An overview of COVID-19 related to fungal infections: what do we know after the first year of pandemic?

In 2019, severe acute respiratory syndrome caused by CoV-2 virus became a pandemic worldwide, being the fast spread of the disease due to the movement of infected people from one country to another, from one continent to another, or within the same country. Associated comorbidities are important factors that predispose to any fungal coinfections. Because of the importance of fungal infections in COVID-19 patients, the aim of this work was to collect data of the more encountered mycoses related to patients undergoing this disease. Aspergillosis was the first COVID-19-related fungal infection reported, being A. fumigatus the most frequent species for CAPA. Other fungal infections related include mainly candidiasis and mucormycosis, being Rhizopus spp. the more prevalent species found. Influenza-associated pulmonary aspergillosis is well documented; thus, similar complications are expected in severe forms of COVID-19 pneumonia. Therefore, in patients with COVID-19, it is important to take special attention to the surveillance and suspicion of fungal coinfections that might worsen the patient's prognosis.

Design of Affinity Chromatography Peptide Ligands Through Combinatorial Peptide Library Screening.

In this chapter, a protocol to design affinity chromatography matrices with short peptide ligands immobilized for protein purification is described. The first step consists of the synthesis of a combinatorial peptide library on the hydroxymethylbenzoyl (HMBA)-ChemMatrix resin by the divide-couple-recombine (DCR) method using the Fmoc chemistry. Next, the library is screened with the protein of interest labeled with a fluorescent dye or biotin. Subsequently, peptides contained on positive beads are identified by tandem matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS/MS), and those sequences showing greater consensus are synthesized in larger quantities and immobilized on chromatographic supports. Finally, target protein adsorption on peptide affinity matrices is evaluated through equilibrium adsorption isotherms and breakthrough curves.

Application of Z-sinapinic matrix in peptide MALDI-MS analysis.

Since introduction of sinapinic acid (SA) and α-cyano-4-hydroxycinnamic acid as matrices, successful application of matrix-assisted laser desorption/ionization mass spectrometry started for protein/polypeptides. Both show some limitations in short peptide analysis because matrix clusters are quite abundant. Cinnamics currently used are E-cinnamics. Here, Z-SA as matrix for peptides is studied and compared with E-SA and α-cyano-4-hydroxycinnamic acid. Minor number of clusters is always observed in the low m/z region allowing the detection of short peptides. The results here described show that this novel matrix is a tool of choice for direct, rapid and sensitive detection of hydrophilic and hydrophobic peptides. Copyright © 2017 John Wiley & Sons, Ltd.