Cryptococcus neoformans and Cryptococcus gattii Species Complex Isolates on the Slopes of Mount Etna, SICILY, Italy

This study investigated the presence of Cryptococcus neoformans and Cryptococcus gattii species complex isolates on olive trees growing in the Eastern part of Sicily (Italy) characterized by the presence of the volcano Etna and the ability of these fungal pathogens to sexually reproduce on medium containing volcanic soil. Samples from 124 olive trees were collected from 14 different sites around Mount Etna. Eighteen trees (14.5%) resulted colonized by C. neoformans VNI-\u3b1A isolates, one (0.8%) by VNIV-\u3b1D isolates, and two (1.6%) by C. gattii VGI-\u3b1B isolates. The ability of environmental and reference strains belonging to VNI, VNIV, and VGI molecular types to sexually reproduce on a medium containing volcanic soil was also tested. VNI and VNIV strains were able to produce filaments and basiodiospores more vigorously than on the control medium, whereas VGI strains were not fertile. In conclusion, the present study identified which C. neoformans and C. gattii species complex genotypes are circulating in Eastern Sicily and confirmed the ecological role of olive trees as environmental reservoir of these pathogens. It also showed that Cryptococcus is able to colonize and sexually reproduce in inhospitable environments such as the slopes of a volcano

Azole-resistant Aspergillus fumigatus in the environment of Northern Italy, May 2011 to June 2012

In recent years acquired azole resistance in Aspergillus fumigatus has been increasingly reported and a dominant mechanism of resistance (TR34/L98H) was found in clinical and environmental isolates.The aim of the present study was to investigate the prevalence of azole resistance in environmental A. fumigatus isolates collected in Northern Italy. A. fumigatus grew from 29 out of 47 soil samples analysed. Azole resistant isolates were detected in 12.7% of the soil samples and in 20.7% of the soil samples containing A. fumigatus. High minimal inhibitory concentrations of itraconazole, posaconazole and voriconazole were displayed by nine isolates from six different soil samples, namely apple orchard (1 sample), rose pot compost (2 samples), and cucurbit yields (3 samples). Seven out of nine resistant isolates harboured the same TR34/L98H mutation of cyp51A. These findings, together with the occurrence of resistant clinical isolates, suggest that azole resistance should be considered in primary patient care. suggest that azole resistance should be considered in primary patient care

Multi-Locus Next-Generation Sequence Typing of DNA Extracted From Pooled Colonies Detects Multiple Unrelated Candida albicans Strains in a Significant Proportion of Patient Samples

The yeast Candida albicans is an important opportunistic human pathogen. For C. albicans strain typing or drug susceptibility testing, a single colony recovered from a patient sample is normally used. This is insufficient when multiple strains are present at the site sampled. How often this is the case is unclear. Previous studies, confined to oral, vaginal and vulvar samples, have yielded conflicting results and have assessed too small a number of colonies per sample to reliably detect the presence of multiple strains. We developed a next-generation sequencing (NGS) modification of the highly discriminatory C. albicans MLST (multilocus sequence typing) method, 100+1 NGS-MLST, for detection and typing of multiple strains in clinical samples. In 100+1 NGS-MLST, DNA is extracted from a pool of colonies from a patient sample and also from one of the colonies. MLST amplicons from both DNA preparations are analyzed by high-throughput sequencing. Using base call frequencies, our bespoke DALMATIONS software determines the MLST type of the single colony. If base call frequency differences between pool and single colony indicate the presence of an additional strain, the differences are used to computationally infer the second MLST type without the need for MLST of additional individual colonies. In mixes of previously typed pairs of strains, 100+1 NGS-MLST reliably detected a second strain. Inferred MLST types of second strains were always more similar to their real MLST types than to those of any of 59 other isolates (22 of 31 inferred types were identical to the real type). Using 100+1 NGS-MLST we found that 7/60 human samples, including three superficial candidiasis samples, contained two unrelated strains. In addition, at least one sample contained two highly similar variants of the same strain. The probability of samples containing unrelated strains appears to differ considerably between body sites. Our findings indicate the need for wider surveys to determine if, for some types of samples, routine testing for the presence of multiple strains is warranted. 100+1 NGS-MLST is effective for this purpose

Multilocus microsatellite analysis of European and African Candida glabrata isolates

This study aimed to elucidate the genetic relatedness and epidemiology of 127 clinical and environmental Candida glabrata isolates from Europe and Africa using multilocus microsatellite analysis. Each isolate was first identified using phenotypic and molecular methods and subsequently, six unlinked microsatellite loci were analyzed using automated fluorescent genotyping. Genetic relationships were estimated using the minimum-spanning tree (MStree) method. Microsatellite analyses revealed the existence of 47 different genotypes. The fungal population showed an irregular distribution owing to the over-representation of genetically different infectious haplotypes. The most common genotype was MG-9, which was frequently found in both European and African isolates. In conclusion, the data reported here emphasize the role of specific C. glabrata genotypes in human infections for at least some decades and highlight the widespread distribution of some isolates, which seem to be more able to cause disease than others.This research was supported in part by the EU Mare Nostrum (EUMN-III Call) program of the European Union, grant agreement number 2011-4050/001-EMA2. Dr Sanae Rharmitt was the recipient of a scholarship (10 months) signed within the EUMN program for PhD students (F.S. 1.04.11.01 UORI) under the supervision of Prof Orazio Romeo.info:eu-repo/semantics/publishedVersio

Method-dependent epidemiological cutoff values (ECVs) for detection of triazole resistance in Candida and Aspergillus species for the SYO colorimetric broth and Etest agar diffusion methods

Although the Sensitrite Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method-agent-dependent): 11,171 Candida albicans, 215 C. dubliniensis, 4,418 C. glabrata species complex (SC), 157 C. (Meyerozyma) guilliermondii, 676 C. krusei (Pichia kudriavzevii), 298 C (Clavispora) lusitaniae, 911 and 3,691 C. parapsilosissensu stricto (SS) and C. parapsilosisSC, respectively, 36 C. metapsilosis, 110 C. orthopsilosis, 1,854 C. tropicalis, 244 Saccharomyces cerevisiae, 1,409 Aspergillus fumigatus, 389 A. flavus, 130 A. nidulans, 233 A. niger, and 302 A. terreus complexes. SYO/Etest MICs for 282 confirmed non-WT isolates were included: ERG11 (C. albicans), ERG11 and MRR1 (C. parapsilosis), cyp51A (A. fumigatus), and CDR2, CDR1 overexpression (C. albicans and C. glabrata, respectively). Interlaboratory modal agreement was superior by SYO for yeast spp., and by the Etest for Aspergillus spp. Distributions fulfilling CLSI criteria for ECV definition were pooled and we proposed SYO ECVs for S. cerevisiae, 9 yeast and 3 Aspergillus species, and Etest ECVs for 5 yeast and 4 Aspergillus species. The posaconazole SYO ECV of 0.06 \ub5g/ml for C. albicans and the Etest itraconazole ECV of 2 \ub5g/ml for A. fumigatus were the best predictors of non-WT isolates. These findings support the need for method-dependent ECVs, as overall, the SYO appears to perform better for susceptibility testing of yeast spp. and the Etest for Aspergillus spp. Further evaluations should be conducted with more Candida mutants

Candida colonization of respiratory tract: to treat or not to treat, will we ever get an answer?

n/

Phylogenomic analysis of a 55.1 kb 19-gene dataset resolves a monophyletic Fusarium that includes the Fusarium solani Species Complex

Scientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user¿s needs and established successful practice. In 2013, the Fusarium community voiced near unanimous support for a concept of Fusarium that represented a clade comprising all agriculturally and clinically important Fusarium species, including the F. solani species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus Fusarium into seven genera, including the FSSC described as members of the genus Neocosmospora, with subsequent justification in 2018 based on claims that the 2013 concept of Fusarium is polyphyletic. Here, we test this claim and provide a phylogeny based on exonic nucleotide sequences of 19 orthologous protein-coding genes that strongly support the monophyly of Fusarium including the FSSC. We reassert the practical and scientific argument in support of a genus Fusarium that includes the FSSC and several other basal lineages, consistent with the longstanding use of this name among plant pathologists, medical mycologists, quarantine officials, regulatory agencies, students, and researchers with a stake in its taxonomy. In recognition of this monophyly, 40 species described as genus Neocosmospora were recombined in genus Fusarium, and nine others were renamed Fusarium. Here the global Fusarium community voices strong support for the inclusion of the FSSC in Fusarium, as it remains the best scientific, nomenclatural, and practical taxonomic option availabl

Anche i funghi producono slime

I lieviti (Candida sp. in particolare) e i funghi filamentosi (Aspergilli) sono un\u2019importante fonte di infezione associata alla loro capacit\ue0 di formare biofilm sia su supporti naturali (mucose, articolazioni, ossa) sia su device (cateteri, valvole cardiache, protesi). Le infezioni da biofilm sono di difficile trattamento con antifungini. I meccanismi di formazione del biofilm sono estremamente complessi e ancora oggetto di numerosi studi