Detection of Mycobacterium bovis in Free-Ranging Sapajus nigritus, Argentina.

Mycobacterium bovis and Mycobacterium tuberculosis are the most relevant among pathogenic mycobacteria, both belonging to the M. tuberculosis complex (MTC). Samples of blood, liver, spleen, kidneys, lungs and caseous tubercles were collected from a free-ranging juvenile black capuchin monkey (Sapajus nigritus) showing non-specific signs of illness.

Antifungal susceptibility testing following the CLSI M27 document, along with the measurement of MFC/MIC ratio, could be the optimal approach to detect amphotericin B resistance in () . Susceptibility patterns of contemporary isolates of this species.

Antifungal susceptibility testing (AST) is crucial in clinical settings to guide appropriate therapy. Nevertheless, discrepancies between treatment response and some results still persist, particularly in detecting resistance to amphotericin B (AMB) in () . This study aimed to assess the susceptibility patterns of 48 recent isolates of to 9 antifungal agents and explore the feasibility of using a CLSI reference-based method to identify AMB resistance.

Black grain eumycetoma due to . Taxonomical update of previous agents of infections due to spp.

A black-grain eumycetoma due to in a kidney transplant recipient is presented. The isolate was identified by using the newly available NCBI's curated database (rRNA_typestrains/ITS_RefSeq_Fungi) and the NCBI's GenBank + EMBL + DDBI + PDB + RefSeq database. The isolate's antifungal susceptibility was evaluated.

Candida auris and some Candida parapsilosis strains exhibit similar characteristics on CHROMagarTMCandida Plus.

Candida auris is considered a public health problem due to its resistance and its tendency to cause nosocomial outbreaks. CHROMagarTMCandida Plus has recently been marketed as capable of presumptively identifying C. auris.

Functional characterization of monothiol and dithiol glutaredoxins from Leptospira interrogans.

Thiol redox proteins and low molecular mass thiols have essential functions in maintaining cellular redox balance in almost all living organisms. In the pathogenic bacterium Leptospira interrogans, several redox components have been described, namely, typical 2-Cys peroxiredoxin, a functional thioredoxin system, glutathione synthesis pathway, and methionine sulfoxide reductases. However, until now, information about proteins linked to GSH metabolism has not been reported in this pathogen.

SARS-CoV-2 and Aspergillus section Fumigati coinfection in an immunocompetent patient treated with corticosteroids.

Background: Patients with severe viral pneumonia are likely to receive high-dose immunomodulatory drugs to prevent clinical worsening. Aspergillus species have been described as frequent secondary pneumonia agents in severely ill influenza patients receiving steroids. COVID-19 patients admitted to Intensive Care Unit (ICU) are receiving steroids as part of their treatment and they share clinical characteristics with other patients with severe viral pneumonias.

Functional characterization of methionine sulfoxide reductases from Leptospira interrogans.

Background: Methionine (Met) oxidation leads to a racemic mixture of R and S forms of methionine sulfoxide (MetSO). Methionine sulfoxide reductases (Msr) are enzymes that can reduce specifically each isomer of MetSO, both free and protein-bound. The Met oxidation could change the structure and function of many proteins, not only of those redox-related but also of others involved in different metabolic pathways.

First evidence of glutathione metabolism in Leptospira interrogans.

Background: Glutathione (GSH) plays a role as a main antioxidant metabolite in all eukaryotes and many prokaryotes. Most of the organisms synthesize GSH by a pathway involving two enzymatic reactions, each one consuming one molecule of ATP. In a first step mediated by glutamate-cysteine ligase (GCL), the carboxylate of l-glutamic acid reacts with l-cysteine to form the dipeptide γ-glutamylcysteine (γ-GC).

Trypanothione synthetase confers growth, survival advantage and resistance to anti-protozoal drugs in Trypanosoma cruzi.

Background: Chagas cardiomyopathy, caused by Trypanosoma cruzi infection, continues to be a neglected illness, and has a major impact on global health. The parasite undergoes several stages of morphological and biochemical changes during its life cycle, and utilizes an elaborated antioxidant network to overcome the oxidants barrier and establish infection in vector and mammalian hosts. Trypanothione synthetase (TryS) catalyzes the biosynthesis of glutathione-spermidine adduct trypanothione (T(SH)) that is the principal intracellular thiol-redox metabolite in trypanosomatids.

Functional thioredoxin reductase from pathogenic and free-living Leptospira spp.

Low molecular mass thiols and antioxidant enzymes have essential functions to detoxify reactive oxygen and nitrogen species maintaining cellular redox balance. The metabolic pathways for redox homeostasis in pathogenic (Leptospira interrogans) and free-living (Leptospira biflexa) leptospires species were not functionally characterized. We performed biochemical studies on recombinantly produced proteins to in depth analyze kinetic and structural properties of thioredoxin reductase (LinTrxR) and thioredoxin (LinTrx) from L.

On the Ancestral UDP-Glucose Pyrophosphorylase Activity of GalF from Escherichia coli.

In bacteria, UDP-glucose is a central intermediate in carbohydrate metabolism. The enzyme responsible for its synthesis is encoded by the galU gene and its deletion generates cells unable to ferment galactose. In some bacteria, there is a second gene, galF, encoding for a protein with high sequence identity to GalU.

Kinetic and structural characterization of a typical two-cysteine peroxiredoxin from Leptospira interrogans exhibiting redox sensitivity.

Little is known about the mechanisms by which Leptospira interrogans, the causative agent of leptospirosis, copes with oxidative stress at the time it establishes persistent infection within its human host. We report the molecular cloning of a gene encoding a 2-Cys peroxiredoxin (LinAhpC) from this bacterium. After bioinformatic analysis we found that LinAhpC contains the characteristic GGIG and YF motifs present in peroxiredoxins that are sensitive to overoxidation (mainly eukaryotic proteins).