No abstract

Disseminated fusariosis has emerged as a significant, usually fatal infection in immunocompromised hosts despite antifungal treatment. We describe here two patients with acute leukemia who developed disseminated amphotericin-resistant fusariosis, and review of six studies of cases series in the literature. Two Fusarium solani strains were isolated from blood and skin cultures of one patient, and one strain from the blood culture of the second patient. Both patients died despite antifungal treatment. Strains were identified by sequencing of ITS1 and ITS4 regions. Random amplified polymorphic DNA analysis of the three F. solani isolates showed a low degree of similarity. Screening for Fusarium spp. contaminants within our facility was negative. Using the CLSI M-38-A2 broth dilution method and E tests(®), we found that the MICs were low for voriconazole (0.12 and 0.5 mg/L, respectively), unexpectedly high for amphotericin B (≥8 and ≥32 μg/mL, respectively) and itraconazole (≥16 mg/ml). Patients with leukemia or persistent neutropenia should be assessed for disseminated fungal infections, including biopsy and skin cultures. Antifungal susceptibility tests are important due to the possibility of the strains being amphotericin resistant. Treatments must be aggressive, with high doses of antifungals or combined therapy.

Cryptococcal infection is transmitted by the inhalation of Cryptococcus spp. propagules. Information about the Cryptococcus species inhabiting plants might be clinically relevant due to the epidemiological role of these habitats as possible sources of human infection. The aim of this study was to increase the knowledge about the environmental occurrence of cryptococcosis agents. Hollow tree vegetal debris of nine plant species was sampled quarterly over a 12-month period. Melanized colonies were screened for Cryptococcus neoformans and C. gattii by biochemical tests, followed by URA5-RFLP molecular analysis, M13 fingerprinting assays, and mating-typing with the specific a and α primers. The susceptibility to fluconazole of all of the confirmed species colonies was determined using the AFST-EUCAST broth dilution method. We found that the typical Brazilian flora tree Hymenaea courbaril yielded a high cryptococcal burden (median, 10(2) CFU/g) during the summer, autumn and winter seasons. C. neoformans VNI molecular type MAT alpha was identified in all of the samples. The fingerprinting analyses showed great molecular variability with no correlation with the susceptibility profile to fluconazole (MIC range 4 to ≥64 mg/l). To our knowledge, this study is the first describing the association between C. neoformans and Hymenaea courbaril. These observations extend the known geographic distribution of and substantiate a new urban environmental niche for C. neoformans and also emphasize the genetic diversity of the environmental C. neoformans VNI molecular type isolates.

In the context of megacities in an urban environment, air quality is an important issue, due to the direct correlation to population's health. The biomonitoring of pollutants can indicate subtle environmental alterations, for that, anemophilous fungi can be monitored for changes in atmospheric conditions related to pollution. In the present study, the concentration of fungi and bacteria in the atmosphere was measured during a specific vehicle fleet reduction in the city of São Paulo, Brazil, from May 24 to 30, 2018, using impactor air samplers. The number of isolated developed colonies was related to atmospheric conditions and the concentration of other air pollutants constantly monitored. Aspergillus, Curvularia, Penicillium, Neurospora, Rhizopus and Trichoderm a were identified. The number of colony-forming units increased by approximately 80% during the sampling period in response to environmental changes favored by the fleet reduction. This result implies the relation between fuel emissions, concentration of atmospheric pollutants, and the presence of viable fungal spores in the urban environment, which highlights the importance of combined public policies for air quality in large cities.

The isolation of Cryptococcosis agents from environmental samples may be difficult due to the presence of groups of fast-growing fungi. We propose a new culture medium based on a modification of Dichloran Rose-Bengal Chloramphenicol Medium (DRBCm) to detect colonies of Cryptococcus neoformans. Our results indicate that DRBCm is superior to the classical Bird Seed Agar in its ability to detect colonies of C. neoformans.