Antarctic rocks from continental Antarctica as source of potential human opportunistic fungi.

We assessed the diversity of culturable fungi associated with rocks of continental Antarctica to evaluate their physiological opportunistic virulence potential in vitro. The seventy fungal isolates obtained were identified as nine species of Acremonium, Byssochlamys, Cladosporium, Debaryomyces, Penicillium, and Rhodotorula. Acremonium sp., D. hansenii, P. chrysogenum, P. citrinum, P. tardochrysogenum, and R. mucilaginosa were able to grow at 37 °C; in addition, B. spectabilis displayed a high level of growth at 37 and 45 °C. Thirty-one isolates of P. chrysogenum, P. citrinum, and P. tardochrysogenum were able to produce partial haemolysis on blood agar at 37 °C. Acremonium sp., P. citrinum, and P. tardochrysogenum showed spore sizes ranging from 2.81 to 5.13 µm diameters at 37 °C. Of these, P. chrysogenum and P. tardochrysogenum displayed macro- and micro morphological polymorphism. Our results suggest that rocks of the ultra-extreme cold and dry environment of Antarctica harbour cryptic fungi phylogenetically close to opportunistic pathogenic and mycotoxigenic taxa with physiologic virulence characteristics in vitro.

Endophytic fungi associated with Sudanese medicinal plants show cytotoxic and antibiotic potential.

In this study, we isolated 15 endophytic fungi from five Sudanese medicinal plants. Each fungal endophytic strain was identified by sequencing of internal transcribed spacer (ITS) regions of rDNA. Ethyl acetate extracts were prepared from each endophyte cultivated in vitro and tested for their respective antibacterial activities and antiproliferative activities against human cancer cells. Antibacterial screening was carried out against two bacterial strains: Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, by the broth dilution method. Cell viability was evaluated by the MTT procedure after exposure of MCF7 breast cancer cells and HT29 or HCT116 human colon adenocarcinoma cells to each endophytic extract. Of interest, Byssochlamys spectabilis isolated from Euphorbia prostata showed cytotoxicity (IC50 = 1.51 ± 0.2 µg mL(-1)) against MCF7 cells, but had a low effect against HT29 or HCT116 cells (IC50 > 20 µg mL(-1)). Cladosporium cladosporioides 2, isolated from Vernonia amygdalina leaves, showed antiproliferative activities against MCF7 cells (IC50 = 10.5 ± 1.5 µg mL(-1)) only. On the other hand, B. spectabilis and Alternaria sp. extract had antibacterial activities against the S. aureus strain. The findings of this work revealed that endophytic fungi associated with medicinal plants from Sudan could be considered as an attractive source of new therapeutic compounds.

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil.

Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) as a pathogen of Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) in Brazil / Registro de Paecilomyces niveus Stolk & Samson, 1971 (Ascomycota: Thermoascaceae) como patógeno de Nasonovia ribisnigri (Mosley, 1841) (Hemiptera, Aphididae) no Brasil

Abstract Nasonovia ribisnigri is a key pest of lettuce (Lactuca sativa L.) in Brazil that requires alternative control methods to synthetic pesticides. We report, for the first time, the occurrence of Paecilomyces niveus as an entomopathogen of the aphid Nasonovia ribisnigri in Pinhais, Paraná, Brazil. Samples of mummified aphids were collected from lettuce crops. The fungus P. niveus (PaePR) was isolated from the insect bodies and identified by macro and micromorphology. The species was confirmed by sequencing Internal Transcribed Spacer (ITS) rDNA. We obtained a sequence of 528 bp (accession number HQ441751), which aligned with Byssochlamys nivea strains (100% identities). In a bioassay, 120 h after inoculation of N. ribisnigri with pathogenic P. niveus had an average mortality of 74%. The presence of P. niveus as a natural pathogen of N. ribisnigri in Brazil suggests that it may be possible to employ P. niveus to minimize the use of chemical insecticides.

Resumo Nasonovia ribisnigri é uma praga-chave do cultivo de alface (Lactuca sativa L.), exigindo métodos alternativos ao controle químico. Este trabalho registrou pela primeira vez, a ocorrência de Paecilomyces niveus como agente entomopatogenico do afídeo N. ribisnigri em Pinhais, Paraná, Brasil. Amostras de afídeos mumificados foram coletadas em plantas de alface. O fungo P. niveus (PaePR) foi isolado do corpo dos insetos e identificado por macro e micromorfologia e, confirmado por sequenciamento da região ITS do DNA ribossomal. A sequencia parcial de 528 bp (número de acesso HQ441751) apresentou alinhamento com 100% de identidade com sequencias de raças de Byssochlamys nivea. No bioensaio de patogenicidade P. niveus apresentou uma mortalidade média de N. ribisnigri de 74% até 120 horas da inoculação. O registro da presença de P. niveus como um patógeno natural de N. ribisnigri no Brasil sugere o potencial de utilização para minimizar o uso de inseticidas.

Variable Efficacy of the Proteinaceous Antifungal YvgO in Select Fruit Juices and Teas as a Complement with UV Methods of Food Protection.

Heat-resistant fungal spores present a processing challenge for beverages and fruit juices, as thermal and UV strategies are often inadequate in reducing heat-resistant fungal burdens to acceptable levels. While effective against pathogenic or invasive bacteria, germicidal UV light treatments also fail to achieve an appreciable reduction of heat-resistant fungal spores. As an alternative, the efficacy of the antifungal protein YvgO was examined across a selection of fruit juices and teas, as well as solid model matrices. Compared with its efficacy in analogous liquid matrices, the apparent efficacy of YvgO was diminished on acidified solid matrices due to a reduction in YvgO diffusion. Using an XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] tetrazolium dye cytotoxicity assay, the effective concentrations to reduce growth by 50% were elucidated in samples challenged with Byssochlamys fulva H25. The MICs were determined and ranged from 2 ppm in apple juice and acidified teas to approximately 3 to 12 ppm for lemonade and orange, white cranberry, blueberry, prune, cherry, and grape juices. Apple cider and nonacidified teas showed reduced efficacy, with MICs exceeding 100 ppm. Tannin-rich products readily removed YvgO from the product, impairing its efficacy. Adding bovine serum albumin as a competitive inhibitor effectively reversed the YvgO-tannin association and restored efficacy in black but not green tea matrices. When challenged with a 5-log CFU inoculum of B. fulva, the shelf lives of the products were extended for various times up to 28 days in a concentrationdependent manner. However, initial efficacy was not predictive of shelf life extension, as some products exhibited improved protection at just two- and fourfold concentrations above the MIC, while others only exhibited long-term stability when concentrations exceeded 20 times the MIC. As such, YvgO may be an attractive alternative to currently available protection strategies and will provide needed diversity for natural food protectants.

Posaconazole salvage treatment for invasive fungal infection.

Invasive fungal infection (IFI) is an important cause of morbidity and mortality. Posaconazole is a second generation triazole with a broad spectrum, and it may be suitable for salvage antifungal treatment although posaconazole is not usually considered to be as first-line antifungal therapy for IFI. The purpose of this study was to assess the utility of posaconazole salvage treatment for IFI. We conducted a retrospective review of patients with salvage antifungal treatment with posaconazole for IFI at our institution between December 2007 and July 2012. A total of ten patients received posaconazole salvage IFI. Etiology of IFI was consisting of mucormycosis (four patients), Paecilomyces variotii (one patient), and unspecified IFI etiology (five patients). Causes of posaconazole treatment were following; intolerance of previous antifungal therapy in five patients, refractory IFI on previous antifungal therapy in four patients, and both intolerance of previous antifungal therapy and refractory IFI on previous antifungal therapy in one patient. Duration of posaconazole salvage treatment ranged from 15 to 355 days with median 47 days. The overall successful posaconazole salvage treatment response rate was 80.0 % (8 of 10 patients). There were three patients who died during the study period. However, only one death was attributed to the progression of IFI. Two patients discontinued posaconazole due to adverse events. Posaconazole salvage treatment was effective antifungal therapy for IFI. Further studies are needed to define the optimal therapeutic strategy.

Isolation of novel benzo[a]anthracene-degrading microorganisms and continuous bioremediation in an expanded-bed bioreactor.

In the present work, several samples from lab waste containers polluted with polycyclic aromatic hydrocarbons (PAHs) and heavy metals were investigated as potential sources of PAH-degrading microorganisms. After isolating, two fungal strains were selected as the best degrading microorganisms. Genetic identification by sequencing was carried out and they were identified as Trichoderma longibrachiatum and Byssochlamys spectabilis. Their degradation ability was determined in liquid cultures with 100 µM of benzo[a]anthracene. T. longibrachiatum cultures showed highest degradation values (around 97%) after 9 days, furthermore in a second batch the time was reduced to 6 days. To analyse the viability of industrial application, a continuous treatment in an expanded-bed bioreactor was developed operating at different residence times with T. longibrachiatum immobilised on cubes of nylon sponge. It is noticeable that the bioreactor working in continuous mode was able to operate without operational problems and attaining high degradation levels depending on the residence time.

A rapid method for identifying Byssochlamys and Hamigera.

Heat-resistant fungi, genera Byssochlamys, Talaromyces, Neosartorya, and Hamigera, contribute significantly to the spoilage of heat-processed acidic foods, due to the formation of heat-resistant ascospores. Here, we first evaluated the differences in the beta-tubulin gene between Byssochlamys and Hamigera and developed specific primers to identify the Byssochlamys species fulva, nivea, and spectabilis, and Hamigera. Using primers designed for B. fulva and B. nivea (B1F/1R), specific PCR products were detected for B. fulva and B. nivea, as well as B. langunculariae and B. zollerniae, two closely related species. Similarly, the Pae4F/4R-1 and H2F/2R primers produced specific PCR products for B. spectabilis and Hamigera, respectively. Using these three primer sets, strains involved in acidic food spoilage and environmental contamination were not detected. The detection limits of all primer sets were 1 ng of DNA by PCR and 10 pg of DNA by nested PCR. Each PCR assay was specific, even if the sample was contaminated 1,000-fold by other fungal DNA. Thus, this method has proved to possess an extremely high degree of specificity.