Dermatophytes are keratinophilic fungi able to infect keratinized tissues of human or animal origin. Among them, Trichophyton mentagrophytes is known to be a species complex composed of several species or variants, which occur in both human and animals. Since the T. mentagrophytes complex includes both anthropophilic and zoophilic pathogens, accurate molecular identification is a critical issue for comprehensive understanding of the clinical and epidemiological implications of the genetic heterogeneity of this complex. Here, 41 T. mentagrophytes isolates from either human patients (14 isolates) or animals (27 isolates) with dermatophytosis were prospectively isolated by culture and identified on morphological bases at the University Hospital Centres of Lille and Poitiers, and the Veterinary School of Alfort, respectively. The isolates were differentiated by DNA sequencing of the variable internal transcribed spacer (ITS) regions flanking the 5.8S rDNA, and of the housekeeping gene encoding the manganese-containing superoxide dismutase (MnSOD), an enzyme which is involved in defence against oxidative stress and has previously provided interesting insight into both fungal taxonomy and phylogeny. ITS1-ITS2 regions and MnSOD sequences successfully differentiate between members of the T. mentagrophytes complex and the related species Trichophyton rubrum. Whatever the phylogenetic marker used, members of this complex were classified into two major clades exhibiting a similar topology, with a higher variability when the ITS marker was used. Relationships between ITS/MnSOD sequences and host origin, clinical pattern and phenotypic characteristics (macroscopic and microscopic morphologies) were analysed.

A disseminated Fusarium oxysporum infection with skin localization was diagnosed in a woman with a relapse of B-acute leukemia during induction chemotherapy. The infection was refractory to amphotericin B-lipid complex alone but responded successfully when voriconazole was added. CASE REPORTA 32-year-old female with relapsing acute lymphoblastic leukemia was hospitalized for induction chemotherapy on 14 June 2001. At the time of hospitalization, the patient did not show clinical alteration. Blood examination showed hyperleukocytosis (27,180 leukocytes/mm 3 ) with 90% blastic forms and 500 polymorphonuclear leukocytes (PMN)/mm 3 . She received broad-spectrum antibiotherapy (amino-penicillin, amikacin, and fluoroquinolone) and granulocyte-colony stimulating factor (Neupogen 30; Roche). On July 1 (day 0), she was aplastic. The patient left the hospital against medical advice on day 3, but she returned on day 6 with fever and neutropenia (Յ500 PMN/mm 3 ) that lasted for 16 days. Clinical and radiographic examination showed no abnormalities. However, as the patient presented again with fever, antibiotherapy was changed empirically to a combination of piperacillin-tazobactam (later changed to cefepime) and vancomycin and the central venous catheter was removed and cultured. Both the catheter and blood cultures remained negative. Four days after the onset of fever (day 10), vesicular and necrotic lesions appeared on both calves. The next day (day 11), the skin lesions were extended to all the surfaces of the legs (Fig. 1). The diagnosis of opportunistic mycosis was considered, and skin biopsy and blood cultures were performed. Consistently, the histopathological analysis of the skin biopsy showed fungal hyphae deeply localized in the skin tissue. Amphotericin Blipid complex (ABLC) (5 mg/kg of body weight/day) was added on day 12 and controlled until the patient was released on day 30. Biopsy and blood sample cultures yielded Fusarium oxysporum, confirming a systemic fungal infection with skin invasion. Evidence of infection was not observed by either cerebral-, thoracic-, and abdominal-computed tomography or by cardiac echography. Despite therapy, fever persisted and the skin lesions extended to the whole body, confirming the disseminated character of the infection (Fig.