greffon hépatique S. Ranque a,*, D. Garcia-Hermoso b, A. Michel-Nguyen a, H. Dumon a a

Parasitology-Mycology Laboratory, AP—HM Timone, 264, Saint-Pierre street, 13385 Marseille cedex 5, France French National Reference Centre for Mycoses and Antifungals (CNR de la mycologie et des antifongiques), Institut Pasteur, Paris, France b

Received 20 June 2008; received in revised form 8 September 2008; accepted 9 September 2008 Available online 31 October 2008

KEYWORDS Trichoderma atroviride; Liver transplant

MOTS CLÉS Trichoderma atroviride ; Greffe hépatique

Abstract Six species of Trichoderma have been associated with 24 human infections to date. This is the first report of Trichoderma atroviride, cultured from a liver biopsy specimen of a liver transplant recipient. In the settings of permissive environmental conditions, we may anticipate that emergent Trichoderma spp. infections will continue to develop. # 2008 Elsevier Masson SAS. All rights reserved. Résumé À ce jour, six espèces de Trichoderma ont été impliquées dans 24 infections humaines. Pour la première fois, Trichoderma atroviride a été isolé d’une biopsie du foie postmortem chez un patient greffé hépatique. Il est prévisible que l’émergence des infections à Trichoderma spp. se poursuive parallèlement à l’augmentation régulière du nombre de patients à risque. # 2008 Elsevier Masson SAS. All rights reserved.

Case report A 49-years-old man underwent a liver transplantation for the treatment of an hepatocellular carcinoma in the context of

* Corresponding author. E-mail address: [email protected] (S. Ranque).

alcoholic cirrhosis. He was administered methylprednisolone, tacrolimus, ganciclovir, amoxicillin/clavulanate, and metronidazole. Biliary tract hemorrhages and cholestasis prompted a reintervention in the early postoperative course. On day-7 after transplantation, the patient suddenly developed respiratory distress. Liver function tests yielded: alanine aminotransferase (ALT), 262 UI/l; aspartate aminotransferase (AST), 126 UI/l; lactic acid dehydrogenase (LDH),

1156-5233/$ — see front matter # 2008 Elsevier Masson SAS. All rights reserved. doi:10.1016/j.mycmed.2008.09.002

Trichoderma atroviride in a liver biopsy 292 UI/l; gammaglutamyl transferase (GGT), 262 UI/l; alkaline phosphatase (ALP), 198 UI/l; direct bilirubin, 19 mmol/l; albumine, 16 g/l; prothrombin time, 72%. On day-12, a probabilistic treatment with 800 mg/day oral fluconazole was started. On day-13, a thrombotic microangiopathy possibly triggered by tracrolimus was suspected because of persistently elevated direct bilirubin and LDH levels, anaemia, thrombopenia, and the presence of schizocytes. Tacrolimus was thus replaced by cyclosporine. On day-15, a CT-scan showed a normal liver vasculature. Histology of a liver biopsy specimen revealed ischemic necrosis. Biological abnormalities persisted and fluconazole was replaced by voriconazole (400 mg bid) on day-16. Plasmapheresis was performed on day-17 because of an elevated (385 mmol/l) direct bilirubin level. On day-19, the patient developed acute renal failure, hypotension, oliguria, metabolic acidosis, and died in a picture of massive hemolysis. A postmortem liver biopsy was performed. A unique sample was sent to the Medical Mycology laboratory. Histological examination showed extensive ischemic necrosis with no direct evidence of a fungal pathogen. Pure culture of T. atroviride grew at the inocluation site on Sabouraud’s dextrose agar plate with chloramphenicol and gentamicin of a biopsy specimen cultured at 30 8C. This T. atroviride isolate (National Reference Centre for Mycology and Antifungals [NRCMA] No 200501312) was identified with respect to morphological [3] and molecular criteria. Its antifungal susceptibility pattern was tested using the EUCAST in vitro microdilution method in liquid medium.

Morphological identification Macroscopic features Macroscopic features were dense and woolly colonies that grew within five days, initially whitish, rapidly becoming dark green.

Microscopic features Microscopic features included: conidiophores with branching pattern at right angles; phialides (8—10 mm  2 mm), flaskshaped often curved in whorls of two, three or four verti-

235 cillate; conidia (3.5 mm  4 mm) dark green sub-globose, short ellipsoidal, smooth-walled; chlamydospores were present (Fig. 1).

Molecular identification A 861 bp DNA sequence of our isolate shared 100% identity with the AF278796 sequence of T. atroviride strain ATCC 36042.

Antifungal susceptibility testing This T. atroviride isolate exhibited the following MIC (mg/l):      

amphotericin B: 1; 5-fluorocytosine:  64; fluconazole:  64; itraconazole:  8; voriconazole: 8; caspofungin: 0.5.

Discussion The susceptible hosts’ reservoir of opportunistic molds widens concomitantly to the increasing number of severely immunocompromised patients such as transplant recipients. With an increasing number of invasive infections reports, molds of the genus Trichoderma can be added to the growing list of emerging human pathogens [1]. Trichoderma spp. are free-living filamentous fungi that are common in soil and root ecosystems. T. atroviride (teleomorph: Hypocrea atroviridis) is an opportunistic, avirulent plant symbiont used as a biological control agent because it parasitizes a variety of phytopathogenic fungi [4]. We report on the first isolation of T. atroviride from a human patient. A positive culture obtained by a sterile procedure from a normally sterile and clinically as well as radiologically abnormal site is consistent with the diagnosis of T. atroviride systemic infection. Yet, the absence of hyphae in the histological examination of the patient’s liver goes against the pathological implication of this mold. However, a

Figure 1 Slide culture of Trichoderma atroviride. A. Flask-shaped phialides in verticils ( 400). B. Sub-globose smooth-walled conidia ( 1000). Culture sur lame de Trichoderma atroviride. A. Verticilles de phialides en forme de bouteille ( 400). B. Conidies sub-globuleuses à paroi lisse ( 1000).

236 contamination of the patient’s sample is unlikely because Trichoderma spp. are seldom isolated from our hospital’s environment and T. atroviride has not been previously cultured in our laboratory. There was no definitive evidence in favor of a disseminated infection in this patient, and the overall pathological importance of this mold infection can only be conjectured with respect to the complex clinical presentation of this patient who ultimately died. A retrospective analysis of the patient’s file revealed no particular expositional risk to Trichoderma spp. or any other mold other than immunosuppression. In a comprehensive review of the literature, Chouaki et al. found 22 human infections caused by Trichoderma spp [1]. Recently, De Miguel at al. reported another case of Trichoderma viride infection [2]. Including one personal observation of a fatal Trichoderma longibrachiatum (NRCMA No 200300360) cholecystitis and peritonitis treated with voriconazole and caspofungin in a 70-year-old man who underwent splenectomy to diagnose a Castelman’s disease and the present T. atroviride infection, brings to 24 the reports of Trichoderma spp. infections in humans to date. Six species: Trichoderma harzianum, Trichoderma koningii, Trichoderma longibrachiatum, Trichoderma pseudokoningii, Trichoderma citrinoviride, and T. viride have been identified as etiologic agents of infections in immunocompromised

S. Ranque et al. hosts or in continuous ambulatory peritoneal dialysis associated peritonitis [1]. In this report, a seventh species, T. atroviride, is implicated for the first time. We may anticipate that emergent Trichoderma spp. infections will continue to develop in the settings of permissive environmental conditions, selective antifungal pressure and an expanding population of immunocompromised hosts.

References [1] Chouaki T, Lavarde V, Lachaud L, Raccurt CP, Hennequin C. Invasive infections due to Trichoderma species: report of 2 cases, findings of in vitro susceptibility testing, and review of the literature. Clin Infect Dis 2002;35:1360—7. [2] De Miguel D, Gomez P, Gonzalez R, Garcia-Suarez J, Cuadros JA, Banas MH, et al. Nonfatal pulmonary Trichoderma viride infection in an adult patient with acute myeloid leukemia: report of one case and review of the literature. Diagn Microbiol Infect Dis 2005;53:33—7. [3] Gams W, Bissett J. Morphology and identification of Trichoderma. In: Kubicek CP, Harman GE, editors. Trichoderma and Gliocladium, vol.1: basic biology, taxonomy and genetics. London: Taylor & Francis Ltd; 1998. p. 278. [4] Harman GE, Howell CR, Viterbo A, Chet I, Lorito M. Trichoderma species-opportunistic, avirulent plant symbionts. Nat Rev Microbiol 2004;2:43—56.