Persistence of COVID-19 Symptoms and Quality of Life at Three and Twelve Months after Hospital Discharge.

Background and Objectives: Medical and public recognition of "long-COVID or post-COVID syndrome", as well as its impact on the quality of life (QoL), is required to better address the disease burden. Objectives: We aimed to describe the persistence of COVID-19 symptoms and QoL among patients at three and twelve months after their discharge from the hospital. Materials and Methods: We conducted an observational, prospective, and longitudinal analytic study from September 2021 to April 2022. To measure QoL, we used a validated version of the 36-item Short-Form Health Survey (SF-36). Results: We included 68 patients in the study. A total of 54 (79.4%) patients reported at least one persistent symptom at three months vs. 52 (76.4%) at twelve months (p = 0.804). Some persistent symptoms (myalgia, alopecia, and cough) decreased significantly at twelve months (50% vs. 30.9%, 29.4% vs. 13.2%, and 23.5% vs. 7.4%; respectively, p = 0.007); in contrast, other persistent symptoms (sleep-wake and memory disorders) were more frequent (5.9% vs. 32.4% and 4.4% vs. 20.6%; respectively, p = ≤0.001). Regarding QoL, a statistically significant improvement was observed in some scores over time, p = ≤0.037. At twelve months, dyspnea, myalgia, and depression were risk factors associated with a poor physical component summary (PCS), p = ≤0.027, whereas anxiety, depression, and fatigue were associated with a poor mental component summary (MCS), p = ≤0.015. Conclusion: As the proportion of persistent symptoms at twelve months is high, we suggest that patients must continue under long-term follow up to reclassify, diagnose, and treat new onset symptoms/diseases.

Host-guest complexation of phthalimide-derived strigolactone mimics with cyclodextrins. Application in agriculture against parasitic weeds.

Parasitic weeds are noxious plants that damage crops of economic relevance, especially in Mediterranean and African countries. The strategy of suicidal germination was proposed to deal with this plague by using seed germination inducers that work as a pre-emergence herbicide and reduce the parasitic seed load before sowing. N-Substituted phthalimides with a furanone ring were found to be efficient in inducing the germination of Phelipanche ramosa and Orobanche cumana, two of the most problematic parasitic weeds of crops. However, the solubility of these compounds in water is low. A strategy for enhancing their aqueous solubility is the synthesis of host-guest complexes with cyclodextrins. Three bioactive phthalimide-lactones (PL01, PL04, and PL07) were selected and studied to form complexes of increased water solubility with α-, ß-, HP-ß-, and γ-cyclodextrin. The complexes obtained by the coprecipitation method, with increased aqueous solubility (up to 3.8 times), were studied for their bioactivity and they showed similar or slightly higher bioactivity than free phthalimide-lactones, even without the addition of organic solvents. A theoretical study using semiempirical calculations of molecular models including a solvation system confirmed the physicochemical empirical results. These results demonstrated that cyclodextrins can be used to improve the physicochemical and biological properties of parasitic seed germination inducers.

Diagnostic Accuracy of the RDW for Predicting Death in COVID-19.

Background and Objectives: An association between high red blood cell distribution width (RDW) and mortality has been found in several diseases, including infection and sepsis. Some studies have aimed at determining the association of elevated RDW with adverse prognosis in COVID-19, but its usefulness has not been well established. The objective of this study was to determine the accuracy of the RDW, measured at hospital admission and discharge, for predicting death in patients with COVID-19. Materials andMethods: An observational, retrospective, longitudinal, and analytical study was conducted in two different COVID-19 reference centers in the state of Guanajuato, Mexico. A total of 323 patients hospitalized by COVID-19 were included. Results: We found higher RDW levels at the time of hospital admission in the non-survivors group compared to levels in survivors (median = 13.6 vs. 13.0, p < 0.001). Final RDW levels were even higher in the deceased group when compared with those of survivors (median = 14.6 [IQR, 12.67−15.6] vs. 12.9 [IQR, 12.2−13.5], p < 0.001). For patients who died, an RDW > 14.5% was more common at the time of death than for patients who survived at the time of discharge (81 vs. 13 patients, p < 0.001; RR = 2.3, 95% CI 1.89−2.81). Conclusions: The RDW is an accessible and economical parameter that, together with other characteristics of the presentation and evolution of patients with COVID-19, can be helpful in determining the prognosis. An RDW that increases during hospitalization could be a more important mortality predictor than the RDW at hospital admission.

Impact of infections and extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae on graft and patient survival in a kidney transplantation program in Mexico.

INTRODUCTION: Immunosuppressive treatments have improved graft and patient survival rates, but can increase the incidence of post-transplant infections. OBJECTIVES: To analyze data from kidney transplant patients and describe the pathogens responsible for the infections they experience. METHODS: Longitudinal, analytical, observational study of 103 patients who underwent kidney transplantation. The follow-up period was 5.07 ± 1.28 years. RESULTS: Overall mortality rate was 10.68% and graft loss rate was 14.56%. Regarding recipient risk of death, the Cox regression model showed a hazard ratio (HR) of 5.66 for positive bacterial cultures and 2.22 for positive extended-spectrum beta-lactamase (ESBL)-producing strains; as for graft loss, HR was 4.59 in those with positive bacterial cultures and 4.25 in those who were positive for ESBL-producing strains. CONCLUSIONS: Significant death risk was found in kidney transplant recipients with positive bacterial cultures and an increased risk of graft loss in those with positive bacterial cultures and in those who were positive for ESBL-producing Enterobacteriaceae isolates. The rate of ESBL-producing Enterobacteriaceae is high, and stricter strategies are therefore necessary to control the use of antibiotics.

INTRODUCCIÓN: Los tratamientos inmunosupresores han mejorado las tasas de supervivencia del injerto y del paciente, pero pueden incrementar las infecciones postrasplante. OBJETIVOS: Analizar los datos de pacientes con trasplante renal y describir las bacterias responsables de las infecciones que presentan. MÉTODOS: Estudio observacional, longitudinal y analítico de 103 pacientes sometidos a trasplante renal. El periodo de seguimiento fue de 5.07 ± 1.28 años. RESULTADOS: La tasa de mortalidad fue de 10.68 % y la de pérdida del injerto de 14.56 %. Respecto al riesgo de muerte del receptor, el modelo de regresión de Cox mostró un cociente de riesgo (HR, hazard ratio) de 5.66 en los pacientes con cultivo bacteriano positivo y de 2.22 en aquellos con cepas productoras de betalactamasas de espectro extendido (BLEE); en cuanto a la pérdida del injerto, el HR fue de 4.59 en quienes tuvieron cultivo bacteriano positivo y de 4.25 en aquellos con cepas productoras de BLEE. CONCLUSIONES: Se encontró riesgo significativo de muerte en receptores de trasplante renal con cultivo bacteriano positivo y mayor riesgo de pérdida del injerto en aquellos con cultivo bacteriano positivo y aislamiento de cepas productoras de BLEE. La tasa de enterobacterias productoras de BLEE es alta, por ello son necesarias estrategias más estrictas para controlar del uso de antibióticos.

Is Clostridioides difficile toxins detection necessary when the glutamate dehydrogenase enzyme is detected?

INTRODUCTION: Clostridioides difficile causes diarrhea and pseudomembranous colitis. Its diagnosis is made with glutamate dehydrogenase (GDH) or toxins A and B detection and is confirmed with nucleic acid amplification tests. OBJECTIVE: To define if GDH determination is redundant to that of toxins. METHODS: Retrospective, observational study in diarrheal stools of patients with suspected Clostridioides difficile infection. Toxins and GDH were determined by immunochromatography. Bayesian simulation was performed with likelihood ratios; a p-value < 0.05 was regarded as significant. RESULTS: 329 GDH and toxin A and B results were analyzed. Clostridioides difficile infection prevalence was 18.2 %. Sensitivity and specificity of the GDH test were 0.90 and 0.89, respectively. Positive likelihood ratio was 8.9, and negative was 0.11. CONCLUSIONS: A negative GDH result considerably reduces the probability of infection but does not rule it out. Clostridioides difficile toxins detection may be necessary in institutions where nucleic acid amplification is not affordable or accessible.

INTRODUCCIÓN: Clostridioides difficile causa diarrea y colitis pseudomembranosa. Su diagnóstico se realiza con la detección de glutamato-deshidrogenasa (GDH) o las toxinas A y B y se confirma con pruebas de amplificación de ácidos nucleicos. OBJETIVO: Definir si la determinación de GDH es redundante a la de las toxinas. MÉTODOS: Estudio observacional retrospectivo de muestras fecales de pacientes con sospecha de infección por Clostridioides difficile. Las toxinas y GDH se determinaron mediante inmunocromatografía. Se realizó una simulación bayesiana con los cocientes de probabilidad; se consideró significativo un valor de p < 0.05. RESULTADOS: Se analizaron 329 resultados de GDH y toxinas A y B. Se encontró una prevalencia de infección de Clostridioides difficile de 18.2 %. La sensibilidad y especificidad de la prueba de GDH fue de 0.90 y 0.89, respectivamente. El cociente de probabilidad positivo fue de 8.9 y el negativo, de 0.11. CONCLUSIONES: Un resultado negativo de GDH disminuye considerablemente la probabilidad de infección, pero no la descarta. La detección de toxinas de Clostridioides difficile puede ser necesaria en instituciones donde la amplificación de ácidos nucleicos no es económica o accesible.

Assessment of emulsion gels formulated with chestnut (Castanea sativa M.) flour and chia (Salvia hispanica L) oil as partial fat replacers in pork burger formulation.

BACKGROUND: The aim of this work was to evaluate the effect on chemical composition, physico-chemical properties, cooking characteristics, fatty acid profile, lipid oxidation, and sensory acceptability of an oil-in-water emulsion gel that was prepared with chestnut flour, chia oil, gellan gum, and water (CEG), used as a fat replacer in pork burgers. The original mixture was used as a control sample (CS). The other samples were formulated partially replacing pork backfat with 5% of CEG (CEG5%) and 10% of CEG (CEG10%). RESULTS: Proximate analysis of samples showed several differences between samples. The CEG addition was found to be effective for improving the cooking yield while diameter reduction and thickness increase were positively affected. As regards lipid oxidation, in cooked burger, the 2-thiobarbituric acid (TBA) values for CS, CEG5% and CEG10% were 0.46, 0.57, and 0.59 mg malonaldehyde/kg sample, respectively. The linolenic and linolenic acid content of pork burger increased as CEG addition increased. Sensory properties for CS and CEG5% were similar whereas CEG10% showed the highest sensory scores. CONCLUSIONS: A combination of chestnut flour and chia oil could be used as a novel ingredient to develop pork burgers with a better nutritional profile without diminishing their sensory and physico-chemical properties. © 2019 Society of Chemical Industry.

An Electronic Nose Based Method for the Discrimination of Weathered Petroleum-Derived Products.

In recent years pollution due to hydrocarbon spills has increased markedly as a result of the numerous advances in technologies and industrial processes. Anthropogenic activities (accidental or illegal) are responsible for most of these incidents. In some cases, the spills are not detected at the moment they occur and the contaminants are subjected to different degradation phenomena that may change the chemical composition of the hydrocarbon over time. An incorrect or ineffective identification of the spill could lead to significant consequences, bearing in mind that most spills are hazardous to the environment. In the present work the capacity of the analytical technique based on the Electronic Nose (eNose) combined with chemometrics in the identification and discrimination of different weathered petroleum-derived products (PDPs) was studied. Different volumes (40 μL and 80 μL) of PDPs (gasoline, diesel, and paraffin) were poured onto different supports (wood, cork, paper, and cotton sheet) and subjected to a natural weathering process by evaporation for one month. The porosity of the support was also studied. The application of linear discriminant analysis allowed the full discrimination of the samples according to the presence/absence of PDP and a 97.7% of correct discrimination of the different PDPs regardless of the weathering time, support or volume used. The results show that the system is capable of detecting and discriminating the presence of petroleum-derived products in any of the situations studied.

[Síndrome de Paget-Schrötter: presentación de cuatro casos]. / Paget-Schrötter syndrome: description of four cases.

Deep vein thrombosis (DVT) of the upper limb is a rare entity, estimated to account for 10% of all cases of DVT. Classically, they are classified into primary (idiopathic, due to subclavian vein compression or exercise related) and secondary (cancer, thrombophilia, trauma, shoulder surgery, associated to venous catheters or due to hormonal causes). The Paget- Schrötter syndrome is a primary thrombosis of the subclavian vein in the subclavian-axillary junction, related either to repetitive movements or to exercise; leading to microtrauma in the endothelium with consequent activation of the coagulation cascade. Clinically, it presents abruptly with pain, edema and feeling of heaviness in the affected limb. The treatment varies from thrombolytics and anticoagulation to surgical intervention, depending on the time of evolution. We present four cases of exercise-related subclavian vein thrombosis.

Bioaccessibility of Phenolic Compounds and Antioxidant Capacity of Chia (Salvia hispanica L.) Seeds.

The aim of this work was to evaluate (i) the phenol and flavonoid recovery and bioaccessibility indexes and (ii) the antioxidant activity of both types of non-defatted and defatted chia seeds during the in vitro gastrointestinal digestion. The ground samples were subjected to in vitro simulated gastrointestinal digestion, and the resultant fractions were extracted and subjected to spectrophotometric assays. The results pointed to increasing concentrations of polyphenolic compounds during digestion, although only a low-medium percentage of phenols and a low percentage of flavonoids were available for absorption in the intestinal tract. In addition, the high level of fats seemed to have a negative effect on the bioaccessibility of flavonoids. Further studies should be undertaken to better understand the stabilization of the bioactive compounds of chia and to improve their bioaccessibility. Meanwhile, the present study represents a solid base for studying the bioavailability of bioactive compounds of chia seeds.

Complexation of sesquiterpene lactones with cyclodextrins: synthesis and effects on their activities on parasitic weeds.

Allelochemicals are safer, more selective and more active alternatives than synthetic agrochemicals for weed control. However, the low solubility of these compounds in aqueous media limits their use as agrochemicals. Herein, we propose the application of α-, ß- and γ-cyclodextrins to improve the physicochemical properties and biological activities of three sesquiterpene lactones: dehydrocostuslactone, costunolide and (-)-α-santonin. Complexation was achieved by kneading and coprecipitation methods. Aqueous solubility was increased in the range 100-4600% and the solubility-phase diagrams suggested that complex formation had been successful. The results of the PM3 semiempirical calculations were consistent with the experimental results. The activities on etiolated wheat coleoptiles, Standard Target Species and parasitic weeds were improved. Cyclodextrins preserved or enhanced the activity of the three sesquiterpene lactones. Free cyclodextrins did not show significant activity and therefore the enhancement in activity was due to complexation. These results are promising for applications in agrochemical design.

Characterization and Differentiation of Petroleum-Derived Products by E-Nose Fingerprints.

Characterization of petroleum-derived products is an area of continuing importance in environmental science, mainly related to fuel spills. In this study, a non-separative analytical method based on E-Nose (Electronic Nose) is presented as a rapid alternative for the characterization of several different petroleum-derived products including gasoline, diesel, aromatic solvents, and ethanol samples, which were poured onto different surfaces (wood, cork, and cotton). The working conditions about the headspace generation were 145 °C and 10 min. Mass spectroscopic data (45-200 m/z) combined with chemometric tools such as hierarchical cluster analysis (HCA), later principal component analysis (PCA), and finally linear discriminant analysis (LDA) allowed for a full discrimination of the samples. A characteristic fingerprint for each product can be used for discrimination or identification. The E-Nose can be considered as a green technique, and it is rapid and easy to use in routine analysis, thus providing a good alternative to currently used methods.

Determination of Ignitable Liquids in Fire Debris: Direct Analysis by Electronic Nose.

Arsonists usually use an accelerant in order to start or accelerate a fire. The most widely used analytical method to determine the presence of such accelerants consists of a pre-concentration step of the ignitable liquid residues followed by chromatographic analysis. A rapid analytical method based on headspace-mass spectrometry electronic nose (E-Nose) has been developed for the analysis of Ignitable Liquid Residues (ILRs). The working conditions for the E-Nose analytical procedure were optimized by studying different fire debris samples. The optimized experimental variables were related to headspace generation, specifically, incubation temperature and incubation time. The optimal conditions were 115 °C and 10 min for these two parameters. Chemometric tools such as hierarchical cluster analysis (HCA) and linear discriminant analysis (LDA) were applied to the MS data (45-200 m/z) to establish the most suitable spectroscopic signals for the discrimination of several ignitable liquids. The optimized method was applied to a set of fire debris samples. In order to simulate post-burn samples several ignitable liquids (gasoline, diesel, citronella, kerosene, paraffin) were used to ignite different substrates (wood, cotton, cork, paper and paperboard). A full discrimination was obtained on using discriminant analysis. This method reported here can be considered as a green technique for fire debris analyses.

Determination of polyphenolic profile, antioxidant activity and antibacterial properties of maqui [Aristotelia chilensis (Molina) Stuntz] a Chilean blackberry.

BACKGROUND: The aim of the present study was to determine (1) the polyphenolic profile (phenolic acids, flavonoids and anthocyanins), (2) the antioxidant using four different methodologies (DPPH, ABTS, FRAP and FIC) and (3) the antibacterial properties of maqui berry [Aristotelia chilensis (Molina) Stuntz] (MB) grown in Chile. RESULTS: The HPLC analysis of MB showed a total of 19 polyphenolic compounds identified as anthocyanins (eight compounds), flavonols (10 compounds) and ellagic acid. Delphinidin derivatives were the predominant anthocyanins while quercetin derivatives were the predominant flavonols. MB showed an antioxidant activity measured with DPPH, ABTS, FRAP and FIC methods of 28.18, 18.66, 25.22 g Trolox equivalent kg(-1) and 0.12 g ethylenediaminetetraacetic acid equivalent kg(-1) , respectively. With regard to the antibacterial activity, all strains tested were affected by MB. Aeromonas hydrophila and Listeria innocua showed the highest sensitivity to maqui berry extracts with MIC values of 40 and a 50 mg mL(-1) , respectively. CONCLUSIONS: The results suggest that maqui berry has a great potential to be employed in the food industry as potential food ingredient to functional food development or as bio-preservative. © 2016 Society of Chemical Industry.

Functional characterization of Sporothrix schenckii glycosidases involved in the N-linked glycosylation pathway.

Protein glycosylation pathways are conserved metabolic processes in eukaryotic organisms and are required for cell fitness. In fungal pathogens, the N-linked glycosylation pathway is indispensable for proper cell wall composition and virulence. In Sporothrix schenckii sensu stricto, the causative agent of sporotrichosis, little is known about this glycosylation pathway. Here, using a genome-wide screening for putative members of the glycosyl hydrolase (CAZy - GH) families 47 and 63, which group enzymes involved in the processing step during N-linked glycan maturation, we found seven homologue genes belonging to family 47 and one to family 63. The eight genes were individually expressed in C. albicans null mutants lacking either MNS1 (for members of family 47) or CWH41 (for the member of family 63). Our results indicate that SsCWH41 is the functional ortholog of CaCWH41, whereas SsMNS1 is the functional ortholog of CaMNS1. The remaining genes of family 47 encode Golgi mannosidases and endoplasmic reticulum degradation-enhancing alpha-mannosidase-like proteins (EDEMs). Since these GH families gather proteins used as target for drugs to control cell growth, identification of these genes could help in the design of antifungals that could be used to treat sporotrichosis and other fungal diseases. In addition, to our knowledge, we are the first to report that Golgi mannosidases and EDEMs are expressed and characterized in yeast cells.

[Is effective a shortened surveillance system of bloodstream infection?]. / Es eficaz un sistema de vigilancia acortado en las infecciones del torrente sanguíneo?

INTRODUCTION: Surveillance is necessary for bloodstream infection control. Daily monitoring of the central venous catheter (CVC) use, a time-demanding process, is the standard denominator to calculate the infection rate; surveillance of only one day per week has been proposed as alternative. OBJECTIVE: To determine whether surveillance of one day per week is similar to daily monitoring in a second-level hospital. MATERIAL AND METHODS: Daily monitoring of CVC utilization ratio was done during nine weeks in four locations of a second-level hospital. For each day, proportional differences respect to the global CVC utilization ratio was estimated. An ANOVA test was done to find differences between each weekday. RESULTS: CVC usage surveillance was performed for 9 weeks, so nine determinations were obtained for each weekday. No significant differences were found between each day (F = 2.20, p = 0.056). The lowest sampling discrepancy was found on Wednesdays. CONCLUSIONS: According to previous studies, and our own data, monitoring the CVC use one day per week is a reasonable alternative to the daily surveillance.

Predictors of retrieval and long-term mortality in patients treated with inferior vena cava filters.

OBJECTIVE: Inferior vena cava filters (VCFs) are a therapeutic resource for the treatment of patients with thromboembolic disease who have a contraindication to full-dose anticoagulation. In the present study, we report the retrieval rate and long-term mortality of patients receiving optional inferior VCFs and identify the predictors for retrieval and all-cause mortality during follow-up. METHODS: We conducted a retrospective cohort study of 739 consecutive recipients of optional inferior VCFs from January 2002 to December 2021 in two hospitals. Different clinical characteristics and procedure-related variables were included in the analysis. The all-cause mortality rate and retrieval rate and the predictive factors were evaluated using multivariate analysis. RESULTS: Of the 739 patients, 393 (53%) were women. The mean patient age was 69 ± 15 years. Of the patients, 67% presented with pulmonary thromboembolism and 43% with deep vein thrombosis (DVT). A contraindication to anticoagulation was present for nearly 90% of the patients, mainly (47%) related to the surgical procedure. In addition, 44% of the patients had active cancer. Follow-up data were available for 94% of the patients, with an average follow-up time of 6.08 ± 5.83 years. Long-term mortality was 53%. Cancer (odds ratio [OR], 3.60; 95% confidence interval [CI], 2.22-5.83), age (OR, 1.03; 95% CI, 1.08-1.42), and DVT (OR, 2.01; 95% CI, 1.08-1.42) were identified as independent predictors of mortality. The retrieval rate at follow-up was 33%. The predictors for retrieval included the indication of the filter related to a surgical procedure (OR, 4.85; 95% CI, 2.54-9.59), the absence of cancer (OR, 2.89; 95% CI, 1.45-5.75), and younger age (OR, 0.98; 95% CI, 0.97-0.99). CONCLUSIONS: High long-term mortality was observed. The predictors of mortality were cancer, older age, and DVT. One third of the filters implanted were retrieved. The predictors for retrieval were a contraindication to surgery-related anticoagulation, the absence of cancer, and younger age.

Silencing of Sporothrix schenckii GP70 Reveals Its Contribution to Fungal Adhesion, Virulence, and the Host-Fungus Interaction.

Sporothrix schenckii is one of the etiological agents of sporotrichosis, a cutaneous and subcutaneous infection distributed worldwide. Like other medically relevant fungi, its cell wall is a molecular scaffold to display virulence factors, such as protective pigments, hydrolytic enzymes, and adhesins. Cell wall proteins with adhesive properties have been previously reported, but only a handful of them have been identified and characterized. One of them is Gp70, an abundant cell wall protein mainly found on the surface of yeast-like cells. Since the protein also has a role in the activity of 3-carboxy-cis,cis-muconate cyclase and its abundance is low in highly virulent strains, its role in the Sporothrix-host interaction remains unclear. Here, a set of GP70-silenced strains was generated, and the molecular and phenotypical characterization was performed. The results showed that mutants with high silencing levels showed a significant reduction in the adhesion to laminin and fibrinogen, enzyme activity, and defects in the cell wall composition, which included reduced mannose, rhamnose, and protein content, accompanied by an increment in ß-1,3-glucans levels. The cell wall N-linked glycan content was significantly reduced. These strains induced poor TNFα and IL-6 levels when interacting with human peripheral blood mononuclear cells in a dectin-1-, TLR2-, and TLR4-dependent stimulation. The IL-1ß and IL-10 levels were significantly higher and were stimulated via dectin-1. Phagocytosis and stimulation of neutrophil extracellular traps by human granulocytes were increased in highly GP70-silenced strains. Furthermore, these mutants showed virulence attenuation in the invertebrate model Galleria mellonella. Our results demonstrate that Gp70 is a versatile protein with adhesin properties, is responsible for the activity of 3-carboxy-cis,cis-muconate cyclase, and is relevant for the S. schenckii-host interaction.

An ELISA-based method for Galleria mellonella apolipophorin-III quantification.

Mammalian models, such as murine, are used widely in pathophysiological studies because they have a high degree of similarity in body temperature, metabolism, and immune response with humans. However, non-vertebrate animal models have emerged as alternative models to study the host-pathogen interaction with minimal ethical concerns. Galleria mellonella is an alternative model that has proved useful in studying the interaction of the host with either bacteria or fungi, performing drug testing, and assessing the immunological response to different microorganisms. The G. mellonella immune response includes cellular and humoral components with structural and functional similarities to the immune effectors found in higher vertebrates, such as humans. An important humoral effector stimulated during infections is apolipophorin III (apoLp-III), an opsonin characterized by its lipid and carbohydrate-binding properties that participate in lipid transport, as well as immunomodulatory activity. Despite some parameters, such as the measurement of phenoloxidase activity, melanin production, hemocytes counting, and expression of antimicrobial peptides genes are already used to assess the G. mellonella immune response to pathogens with different virulence degrees, the apoLp-III quantification remains to be a parameter to assess the immune response in this invertebrate. Here, we propose an immunological tool based on an enzyme-linked immunosorbent assay that allows apoLp-III quantification in the hemolymph of larvae challenged with pathogenic agents. We tested the system with hemolymph coming from larvae infected with Escherichia coli, Candida albicans, Sporothrix schenckii, Sporothrix globosa, and Sporothrix brasiliensis. The results revealed significantly higher concentrations of apoLp-III when each microbial species was inoculated, in comparison with untouched larvae, or inoculated with phosphate-buffered saline. We also demonstrated that the apoLp-III levels correlated with the strains' virulence, which was already reported. To our knowledge, this is one of the first attempts to quantify apoLp-III, using a quick and easy-to-use serological technique.

The inorganic pyrophosphatases of microorganisms: a structural and functional review.

Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The accumulation of PPi in the cell can result in cell death. Although the substrate is the same, there are variations in the catalysis and features of these enzymes. Two enzyme forms have been identified in bacteria: cytoplasmic or soluble pyrophosphatases and membrane-bound pyrophosphatases, which play major roles in cell bioenergetics. In eukaryotic cells, cytoplasmic enzymes are the predominant form of PPases (c-PPases), while membrane enzymes (m-PPases) are found only in protists and plants. The study of bacterial cytoplasmic and membrane-bound pyrophosphatases has slowed in recent years. These enzymes are central to cell metabolism and physiology since phospholipid and nucleic acid synthesis release important amounts of PPi that must be removed to allow biosynthesis to continue. In this review, two aims were pursued: first, to provide insight into the structural features of PPases known to date and that are well characterized, and to provide examples of enzymes with novel features. Second, the scientific community should continue studying these enzymes because they have many biotechnological applications. Additionally, in this review, we provide evidence that there are m-PPases present in fungi; to date, no examples have been characterized. Therefore, the diversity of PPase enzymes is still a fruitful field of research. Additionally, we focused on the roles of H+/Na+ pumps and m-PPases in cell bioenergetics. Finally, we provide some examples of the applications of these enzymes in molecular biology and biotechnology, especially in plants. This review is valuable for professionals in the biochemistry field of protein structure-function relationships and experts in other fields, such as chemistry, nanotechnology, and plant sciences.

High-Throughput Screening Method Using Escherichia coli Keio Mutants for Assessing Primary Damage Mechanism of Antimicrobials.

The Escherichia coli Keio mutant collection has been a tool for assessing the role of specific genes and determining their role in E. coli physiology and uncovering novel functions. In this work, specific mutants in the DNA repair pathways and oxidative stress response were evaluated to identify the primary targets of silver nanoparticles (NPs) and their mechanism of action. The results presented in this work suggest that NPs mainly target DNA via double-strand breaks and base modifications since the recA, uvrC, mutL, and nfo mutants rendered the most susceptible phenotype, rather than involving the oxidative stress response. Concomitantly, during the establishment of the control conditions for each mutant, the katG and sodA mutants showed a hypersensitive phenotype to mitomycin C, an alkylating agent. Thus, we propose that KatG catalase plays a key role as a cellular chaperone, as reported previously for the filamentous fungus Neurospora crassa, a large subunit catalase. The Keio collection mutants may also be a key tool for assessing the resistance mechanism to metallic NPs by using their potential to identify novel pathways involved in the resistance to NPs.