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Abstract Background Acinetobacter baumannii and species within the Burkholderia cepacia complex (BCC) are significant opportunistic bacterial pathogens of humans. These species exhibit a high degree of antibiotic resistance, and some clinical isolates are resistant to all currently available antimicrobial drugs used for treatment. Thus, new drugs are needed to treat infections by these species. Mushrooms could be a potential source for new drugs to treat A. baumannii and BCC infections. Methods The aim of this study was to screen a library of crude extracts from 330 wild mushrooms by disk diffusion assays for antibacterial activity against A. baumannii and Burkholderia cepacia in the hope of identifying a novel natural drug that could be used to treat infections caused by these species. Once positive hits were identified, the extracts were subjected to bioassay-guided separations to isolate and identify the active drug molecules. MICs were performed to gauge the in vitro activity of the purified compounds. Results Only three crude extracts (0.9%) had activity against A. baumannii and B. cepacia. Compounds from two of these extracts had MICs greater than 128 μg/ml, and further analyses were not performed. From the third extract, prepared from Leucopaxillus albissimus, 2-aminoquinoline (2-AQ) was isolated. This compound exhibited a modest MIC in vitro against strains from nine different BCC species, including multi-drug resistant clinical isolates (MIC = 8-64 μg/ml), and a weak MIC (128 μg/ml) against A baumannii. The IC50 against a murine monocyte line was 1.5 mg/ml. Conclusion The small number of positive hits in this study suggests that finding a new drug from mushrooms to treat Gram-negative bacterial infections may be difficult. Although 2-AQ was identified in one mushroom, and it was shown to inhibit the growth of multi-drug resistant BCC isolates, the relatively high MICs (8-128 μg/ml) for both A. baumannii and BCC strains suggests that 2-AQ is not suitable for further drug development in its current form.

Arbuscular mycorrhizal fungi (AMF) have numerous effects on temperate grassland ecosystems, but prairie restorations are frequently located in sites with depauperate AMF communities. In this greenhouse study, four native species ( Schizachyrium scoparium, Elymus canadensis, Monarda punctata, and Aster ericoides) and an invasive grass (Bromus inermis) were grown in unsterilized field soils and treated with two types of commercial AMF inoculum. Inocula were applied at one and two times the manufacturers' suggested rate. Soil was collected from a meadow enrolled in the Conservation Reserve Program (CRP), and from an active agricultural field. Inoculum addition had no effect on biomass or percent colonization by AMF for any grass species, regardless of soil type. Inoculum type significantly affected Aster biomass and percent colonization, although pairwise comparisons of treated individuals and controls were not significant. The overall lack of effectiveness of the commercial inocula may reflect the small number of propagules added, even when used at twice the recommended rate. Higher rates of fungal colonization in all three grasses and increased biomass in the native grasses were observed in individuals grown in the CRP soil. Plants were also colonized by dark septate endophytic fungi; for Schizachyrium, endophyte colonization was significantly greater in tilled than CRP soil. Our results indicate that an existing soil fungal community promotes colonization by AMF more than the addition of commercial inocula, and that soil characteristics associated with land use history significantly affect the growth of native species in a restoration setting. [ABSTRACT FROM AUTHOR]

Background: Acinetobacter baumannii and species within the Burkholderia cepacia complex (BCC) are significant opportunistic bacterial pathogens of humans. These species exhibit a high degree of antibiotic resistance, and some clinical isolates are resistant to all currently available antimicrobial drugs used for treatment. Thus, new drugs are needed to treat infections by these species. Mushrooms could be a potential source for new drugs to treat A. baumannii and BCC infections. Methods: The aim of this study was to screen a library of crude extracts from 330 wild mushrooms by disk diffusion assays for antibacterial activity against A. baumannii and Burkholderia cepacia in the hope of identifying a novel natural drug that could be used to treat infections caused by these species. Once positive hits were identified, the extracts were subjected to bioassay-guided separations to isolate and identify the active drug molecules. MICs were performed to gauge the in vitro activity of the purified compounds. Results: Only three crude extracts (0.9%) had activity against A. baumannii and B. cepacia. Compounds from two of these extracts had MICs greater than 128 µg/ml, and further analyses were not performed. From the third extract, prepared from Leucopaxillus albissimus, 2-aminoquinoline (2-AQ) was isolated. This compound exhibited a modest MIC in vitro against strains from nine different BCC species, including multi-drug resistant clinical isolates (MIC = 8-64 µg/ml), and a weak MIC (128 µg/ml) against A baumannii. The IC50 against a murine monocyte line was 1.5 mg/ ml. Conclusion: The small number of positive hits in this study suggests that finding a new drug from mushrooms to treat Gram-negative bacterial infections may be difficult. Although 2-AQ was identified in one mushroom, and it was shown to inhibit the growth of multi-drug resistant BCC isolates, the relatively high MICs (8-128 µg/ml) for both A. baumannii and BCC strains suggests that 2-AQ is not suitable for further drug development in its current form. [ABSTRACT FROM AUTHOR]

Abstract: The association of fungus with plant leaves and roots is ubiquitous. While many of these occurrences are considered to be pathogenic, mycorrhizzal fungal associations with roots are essential for plant growth. Despite the common knowledge of such relationships in plant science, with a few exceptions, the fungus/leaf/root/stem association as the macerals funginite, cutinite, and suberinite in coals has not been extensively studied. In this work, examples of funginite associations with cutinite and suberinite are discussed. [ABSTRACT FROM AUTHOR]