Comet assay to evaluate chromosomal changes in chickens (Gallus gallus domesticus) contaminated by lead in a city in Bahia.

Chicken (Gallus gallus domesticus) is one of the primary sources of animal protein for the Brazilian population. Thus, the safety of this food is highly relevant. This study was based on the evidence of severe contamination of these animals by metals such as lead in Santo Amaro, Bahia. This exploratory study aimed to evaluate associations between lead levels in blood of chicken exposed to a contaminated area with the occurrence of chromosomal alterations, evidencing genotoxic effects. Serum lead analysis was performed by GF-AAS after dilution with a matrix modifier solution (Triton X-100 0.2% v/v and HNO3 0.1% v/v), while chromosomal damage was evaluated using the comet assay. The results showed genotoxic effects (positive comet assay) only for the specimen sample with higher serum lead concentrations (33.9 µg dL-1), suggesting the occurrence of toxic effects at this level of exposure. This work evaluated a relationship between the reduction of serum lead levels in chicken and increased distance from the primary polluting source - a lead processing plant (COBRAC). It also showed that lead is bioavailable in this territory, contaminating chicken and causing genotoxic effects in these animals, further expanding the concern with the local biota and the health of the residents of Santo Amaro.

New potential antiproliferative monophosphoester 2-aminoethyl dihydrogen phosphate in K-562 and K-562 MDR+ leukemia cells.

The main obstacle in the treatment of cancer patients has been resistance to multiple drugs, leading to the need to develop molecules with a higher specificity target. The liposomal formulation DODAC/2-AEH2P has antitumor potential, inducing apoptosis in several tumor types. Human chronic myeloid leukemia K-562 and K-562 Lucena (MDR+) cells were treated with the DODAC carrier and the liposomal formulation 2-AEH2P. Viability, cell cycle phases, apoptosis, marker expression and mitochondrial potential were analyzed. Significant reduction in viability was observed for all treatments. Changes in the distribution of the cell cycle phases and expression of markers involved in the apoptosis pathways were observed. Reduction of the mitochondrial electrical potential mediated by Bcl-2, being regulated by the reduction of the MTCH2 protein linked to the progression of myeloid leukemia and an increase in the pro-apoptotic proteins Bad and Bax, dependent on p53. This study demonstrated a significant therapeutic potential through apoptotic effects in leukemic cells, regardless of the molecular resistance profile (MDR+).

Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819) / Presença de genes de virulência em isolados de Escherichia coli provenientes de sururu Mytella guyanensis (Lamarck, 1819) comercializado

Abstract The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumer's health.

Resumo O isolamento de Escherichia coli a partir de alimentos é uma grande preocupação, pois cepas patogênicas desta bactéria podem causar desde diarreia até síndrome hemolítico-urêmica. Diante do exposto, o objetivo do trabalho foi pesquisar genes de virulência em isolados de Escherichia coli provenientes do sururu Mytella guyanensis comercializado na cidade de Cachoeira, Bahia, Brasil. As amostras foram adquiridas de quatro comerciantes, sendo duas de mercados e duas em pontos de venda na feira livre da cidade de Cachoeira, acondicionadas em caixas isotérmicas com gelo reutilizável e transportadas até o laboratório para a análise. Após a análise microbiológica, as cepas de Escherichia coli foram isoladas em ágar Eosina Azul de Metileno e preservadas em caldo Brian Heart Infusion e glicerol a 15% e mantidas a - 20° C. A identificação dos genes de virulência nas cepas isoladas foi realizada utilizando primers específicos, por meio da Reação em Cadeia da Polimerase. Foram obtidos 24 isolados de Escherichia coli, destes a prevalência do gene elt , característico de Escherichia coli enterotoxigênica, foi de 75% dos isolados. Não houve a detecção dos genes stx e bfpA nos isolados, os quais são prevalentes nas cepas de Escherichia coli enterohemorrágica e Escherichia coli enteropatogênica, respectivamente. A presença do gene elt relacionado à virulência de Escherichia coli nos isolados de Mytella guyanensis revela a necessidade da melhoria no processamento, incluindo boas práticas de manipulação, armazenamento adequado e cocção previa ao consumo, visando a garantia da saúde do consumidor.

Dihydrocaffeic Acid Prevents UVB-Induced Oxidative Stress Leading to the Inhibition of Apoptosis and MMP-1 Expression via p38 Signaling Pathway.

Chronic UVB exposure promotes oxidative stress, directly causes molecular damage, and induces aging-related signal transduction, leading to skin photoaging. Dihydrocaffeic acid (DHCA) is a phenolic compound with potential antioxidant capacity and is thus a promising compound for the prevention of UVB-induced skin photodamage. The aim of this study was to evaluate the antioxidant and protective effect of DHCA against oxidative stress, apoptosis, and matrix metalloproteinase (MMP) expression via the mitogen-activated protein kinase (MAPK) signaling pathway on L929 fibroblasts irradiated with UVB. DHCA exhibited high antioxidant capacity on 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS•+), and xanthine/luminol/xanthine oxidase (XOD) assays and reduced UVB-induced cell death in the neutral red assay. DHCA also modulated oxidative stress by decreasing intracellular reactive oxygen species (ROS) and extracellular hydrogen peroxide (H2O2) production, enhancing catalase (CAT) and superoxide dismutase (SOD) activities and reduced glutathione (GSH) levels. Hence, cellular damage was attenuated by DHCA, including lipid peroxidation, apoptosis/necrosis and its markers (loss of mitochondria membrane potential, DNA condensation, and cleaved caspase 9 expression), and MMP-1 expression. Furthermore, DHCA reduced the phosphorylation of MAPK p38. These findings suggest that DHCA can be used in the development of skin care products to prevent UVB-induced skin damage.

Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819).

The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumer's health.

Frequent MRSA nasal colonization among hospitalized children and their parents in Angola and São Tomé and Príncipe.

BACKGROUND: The prevalence of nosocomial meticillin-resistant Staphylococcus aureus (MRSA) was previously estimated as 23% in a paediatric hospital in Luanda, Angola and 18% in a general hospital in São Tomé and Príncipe. AIM: To evaluate the prevalence of S. aureus/MRSA colonization among hospitalized children and their parents at two hospitals in Angola and São Tomé and Príncipe. METHODS: In 2017, 127 hospitalized children and 129 of their parents had nasal swabs for S. aureus/MRSA carriage in the two countries. The isolates were tested for the presence of the mecA and Panton-Valentine leukocidin (PVL) genes, and characterized by pulsed-field gel electrophoresis (PFGE), spa typing, multi-locus sequence typing and SCCmec typing. FINDINGS: Twenty of 127 children (15.7%) and 13 of 129 parents (10.1%) were MRSA nasal carriers. Three lineages comprised 88% of the MRSA isolates: (i) PFGE A-ST5-SCCmec IVa (N=15; 45%), associated with spa type t105, recovered in Angola alone; (ii) PFGE N-ST8-IV/V (N=7; 21%), associated with spa types t008/t121, recovered in São Tomé and Príncipe alone; and (iii) PFGE B-ST88-IVa (N=7; 21%), associated with spa types t325/t786, present in both countries. Fifteen child/guardian pairs were colonized with identical MRSA (N=8) or meticillin-susceptible S. aureus (N=7) strains. PVL was detected in 25% of isolates, including two MRSA (ST30-V and ST8-IVa). CONCLUSION: Hospitalized children and their parents are important reservoirs of MRSA. Infection control measures should focus on parents in order to minimize the spread of MRSA to the community.

Immunoexpression of tumour necrosis factor-α, interleukin-1α and interleukin-10 on odontogenic cysts and tumours.

AIM: To analyse the immunoreactivity of IL-1α, TNF-α and IL-10 in odontogenic cysts and tumours and to investigate possible associations with established biological behaviours of these different lesions. METHODOLOGY: Immunohistochemical expression of anti-IL-1α, anti-TNF-α and anti-IL-10 antibodies was assessed on epithelium and mesenchyme of 20 radicular cysts (RCs), 20 residual cysts (RECs), 20 dentigerous cysts (DCs), 18 solid ameloblastomas (SAs), 20 keratocystic odontogenic tumours (KCOTs) and 15 dental follicles (DFs). Comparative analysis of data was performed using the nonparametric Wilcoxon signed-rank test and Kruskal-Wallis's test. RESULTS: Significantly greater expression of IL-1α in the epithelium was noted in RC, KCOT and SA (P = 0.01), whilst IL-10 and TNF-α was in the epithelium of RC, DC and KCOT (P < 0.01). In the mesenchyme, significantly greater immunopositivity was observed for IL-1α, IL-10 and TNF-α in KCOT, DC and RC (P < 0.01). In epithelial and mesenchymal tissues, there were a significant number of cases of RC and DC with IL-1α < IL-10 ratio (P < 0.01), whilst SA and KCOT showed IL-1α > IL-10 (P < 0.01). There was a significantly greater percentage of DF, DC and KCOT with TNF-α > IL10 ratio (P < 0.01). CONCLUSION: These results suggest involvement of the proteins in the pathogenesis of odontogenic cysts and tumours, with emphasis on the highest immunoreactivity of osteolysis stimulating factors in tumours with aggressive biological behaviour, such as SA and KCOT.

Virulence genes in Escherichia coli isolates from commercialized saltwater mussels Mytella guyanensis (Lamarck, 1819)

Abstract The isolation of Escherichia coli from food is a major concern. Pathogenic strains of these bacteria cause diseases which range from diarrhea to hemolytic-uremic syndrome. Therefore the virulence genes in E. coli isolates from the mussel ( Mytella guyanensis) commercialized in Cachoeira, Bahia, Brazil were investigated. Samples were purchased from four vendors: two from supermarkets and two from fair outlets. They were conditioned into isothermal boxes with reusable ice and transported to the laboratory for analysis. E. coli strains were isolated in eosin methylene blue agar, preserved in brain-heart infusion medium with 15% glycerol and stored at -20 °C, after microbiological analysis. Virulence genes in the isolated strains were identified by specific primers, with Polymerase Chain Reaction. Twenty-four isolates were obtained, with a prevalence of elt gene, typical from enterotoxigenic infection, in 75% of the isolates. The stx and bfpA genes, prevalent in enterohemorragic and enteropathogenic E. coli, respectively, were not detected. The occurrence of elt virulence-related gene in the E. coli isolates of Mytella guyanensis reveals urgent improvement in food processing, including good handling practices, adequate storage and cooking before consumption, to ensure consumers health.

Resumo O isolamento de Escherichia coli a partir de alimentos é uma grande preocupação, pois cepas patogênicas desta bactéria podem causar desde diarreia até síndrome hemolítico-urêmica. Diante do exposto, o objetivo do trabalho foi pesquisar genes de virulência em isolados de Escherichia coli provenientes do sururu Mytella guyanensis comercializado na cidade de Cachoeira, Bahia, Brasil. As amostras foram adquiridas de quatro comerciantes, sendo duas de mercados e duas em pontos de venda na feira livre da cidade de Cachoeira, acondicionadas em caixas isotérmicas com gelo reutilizável e transportadas até o laboratório para a análise. Após a análise microbiológica, as cepas de Escherichia coli foram isoladas em ágar Eosina Azul de Metileno e preservadas em caldo Brian Heart Infusion e glicerol a 15% e mantidas a - 20° C. A identificação dos genes de virulência nas cepas isoladas foi realizada utilizando primers específicos, por meio da Reação em Cadeia da Polimerase. Foram obtidos 24 isolados de Escherichia coli, destes a prevalência do gene elt , característico de Escherichia coli enterotoxigênica, foi de 75% dos isolados. Não houve a detecção dos genes stx e bfpA nos isolados, os quais são prevalentes nas cepas de Escherichia coli enterohemorrágica e Escherichia coli enteropatogênica, respectivamente. A presença do gene elt relacionado à virulência de Escherichia coli nos isolados de Mytella guyanensis revela a necessidade da melhoria no processamento, incluindo boas práticas de manipulação, armazenamento adequado e cocção previa ao consumo, visando a garantia da saúde do consumidor.

Contamination of public transports by Staphylococcus aureus and its carriage by biomedical students: point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains.

OBJECTIVES: To analyse the contamination of public transports by Staphylococcus aureus and assess its carriage by biomedical students, focussing on the point-prevalence, related risk factors and molecular characterization of methicillin-resistant strains. STUDY DESIGN: Cross-sectional survey. METHODS: Methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA) isolated from handrails of buses (n = 112) and trains (n = 79) circulating in Porto and from nasal swabs of local university students (n = 475) were quantified, characterized by molecular typing methods and related to possible risk factors. RESULTS: The MRSA prevalence in buses (16.1%) was not significantly different from trains (8.9%). There was also no identifiable association between the counts of MSSA and MRSA in buses and trains and the number of travellers in each sampling day, specific routes (including those passing by main hospitals) or other risk factors. Of the students, 37.1% carried S. aureus, and having a part-time job or smoking were found to be risk factors for carriage. EMRSA-15 (ST22-SCCmecIVh) was the prevalent MRSA clonal lineage, found not only in the buses (n = 14) and trains (n = 2) but also in the single MRSA-carrier among the students. The characteristics of the community-associated Southwest Pacific MRSA clone were found in a single ST30-IVa isolate, which may suggest a recent SCCmec acquisition by an MSSA background in the community. CONCLUSIONS: The spread of EMRSA-15, a common hospital-associated lineage, among different public transports and as a nasal coloniser is of concern and warrants adequate public health control measures.

Nectandra falcifolia: potential phytopharmaceutical for skin damage protection designed by statistical approach and characterized by photoacoustic spectroscopy

AbstractPhytopharmaceutical products are being used in the treatment and prevention of health problems. Nowadays, the development and evaluation of novel pharmaceutical products is expensive and time consuming. A statistical approach is a good tool for optimal development processes. Nectandra falcifolia (Nees) J.A. Castigl. ex Mart. Crov. & Piccinini, Lauraceae, a Brazilian species, is reported as anti-inflammatory, anti-leishmanial and anti-microbial. However, there is little known about its chemical composition. For other species of Nectandra genus, the presence of antioxidant compounds is reported. In order to optimize the process of obtaining extract with high antioxidant activity, different extraction conditions were tested following a statistical approach. Two sequential experimental designs were used – first, a factorial 23 design, followed by central composite 22. The extracts manufactured by these experimental statistical matrixes had their antioxidant activity and phenolic contents quantified and the response surface plots were fitted in quadratic models and they predicted the best extraction condition for the best antioxidant activity. This standardized extract and its antioxidant activity were better evaluated by two complementary tests (ABTS and Burst respiratory). A topical formulation containing 1% (w/w) of standardized extract was prepared and used for an in vivo skin permeation study using a two-dose application. The photoacoustic spectroscopy was used to analyze the samples from the permeation study and the composition profile of standardized extract. In rat skin samples, the data demonstrated that for the higher dose of topical formulation (5 g/cm2), the standardized extract could cross skin and be seen in epidermis and dermis. This was not the case for the lower dose (2 g/cm2) which was only present in the epidermis. This information suggests that this novel standardized extract of N. falcifoliacould be explored for skin damage prevention or treatment for diseases developed by oxidative damage.

Staphylococcus aureus in former Portuguese colonies from Africa and the Far East: missing data to help fill the world map.

The aim of the present study was to determine the prevalence and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage among patients and healthcare workers in Angola (ANG), São Tomé and Príncipe (STP), Cape Verde (CV) and East Timor (ET), and to characterize the antimicrobial susceptibility, virulence content and population structure of all S. aureus. Despite the importance of MRSA as a major human pathogen, data from these former Portuguese colonies in Africa and Asia are scarce. A total of 2065 nasal swabs recovered between 2010-14 were included in the study. Antimicrobial susceptibility testing and molecular characterization of S. aureus showed: (i) a very high MRSA prevalence in ANG (61.6%), moderate in STP (25.5%), low in CV (5.6%) and null in ET; (ii) a high prevalence of Panton-Valentine leukocidin in STP (36.8%), ET (29.2%) and CV (28.3%) contrasting with ANG (7.9%); (iii) ST5-SCCmecIVa, ST8-IV/V and ST5-VI were the major MRSA clones in ANG (65.2%), STP (44.8%) and CV (50%), respectively; (iv) a high resistance to trimethoprim-sulfamethoxazole in ANG (66.5%) and STP (50.9%), to rifampin in ANG (77.3%), and to tetracycline in STP (26.3%) and ET (20.8%); (v) three major methicillin-susceptible S. aureus clones (ST15, ST508, ST152) were present in all four countries. Age <18 years (OR 2.03, 95% CI 1.24-3.31), previous surgery (OR 2.45, 95% CI 1.24-4.83), no smoking (OR 4.04, 95% CI 1.05-15.50), and longer hospitalization (OR 2.53, 95% CI 1.49-4.28) were risk factors for MRSA carriage. This study provided the first comprehensive overview on MRSA in former Portuguese colonies in Africa and Asia, missing data in the world map.

Evidence of deep percutaneous penetration associated with anti-inflammatory activity of topically applied Helicteres gardneriana extract: a photoacoustic spectroscopy study.

PURPOSE: To apply the photoacoustic spectroscopy technique to investigate the penetration rate of topically applied Helicteres gardneriana extract used as anti-inflammatory agent. METHODS: Experiments were performed ex vivo in a well-controlled group of mice. The crude extract was obtained from leaves of the plant Helicteres gardneriana. Croton oil was applied into the ventral surface of the mouse's right and left auricles in order to induce an inflammatory response. The left auricle was treated with crude extract, while the right one served as the control. After 6 h, the auricles were sectioned for measurements of edema intensity, myeloperoxidase activity and the formulation penetration rate. RESULTS: Croton oil induced inflammatory response in both auricles. The application of Helicteres gardneriana extract reduced significantly the edema of the auricle and inhibited the activity of the myeloperoxidase enzyme. The photoacoustic data showed that the propagation of the formulation was efficient to reach the deep region of the auricle, crossing the cartilage. The strong anti-inflammatory effect was associated with the observed deep penetration of the formulation. CONCLUSION: This pre-clinical study showed the anti-inflammatory effect of Helicteres gardneriana extract. The photoacoustic technique was useful to demonstrate that this anti-inflammatory activity was associated with deep percutaneous penetration.

High prevalence of ST121 in community-associated methicillin-susceptible Staphylococcus aureus lineages responsible for skin and soft tissue infections in Portuguese children.

In order to evaluate the incidence of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) in Portugal, we analyzed a collection of 38 S. aureus isolates recovered from 30 children attending the pediatric emergency department of a central hospital in Lisbon due to skin and soft tissue infections. Molecular characterization identified seven clonal lineages among the 35 methicillin-susceptible S. aureus (MSSA) isolates, of which the major lineage PFGE A/t159/ST121 included 63% of the isolates. The three MRSA isolates belonged to the Pediatric clone PFGE D/t535/ST5-IV (n = 2) and to the European CA-MRSA clone PFGE G/t044/ST80-IVc (n = 1). All isolates harbored several virulence factors, namely, leukocidins. Panton-Valentine leukocidin (PVL) was produced by isolates from five MSSA lineages and by the ST80 MRSA. Of interest, this is the first reported isolation of CA-MRSA ST80 in Portugal.

Prevalence and clonality of methicillin-resistant Staphylococcus aureus (MRSA) in the Atlantic Azores islands: predominance of SCCmec types IV, V and VI.

In order to obtain insights into the methicillin-resistant Staphylococcus aureus (MRSA) population structure in the Azores archipelago, 106 MRSA isolates were collected from patients attending an Azorean central hospital between January 2007 and February 2008. Antimicrobial resistance was determined for all isolates. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE), spa typing, multilocus sequence typing (MLST), staphylococcal chromosome cassette mec (SCCmec) typing and the presence of Panton-Valentine leukocidin (PVL). The majority of the isolates (87%, n = 92) belonged to the EMRSA-15 clone (ST22, SCCmec-IVh), followed by the Pediatric clone (ST5-VI/IVc) (11%, n = 12). The Berlin clone (ST45-IVa) and a new clone (spa type t1839, ST1339 and SCCmec V variant) were represented by single isolates. All of the isolates carried SCCmec types IV, V or VI and a non-multiresistant antibiotic profile, resembling the currently emerging community MRSA. Moreover, PVL was described for the first time to be associated with the Pediatric clone carrying SCCmec type VI. We provided the first description of the population structure of MRSA in the Azores islands, which seems to be shaped by genetic events occurring locally, as well as by the regular population exchange between the islands, continental Portugal, the United Kingdom and the United States.

Free radical scavenging and anti-edematogenic activities of Paullinia elegans Cambess., Sapindaceae, leaves extracts / Atividades sequestradora de radicais livres e anti-edematogênica de extratos das folhas de Paullinia elegans Cambess., Sapindaceae

Ethanol extract of the leaves of Paullinia elegans Cambess., Sapindaceae, and its hexane, chloroform, ethyl acetate, and hydroethanol fractions were evaluated for their antiedematogenic and free radical scavenging activities. The ethanol extract and the hexane fraction produced statistically significant inhibition (74.4 and 76.0 percent, respectively) of the ear edema induced by croton oil in mice, observed at doses of 5 mg/ear. The ethyl acetate and hydroethanol fractions showed significant radical scavenging effect in the DPPH assay, with IC50 of 36.7 and 30.1 µg/mL, respectively. Fractionation of the extracts through chromatographic methods afforded epifriedelanol, oleanolic acid 3-O-acetyl, a mixture of stigmasterol 3-β-O-glucopyranoside and sitosterol 3-β-O-glucopyranoside, kaempferol 3,7-O-α-dirhamnopyranoside, kaempeferol-3-O-α-rhamnopyranoside and 2-O-methyl-chiro-inositol. The compounds were identified on the basis of their NMR spectral data and comparison with those of literature.

O extrato etanólico das folhas de Paullinia elegans Cambess., Sapindaceae, e as frações n-hexano, clorofórmio, acetato de etila e hidroetanólica, obtidas de seu fracionamento, foram avaliadas quanto às suas atividades anti-edematogênica e sequestradora de radicais livres. O extrato etanólico e a fração hexano produziram inibição significativa (74,4 e 76,0 por cento, respectivamente) do edema da orelha induzido pelo óleo de cróton em ratos, em doses de 5 mg/orelha. As frações acetato de etila e hidroetanólica mostraram atividade sequestradora de radicais livres no ensaio de DPPH, com IC50 de 36,7 e de 30,1 µg/mL, respectivamente. O fracionamento dos extratos pelo uso de métodos cromatográficos resultou no isolamento do epifriedelanol, ácido 3-O-acetil oleanólico, mistura do stigmasterol 3-β-O-glucopiranosídeo e sitosterol 3-β-O-glucopiranosídeo, canferol, canferol 3,7-O-α-diramnopiranosídeo, canferol 3-O-α-ramnopiranosídeo e 2-O-metil-chiro-inositol. Os compostos foram identificados com base na comparação de seus dados espectroscópicos de RMN com os da literatura.

Dengue virus-induced regulation of the host cell translational machinery

Dengue virus (DV)-induced changes in the host cell protein synthesis machinery are not well understood. We investigated the transcriptional changes related to initiation of protein synthesis. The human hepatoma cell line, HepG2, was infected with DV serotype 2 for 1 h at a multiplicity of infection of one. RNA was extracted after 6, 24 and 48 h. Microarray results showed that 36.5 percent of the translation factors related to initiation of protein synthesis had significant differential expression (Z-score ≥ ±2.0). Confirmation was obtained by quantitative real-time reverse transcription-PCR. Of the genes involved in the activation of mRNA for cap-dependent translation (eIF4 factors), eIF4A, eIF4G1 and eIF4B were up-regulated while the negative regulator of translation eIF4E-BP3 was down-regulated. This activation was transient since at 24 h post-infection levels were not significantly different from control cells. However, at 48 h post-infection, eIF4A, eIF4E, eIF4G1, eIF4G3, eIF4B, and eIF4E-BP3 were down-regulated, suggesting that cap-dependent translation could be inhibited during the progression of infection. To test this hypothesis, phosphorylation of p70S6K and 4E-BP1, which induce cap-dependent protein synthesis, was assayed. Both proteins remained phosphorylated when assayed at 6 h after infection, while infection induced dephosphorylation of p70S6K and 4E-BP1 at 24 and 48 h of infection, respectively. Taken together, these results provide biological evidence suggesting that in HepG2 cells DV sustains activation of the cap-dependent machinery at early stages of infection, but progression of infection switches protein synthesis to a cap-independent process.

Dengue virus-induced regulation of the host cell translational machinery.

Dengue virus (DV)-induced changes in the host cell protein synthesis machinery are not well understood. We investigated the transcriptional changes related to initiation of protein synthesis. The human hepatoma cell line, HepG2, was infected with DV serotype 2 for 1 h at a multiplicity of infection of one. RNA was extracted after 6, 24 and 48 h. Microarray results showed that 36.5% of the translation factors related to initiation of protein synthesis had significant differential expression (Z-score >or= +/-2.0). Confirmation was obtained by quantitative real-time reverse transcription-PCR. Of the genes involved in the activation of mRNA for cap-dependent translation (eIF4 factors), eIF4A, eIF4G1 and eIF4B were up-regulated while the negative regulator of translation eIF4E-BP3 was down-regulated. This activation was transient since at 24 h post-infection levels were not significantly different from control cells. However, at 48 h post-infection, eIF4A, eIF4E, eIF4G1, eIF4G3, eIF4B, and eIF4E-BP3 were down-regulated, suggesting that cap-dependent translation could be inhibited during the progression of infection. To test this hypothesis, phosphorylation of p70S6K and 4E-BP1, which induce cap-dependent protein synthesis, was assayed. Both proteins remained phosphorylated when assayed at 6 h after infection, while infection induced dephosphorylation of p70S6K and 4E-BP1 at 24 and 48 h of infection, respectively. Taken together, these results provide biological evidence suggesting that in HepG2 cells DV sustains activation of the cap-dependent machinery at early stages of infection, but progression of infection switches protein synthesis to a cap-independent process.

Replacement of methicillin-resistant Staphylococcus aureus clones in Hungary over time: a 10-year surveillance study.

The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in Hungary has been increasing and is now close to 20% among invasive isolates of S. aureus. In order to understand the evolution of MRSA in Hungary, two collections of isolates were studied: 22 representatives of a collection of 238 MRSA isolates recovered between 1994 and 1998, and a collection of 299 MRSA isolates recovered between 2001 and 2004. The isolates were first characterised by pulsed-field gel electrophoresis (PFGE) and were distributed into 19 different PFGE patterns. Representatives of each pattern were further characterised by spa typing, multilocus sequence typing (MLST) and staphylococcal cassette chromosome mec (SCCmec) typing. The Hungarian clone that was predominant in 1994-1998 (PFGE E, ST239-III) had almost disappeared in 2003-2004, being replaced by the Southern German clone (PFGE B, ST228-I) and the New York/Japan epidemic clone (PFGE A, ST5-II), which represented c. 85% of the 2001-2004 isolates. Thus, this study describes, for the first time, the co-dominance and extensive spread of the New York/Japan clone in a European country.

Unusually high prevalence of nosocomial Panton-Valentine leukocidin-positive Staphylococcus aureus isolates in Cape Verde Islands.

Characterization of nosocomial methicillin-susceptible Staphylococcus aureus isolates from Cape Verde showed that (i) Panton-Valentine leukocidin genes were present in 35% of the isolates and (ii) half of the collection had the same genetic background as methicillin-resistant pandemic clones. Introduction of the staphylococcal chromosome cassette mec (SCCmec) into virulent and epidemic isolates could pose serious threats to public health.

Comparison of genetic backgrounds of methicillin-resistant and -susceptible Staphylococcus aureus isolates from Portuguese hospitals and the community.

In order to understand the origins of the dominant methicillin-resistant Staphylococcus aureus (MRSA) clones in Portuguese hospitals, we compared the genetic backgrounds of nosocomial MRSA with methicillin-susceptible S. aureus (MSSA) isolates from the same hospitals (n=155) and from the community (n=157) where they were located. Pulsed-field gel electrophoresis, spa typing, multilocus sequence typing, and agr type analysis revealed that the genetic backgrounds correspondent to the dominant MRSA clones in Portuguese hospitals during the last 15 years (Iberian ST 247, Brazilian ST 239, and EMRSA-15 ST 22) were scarcely or not found among the present MSSA collection. The four major MSSA clones encountered (A-ST 30, B-ST 34, C-ST 5, and H-ST 45) correspond, or are very similar, to the background of other international MRSA pandemic clones, i.e., EMRSA-16, New York/Japan, Pediatric, and Berlin clones. However, with the exception of the Pediatric clone, none of these MRSA clones has been detected in Portugal. Our findings suggest the three major MRSA clones identified in Portuguese hospitals have not originated from the introduction of SCCmec into dominant MSSA backgrounds present in the Portuguese nosocomial or community environment but were probably imported from abroad. In contrast, the MRSA Pediatric clone might have originated in our country by the acquisition of SCCmec type IV into MSSA clone C. Furthermore, we provide evidence that the introduction of SCCmec into sensitive clones is most likely a relatively infrequent event that seems to depend not exclusively on the presence of a successful MSSA lineage.