Protective effect of Ginkgo biloba extract against genotoxic stress

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Optimization of in vitro model for growth of Gardnerella vaginalis biofilm

Bacterial vaginosis (BV) is the most common vaginal disorder in women of reproductive age. Despite its high prevalence, BV aetiology remains elusive. Recently, it was described that BV occurrence involves the presence of an adherent biofilm on vaginal epithelium, being Gardnerella vaginalis the predominant bacterial species. Furthermore, this bacterial biofilm persists on the vaginal epithelium after therapy with metronidazole, suggesting that G. vaginalis biofilm plays a key role in treatment failure and recurrence of BV. Despite the relevance of G. vaginalis biofilms in the BV pathogenesis, there has not been detailed information addressing the environmental conditions influence in G. vaginalis biofilm formation. In this sense, we designed a series of in vitro assays in order to evaluate the influence of some common culture conditions on biofilm formation of this bacterial species. Thus, we used four G. vaginalis strains isolated from women with BV and compared their biofilm-forming ability using distinct culture conditions, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that growth conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, supplemented the medium with glucose and using a fed-batch system. To conclude, this study provides new insights about optimized culture conditions for G. vaginalis biofilm formation, which is extremely important for future fundamental studies involving this bacterial community. This work was co-funded by FCT project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), FCT Strategic Project PEst-C/SAU/UI0709/2011 and by QREN, FEDER, ON2 project (NORTE-07-0124-FEDER-000027)

Are endolysins promising agents in controlling E. coli associated post-weaning diarrhea in piglets?

Enterotoxigenic Escherichia coli (ETEC) associated infections are the major cause of piglets mortality in weaning and post-weaning period, resulting in significant economic losses to the swine industry. Furthermore, the increase of multidrug resistant ETECs have been recognized a public health danger due to the potential transfer of resistance into the food chain. Bacterio(phages) endolysins are enzymes produced in the end of phage lytic cycle that are responsible for cell lysis. So far, no resistance has been reported, which make endolysins an attractive alternative to antibiotics. In the present work, endolysins were exploited to tackle ETECs in piglets. Two enzymes previously cloned were tested against ETEC SP23 strain exponential cells. First, Lys68 (used herein as proof of concept) was tested alone or in combination with 5 different organics acids (already implemented in the piglets diet) citric, malic, formic, lactic and sorbic acids in 20 mM HEPES, 149 mM PBS and 140.33 mM simulated intestinal fluid (SIF). Later, PlyF307 endolysin was also tested with malic and citric acids in SIF. Results demonstrated that both enzymes reduced ETEC concentration in more than 4 orders of magnitude in HEPES. Lys68 together with malic acid displayed the best antibacterial activity in PBS, being able to reduce approximately 1 order of magnitude. However, enzymes efficacy was drastically reduced when tested in buffers that mimicked physiological conditions. In SIF, Lys68 and PlyF307 did not display antibacterial activity. In summary, phage endolysins revealed to be ineffective to treat ETEC bacterial load in more complex environments.info:eu-repo/semantics/publishedVersio

Complete genome sequences of eight phages infecting enterotoxigenic Escherichia coli in swine

We report eight phages infecting enterotoxigenic Escherichia coli responsible for intestinal infections in piglets. Phages vB_EcoM_F1, vB_EcoM_FB, vB_EcoS_FP, vB_EcoM_FT, vB_EcoM_SP1, vB_EcoP_SP5M, vB_EcoP_SP7, and vB_EcoS_SP8 were isolated between 2007 and 2018 in the Iberian Peninsula. These viruses span the three tailed phage families, Podoviridae, Siphoviridae, and Myoviridae.This study was supported by the project SusPhage, POCI-01-0247-FEDER-033679,funded byFEDER funds through the COMPETE 2020-Programa Operacional Competi-tividade e Internacionalização (POCI). The work was also supported by the PortugueseFoundation for Science and Technology (FCT) under the scope of the strategic fundingof the UIDB/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte and by the project PTDC/CVT-CVT/29628/2017 (POCI-01-0145-FEDER-029628).info:eu-repo/semantics/publishedVersio

The predominance of M2-polarized macrophages in the stroma of low-hypoxic bladder tumors is associated with BCG immunotherapy failure

OBJECTIVE: Bacillus Calmette-Guérin (BCG) immunotherapy is the gold standard treatment for superficial bladder tumors with intermediate/high risk of recurrence or progression. However, approximately 30% of patients fail to respond to the treatment. Effective BCG therapy needs precise activation of the type 1 helper cells immune pathway. Tumor-associated macrophages (TAMs) often assume an immunoregulatory M2 phenotype and may directly interfere with the BCG-induced antitumor immune response. Thus, we aim to clarify the influence of TAMs, in particular of the M2 phenotype in stroma and tumor areas, in BCG treatment outcome. PATIENTS AND METHODS: The study included 99 patients with bladder cancer treated with BCG. Tumors resected before treatment were evaluated using immunohistochemistry for CD68 and CD163 antigens, which identify a lineage macrophage marker and a M2-polarized specific cell surface receptor, respectively. CD68+ and CD163+ macrophages were evaluated within the stroma and tumor areas, and high density of infiltrating cells spots were selected for counting. Hypoxia, an event known to modulate macrophage phenotype, was also assessed through hypoxia induced factor (HIF)-1α expression. RESULTS: Patients in whom BCG failed had high stroma-predominant CD163+ macrophage counts (high stroma but low tumor CD163+ macrophages counts) when compared with the ones with a successful treatment (71% vs. 47%, P = 0.017). Furthermore, patients presenting this phenotype showed decreased recurrence-free survival (log rank, P = 0.008) and a clear 2-fold increased risk of BCG treatment failure was observed in univariate analysis (hazard ratio = 2.343; 95% CI: 1.197-4.587; P = 0.013). Even when adjusted for potential confounders, such as age and therapeutic scheme, multivariate analysis revealed 2.6-fold increased risk of recurrence (hazard ratio = 2.627; 95% CI: 1.340-5.150; P = 0.005). High stroma-predominant CD163+ macrophage counts were also associated with low expression of HIF-1α in tumor areas, whereas high counts of CD163+ in the tumor presented high expression of HIF-1α in tumor nests. CONCLUSIONS: TAMs evaluation using CD163 is a good indicator of BCG treatment failure. Moreover, elevated infiltration of CD163+ macrophages, predominantly in stroma areas but not in the tumor, may be a useful indicator of BCG treatment outcome, possibly owing to its immunosuppressive phenotype

Lipase-catalyzed ethanolysis of Jatropha curcas L. oil assisted by ultrasonication

ABSTRACT Transesterification of non-edible oils using immobilized lipase is a promising process for biodiesel production. Thus, this study aimed to evaluate the enzymatic transesterification of the non-edible Jatropha curcas oil for FAEE production under ultrasound irradiation in a solvent-free system. The effects of enzyme concentration, water concentration, molar ratio of ethanol to oil and ultrasound power on the FAEE conversion have been evaluated. The results show that enzyme concentration and irradiation power have a positive significant effect on FAEE conversion, where an increase in these variables leads to higher conversions. Conversion above 54% of FAEE was achieved with 1.5 hours of reaction time using ultrasound irradiation, reducing reaction time by at least 3 times, when compared with the same experimental conditions without ultrasound irradiation. Results showed that ultrasound can improve reaction conversion mainly by enhancing the mass transfer between the constituents of the reactions

Preliminary studies for the aplication of Thymbra capitata essential oil as potential antimicrobial agent in Bacterial Vaginosis

Bacterial vaginosis (BV) is the most common gynecological clinical condition in women in reproductive age, and has been associated with an increased risk of development of preterm labor, spontaneous abortion, and several sexually transmitted diseases such as HIV [1]. BV is not only a condition that involves excessive growth of anaerobic microorganisms, but also involves the presence of an adherent biofilm [2]. Despite its high prevalence, the aetiology of BV remains unknown, but frequently Gardnerella vaginalis is the main microorganism associated with this disorder [3], that is often the main species in biofilms presented in BV [4]. These results led to the theory that the microorganisms that form biofilms may be relevant for the aetiology of BV [5]. Traditionally, the treatment of BV involves the antibiotics metronidazole, clindamicin or tinidazole [6]. However, the recurrence rate remains high and this can be related to the biofilm-forming ability of G. vaginalis [5]. In this context, recently it was reported that natural compounds, such as Thymbra capitata essential oil, can reduce the activity of biofilms [7]. To test if T. capitata could be used in the treatment of BV, we determined the biofilm-forming ability and the effect of essential oil in seven strains of G. vaginalis isolated from women with BV. Thus, the biofilm-forming ability was assessed under anaerobic conditions for 48 hours, allowing each strain to form biofilm. These assays revealed that in fact, G. vaginalis strains produced moderate to tenacious biofilm. We then determined the sensibility of the tested bacteria to the common antibiotics used to treat BV. Not surprisingly, most of strains were resistant of metronidazole and tinidazole which are more commonly administered. However half of strains were sensitive to clindamicin. We then evaluated the antibacterial activity of essential oil upon G. vaginalis strains, determining minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC). The T. capitata essential oil exhibited a potent anti-G. vaginalis effect, which was confirmed by the low values of MIC (0.16 µL.mL-1) and MLC (0.16 - 0.31 µL.mL-1). To conclude, these results showed that T. capitata essential oil presents a strong antibacterial activity upon antibiotic resistant and biofilm forming of G. vaginalis strains, reinforcing the potential interest of this essential oil as antimicrobial agent in the treatment of BV

The Glance of an Observer on the War of Brands of Food Products

The present work proposes a model to compare means of many constructs that evaluate competitiveness of brands of the Brazilian chilled and frozen food industry. Such a model is based on a nomological network, which was built over the concepts pointed by [4] [13] [8], and [7] by the NUME – Marketing and Strategy Research Center of the Federal University of Minas Gerais - research group. Besides the validation of the new research instrument for gauging and generalization, it will be made an evaluation of brands - the ones well-positioned at the market - using the comparison of the indexes and averages of the nomological chain built for the companies, in relation to the following concepts: Tangibility (perception of packings, flavors and smells); Reliability in the Brand; Satisfaction; Loyalty; Image of the Brand; Perceived Value and Functional Conflict