Detection of vanA-containing Enterococcus species in faecal microbiota of gilthead seabream (Sparus aurata)

Vancomycin-resistant Enterococcus faecalis, E. faecium and E. durans isolates with the genotype vanA were detected in 7 of 118 faecal samples (5.9%) of natural gilthead seabream recovered off the coast of Portugal, and one vancomycinresistant isolate/sample was further characterized. The genes erm(B), tet(L), tet(M), aac(6')-aph(2"), aph(3')-IIIa and/ or ant(6)-Ia were identified in most of the 7 vancomycin-resistant enterococci. Sequence types ST273, ST313 and ST76 were detected in three E. faecium isolates and ST6 in two E. faecalis isolates. VanA-containing enterococci are suggested to be disseminated in fish in marine ecosystems close to areas of human activity

Kefiran biopolymer: Evaluation of its physicochemical and biological properties

Kefiran, an exopolysaccharide produced by lactic acid bacteria, has received a great interest due to a variety of health claims. In this study, we aim to investigate the physicochemical and biological properties of Kefiran polysaccharide extracted from Portuguese kefir grains. The kefir growth rate was about 56% (w/w) at room temperature and the kefir pH after 24 h was about 4.6. The obtained yield of Kefiran polysaccharide extracted from the kefir grains was about 4.26% (w/w). The Kefiran structural features were showed in the 1H nuclear magnetic resonance spectrum. The bands observed in the infrared spectrum confirmed that the Kefiran had a β-configuration; and the X-ray photoelectron spectroscopy analysis confirmed the structure and composition of Kefiran and revealed a C/O atomic ratio of 1.46. Moreover, Kefiran showed an average molecular weight (Mw) of 534 kDa and a number-average molecular weight (Mn) of 357 kDa. Regarding the rheological data obtained, Kefiran showed an interesting adhesive performance accompanied by a pseudoplastic behavior, and the extrusion force of Kefiran was 1 N. Furthermore, Kefiran exhibited a higher resistance to hyaluronidase degradation than hyaluronic acid. Finally, Kefiran showed a lack of cytotoxic response through its ability to support metabolic activity and proliferation of L929 cells, and had no effect on these cells’ morphology. Our research suggested that Kefiran polymer has attractive and interesting properties for a wide range of biomedical applications, such as tissue engineering and regenerative medicine.H.R., C.G., and F.R.M. were supported by grants with reference SFRH/BPD/100957/2014, SFRH/ BPD/94277/2013, and SFRH/BPD/117492/2016, respectively, of Fundação para a Ciência e a Tecnologia (FCT) from Portugal. J.M.O. thanks the FCT for the funds provided under the program Investigador 2015 (IF/01285/2015).info:eu-repo/semantics/publishedVersio

Biological performance of a promising Kefiran-biopolymer with potential in regenerative medicine applications: a comparative study with hyaluronic acid

Kefiran from kefir grains, an exopolysaccharide (EPS) produced by lactic acid bacteria (LAB), has received an increasing interest because of its safe status. This natural biopolymer is a water-soluble glucogalactan with probed health-promoting properties. However, its biological performance has yet to be completely recognized and properly exploited. This research was carried out to evaluate the in vitro antioxidant and the in vitro anti-inflammatory properties of Kefiran biopolymer. Regarding antioxidant activity, the results demonstrated that the Kefiran extract possessed the strongest reducing power and superoxide radical scavenging, over hyaluronic acid (HA, gold standard viscosupplementation treatment). This exopolysaccharide showed a distinct antioxidant performance in the majority of in vitro working mechanisms of antioxidant activity comparing to HA. Moreover, Kefiran presented an interesting capacity to scavenge nitric oxide radical comparing to the gold standard that did not present any potency. Finally, the cytotoxic effects of Kefiran extracts on hASCs were also performed and demonstrated no cytotoxic response, ability to improve cellular function of hASCs. This study demonstrated that Kefiran represented a great scavenger for reactive oxygen and nitrogen species and showed also that it could be an excellent candidate to promote tissue repair and regeneration.Hajer Radhouani, Cristiana Gonçalves and F. Raquel Maia were supported by grants with reference SFRH/BPD/100957/2014, SFRH/BPD/94277/2013 and SFRH/BPD/117492/2016, respectively of Fundação para a Ciência e a Tecnologia (FCT) from Portugal. JM Oliveira also would like to thank FCT for the fund provided under the program Investigador FCT 2015 (IF/01285/2015).info:eu-repo/semantics/publishedVersio

Detection and genetic characterisation of vanA-containing enterococcus strains in healthy lusitano horses

Lusitano horses were investigated in order to detect the presence of vancomycin-resistant enterococci. vanA isolates showed high level vancomycin (Minimum inhibitory concentration; MIC 128 mg/l) and teicoplanin resistance (MIC 64 mg/l), as well as resistance to ciprofloxacin, erythromycin and tetracycline. The tet(L) and erm(B) genes, associated with tetracycline and erythromycin resistance, respectively, were found in all vanA isolates.The intestinal tract of Lusitano horses can be a potential reservoir for vanA-containing enterococci. © 2009 EVJ Ltd

Unveiling the physicochemical properties of a sulfated polysaccharide based on Ulvan with high biomedical potential

Introduction: Ulvan, extracted from the green algae Ulva lactuca displays physico-chemical and biological features of potential interest for biomedical applications1. This sulfated polysaccharide is mainly built on disaccharides repeating sequences composed of sulphated rhamnose and glucuronic acid, iduronic acid or xylose2. In this work, structural, chemical degradation and rheological studies were performed in order to complement in vitro and in vivo performance studies and to screen its potential biomedical interest

Proteomic study in an Escherichia coli strain from seagulls of the berlengas natural reserve of Portugal

The increasing bacterial resistance among common pathogens is threatening the effectiveness of several antibiotics. This represents a serious public health problem as such bacterial strains have already been detected in domestic, wild-life animals and humans. Using Escherichia coli as a model organism, we applied a proteomic approach to the topic of antimicrobial resistance. In order to identify and characterize the proteome of extendedspectrum -lactamase (ESBL) type TEM-52 producing-Escherichia coli strain of a faecal sample taken from Yellow-legged seagulls (Larus cachinnans) a bidimensional electrophoresis (2-DE) technique with an isoelectric focusing followed by a SDS-PAGE, was used. Eighty seven individualized protein spots were identified. All were suitable for peptide mass fingerprinting by a mass spectrometric technique (MALDI/TOF MS). Their identification was carried out by searching appropriate bioinformatic databases. All proteins were related to E. coli strains. Detection of proteins related to several E. coli strains linked with virulent and enterohaemorrhagic consequences in ESBL producing-E. coli isolates of seagull samples raises the question of how such similarities arise bearing in mind these remarkably different microbial ecosystems. © 2011, Proteomass Scientific Society. All rights reserved

Wild boars as reservoirs of extended-spectrum beta-lactamases in Escherichia coli isolates of the A, B1 and B2 phylogenetic groups

ESBL-producing E. coli isolates have been isolated from eight of seventy seven faecal samples (10.4%) of wild boars in Portugal. The ESBL types identified by PCR and sequencing were blaCTX-M-1 (6 isolates) and blaCTX-M-1 + blaTEM1-b (2 isolates). Further resistance genes detected included tet(A) or tet(B) (in three tetracycline-resistant isolates), aadA (in three streptomycin- resistant isolates), cmlA (in one chloramphenicol-resistant isolate), sul1 and/or sul2 and/or sul3 (in all sulfonamide-resistant isolates). The intI1 gene encoding class 1 integrase was detected in all ESBL-producing E. coli isolates. One isolate also carried the intI2 gene, encoding class 2 integrase. The ESBL-producing E. coli isolates could be assigned to phylogenetic groups B1 (3 isolates), B2 (3 isolates) or A (2 isolates). Amino acid change in GyrA protein (Ser83Leu or Asp87Tyr) was detected in three nalidixic acid-resistant and ciprofloxacin-susceptible isolates. Two amino acid changes in GyrA (Ser83Leu + Asp87Asn) and one in ParC (Ser80Ile) were identified in two nalidixic acid- and ciprofloxacin-resistant isolates. As evidenced by this study wild boars could be a reservoir of antimicrobial resistance genes. © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Arterial Tortuosity.

Item does not contain fulltex