Alternative sulphur metabolism in the fungal pathogen Candida parapsilosis.

Candida parapsilosis is an opportunistic fungal pathogen commonly isolated from the environment and associated with nosocomial infection outbreaks worldwide. We describe here the construction of a large collection of gene disruptions, greatly increasing the molecular tools available for probing gene function in C. parapsilosis.

Candida parapsilosis isolates carrying mutations outside FKS1 hotspot regions confer high echinocandin tolerance and facilitate the development of echinocandin resistance.

Candida parapsilosis is a significant cause of candidemia worldwide. Echinocandin-resistant (ECR) and echinocandin-tolerant (ECT) C. parapsilosis isolates have been reported in various countries but are rare.

A widespread inversion polymorphism conserved among Saccharomyces species is caused by recurrent homogenization of a sporulation gene family.

Saccharomyces genomes are highly collinear and show relatively little structural variation, both within and between species of this yeast genus. We investigated the only common inversion polymorphism known in S. cerevisiae, which affects a 24-kb 'flip/flop' region containing 15 genes near the centromere of chromosome XIV.

CRISPR-Cas9 Editing Induces Loss of Heterozygosity in the Pathogenic Yeast Candida parapsilosis.

Genetic manipulation is often used to study gene function. However, unplanned genome changes (including single nucleotide polymorphisms [SNPs], aneuploidy, and loss of heterozygosity [LOH]) can affect the phenotypic traits of the engineered strains. Here, we compared the effect of classical deletion methods (replacing target alleles with selectable markers by homologous recombination) with CRISPR-Cas9 editing in the diploid human-pathogenic yeast Candida parapsilosis.

Determinants of fluconazole resistance and echinocandin tolerance in isolates causing a large clonal candidemia outbreak among COVID-19 patients in a Brazilian ICU.

Patients presenting with severe COVID-19 are predisposed to acquire secondary fungal infections such as COVID-19-associated candidemia (CAC), which are associated with poor clinical outcomes despite antifungal treatment. The extreme burden imposed on clinical facilities during the COVID-19 pandemic has provided a permissive environment for the emergence of clonal outbreaks of multiple species, including and . Here we report the largest clonal CAC outbreak to date caused by fluconazole resistant (FLZR) and echinocandin tolerant (ECT) .

Plasmid-Based CRISPR-Cas9 Editing in Multiple Candida Species.

CRISPR-Cas9 technology radically changed the approach to genetic manipulation of both medically and industrially relevant Candida species, as attested by the ever-increasing number of applications to the study of pathogenesis, drug resistance, gene expression, and host pathogen interaction and drug discovery. Here, we describe the use of plasmid-based systems for high efficiency CRISPR-Cas9 gene editing into any strain of four non-albicans Candida species, namely, Candida parapsilosis, Candida orthopsilosis, Candida metapsilosis, and Candida tropicalis. The plasmids pCP-tRNA and pCT-tRNA contain all the elements necessary for expressing the CRISPR-Cas9 machinery, and they can be used in combination with a repair template for disrupting gene function by insertion of a premature stop codon or by gene deletion.

The yeast mating-type switching endonuclease HO is a domesticated member of an unorthodox homing genetic element family.

The mating-type switching endonuclease HO plays a central role in the natural life cycle of , but its evolutionary origin is unknown. is a recent addition to yeast genomes, present in only a few genera close to . Here we show that is structurally and phylogenetically related to a family of unorthodox homing genetic elements found in and yeasts.

The CRISPR toolbox in medical mycology: State of the art and perspectives.

Fungal pathogens represent a major human threat affecting more than a billion people worldwide. Invasive infections are on the rise, which is of considerable concern because they are accompanied by an escalation of antifungal resistance. Deciphering the mechanisms underlying virulence traits and drug resistance strongly relies on genetic manipulation techniques such as generating mutant strains carrying specific mutations, or gene deletions.

Correlating Genotype and Phenotype in the Asexual Yeast Implicates in Sensitivity to Caffeine.

is diploid asexual yeast that causes human disease. Most isolates arose from at least four separate hybridizations between related, but not identical, parents. Here, we used population genomics data to correlate genotypic and phenotypic variation in 28 isolates.

Precise genome editing using a CRISPR-Cas9 method highlights the role of CoERG11 amino acid substitutions in azole resistance in Candida orthopsilosis.

Background: Azoles are one of the main antifungal classes for the treatment of candidiasis. In the current context of emerging drug resistance, most studies have focused on Candida albicans, Candida glabrata or Candida auris but, so far, less is known about the underlying mechanisms of resistance in other species, including Candida orthopsilosis.

Objectives: We investigated azole resistance in a C.

Characterization of the Candida orthopsilosis agglutinin-like sequence (ALS) genes.

Agglutinin like sequence (Als) cell-wall proteins play a key role in adhesion and virulence of Candida species. Compared to the well-characterized Candida albicans ALS genes, little is known about ALS genes in the Candida parapsilosis species complex. Three incomplete ALS genes were identified in the genome sequence for Candida orthopsilosis strain 90-125 (GenBank assembly ASM31587v1): CORT0C04210 (named CoALS4210), CORT0C04220 (CoALS4220) and CORT0B00800 (CoALS800).

Plasmid-Based CRISPR-Cas9 Gene Editing in Multiple Species.

Many species that cause infection have diploid genomes and do not undergo classical meiosis. The application of clustered regularly interspaced short palindromic repeat-Cas9 (CRISPR-Cas9) gene editing systems has therefore greatly facilitated the generation of gene disruptions and the introduction of specific polymorphisms. However, CRISPR methods are not yet available for all species.

Bacteriophage Sb-1 enhances antibiotic activity against biofilm, degrades exopolysaccharide matrix and targets persisters of Staphylococcus aureus.

Most antibiotics have limited or no activity against bacterial biofilms, whereas bacteriophages can eradicate biofilms. We evaluated whether Staphylococcus aureus-specific bacteriophage Sb-1 could eradicate biofilm, both alone and in combination with different classes of antibiotics, degrade the extracellular matrix and target persister cells. Biofilm of methicillin-resistant S.

CORT0C04210 is required for Candida orthopsilosis adhesion to human buccal cells.

Candida orthopsilosis is a human fungal pathogen belonging to the Candida parapsilosis sensu lato species complex. C. orthopsilosis annotated genome harbors 3 putative agglutinin-like sequence (ALS) genes named CORT0B00800, CORT0C04210 and CORT0C04220.

TPP riboswitch-dependent regulation of an ancient thiamin transporter in Candida.

Riboswitches are non-coding RNA molecules that regulate gene expression by binding to specific ligands. They are primarily found in bacteria. However, one riboswitch type, the thiamin pyrophosphate (TPP) riboswitch, has also been described in some plants, marine protists and fungi.

Use of Amplification Fragment Length Polymorphism to Genotype Pseudomonas stutzeri Strains Following Exposure to Ultraviolet Light A.

Changes in ultraviolet light radiation can act as a selective force on the genetic and physiological traits of a microbial community. Two strains of the common soil bacterium Pseudomonas stutzeri, isolated from aquifer cores and from human spinal fluid were exposed to ultraviolet light. Amplification length polymorphism analysis (AFLP) was used to genotype this bacterial species and evaluate the effect of UVA-exposure on genomic DNA extracted from 18 survival colonies of the two strains compared to unexposed controls.

Characterization of carboxylate nanoparticle adhesion with the fungal pathogen Candida albicans.

Candida albicans is the lead fungal pathogen of nosocomial bloodstream infections worldwide and has mortality rates of 43%. Nanoparticles have been identified as a means to improve medical outcomes for Candida infections, enabling sample concentration, serving as contrast agents for in vivo imaging, and delivering therapeutics. However, little is known about how nanoparticles interact with the fungal cell wall.

Gene editing in clinical isolates of Candida parapsilosis using CRISPR/Cas9.

Candida parapsilosis is one of the most common causes of candidiasis, particularly in the very young and the very old. Studies of gene function are limited by the lack of a sexual cycle, the diploid genome, and a paucity of molecular tools. We describe here the development of a plasmid-based CRISPR-Cas9 system for gene editing in C.

Antimicrobial peptides for the control of biofilm formation.

Antimicrobial peptides (AMPs) are an abundant and varied group of molecules recognized as the most ancient components of the innate immune system. They are found in a wide group of organisms including bacteria, plants and animals as a defense mechanism against different kinds of infectious pathogens. Over the past two decades, a fast-growing number of AMPs have been identified/designed and their wide-spectrum antimicrobial activity has been deeply investigated.

Targeted gene disruption in Candida parapsilosis demonstrates a role for CPAR2_404800 in adhesion to a biotic surface and in a murine model of ascending urinary tract infection.

Candida parapsilosis is an emerging opportunistic pathogen, second in frequency only to C. albicans and commonly associated with both mucosal and systemic infections. Adhesion to biotic surfaces is a key step for the development of mycoses.

Pushing the Limits of MALDI-TOF Mass Spectrometry: Beyond Fungal Species Identification.

Matrix assisted laser desorption ionization time of flight (MALDI-TOF) is a powerful analytical tool that has revolutionized microbial identification. Routinely used for bacterial identification, MALDI-TOF has recently been applied to both yeast and filamentous fungi, confirming its pivotal role in the rapid and reliable diagnosis of infections. Subspecies-level identification holds an important role in epidemiological investigations aimed at tracing virulent or drug resistant clones.

Insights into the antimicrobial properties of hepcidins: advantages and drawbacks as potential therapeutic agents.

The increasing frequency of multi-drug resistant microorganisms has driven research into alternative therapeutic strategies. In this respect, natural antimicrobial peptides (AMPs) hold much promise as candidates for the development of novel antibiotics. However, AMPs have some intrinsic drawbacks, such as partial degradation by host proteases or inhibition by host body fluid composition, potential toxicity, and high production costs.