Diagnosis of fusariosis in urine cytology

Molecular and MALDI-ToF MS differentiation and antifungal susceptibility of prevalent clinical Fusarium species in China

BACKGROUND

Fusarium species are emerging causative agents of superficial and disseminated human infections. Early diagnosis and treatment contribute to better prognosis of severe infection.

OBJECTIVES

To detect the effectiveness of matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-ToF MS) for Fusarium identification, and evaluate the susceptibility profiles to clinical available antifungals.

METHODS

All 203 clinical Fusarium isolates and 25 environmental isolates were identified by using translation elongation factor 1-alpha (TEF1) and RNA polymerase subunit II (RPB2) sequencing and MALDI-ToF MS. Antifungal susceptibility testing was determined by a microdilution method following the CLSI approved standard M38-A3 document.

RESULTS

Correct identification rates at the species and genus levels were 89.04% (203/228) and 95.18% (217/228), respectively, using Bruker Filamentous Fungi Library 1.0 combined with the novel database. Seven species complexes with 19 Fusarium species were identified, including F. solani (59.21%, n = 135), F. verticillioides (17.54%, n = 40), F. proliferatum (6.58%, n = 15) and F. oxysporum (4.39%, n = 10). Four uncommon species complexes (F. incarnatum-equiseti SC, F. dimerum SC, F. redolens SC and F. sporotrichioides SC) were also identified. A high degree of antifungal resistance was observed. Fusarium isolates exhibited lower MICs to luliconazole and terbinafine compared with amphotericin B and voriconazole, which in turn were significantly more active than amorolfine, fluconazole and itraconazole.

CONCLUSIONS

MALDI-ToF MS showed good performance in Fusarium species with an adapted Bruker library and expanded database. Fusarium isolates exhibited lower MICs to luliconazole and terbinafine compared to amphotericin B and voriconazole.

Fusarium infections: Epidemiological aspects over 10 years in a university hospital in France

BACKGROUND

Fusarium is an environmental mold that causes deep or superficial mycosis in immunocompromised or immunocompetent patients respectively.

METHODS

This epidemiological study evaluated the frequency of Fusarium infections in our university hospital center in France over a decade from 2007 to 2016 and its representativeness in the main clinical infections.

RESULTS

A total of 715 Fusarium sp. were isolated from various sampling sites. Fusarium was detected in 0.47% of blood cultures, 31.1% of ophthalmic samples, and 8.48% of nail samples. The frequency of Fusarium infections was stable over this decade.

CONCLUSIONS

The main Fusarium species complexes recorded in this study were Fusarium oxysporum species complex and Fusarium solani species complex, indicating the importance of Fusarium as a fungal agent that should be considered in clinical practice. A focus on invasive fusarioses shows that they all occur in hematology patients.

Molecular Characterization and Antifungal Susceptibility of Clinical Fusarium Species From Brazil

Fusarium is widely distributed in the environment and is involved with plant and animal diseases. In humans, several species and species complexes (SC) are related to fusariosis, i.e., F. solani SC, F. oxysporum SC, F. fujikuroi SC, F. dimerum, F. chlamydosporum, F. incarnatum-equiseti, and F. sporotrichoides. We aimed to investigate the susceptibility of Fusarium clinical isolates to antifungals and azole fungicides and identify the species. Forty-three clinical Fusarium isolates were identified by sequencing translation elongation factor 1-alpha (TEF1α) gene. Antifungal susceptibility testing was performed to the antifungals amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole, and the azole fungicides difenoconazole, tebuconazole, and propiconazole. The isolates were recovered from patients with median age of 36 years (range 2-78 years) of which 21 were female. Disseminated fusariosis was the most frequent clinical form (n = 16, 37.2%) and acute lymphoblastic leukemia (n = 7; 16.3%) was the most commonly underlying condition. A few species described in Fusarium solani SC have recently been renamed in the genus Neocosmospora, but consistent naming is yet not possible. Fusarium keratoplasticum FSSC 2 (n = 12) was the prevalent species, followed by F. petroliphilum FSSC 1 (n = 10), N. gamsii FSSC 7 (n = 5), N. suttoniana FSSC 20 (n = 3), F. solani sensu stricto FSSC 5 (n = 2), Fusarium sp. FSSC 25 (n = 2), Fusarium sp. FSSC 35 (n = 1), Fusarium sp. FSSC18 (n = 1), F. falciforme FSSC 3+4 (n = 1), F. pseudensiforme (n = 1), and F. solani f. xanthoxyli (n = 1). Amphotericin B had activity against most isolates although MICs ranged from 0.5 to 32 μg mL^-1. Fusarium keratoplasticum showed high MIC values (8->32 μg mL^-1) for itraconazole, voriconazole, posaconazole, and isavuconazole. Among agricultural fungicides, difenoconazole had the lowest activity against FSSC with MICs of >32 μg mL^-1 for all isolates.

Urinary tract infection due to Fusarium oxysporum in an immunocompetent patient with chronic kidney disease

Infections due to Fusarium species are collectively referred to as fusariosis. Fusarium oxysporum has been reported to cause keratitis, onychomycosis, skin infections, catheter associated fungemia and has not been described as a cause of urinary tract infection. Here, we present the first case of fusariosis with urinary tract involvement in a 67 year old male, with chronic kidney disease and type 2 diabetes mellitus. This case illustrates the ever increasing spectrum of rare but offending pathogenic fungi. Early diagnosis of infection with a specific pathogen may lead to changes in antifungal therapy and may be critical for an improved outcome.