Corrigendum: Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): a study protocol for a randomized clinical trial

[This corrects the article DOI: 10.3389/fmed.2022.1087188.].

Home-based exercise program in the indeterminate form of Chagas disease (PEDI-CHAGAS study): A study protocol for a randomized clinical trial

Background

Chagas disease (CD) is a neglected endemic disease with worldwide impact due to migration. Approximately 50-70% of individuals in the chronic phase of CD present the indeterminate form, characterized by parasitological and/or serological evidence of Trypanosoma cruzi infection, but without clinical signs and symptoms. Subclinical abnormalities have been reported in indeterminate form of CD, including pro-inflammatory states and alterations in cardiac function, biomarkers and autonomic modulation. Moreover, individuals with CD are usually impacted on their personal and professional life, making social insertion difficult and impacting their mental health and quality of life (QoL). Physical exercise has been acknowledged as an important strategy to prevent and control numerous chronic-degenerative diseases, but unexplored in individuals with the indeterminate form of CD. The PEDI-CHAGAS study (which stands for "Home-Based Exercise Program in the Indeterminate Form of Chagas Disease" in Portuguese) aims to evaluate the effects of a home-based exercise program on physical and mental health outcomes in individuals with indeterminate form of CD.

Methods and design

The PEDI-CHAGAS is a two-arm (exercise and control) phase 3 superiority randomized clinical trial including patients with indeterminate form of CD. The exclusion criteria are <18 years old, evidence of non-Chagasic cardiomyopathy, musculoskeletal or cognitive limitations that preclude the realization of exercise protocol, clinical contraindication for regular exercise, and regular physical exercise (≥1 × per week). Participants will be assessed at baseline, and after three and 6 months of follow-up. The primary outcome will be QoL. Secondary outcomes will include blood pressure, physical fitness components, nutritional status, fatigability, autonomic modulation, cardiac morphology and function, low back pain, depression and anxiety, stress, sleep quality, medication use and adherence, and biochemical, inflammatory and cardiac biomarkers. Participants in the intervention group will undergo a home-based exercise program whilst those in the control group will receive only general information regarding the benefits of physical activity. Both groups will receive the same general nutritional counseling consisting of general orientations about healthy diets.

Conclusion

The findings from the present study may support public health intervention strategies to improve physical and mental health parameters to be implemented more effectively in this population.

Clinical trial registration

[https://ensaiosclinicos.gov.br/rg/RBR-10yxgcr9/], identifier [U1111-1263-0153].

Amoeba Predation of Cryptococcus neoformans Results in Pleiotropic Changes to Traits Associated with Virulence

Amoeboid predators, such as amoebae, are proposed to select for survival traits in soil microbes such as Cryptococcus neoformans; these traits can also function in animal virulence by defeating phagocytic immune cells, such as macrophages. Consistent with this notion, incubation of various fungal species with amoebae enhanced their virulence, but the mechanisms involved are unknown. In this study, we exposed three strains of C. neoformans (1 clinical and 2 environmental) to predation by Acanthamoeba castellanii for prolonged times and then analyzed surviving colonies phenotypically and genetically. Surviving colonies comprised cells that expressed either pseudohyphal or yeast phenotypes, which demonstrated variable expression of traits associated with virulence, such as capsule size, urease production, and melanization. Phenotypic changes were associated with aneuploidy and DNA sequence mutations in some amoeba-passaged isolates, but not in others. Mutations in the gene encoding the oligopeptide transporter (CNAG_03013; OPT1) were observed among amoeba-passaged isolates from each of the three strains. Isolates derived from environmental strains gained the capacity for enhanced macrophage toxicity after amoeba selection and carried mutations on the CNAG_00570 gene encoding Pkr1 (AMP-dependent protein kinase regulator) but manifested reduced virulence in mice because they elicited more effective fungal-clearing immune responses. Our results indicate that C. neoformans survival under constant amoeba predation involves the generation of strains expressing pleiotropic phenotypic and genetic changes. Given the myriad potential predators in soils, the diversity observed among amoeba-selected strains suggests a bet-hedging strategy whereby variant diversity increases the likelihood that some will survive predation.IMPORTANCECryptococcus neoformans is a ubiquitous environmental fungus that is also a leading cause of fatal fungal infection in humans, especially among immunocompromised patients. A major question in the field is how an environmental yeast such as C. neoformans becomes a human pathogen when it has no need for an animal host in its life cycle. Previous studies showed that C. neoformans increases its pathogenicity after interacting with its environmental predator amoebae. Amoebae, like macrophages, are phagocytic cells that are considered an environmental training ground for pathogens to resist macrophages, but the mechanism by which C. neoformans changes its virulence through interactions with protozoa is unknown. Our study indicates that fungal survival in the face of amoeba predation is associated with the emergence of pleiotropic phenotypic and genomic changes that increase the chance of fungal survival, with this diversity suggesting a bet-hedging strategy to ensure that some forms survive.

Structural analysis of glucosylceramides (GlcCer) from species of the Pseudallescheria/Scedosporium complex

Glucosylceramides (GlcCer) are the main neutral glycosphingolipids expressed in fungal cells. In this work, glucosylceramides (GlcCer) were extracted from three strains of Scedosporium (Pseudallescheria) boydii, one strain of Pseudallescheria ellipsoidea and one strain of Pseudallescheria angusta and purified by several chromatographic steps. Using high-performance thin layer chromatography (HPTLC), we found a similarity between GlcCer obtained from all of the analysed strains. A detailed structural analysis of the P. ellipsoidea GlcCer was performed via electrospray ionization mass spectrometry (ESI-MS) and confirmed in 1- and 2-D heteronuclear NMR experiments ((1)H-(13) C HSQC). GlcCer species produced by mycelial forms of these strains displayed the same structure previously demonstrated by our group for P. boydii, Cryptococcus neoformans, Pseudallescheria minustipora, Fusarium solani, and Colletotrichum gloesporioides. A monoclonal antibody (mAb) against GlcCer was used for immunofluorescence experiments. Our results revealed that GlcCer is present on the surface of these fungi, and no difference was observed in the GlcCer structure of the present set of strains in terms of geographic or clinical origin, suggesting a conserved GlcCer structure similar to those previously described for Scedosporium apiospermum, Scedosporium aurantiacum, and P. minutispora. The surface distribution of GlcCer in these fungi is suggestive of the involvement of this molecule in fungal growth.