Two new aflatoxin producing species, and an overview of Aspergillus section Flavi

Aspergillus subgenus Circumdati section Flavi includes species with usually biseriate conidial heads, in shades of yellow-green to brown, and dark sclerotia. Several species assigned to this section are either important mycotoxin producers including aflatoxins, cyclopiazonic acid, ochratoxins and kojic acid, or are used in oriental food fermentation processes and as hosts for heterologous gene expression. A polyphasic approach was applied using morphological characters, extrolite data and partial calmodulin, β-tubulin and ITS sequences to examine the evolutionary relationships within this section. The data indicate that Aspergillus section Flavi involves 22 species, which can be grouped into seven clades. Two new species, A. pseudocaelatus sp. nov. and A. pseudonomius sp. nov. have been discovered, and can be distinguished from other species in this section based on sequence data and extrolite profiles. Aspergillus pseudocaelatus is represented by a single isolate collected from Arachis burkartii leaf in Argentina, is closely related to the non-aflatoxin producing A. caelatus, and produces aflatoxins B & G, cyclopiazonic acid and kojic acid, while A. pseudonomius was isolated from insects and soil in the USA. This species is related to A. nomius, and produces aflatoxin B1 (but not G-type aflatoxins), chrysogine and kojic acid. In order to prove the aflatoxin producing abilities of the isolates, phylogenetic analysis of three genes taking part in aflatoxin biosynthesis, including the transcriptional regulator aflR, norsolonic acid reductase and O-methyltransferase were also carried out. A detailed overview of the species accepted in Aspergillus section Flavi is presented

ATR-FTIR Spectroscopy Highlights the Problem of Distinguishing Between Exophiala dermatitidis and E-phaeomuriformis Using MALDI-TOF MS

WOS: 000369061400008PubMed ID: 26373644The present study compared two chemical-based methods, namely, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, to understand the misidentification of Exophiala dermatitidis and Exophiala phaeomuriformis. The study utilized 44 E. dermatitidis and 26 E. phaeomuriformis strains, which were partially treated with strong acids and bases for further evaluation. MALDI-TOF MS and ATR-FTIR spectroscopy data of the two Exophiala species were compared. Data groupings were observed for the chromic acid- and nitric acid-treated species when the black yeast sources were categorized as creosoted-oak sleepers, concrete sleepers, or dishwasher isolates. The MALDI-TOF MS data for the metalloenzyme-containing regions were consistent with the ATR-FTIR spectroscopy data. These results indicated that environmental isolates might contain metals not found in human isolates and might interfere with chemical-based identification methods. Therefore, MALDI-TOF MS reference libraries should be created for clinical strains and should exclude petroleum-associated environmental isolates

Evaluation of the BD Phoenix System for detection of Methicilin Resistance in Staphylococcus aureus Isolates in comparison to BD GeneOhm MRSA Assay

Background: In order to identify methicillin-resistant Staphylococcus aureus isolates quickly, automated and semiautomated systems, commercial media, and identification kits are widely used. The Phoenix system (BD, Sparks, MD, USA) has been available since 2004 in our laboratory. This study evaluated the reliability of the Phoenix system for the detection of methicillin resistance in Staphylococcus aureus isolates in comparison to BD GeneOhm MRSA assay (Becton Dickinson Diagnostics GeneOhm, CA, USA)

Disseminated Fusariosis Caused by Fusarium verticillioides in an Acute Lymphoblastic Leukemia Patient after Allogeneic Hematopoietic Stem Cell Transplantation▿

Fusarium species are saprophytic molds which cause disseminated or localized infections in humans. Disseminated Fusarium infection can cause significant morbidity and mortality in immunocompromised patients. We present a case of disseminated fusariosis caused by Fusarium verticillioides in a patient with acute lymphoblastic leukemia and successfully treated using both liposomal amphotericin B and voriconazole

Epidemiology of pertussis in adolescents and adults in Turkey

Two hundred and fourteen patients who had a cough illness lasting at least 2 weeks were studied to investigate Bordetella pertussis as a cause of prolonged cough in adolescents and adults. Medical history and nasopharyngeal swab specimens for culture and polymerase chain reaction (PCR) were obtained at presentation. Three (1.4%) patients were B. pertussis culture-positive; 15 (7%) were B. pertussis PCR-positive (including the culture-positive patients) and 11 (5.1%) were Bordetella spp. PCR-positive. Symptom combinations were significantly high both in patients with pertussis and patients with indeterminate results (P < 0.05). We conclude that B. pertussis should be considered among differential diagnoses of prolonged cough in adolescents and adults and PCR and culture should be used to detect these cases and facilitate public health response