The small heat shock protein Hsp12.1 has a major role in the stress response and virulence of Cryptococcus gattii.

Cryptococcus gattii is one of the etiological agents of cryptococcosis. To achieve a successful infection, C. gattii cells must overcome the inhospitable host environment and deal with the highly specialized immune system and poor nutrients availability. Inside the host, C. gattii uses a diversified set of tools to maintain homeostasis and establish infection, such as the expression of remarkable and diverse heat shock proteins (Hsps). Grouped by molecular weight, little is known about the Hsp12 subset in pathogenic fungi. In this study, the function of the C. gattii HSP12.1 and HSP12.2 genes was characterized. Both genes were upregulated during murine infection and heat shock. The hsp12.1 Δ null mutant cells were sensitive to plasma membrane and oxidative stressors. Moreover, HSP12 deletion induced C. gattii reactive oxygen species (ROS) accumulation associated with a differential expression pattern of oxidative stress-responsive genes compared to the wild type strain. Apart from these findings, the deletion of the paralog gene HSP12.2 did not lead to any detectable phenotype. Additionally, the double-deletion mutant strain hsp12.1 Δ /hsp12.2 Δ presented a similar phenotype to the single-deletion mutant hsp12.1 Δ, suggesting a minor participation of Hsp12.2 in these processes. Furthermore, HSP12.1 disruption remarkably affected C. gattii virulence and phagocytosis by macrophages in an invertebrate model of infection, demonstrating its importance for C. gattii pathogenicity.

Molecular characterization of a novel victorivirus (order Ghabrivirales, family Totiviridae) infecting Metarhizium anisopliae.

Here, we report the occurrence and complete genome sequence of a novel victorivirus infecting Metarhizium anisopliae, named "Metarhizium anisopliae victorivirus 1" (MaVV1). The genome is 5353 bp in length and contains two open reading frames (ORFs), encoding a coat protein and an RNA-dependent RNA polymerase (RdRp), that overlap at the octanucleotide sequence AUGAGUAA. These ORFs showed sequence similarity to the corresponding ORFs of Ustilaginoidea virens RNA virus L (68.23%) and Ustilaginoidea virens RNA virus 13 (58.11%), respectively, both of which belong to the family Totiviridae. Phylogenetic analysis based on RdRp sequences revealed that MaVV1 clustered with members of the genus Victorivirus. This is the first genome sequence reported for a virus belonging to the genus Victorivirus infecting the entomopathogenic fungus M. anisopliae.

Intra-hemocoel injection of pseurotin A from Metarhizium anisopliae, induces dose-dependent reversible paralysis in the Greater Wax Moth (Galleria mellonella).

Species from the Metarhizium genus are the causal agents of the green muscardine disease of insects. These fungi have been successfully employed for the biological control of pests over decades. Besides the biocontrol applications, recent efforts for genome sequencing of species in this genus have revealed a great diversity of biosynthetic gene clusters potentially associated with secondary metabolite synthesis. Amongst such molecules are the pseurotins, compounds with several activities, as chitin synthase inhibitors, and immunoglobulin E suppressors. Here, we report, for the first time, the isolation of pseurotin A from the culture broth of M. anisopliae, as well as the characterization of the effects of this compound over the model-arthropod Galleria mellonella. Pseurotin A displayed dose-dependent reversible paralysis effects when injected into the larvae hemocoel. However, the posterior challenge of the treated insects with M. anisopliae conidia did not lead to increased mortality, suggesting that pseurotin A treatment did not increase larvae susceptibility to the green muscardine disease. Although apparent insecticidal effects were not observed for pseurotin A, the paralysis effect observed can be important in M. anisopliae infection development.

An efficient Agrobacterium tumefaciens-mediated transformation method for Simplicillium subtropicum (Hypocreales: Cordycipitaceae).

Filamentous fungi are the organisms of choice for most industrial biotechnology. Some species can produce a variety of secondary metabolites and enzymes of commercial interest, and the production of valuable molecules has been enhanced through different molecular tools. Methods for genetic manipulation and transformation have been essential for the optimization of these organisms. The genus Simplicillium has attracted increased attention given several potential biotechnological applications. The Simplicillium genus harbors several entomopathogenic species and some isolates have been explored for bioremediation of heavy metal contaminants. Furthermore, the myriad of secondary metabolites isolated from Simplicillium spp. render these organisms as ideal targets for deep exploration and further biotechnological mining possibilities. However, the lack of molecular tools hampered the exploration of this genus. Thus, an Agrobacterium tumefaciens-mediated transformation method was established for Simplicillium subtropicum, employing the far-red fluorescent protein TURBOFP635/Katushka, as a visual marker, and the selection marker SUR gene, that confers resistance to chlorimuron ethyl. Notably, one round of transformation using the established method yielded almost 400 chlorimuron resistant isolates. Furthermore, these transformants displayed mitotic stability for, at least, five generations. We anticipate that this method can be useful for deep molecular exploration and improvement of strains in the Simplicillium genus.

The prognostic value of the serum ferritin in a southern Brazilian cohort of patients with Gaucher disease.

The clinical utility of serum ferritin as a biomarker of disease severity and prognosis in Gaucher disease (GD) is still debated. Here, we aimed to evaluate ferritin and its relation to clinicolaboratory parameters of GD patients seen at the Reference Center for Gaucher Disease of Rio Grande do Sul, Brazil, so as to gather evidence on the utility of ferritin as a biomarker of this condition. A retrospective chart review was performed collecting pre-and posttreatment data from GD patients. Eighteen patients with ferritin levels available before and after treatment were included in the study. Nine of these participants were males, and seventeen had type I GD. All patients were given either enzyme replacement (n = 16) or substrate reduction therapy (n = 2), and ferritin was found to decrease from 756 [318-1441] ng/mL at baseline to 521 [227-626] ng/mL (p=0.025) after 28.8 month soft treatment. Serum ferritin levels did not correlate with measures of disease severity, but showed an association with age at onset of treatment (ρ= 0.880; n = 18; p < 0.001). In conclusion, although serum ferritin did not correlate with disease severity, after a median 28.8 months of treatment, clinical outcomes had clearly improved, and ferritin levels had decreased.

Feed Forward Modeling: an efficient approach for mathematical modeling of the force frequency relationship in the rabbit isolated ventricular myocyte.

Background and Objective. This study addresses the Force-Frequency relationship, a fundamental characteristic of cardiac muscle influenced byß1-adrenergic stimulation. This relationship reveals that heart rate (HR) changes at the sinoatrial node lead to alterations in ventricular cell contractility, increasing the force and decreasing relaxation time for higher beat rates. Traditional models lacking this relationship offer an incomplete physiological depiction, impacting the interpretation of in silico experiment results. To improve this, we propose a new mathematical model for ventricular myocytes, named 'Feed Forward Modeling' (FFM).Methods. FFM adjusts model parameters like channel conductance and Ca2+pump affinity according to stimulation frequency, in contrast to fixed parameter values. An empirical sigmoid curve guided the adaptation of each parameter, integrated into a rabbit ventricular cell electromechanical model. Model validation was achieved by comparing simulated data with experimental current-voltage (I-V) curves for L-type Calcium and slow Potassium currents.Results. FFM-enhanced simulations align more closely with physiological behaviors, accurately reflecting inotropic and lusitropic responses. For instance, action potential duration at 90% repolarization (APD90) decreased from 206 ms at 1 Hz to 173 ms at 4 Hz using FFM, contrary to the conventional model, where APD90 increased, limiting high-frequency heartbeats. Peak force also showed an increase with FFM, from 8.5 mN mm-2at 1 Hz to 11.9 mN mm-2at 4 Hz, while it barely changed without FFM. Relaxation time at 50% of maximum force (t50) similarly improved, dropping from 114 ms at 1 Hz to 75.9 ms at 4 Hz with FFM, a change not observed without the model.Conclusion. The FFM approach offers computational efficiency, bypassing the need to model all beta-adrenergic pathways, thus facilitating large-scale simulations. The study recommends that frequency change experiments include fractional dosing of isoproterenol to better replicate heart conditionsin vivo.

Serum ß2-microglobulin is frequently elevated in type 1 Gaucher patients.

ß2-Microglobulin is the major prognostic factor in multiple myeloma, a known comorbidity of Gaucher disease. We evaluated herein serum ß2-microglobulin levels of 31 type 1 Gaucher patients; for 8/31 patients, pre- and post-treatment comparisons were made. Thirteen patients (on treatment = 6) had high levels of ß2-microglobulin, and showed higher chitotriosidase activity and Severity Score Index, and lower concentration of platelets, than patients with normal levels. Levels of ß2-microglobulin correlated with chitotriosidase activity (ρ = 0.65; p < 0.01), platelets (ρ = - 0.42; p = 0.02) and α1- (ρ = 0.43; p = 0.02) and α2-protein bands (ρ = - 0.40; p = 0.03). Regarding pre- and post-treatment values, median ß2-microglobulin levels decreased after treatment (pre- = 2931 ng/mL; post- = 1970 ng/mL; p < 0.01). Our data suggest that levels of serum ß2-microglobulin are frequently elevated in type 1 Gaucher patients, correlate with severity of the disease and decrease after treatment.

Rotavírus em alimentos: revisão de literatura / Rotavirus in food: a review

O rotavírus é um agente etiológico de doenças alimentares, cuja contaminação é de natureza infecciosa transmitida através de consumo de alimentos ou água. O presente estudo reúne informações sobre este agente etiológico, a melhor forma de prevenir a contaminação dos alimentos pelo rotavírus, a fim de evitar a propagação de agentes etiológicos veiculados por alimentos. O patógeno afeta animais, homens adultos e principalmente crianças com menos de cinco anos de idade, podendo levar ao óbito. Tem distribuição mundial e apresenta uma significativa morbidade e mortalidade em países subdesenvolvidos e em desenvolvimento. Ocorre com mais freqüência em períodos secos nas regiões temperadas, e durante todo o período do ano em regiões tropicais. Tem grande potencial infectante e é eliminado em grande quantidade nas fezes sendo a transmissão fecal-oral. Não são eliminados da água pelos métodos convencionais de tratamento. Os indivíduos com infecção assintomática representam um obstáculo ao controle endêmico, sendo a doença autolimitante. O afastamento da função do indivíduo infectado torna-se obrigatório evitando-se propagação. Devem ser seguidas as orientações e normas para manipuladores, além da vacinação em crianças pequenas.