[Invasive fungal infections in immunocompromised patients with focus on aspergillosis and its causative agents]. / Invazivní mykatické infekce u imunokompromitovaných nemocných se zamerením na aspergilózu a její puvodce.

Invasive fungal diseases (IFD) are a life-threatening infectious complications in immunocompromised patients and are associated with high rate of morbidity and mortality. The most common invasive mycosis in patients who underwent an allogeneic hematopoietic stem cell transplantation is invasive aspergilosis (IA), most frequently caused by the clinically dominant species Aspergillus fumigatus and, rarely, also by Aspergillus flavus, Aspergillus terreus and Aspergillus niger. In recent years, other related Aspergillus species were also reported to cause IFD, phenotypically similar to A. fumigatus and moreover, frequently exhibiting resistance towards various antifungals. For example, it is Aspergillus lentulus, Aspergillus viridinutans, Neosartoya fischeri, etc. Classical microbiological methods such as direct microscopy or culture are usually used for the identification of Aspergillus species. The application of PCR-based molecular techniques and monitoring of secondary metabolites production enable detection and identification of species, which are not distinguishable solely by their morphology. PCR methods are also useful for molecular strain typing of aspergilli and can reveal the genetic diversity of isolates.

[Detection and identification of filamentous fungi causing mycoses using molecular genetic methods]. / Detekce a identifikace puvodcu mykotických infekcí zpusobených vlaknitými houbami pomocí metod molekulární genetiky.

Methods of molecular genetics offer rapid and sensitive detection and identification of fungal pathogens. The currently used methods are based mainly on PCR. With regard to the ubiquitous presence of fungi, it is important to prevent contamination during the whole process, from sampling to laboratory analyses. Molecular genetic methods are not included among the EORTC/MSG criteria used for the diagnosis of invasive fungal diseases since interlaboratory standardization is still missing. Another reason is the use of different target genes for PCR. ITS sequences from rDNA clusters are recommended for DNA barcoding of fungi. The use of DNA sequencing for identification of fungi in clinical samples has certain limitations and interpretation of results could be problematic in some cases. DNA sequences are searched and compared in public databases on the Internet, the best known of them being the GenBank. However, more reliable data for identification of fungi are offered by specialized mycological databases.

[Role of PCR detection and quantification of herpes viruses in bronchoalveolar lavage of immunocompromised patients]. / Význam PCR detekce a kvantifikace herpetických viru v bronchoalveolární lavázi imunokompromitovaných pacientu.

Herpes virus infections represent common complications associated with respiratory tract involvement which may result in pneumonia development in immunocompromised patients. The analysis of bronchoalveolar lavage (BAL) fluid obtained from the lower respiratory tract may contribute to detection of aetiological agents of the disease. The routine use of quantitative molecular methods enables the discrimination between acute infection and viral reactivation with asymptomatic virus shedding. The aim of this review is to evaluate the contribution of BAL viral load monitoring in high-risk patients and to determine the cut-off of viral load leading to progression to herpes virus pneumonia.

Rapid detection and identification of mucormycetes from culture and tissue samples by use of high-resolution melt analysis.

We present a method for rapid and simple detection of clinically relevant mucormycetes of the Mucorales order in cultures and clinical samples. This seminested real-time PCR uses mucormycete-specific primers and is followed by species identification using high-resolution melt (HRM) analysis. The method is highly suitable for routine clinical diagnostics.