Flours from Spondias mombin and Spondias tuberosa seeds: Physicochemical characterization, technological properties, and antioxidant, antibacterial, and antidiabetic activities.

Yellow mombin (Spondias mombin) and Brazil plum (Spondias tuberosa) seeds are byproducts of exploiting their pulp and currently have no relevant food or industrial applications. Thus, the present study aimed to evaluate the physicochemical, technological, and functional characteristics of flours obtained from yellow mombin (YMF) and Brazil plum (BPF) residues. The flours presented a high percentage of insoluble fiber (68.8-70.2 g/100 g) and low carbohydrate (2.7-4.0 g/100 g) and caloric (91.9-95.3 kcal) values. The flours showed potential for technological application. In addition, the highest concentration of total phenolic content (31.1-50.2 mg GAE/g) was obtained with 70% acetone, which provided excellent results for antioxidant capacity evaluated by 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (81.0%-89.7%) and 2,2-diphenyl-1-picrylhydrazyl (60.6%-69.1%) radical scavenging capacity assays. Flour extracts in 70% acetone also exhibited inhibition of α-amylase (63.3%-78.8%) and amyloglucosidase (63.5%-71.0%). The antibacterial study revealed that extracts inhibited the growth of Escherichia coli, Burkholderia cepacia, and Burkholderia multivorans. Therefore, this study suggests the use of yellow mombin and Brazil plum residues for different food or industrial applications. PRACTICAL APPLICATION: The knowledge gained from this study will open a new approach to add value to yellow mombin and Brazil plum fruit seeds as sources of fiber and bioactive compounds, with promising application in the formulation of functional and nutraceutical products, benefiting both a sustainable environment and a sustainable industry.

Microencapsulation of Probiotics by Oil-in-Water Emulsification Technique Improves Cell Viability under Different Storage Conditions.

Probiotics are associated with health benefits to the host. However, their application can be limited due to a decrease in cell viability during processing, storage, and passage through the gastrointestinal tract. Microencapsulation is a simple and efficient alternative to improve the physical protection and stability of probiotics. The present study aimed to produce and characterize alginate or gelatin-based microparticles containing Lactobacillus acidophilus NRRL B-4495 or Lactiplantibacillus plantarum NRRL B-4496 by oil-in-water (O/W) emulsification and to evaluate the stability under storage conditions. The results showed that L. acidophilus and L. plantarum encapsulated in gelatin (LAEG and LPEG) presented diameters of 26.08 ± 1.74 µm and 21.56 ± 4.17 µm and encapsulation efficiencies of 89.6 ± 4.2% and 81.1 ± 9.7%, respectively. However, those encapsulated in alginate (LAEA and LPEA) showed an encapsulation efficiency of <1.0%. Furthermore, LAEG was stable for 120 days of storage at 5 °C and 25 °C. Therefore, encapsulation in gelatin by O/W emulsification is a promising strategy for protecting and stabilizing probiotic bacteria, enabling future application in foods.

Faveleira (Cnidoscolus quercifolius Pohl) seed press cake flour: production, characterization and application for use in cookies.

BACKGROUND: Food processing produces large volumes of waste that can be transformed into useful and relevant ingredients. The by-product of oil extraction from faveleira seeds is a potentially low-cost raw material that can be used for obtaining functional foods. This study aimed to analyze the physicochemical properties, chemical composition, and antioxidant activity of faveleira (Cnidoscolus quercifolius Pohl) seed press cake flour (FSPCF). Additionally, the chemical composition, antioxidant activity, and physical, microbiological, and sensory aspects of cookies with 0, 25%, or 50% substitution of refined wheat flour (RWF) with FSPCF (0-FSPCF, 25-FSPCF, and 50-FSPCF cookies, respectively) were evaluated. RESULTS: FSPCF exhibited good physicochemical properties, high antioxidant activity (0.45 ± 0.00 and 42.83 ± 1.30 g TE g-1 for the DPPH and ABTS methods, respectively), and high polyphenol content (particularly gallic acid at 21015.85 ± 4981.76 g kg-1 ) and is also rich in minerals and fiber (359.40 ± 1.10 g kg-1 ). Replacement of RWF with FSPCF increased the activity of antioxidants and the levels of polyphenols, ash, lipids, proteins, and fibers. The 50-FSPCF cookie possessed the highest linoleic acid content (97.50 ± 8.47 g kg-1 ). Flour replacement influenced the weight of the cookies without affecting the other physical characteristics. The cookies yielded good sensory acceptance and purchase intentions. Contamination was not detected. CONCLUSION: Faveleira flour possesses high nutritional and bioactive value and can be used as a functional ingredient in cookies and possibly in other bakery products such as bread, cakes, and pastas. © 2022 Society of Chemical Industry.

Enhancing the expression of multi-antigen chimeric TGAGS/BST protein from Toxoplasma gondii in Escherichia coli BL 21 Star during batch cultivation.

Toxoplasmosis, despite advances in science and technology, is a disease that requires attention since there is no vaccine capable of immunizing humans and animals against all isolated types of Toxoplasma gondii. Thus, the use of chimeric proteins, which can contain multiple antigens, is a very promising alternative for the process of obtaining a vaccine and diagnostic test for toxoplasmosis due to the great diversity of antigens presented by T. gondii. In this context, the present study evaluates batch culture strategies in the production of the multi-antigenic chimeric protein TgAGS/BsT from Toxoplasma gondii. Several exploratory cultures were initially carried out to observe the kinetic behavior of E. coli BL21 Star in five different medium compositions without the addition of IPTG (inducer). Cultures of E. coli B21 Star were carried out with 1.0 mM IPTG at different times of initiation of induction (0.5, 1, and 6 h) to evaluate the effects on cell growth, production of the protein of interest, culture pH, and acetic acid formation. The results showed that among the culture media evaluated, 2xTY and TB supplemented with glycerol had the best cell concentration values of 3.42 ± 0.05 g/L and 5.48 ± 0.05 g/L, respectively. In the assays induced by IPTG, a higher expression of TgAGS/BsT protein was observed, with induction beginning within 6 h of culture, with a maximum concentration of protein of interest of 1.82 ± 0.02 g/L for the 2xTY and 2.49 ± 0.03 g/L for the TB medium. In addition, later induction by IPTG provided greater stability of plasmid pET-TgAGS, remaining with values above 90% at the end of culture.

Prevalence of helminths in fresh vegetables: a narrative literature review.

The consumption of fresh vegetables is related to healthy lifestyle habits present in culinary preparations in different regions. The presence of pathogenic parasites in these foods can cause gastrointestinal disorders. Thus, the objective of the present study was to carry out a narrative review of the literature on the prevalence of helminths in fresh vegetable samples. The analysis of the studies published from 2016 to 2022 showed that hookworms and Ascaris lumbricoides are the most common pathogenic helminths in fresh vegetable samples, with a prevalence of up to 73.8% and 55.1%, respectively. In addition, studies have shown associations between the presence of helminths and pathogenic protozoa. The results obtained in this review indicate the urgent need to implement actions at all stages of the vegetable production chain, from the water used in planting irrigation to cleaning before sale to the final consumer. © 2022 Society of Chemical Industry.

The beneficial effects of Lacticaseibacillus casei on the small intestine and colon of Swiss mice against the deleterious effects of 5-fluorouracil.

Background: Intestinal mucositis is one of the most common and important side effects of 5-fluorouracil (5-FU). Currently, there are still no specific and effective protocols for its prevention and treatment. The aim of the present study was to evaluate the effect of oral administration of Lacticaseibacillus casei (L. casei) on the progression of 5-FU-induced intestinal mucositis. Methods: L. casei (1x109 CFU/ml) or saline was orally administered to Swiss mice, beginning 15 days before intestinal mucositis induction by single intraperitoneal 5-FU administration (450 mg/kg). Body weight, number of peripheral leukocytes and fecal lactic acid bacteria were monitored. After euthanasia, on day 18, tissue samples from colon and each small intestine segment were collected for histopathology. Jejunal tissues were collected and evaluated for iNOS and TNF-alpha immunoexpression, IL-1-beta, IL-6 and TNF-alpha levels, malonaldehyde (MDA) accumulation, invertase activity and factor nuclear kappa B (NFkB-P65) gene expression, toll like receptor-4 (TLR-4), mucin-2 (MUC-2), occludin and zonula occludens-1 (ZO-1). Results: The positive impact of L. casei on 5-FU-induced leukopenia was observed, but not on 5-FU-induced weight loss in mice. L. casei reduced 5-FU-induced inflammation in the colon and small intestine (p<0.05). Decreased TNF-α, IL-1ß, IL-6 (p<0.05) and MDA (p<0.05) levels, as well as decreased iNOS and TNF-alpha protein expressions (p<0.05) were found in the jejunum from L casei group. In addition, L-casei down-regulated NFKB-P65 (p<0.05) and TLR-4 (p<0.05) gene expressions and up-regulated MUC-2 and mucosal barrier proteins occludin and ZO-1 gene expressions (p<0.05). Furthermore, greater lactic acid bacteria population (p<0.05) was found in the L. casei group when compared to control groups. Conclusion: Oral L. casei administration can protect the intestine of Swiss mice from 5-FU-induced intestinal mucositis, thus contributing to overall health.

Efficacy of sanitization protocols in removing parasites in vegetables: A protocol for a systematic review with meta-analysis.

BACKGROUND: Parasitic contamination of vegetables is a public health problem in several countries and a challenge for food safety. With a short path from the field to the table, these foods can suffer several flaws in the good practices of production, transport and packaging which culminate in an offer of contaminated food to consumers. Therefore, this study describes a systematic review protocol with meta-analysis on evaluating the effectiveness of existing sanitation methods in removing parasites from vegetables. METHODS: The study will be conducted from published studies that report analyzes of parasites in vegetables before and after sanitization processes. The MEDLINE, Embase, Web of Science, FSTA, LILACS, Scopus and AGRIS electronic databases will be used. In addition, manual searches will be carried out through related articles, references to included articles and directories of theses and dissertations. The primary outcome will be the reduction or absence of parasitic forms in vegetables after the intervention or combined interventions, and the secondary outcomes will include: identification of the main parasites, assessment of the time required for processing and cost-effectiveness analysis. Two authors will independently screen the studies and extract data. Disagreements will be resolved by discussion, and a third reviewer will decide if there is no consensus. The criteria established by the Cochrane Manual (with some adaptations) will be used to assess the risk of bias in the studies and if the results are considered acceptable and sufficiently homogeneous, and a meta-analysis will be performed to synthesize the findings. DISCUSSION: The systematic review produced from this protocol will provide evidence on the effectiveness of sanitation protocols for removing parasitic forms in vegetables and will contribute to strengthening food safety, with the adoption of best sanitation practices and prevention of health risks. In addition, the study may highlight possible knowledge gaps that need to be filled with new research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number: CRD42020206929.

Nanoencapsulation of buriti oil (Mauritia flexuosa L.f.) in porcine gelatin enhances the antioxidant potential and improves the effect on the antibiotic activity modulation.

The present study evaluated the cytotoxicity, antioxidant potential, and antimicrobial effect on the antibiotic activity modulation of gelatin nanoparticles containing buriti oil (OPG). The cytotoxicity analysis was performed on Chinese Hamster Ovary Cells (CHO) using a MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. The antioxidant potential of buriti oil and OPG was determined by total antioxidant capacity, reducing power, and the ABTS (2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid) test. The modulating antimicrobial activity was evaluated by determining the minimum inhibitory concentration (MIC) concentration against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, gentamicin and norflaxacillin. The nanoformulation of OPG did not show a cytotoxic effect on CHO cells and had a higher antioxidant potential than free buriti oil (p<0.05). The combination of antibiotics with free buriti oil and OPG was more efficient in inhibiting E. coli and P. aeruginosa than isolated norfloxacillin and gentamicin (p<0.05). Regarding the inhibition of S. aureus, OPG in combination with norfloxacillin reduced MIC by 50%. Nanoencapsulation was a viable alternative to enhance functionality and adding commercial value to buriti oil.

Physicochemical characterization and in vitro antioxidant activity of hyaluronic acid produced by Streptococcus zooepidemicus CCT 7546.

Hyaluronic acid (HA) is a biopolymer with applications in different areas such as medicine and cosmetics. HA is currently either isolated from animal sources or produced by microbial fermentation. Animal HA presents some disadvantages such as high cost and risk of viral cross-species or another infectious agent. In the present study, we evaluated the physicochemical characteristics and in vitro antioxidant capacity of HA produced by Streptococcus zooepidemicus CCT 7546. In addition, commercial sodium hyaluronate (SH) from an animal source was used as control. The microbial HA yield after purification was 69.8 mg/L. According to Fourier transform infrared spectroscopy, it was seen that bacterial and animal HA spectra are overlapped. The thermogravimetric analysis revealed that microbial HA was more stable than its equivalent from the animal source. However, scanning electron microscopy indicates that the purification method used in the animal product was more effective. Microbial HA showed activity in total antioxidant capacity (14.02 ± 0.38%), reducing power (18.18 ± 6.43%), DPPH radical-scavenging (5.57 ± 0.23 kmol TE/g), and hydroxyl radical-scavenging (28.39 ± 2.40%) tests. Therefore, in vitro antioxidant tests demonstrated that the antioxidant action mechanism occurs through scavenging reactive oxygen species (ROS) and donating electrons/hydrogen atoms.

Chemical and biological activities of faveleira (Cnidoscolus quercifolius Pohl) seed oil for potential health applications.

Faveleira (Cnidoscolus quercifolius) is an emerging Brazilian plant, with seeds rich in edible oil. This study investigates physicochemical properties, chemical composition, thermal and oxidative stability, in vitro and in vivo toxicity, antioxidant, antinociceptive and anti-inflammatory activities of faveleira seed oil. It was observed that the oil has low acidity, value of peroxide, chlorophyll, carotenoids, ß-carotene and high concentrations of unsaturated fatty acids. In addition to presenting thermal and oxidative stability and high total phenolic content, with vanillin, eugenol and quercetin were predominating. The oil showed no toxicity in vitro and in vivo, and presented antioxidant, anti-inflammatory and antinociceptive activities. These findings provide relevant and appropriate conditions for processing of faveleira seed oil as functional food.

Lactose hydrolysis using ß-galactosidase from Kluyveromyces lactis immobilized with sodium alginate for potential industrial applications.

The present study aimed to evaluate the lactose hydrolysis conditions from "coalho" cheese whey using ß-galactosidase (ß-gal) produced by Kluyveromyces lactis immobilized with sodium alginate. Three sodium alginate-based immobilization systems were evaluated (0.5, 0.7, and 1% w/v) for maximizing the immobilization yield (Y), efficiency (EM), and recovered activity (ar). The lactose hydrolysis capacity of the immobilized form of ß-gal was determined, and simulated environments were used to assess the preservation of the immobilized enzyme in the gastrointestinal tract. The results showed that ß-gal immobilization with 1% (w/v) sodium alginate presented the best results (EM of 66%, Y of 41%, and ar of 65%). The immobilization system maintained the highest pH stability in the range between 5.0 and 7.0, with the highest relative activity obtained under pH 5 conditions. The temperature stability was also favored by immobilization at 50 °C for 30 min was obtained a relative activity of 180.0 ± 1.37%. In 6 h, the immobilized ß-gal was able to hydrolyze 46% of the initial lactose content. For the gastrointestinal simulations, around 40% of the activity was preserved after 2 h. Overall, the results described here are promising for the industrial applications of ß-galactosidase from K. lactis.

Whey protein isolate-gelatin nanoparticles enable the water-dispersibility and potentialize the antioxidant activity of quinoa oil (Chenopodium quinoa).

The quinoa oil presents benefits to health, but its low water dispersibility in the aqueous matrix and instability of bioactive compounds is challenging for food application. This study performed the physicochemical and chemical characterization of quinoa oil and evaluated its water dispersibility and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity after nanoencapsulation in porcine gelatin and combination with whey protein isolate by emulsification O/W technique. Thus, three formulations were obtained: 1) OG-containing quinoa oil and porcine gelatin in aqueous phase 2; 2) OWG1-containing quinoa oil, whey protein isolate, and porcine gelatin in aqueous phase 2; and 3) OWG2-containing quinoa oil and whey protein isolate in aqueous phase 1, and porcine gelatin in aqueous phase 2. The oil characterization showed that quinoa oil presented the predominance of linoleic acid (53.4%), and concentration of alpha and gamma-tocopherol, respectively, of 8.56 and 6.28 mg.100g-1. All formulations presented a smooth surface without depression or cracking, an average diameter between 165.77 and 529.70 nm. Fourier transform infrared spectroscopy indicated chemical interaction between the encapsulating agents and the oil in all formulations, being more intensified in OWG1 and OWG2. Based on this, these formulations showed higher dispersibility in aqueous solution [68% (3.48) and 71% (2.97)]. This resulted in higher antioxidant activity for OWG1 and OWG2, showing the amounts that reduces antioxidant activity by 50% equal to 5.30 (0.19) mg/mL and 5.54 (0.27) mg/mL, respectively, compared to quinoa oil [13.36 (0.28) mg/mL] (p < 0.05). Thus, quinoa oil nanoencapsulation proved to be an efficient alternative to enable water-dispersibility and enhance antioxidant activity, increasing its potential for application in the food industry.

Potential of "coalho" cheese whey as lactose source for ß-galactosidase and ethanol co-production by Kluyveromyces spp. yeasts.

The present study evaluated the co-production of ß-galactosidase and ethanol by Kluyveromyces marxianus ATCC 36907 and Kluyveromyces lactis NRRL Y-8279 using as carbon source the lactose found on "coalho" cheese whey. Cheese whey was subjected to partial deproteinization, and physicochemical parameters were assessed. Cultivations were carried out in an shaker to evaluate two carbon/nitrogen (C:N) ratios. The best C:N ratio (1.5:1) was carried to 1.5-L bioreactor cultivation in order to increase co-production yields. The stability of ß-galactosidase was assessed against different temperatures and pH, and in the presence of metal ions. Concerning the co-production of ß-galactosidase and ethanol, K. lactis proved to be more efficient in both the C:N ratios, reaching 21.09 U·mL-1 of activity and 7.10 g·L-1 of ethanol in 16 h. This study describes the development of a viable and value-adding biotechnological process using a regional cheese by-product from Northeast Brazil for co-production of biomolecules of industrial interest.

Use of plasmids for expression of proteins from the genus Leishmania in Escherichia coli: current state and perspectives.

Leishmaniosis is caused by the protozoa of the genus Leishmania with a wide spectrum of clinical and epidemiological manifestations which are characterized into four clinical groups: cutaneous, mucocutaneous, diffuse cutaneous, and visceral. American visceral leishmaniosis (AVL) or visceral leishmaniosis (VL) has been known as the most severe form of the disease. However, despite the growing number of people exposed to the infection risk and the great effort done by the scientific community worldwide to significantly increase the knowledge about these diseases, there is no vaccine capable of preventing VL in humans. In this short review, we present some of the plasmids used for the expression of recombinant protein by Escherichia coli strains used mainly for the second generation of vaccines for leishmaniosis. It can be emphasized that currently, these vectors and hosts play an important role in developing vaccine strategies against the disease. Indeed, use of the E. coli BL21 (DE) strain is remarkable mainly due to its characteristics for being a stable protein producer as well as the use of histidine tags for antigen purification. KEY POINTS: • Plasmid vectors and E. coli will continue being important for studies about leishmaniosis. • Protein purification exploiting histidine tags is a key technique.

From seed to flour: Sowing sustainability in the use of cantaloupe melon residue (Cucumis melo L. var. reticulatus).

Reduction of waste from food industry and food services is a current concern due to the large amount of waste generated, including peels and fruit seeds. The objective of this study was to obtain a flour produced from Cantaloupe melon seeds (Cucumis melo L. var. reticulatus) and to evaluate the viability of using the product as an ingredient in cake manufacturing. In this study, different formulations were developed: standard cake-0% (F1) and cakes containing melon seed flour as substitute of wheat flour in 10% (F2), 30% (F3), and 50% (F4) concentrations. Centesimal composition, dietary fibre, structural and morphological characterization, determination of mineral composition, and evaluation of fatty acids profile in melon seed flour were carried out. To determine the overall acceptance of cake formulations, sensory analysis was performed with 135 non-trained panelists, which also included the identification of sensorial attributes using the Just About Right ideal scale test. The results showed that the melon seed flour has considerable nutritional value, with 18% proteins, 3% moisture, 4% ash, 30% lipids, and 35% dietary fibre. Melon flour also has a significantly high content of minerals, mainly phosphorus (1507.62 mg/100 g), potassium (957.35 mg/100 g), and magnesium (504.03 mg/100 g). The polyunsaturated fatty acid fraction was the most abundant in melon seed flour, with predominance of omega-6 fatty acids (17.95 g/mg of sample). Sensorial analysis disclosed good acceptance for formulations containing 10% and 30% of melon seed flour, with the 10% formulation being the most accepted. The research showed the feasibility of using the melon seed flour in cake production, as well as the possibility of using food waste in restaurants and food industries in order to adhere to sustainable production actions.

Evaluation of induction conditions for plasmid pQE-30 stability and 503 antigen of Leishmania i. chagasi expression in E. coli M15.

The present study aimed to evaluate the influence of induction conditions (IPTG concentration, temperature, and induction time) on the plasmid pQE-30 stability and 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15. Batch cultures were performed at 37 °C and induced by the addition of different IPTG concentrations (0.01 to 1.5 mM). Subsequently, experiments were carried out at different temperatures (27 to 42 °C), evaluating the influence of induction time (0.5 to 6 h after the start of the culture). The results showed that IPTG toxicity caused a metabolic stress in the cells and, consequently, the microorganism growth reduced. The induction with IPTG may also be associated with the plasmid pQE-30 instability, due to metabolic burden imposed by the recombinant protein expression. The optimal conditions for 503 antigen expression of Leishmania i. chagasi in Escherichia coli M15 were an IPTG concentration of 1.0 mM, temperature of 37 °C, and induction time of 2 h. The maximum antigen concentration obtained was 0.119 ± 0.009 g/L, about seven times higher than the lowest concentration. Therefore, the results showed that 503 antigen can be produced in laboratory; however, it requires more studies to minimize the plasmid instability and improve to industrial scale.

Optimization of the 503 antigen induction strategy of Leishmania infantum chagasi expressed in Escherichia coli M15.

Leishmaniosis is a complex of diseases that can be fatal, if not given proper attention. Despite its relevance in the public health system, there is no vaccine capable of preventing the disease in humans so far and its treatment is expensive and aggressive to human health. The present study aims to optimize the induction parameters of the 503 Leishmania i. chagasi antigen expressed in recombinant Escherichia coli M15. The induction at different cell densities was evaluated in order to analyze the influence of the induction time on the yield of the protein of interest. In this segment, lactose and isopropyl-ß-d-thiogalactopyranoside (IPTG) were used as inducer molecules, using various concentrations: 0.1 g/L, 1.0 g/L, and 10 g/L for lactose and 20 µM, 100 µM, 500 µM, and 1000 µM for IPTG. The results presented that the concentration of IPTG that obtained the higher antigen levels was that of 100 µM (0.087 g/L), a 10-fold lower concentration than was being previously used in this type of system and for lactose, it was 1 g/L (0.016 g/L). Thus, the induction with 100 µM allowed obtaining the antigen with a concentration 5.6 times higher than the lactose induction maximum concentration.

Enhancing enzymatic hydrolysis of coconut husk through Pseudomonas aeruginosa AP 029/GLVIIA rhamnolipid preparation.

This work investigated the influence of chemical (Triton X-100) and biological surfactant preparation (rhamnolipids) in coconut husk hydrolysis that was subjected to pretreatment with acid-alkali or alkaline hydrogen peroxide. The natural and pretreated biomass was characterized using the National Renewable Energy Laboratory protocol analysis as well as X-ray diffraction and scanning electron microscopy. The results demonstrated that in terms of the total reducing sugars, there was no significant difference between the hydrolysis using Triton X-100 and rhamnolipids, regardless of the pretreatment. A cellulosic conversion value as high as 33.0% was obtained in experiments with rhamnolipids. The coconut husk was observed to be a potential biomass that could produce second generation ethanol, and the rhamnolipid preparation can be used to support for the enzymatic hydrolysis, enhancing the advantage of cellulose conversion into glucose over chemical surfactants because it is an environmentally friendly approach.

Recovery and purification of recombinant 503 antigen of Leishmania infantum chagasi using expanded bed adsorption chromatography.

Visceral leishmaniasis, a disease caused by Leishmania infantum chagasi, represents a major public health problem in many areas of the world. However, there is currently no vaccine for human use. The aim of this work was to purify the 503 antigen of Leishmania i. chagasi directly from unclarified Escherichia coli feedstock through expanded bed adsorption (EBA) chromatography. Batch experiments were performed to optimize the adsorption and elution conditions of the antigen onto a STREAMLINE Chelating resin using two central composite rotatable designs (CCRD). The results showed that the optimal binding conditions of the 503 antigen were pH 8.0 in the presence of 2.4 M NaCl. For the elution of the target protein, the optimized conditions included the presence of 600.0 mM imidazole. The adsorption isothermal data of the 503 antigen were fitted to the Langmuir adsorption isotherm. The EBA experiment successfully recovered 59.2% of the 503 antigen from the unclarified E. coli homogenate with a purification factor of 6.0.

A 7-year survey of superficial and cutaneous mycoses in a public hospital in Natal, Northeast Brazil.

In the present study, we determined the frequency of superficial and cutaneous mycoses and their etiologic agents during a 7-year period (2002-2008) in Natal, Brazil. A total of 1,717 specimens of skin, nail, and hair were collected from 1,382 patients with suspected mycoses lesions and were then subjected to direct microscopy and culture.