Identification of cultured isolates of clinically important yeast species using fluorescent fragment length analysis of the amplified internally transcribed rRNA spacer 2 region

BACKGROUND: The number of patients with yeast infection has increased during the last years. Also the variety of species of clinical importance has increased. Correct species identification is often important for efficient therapy, but is currently mostly based on phenotypic features and is sometimes time-consuming and depends largely on the expertise of technicians. Therefore, we evaluated the feasibility of PCR-based amplification of the internally transcribed spacer region 2 (ITS2), followed by fragment size analysis on the ABI Prism 310 for the identification of clinically important yeasts. RESULTS: A rapid DNA-extraction method, based on simple boiling-freezing was introduced. Of the 26 species tested, 22 could be identified unambiguously by scoring the length of the ITS2-region. No distinction could be made between the species Trichosporon asteroides and T. inkin or between T. mucoides and T. ovoides. The two varieties of Cryptococcus neoformans (var. neoformans and var. gattii) could be differentiated from each other due to a one bp length difference of the ITS2 fragment. The three Cryptococcus laurentii isolates were split into two groups according to their ITS2-fragment lengths, in correspondence with the phylogenetic groups described previously. Since the obtained fragment lengths compare well to those described previously and could be exchanged between two laboratories, an internationally usable library of ITS2 fragment lengths can be constructed. CONCLUSIONS: The existing ITS2 size based library enables identification of most of the clinically important yeast species within 6 hours starting from a single colony and can be easily updated when new species are described. Data can be exchanged between laboratories

Cryptococcus neoformans(San Felice) Vuillemin 1894 et l'épidémiologie de la cryptococcose

Doctorat en Sciencesinfo:eu-repo/semantics/nonPublishe

Screening of strains of the Candida parapsilosis group of the BCCM/IHEM collection by MALDI-TOF MS

One hundred sixty-three strains stored as Candida parapsilosis in the BCCM/IHEM collection were reidentified based on internal transcribed spacer sequencing: 92% were identified as true C. parapsilosis, while 4.3% and 3% belonged to the closely related species C. metapsilosis and C. orthopsilosis, respectively, providing important epidemiologic information. Furthermore, we showed that matrix-assisted laser desorption ionisation time-of-flight mass spectrometry is a fast method that can discriminate between these species. © 2011 Elsevier Inc

Erfahrungen mit BAY b 5097

Die antimykotisdie Wirkung von BAY b 5097 wurde in vitro und in vivo untersucht. In vitro liegt die MIC 14 (minimale Hemmkonzentration nach 14tägiger Inkubation) nach der Röhrchen‐Verdünnungsmethode für Coccidioides immitis (4 Stämme), Clado‐sporium trichoides (1 Stamm), C. carrionii (1 Stamm), Phialophora compacta (1 Stamm), P. jeanselmei (1 Stamm), P. pedrosoi (1 Stamm) und Histoplasma duboisii (1 Stamm) zwischen 1 und 8 mcg pro ml. Für Cryptococcus neoformans (20 Stämme) liegen sie zwischen 5 und mehr als 10 mcg/ml. Die MIC 14 für vier Stämme Sporothrix schenckii liegt über 10 mcg/ml. Für Basidiobolus meristosporus (2 Stämme) liegt sie über 100 mcg/ml, für B. ranarum beträgt sie 1 mcg/ml für einen Stamm und über 100 meg für einen anderen Stamm. Die Versuche in vivo wurden mit Albinomäusen durchgeführt, die 7 Tage lang täglich 150 mg/kg BAY b 5097 erhielten. Bei der experimentellen Sporotrichose wich die Mortalitätskurve für die Versuchstiere von der Kurve für die Kontrolltiere ab, was einer gewissen Wirksamkeit von BAY b 5097 zuzuschreiben sein dürfte. Eine günstige therapeutische Wirkung von BAY b 5097 kam bei experimenteller Cocci‐dioidomykose in einer geringeren Frequenz bestimmter autopsisch festgestellter Schädi‐gungen zur Geltung. Bei experimenteller Cryptococcose war keine günstige Wirkung nachzuweisen. Bei Basidiolobomykose war eine gewisse Differenz zu erkennen, die in umfangreicheren Versuchen nachzuprüfen wäre. The antifungal activity of Bay b 5097 has been investigated in vitro and in vivo. The minimal inhibitory concentration after 14 days (MIC 14) in dilution tests for Coccidioides immitis (4 strains), Cladosporium trichoides (1 strain), C. carrionii (1 strain), Phialophora compacta (1 strain), P. jeanselmii (1 strain), P. pedrosoi (1 strain) and Histoplasma duboisii (1 strain) lies between 1 to 8 mcg per ml. The MIC 14 for Cryptococcus neoformans (20 strains) varies from 5 to 10 mcg/ml. For Sporothrix schenckii (4 strains) the MIC 14 is higher than 10 mcg/ml. Basidiobolus meristosporus (2 strains) shows a MIC 14 over 100 mcg/ml; for one strain of B. ranarum the MIC 14 is 1 mcg/ml, for another strain over 100 mcg/ml. In the “in vivo studies” white mice where orally treated with 150 mcg/kg Bay b 5097 for 7 days. In experimental sporotrichosis the antifungal activity is apparent only when the mortality curves of treated and control groups are compared. The therapeutic effect of Bay b 5097 in experimental coccidioidomycosis is apparent when the number of lesions and their extent at necropsy in treated and control animals are compared. No therapeutic effect could be detected in experimental cryptococcosis. The results obtained in experimental basidiobolomycosis need further investigations. 1975 Blackwell Verlag GmbHSCOPUS: ar.jinfo:eu-repo/semantics/publishe