http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Mon, 03 Jun 2013 08:01:35 +0000 http://www.hindawi.com/journals/mycology/2013/753692/ Fungal chitosan was extracted from Aspergillus niger mycelia. The produced chitosan was characterized with deacetylation degree of 89.2%, a molecular weight of 2.4 × 104 Da, and 96.0% solubility in 1% acetic acid solution. The antibacterial activity of fungal chitosan was evaluated against two foodborne pathogens, that is, Salmonella typhimurium and Staphylococcus aureus, using the established antibacterial assays, for example, zone of growth inhibition and agar plat count tests, and using 2,3,5,-triphenyltetrazolium chloride (TTC) as chromogenic marker for qualitative and quantitative determining of antibacterial potentiality. The TTC (0.5% w/v) was added, at concentration of 10%, to cultured broth, containing chitosan with different concentrations then the formed formazan was separated. The formation of red formazan could be considered as a qualitative indication for antibacterial activity, whereas the measurement of color intensity for the resuspended red formazan, using spectrophotometer at 480 nm, provided a quantitative evidence for the strength of the used antibacterial agent. Regarding the rapidity, technical simplicity, and cost-effectiveness, TTC assay could be recommended as an efficient alternative method for qualitative and quantitative determination of chitosan antibacterial activity and could be suggested for general evaluation of antibacterial agents. Shaaban H. Moussa, Ahmed A. Tayel, Ahmed A. Al-Hassan, and A. Farouk Copyright © 2013 Shaaban H. Moussa et al. All rights reserved. Tue, 28 May 2013 08:37:07 +0000 http://www.hindawi.com/journals/mycology/2013/781914/ Endophytes are fungi associated with plants without causing symptoms, and they are quite diverse and have enormous potential for production of important secondary metabolites for the pharmaceutical industry. In this study, we report for the first time fungi (both endophytes and saprobes) from Antidesma madagascariense, a medicinal plant in Mauritius, in view of identifying potential candidates for screening of fungi for pharmaceutical importance. In addition the phylogenetic placement of fungi recovered from leaves samples was investigated based on rDNA sequence analysis. Most commonly isolated fungi were related to Aspergillus, Guignardia, Fusarium, Penicillium, Pestalotiopsis, and Trichoderma. Phylogenetic analyses revealed that fungi recovered belong to 5 different fungal lineages (Hypocreaceae, Trichocomaceae, Nectriaceae, Xylariaceae, and Botryosphaeriaceae). DNA data from the ITS regions were reliable in classification of all recovered isolates up to genus level, but identification to an exact species name was not possible at this stage. Despite criticisms pertaining to the use of ITS sequence data in molecular systematics, our approach here provides an opportunity to justify the reliability of ITS sequence data for possible identification and discovering of evolutionary scenarios among isolates that do not sporulate under cultural conditions. Rajesh Jeewon, Jayesh Ittoo, Devendra Mahadeb, Yasmina Jaufeerally-Fakim, Hong-Kai Wang, and Ai-Rong Liu Copyright © 2013 Rajesh Jeewon et al. All rights reserved. Wed, 15 May 2013 14:16:24 +0000 http://www.hindawi.com/journals/mycology/2013/324570/ Five commercial composts were evaluated to suppress the root-rot pathogens (Fusarium solani (Mart.) App. and Wr, Pythium ultimum Trow, Rhizoctonia solani Kuhn, and Sclerotium rolfsii Sacc.) of cucumber plants under in vitro and greenhouse conditions. In vitro tests showed that all tested unautoclaved and unfiltrated composts water extracts (CWEs) had inhibitor effect against pathogenic fungi, compared to autoclaved and filtrated ones. Also, the inhibitor effects of 40 bacteria and 15 fungi isolated from composts were tested against the mycelial growth of cucumber root-rot pathogens. Twenty two bacteria and twelve fungal isolates had antagonistic effect against root-rot pathogens. The antagonistic fungal isolates were identified as 6 isolates belong to the genus Aspergillus spp., 5 isolates belong to the genus Penicillium spp. and one isolate belong to the genus Chaetomium spp. Under greenhouse conditions, the obtained results in pot experiment using artificial infested soil with cucumber root-rot pathogens showed that the compost amended soil reduced the percentage of disease incidence, pathogenic fungi population, and improved the cucumber vegetative parameters as shoot length, root length, fresh weight, and dry weight. These results suggested that composts are consequently considered as control measure against cucumber root-rot pathogens. Kamel Kamal Sabet, Magdy Mohamed Saber, Mohamed Adel-Aziz El-Naggar, Nehal Samy El-Mougy, Hatem Mohamed El-Deeb, and Ibrahim El-Saied El-Shahawy Copyright © 2013 Kamel Kamal Sabet et al. All rights reserved. Thu, 09 May 2013 15:14:30 +0000 http://www.hindawi.com/journals/mycology/2013/970216/ Four species of Umbelopsis newly found in China, that is, U. angularis, U. dimorpha, U. nana, and U. versiformis, are reported in this paper. Descriptions and illustrations are provided for each of them. Ya-ning Wang, Xiao-yong Liu, and Ru-yong Zheng Copyright © 2013 Ya-ning Wang et al. All rights reserved. Sun, 17 Mar 2013 09:29:51 +0000 http://www.hindawi.com/journals/mycology/2013/413874/ Candida is the second leading cause of sepsis related death in the neonatal intensive care unit (NICU). Using the C. parapsilosis paradigm, the endogenous and exogenous routes of infection were simulated in order to enhance prevention among neonates at highest risk. A deterministic model was constructed with transmission parameters calculated from the basic reproductive number (), derived from the mean serial interval from two published outbreaks. Uncertainty and sensitivity analyses were performed via Latin hypercube sampling. Prevention measure effects were ascertained by incorporating percent coverage and efficacies into the existing model. The colonized and infected neonatal prevalence peaked at 17.4% and 39.4%, respectively, and reduction was achieved by compartmental replacement with susceptibles. Containment of greater than 60% of the cohort had minimal effect on the effective reproductive number () unless hand hygiene compliance dropped below 40% at a fixed ratio of nurses to neonates. Antifungal prophylaxis in combination with hand hygiene and cohorting extinguished an outbreak 14 days sooner than baseline. The critical proportion () requiring prophylaxis in order to stop an outbreak increases, as rises, and the prophylaxis efficacies decrease. Internal and external sources of Candida lead to invasive disease in neonates differentially. Optimal prevention is dependent upon understanding the dynamics of this disease process under diverse circumstances. Anil A. Panackal Copyright © 2013 Anil A. Panackal. All rights reserved. Mon, 04 Mar 2013 16:20:38 +0000 http://www.hindawi.com/journals/mycology/2013/152941/ Filamentous fungi have been constantly recovered from diverse aquatic environments including drinking water distribution systems. Although most of the works are focused on the study of planktonic form, recent researches have shown that fungi develop biofilm within these systems. In this study, Aspergillus sp. (section Nigri), Aspergillus sp. (section Flavi), Alternaria sp., Botrytis sp., Cladosporium sp., and Penicillium sp. recovered from water biofilms were used to evaluate their capability to grow as biofilms under laboratorial conditions. Morphological and physiological characteristics were analysed using image analysis and biomass and cell activity estimation. All six isolates were able to form biofilm, though different patterns of development were observed. Only Alternaria sp. formed biofilm in water over 24 h of analysis. MEB was shown to be the best culture media for biofilm formation. A direct correlation between biomass and cell activity was not observed, but biomass values and morphological parameters, that is, monolayer and EPS production, were directly correlated. Thus, the results present here highlight the capability of fungi to form biofilms and the emergent necessity to standardize methods for further research in this area. Virgínia M. Siqueira and Nelson Lima Copyright © 2013 Virgínia M. Siqueira and Nelson Lima. All rights reserved.