A Case of Histoplasmosis Detected Through Bone Marrow Analysis.

Histoplasmosis is an endemic infection caused by Histoplasma capsulatum, leading to a broad spectrum of disease from asymptomatic to severe disseminated disease. To diagnose Histoplasmosis, culture remains the gold standard for the laboratory diagnosis; however, this fungus grows slowly, taking a long time 2 to 3 weeks or may take up to 8 weeks. Therefore, some other methods such as bone marrow examination play an essential role in rapid identification and early diagnosis, especially in cases of severe disseminated disease. In this case, we report a 55-year-old man with a 1-year history of gout, self-medicating (including Medrol) who was admitted to the hospital because of persistent fever and swelling of his left arm. About laboratory investigation, there was a bicytopenia (RBC and PLT), blood and pus cultures many times were negative. On the slide of the bone marrow specimen, images of yeast suspected of Histoplasma capsulatum were observed. Therefore, the patient was treated with antifungal medication, and the culture was repeated with prolonged follow-up time and positive results with H. capsulatum after 16 days. In conclusion, bone marrow test plays a significant role in the diagnosis of some fungal infections, which can contribute to an early diagnosis, especially in cases of culture and serological tests are not available or cannot be performed. Patients who present with fever and bicytopenia or pancytopenia should be performed early bone marrow test, which can support the earlier diagnosis to have appropriate treatment.

Establishment of a new and efficient Agrobacterium-mediated transformation system in the nematicidal fungus Purpureocillium lilacinum.

Purpureocillium lilacinum (formerly Paecilomyces lilacinus) is widely commercialized for controlling plant-parasitic nematodes and represents a potential cell factory for enzyme production. This nematicidal fungus is intrinsically resistant to common antifungal agents used for genetic transformation. Therefore, molecular investigations in P. lilacinum are still limited so far. In the present study, we have established a new Agrobacterium tumefaciens-mediated transformation (ATMT) system in P. lilacinum based on the uridine/uracil auxotrophic mechanism. Here, uridine/uracil auxotrophic mutants were simply generated via UV irradiation instead of a complicated genetic approach for the pyrG gene deletion. A stable uridine/uracil auxotrophic mutant was then selected as a recipient for fungal transformation. We further indicated that the pyrG gene from Aspergillus niger can be used as a selectable marker for genetic transformation of P. lilacinum. Under optimized conditions for ATMT, the transformation efficiency reached 2873 ± 224 transformants per 106 spores. Using the constructed ATMT system, we succeeded in expressing the DsRed reporter gene in P. lilacinum. Additionally, we have identified a very promising mutant for chitinase production from a collection of T-DNA insertion transformants. This mutant possesses a special phenotype of hyper-branching mycelium and produces more conidia in comparison to the wild strain. Conclusively, our ATMT system can be exploited for overexpression of target genes or for T-DNA insertion mutagenesis in the agriculturally important fungus P. lilacinum. The genetic approach in the present work may also be applied for developing similar ATMT systems in other fungi, especially for fungi that their genome databases are currently not available.

New insight into microbial diversity and functions in traditional Vietnamese alcoholic fermentation.

The roles of microorganisms in traditional alcoholic fermentation are often assumed based on abundance in the starter and activity in pure culture. There is a serious lack of hard evidence on the behavior and activity of individual microbial species during the actual fermentation process. In this study, microbial succession and metabolite changes during 7days of traditional Vietnamese alcoholic fermentation were monitored. Special attention was devoted to starch degradation. In total, 22 microbial species, including 6 species of filamentous fungi (Rhizopus microsporus, Rhizopus arrhizus, Mucor indicus, Mucor circinelloides, Cunninghamella elegans, Aspergillus niger), 1 yeast-like fungus (Saccharomycopsis fibuligera), 7 yeasts (Saccharomyces cerevisiae, Clavispora lusitaniae, Wickerhamomyces anomalus, Lindnera fabianii, Pichia kudriavzevii, Candida rugosa, Candida tropicalis), and 8 bacteria (Stenotrophomonas maltophilia, Lactobacillus brevis, Lactobacillus helveticus, Acinetobacter baumannii, Staphylococcus hominis, Bacillus megaterium, Enterobacter asburiae, Pediococcus pentosaceus) were identified. Despite the presence of a complex microbiota in the starter, the fermentation process is consistent and involves a limited number of functional species. Rapid change in microbial composition of fermentation mash was observed and it was correlated with ethanol content. Microbial biomass reached maximum during first 2days of solid state fermentation. Acidification of the medium took place in day 1, starch degradation in days 2, 3, 4, and alcohol accumulation from day 3. Although Sm. fibuligera dominated by cell count amongst potential starch degraders, zymography indicated that it did not produce amylase in the fermentation mash. In mixed culture with Rhizopus, amylase production by Sm. fibuligera is regulated by the moisture content of the substrate. Rhizopus was identified as the main starch degrader and S. cerevisiae as the main ethanol producer. Bacterial load was high but unstable in species composition and dominated by acid producers. M. indicus, Sm. fibuligera, W. anomalus and bacteria were regarded as satellite microorganisms. Their possible influence on organoleptic quality of fermentation product was discussed.