586 research outputs found
In vitro evaluation on HeLa cells of protective mechanisms of probiotic lactobacilli against Candida clinical isolates
No full textAims: To characterize in vitro the ability of human Lactobacillus strains to inhibit the adhesion, to displace and to compete with clinically isolated Candida strains.
Methods and Results: Three types of assays were performed to determine the inhibitory effect of Lactobacillus plantarum 319, Lactobacillus rhamnosus IMC 501, Lactobacillus paracasei IMC 502 and a specific probiotic combination
(SYNBIO) on adhesion of Candida pathogens to HeLa cells: blockage by exclusion (lactobacilli and HeLa followed by pathogens), competition (lactobacilli, HeLa and pathogens together) and displacement (pathogens and HeLa followed by the addition of lactobacilli). Bacterial adhesion to HeLa was quantified by microscopy after May-Grunwald/Giemsa stain. The inhibition results highlight a significant (P < 0.05) competition of the considered probiotics against all the Candida strains. The results suggest that the probiotic strains used in this study could prevent colonization of the urogenital tract by
relevant pathogens such as Candida strains through barrier and interference mechanisms (mainly displacement and competition), but the degree of inhibition of adhesion was bacterial strain-dependent.
Conclusions: The results support the potential of these Lactobacillus probiotic strains as anti-infective agents in the vagina and encourage further studies about their capacity to prevent and manage urogenital tract infections in females.
Significance and Impact of the Study: To optimize the defensive properties of the vaginal microbiota, improving the health of many women by probiotic intervention
Le cone des fonctions plurisousharmoniques negatives et une conjecture de Coman
No full textLes fonctions plurisousharmoniques n'egatives dans un domaine Omega de C^n forment un c^one convexe. Nous consid'erons les points extr'emaux de ce c^one, et donnons trois exemples. En particulier, nous traitons le cas de la fonction de Green pluricomplexe. Nous calculons celle du bidisque, lorsque les p^oles se situent sur un axe. Nous montrons que cette fonction ne se confonde pas avec la fonction de Lempert correspondante. Cela donne un contre-exemple `a une conjecture de Dan Coman
Probiotic characterization of Lactobacillus isolates from canine faeces
No full textAims: There is interest in using probiotics such as Lactobacillus species to control canine intestinal infections. The bacterial species should be of canine intestinal origin exhibiting host specificity. Bacterial strains were isolated from dog faecal samples and characterized to select specific probiotics as dietary supplements in feed, promoting health status. Methods and Results: Bacterial strains have been screened for their probiotic properties including survival to gastric and pancreatic juices and bile salts, resistance to antibiotics and antipathogenicity. Five of 14 isolated Lactobacillus strains were tolerant to gastric stress. They were also resistant to clindamycin and with a significant antimicrobial capacity towards the pathogenic strains tested, variable according to the strain. They were identified by morphological and molecular characterization comparing the 16S rRNA gene sequence with the blast database. Three strains were identified as Lactobacillus reuteri and two as Lactobacillus johnsonii. Sugar fermentation profiles and adhesion to HT29 epithelial cells have been in vitro verified on L. reuteri AI, chosen as probiotic candidate. Resistance to freeze-drying, production and subsequent in vivo administration evaluating strain permanence, were also performed. No loss of vitality has been recorded due to the freeze-drying process. The average value of recovery percentage of L. reuteri AI at the end of the administration period and after 1 week of follow-up was respectively 26·7 and 17·4% of the total Lactobacillus sp. Conclusions: Among several selected probiotic strains, L. reuteri AI proved to be the best probiotic candidate to use as a supplement for dogs. Significance and Impact of the Study: Control of intestinal pathogenic micro-organisms in dogs is a growing concern and the selection of autochthonous probiotic bacterial strains to overcome some of the gut problems associated with the modern domestication of animals is a valuable tool
Study of natural compounds of Rosmarinus Officinalis as additives in food active packaging.
No full textThe use of natural extracts categorized as flavorings by the European Union (EU) and generally recognized as safe (GRAS) by the US Food and Drug Administration (FDA), represents an interesting approach in the active packaging technology. Considerable research, especially from a biological point of view, have been carried out on the assessment of the antioxidant and antimicrobial activity of many herbs [1]. For example, the Rosemary (Rosmarinus officinalis L.) essential oil (REO) contains bioactive compounds having antimicrobial activities [2]. On the other side, the natural extracts (E392) from Rosemary plant contains molecules (carnosol and carnosic acid) that have antioxidant activity. The latter is regulated from European Commission (2010/67/UE) as food additive for processed meat. The aim of this research work was:
• to characterize chemical profile of REO (GC/MS) and E392 (HPLC/MS ion trap and SPME-GC/MS);
• to analyze their antimicrobial and antioxidant properties;
• to produce an innovative active packaging enriched with these natural additives;
• and finally, to study the storage of packaged food.
The shelf life of meat and derivatives has been widely studied by monitoring the follows freshness markers: biogenic amines (BAs), hexanal, microbial growth, pH and organoleptic properties. The major attention was focused on BAs, because they are considered markers of freshness and hygiene during storage of meat product, not only, an high level of BAs can form carcinogenic nitrosamines [3-4]. Ten BAs were analyzed and quantified by HPLC-DAD and a new fast method was developed with HPLC-MS/MS (Figure 1) [5]. REO results showed a good preservation of food, because the level of BAs, hexanal and bacteria were lower on food wrapped in the active packaging (Figure 2). Not only, the REO has a good inhibitory action against bacteria responsible to the formation of BAs [6]. The strong aroma of REO can change organoleptic qualities of meat, and this could affect consumers acceptance. To improve the shelf life of food, without changing the sensory properties, the active packaging was formulated with E392. This extract showed antioxidant properties, and sensorial analyses results confirm the quality of the active packaging, which does not changes the taste and flavor of packaged food. Preliminary analyses about BAs and bacteria showed interesting results on meat wrapped in active packaging enriched with E392. Finally, monitoring carnosol and carnosic acid concentrations, the conservation of E392 was investigated
Chemical composition and antimicrobial activity of the essential oil from Ferula glauca L. (F. communis L. subsp. glauca) growing in Marche (central Italy)
No full textAntimicrobial activity of SYNBIO® probiotic formulation on pathogens isolated from chronic ulcerative lesions: in vitro studies
No full textAIMS: Probiotics have the ability to enhance the immune system, produce anti-inflammatory action and promote wound healing process. The first aim of the study was to isolate pathogenic microorganisms from sites of chronic ulcerative lesion. A second aim consisted of an evaluation of probiotic efficacy of SYNBIO® (1:1 combination of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502®) in counteracting wound infections. METHODS AND RESULTS: Several bacterial pathogens were isolated from chronic ulcerative lesions and identified by morphological, biochemical and molecular techniques. SYNBIO® probiotic formulation was investigated for its antimicrobial activity, minimum inhibitory concentration, co-aggregation and adherence capacity against the isolated pathogens. Moreover, SYNBIO® was also tested in combination with some medical devices, using an in vitro model, in order to simulate a real ulcerative wound infection. Probiotic formulation demonstrated an inhibitory action against all the tested pathogens and their mixture (MIX), with an increased ability of co-aggregation during time. In addition, the adhesion percentage of probiotic microorganisms to human keratinocyte (HaCaT cells) and human fibroblasts (NHF), calculated by an in vitro model, was 19% and 17% respectively, highlighting the possibility to create a protective environment preventing pathogens' biofilm formation in order to contrast infections. CONCLUSIONS: SYNBIO® probiotics showed a very good antimicrobial capacity and adhesion percentage to HaCaT cells and fibroblasts, giving the opportunity to be successfully used as complement to conventional therapies in the treatment of chronic ulcerative lesions. SIGNIFICANCE AND IMPACT OF THE STUDY: A new therapeutic approach with probiotics (supplemented in topical applications, excluding side effects) able to eliminate pathogenic microorganisms and improve healing of chronic ulcerative lesions
Lactobacillus strains treatment on commercial packaging paper as preliminary study for extending the shelf-life of chicken meat
No full textLactobacillus plantarum IMC 509 and SYNBIO® (1:1 combination of Lact. rhamnosus IMC 501® and Lact. paracasei IMC 502®), were investigated as natural anti-spoilage agents sprinkled on commercial packaging, polyethylene (PE) laminated paper sheet, to extend raw chicken breast meat shelf-life at 4°C. Slices of chicken breast meat, wrapped in commercial packaging papers sheet sprayed by Lactobacillus cell suspensions, were analyzed at 0, 2, 5, 7 days of storage. Total aerobic mesophilic bacteria, pH value, sensory changes and biogenic amines (BAs) production were checked. Lactobacillus strains viability on paper packaging was also monitored. The best ability of preserving meat parameters was observed in Lactobacillus sprayed PE laminated papers compared to control paper. The BAs extracted from meat preserved into Lact. plantarum IMC 509 sprayed PE laminated paper sheet were significantly less than other samples. Lact. plantarum IMC 509 showed a high stability, keeping its viability in all paper surfaces. It reduced both spoilage microbial growth and BAs accumulation, providing further evidence for its suitability to be used in packaging application. Lactobacillus
strains may be assumed as bio-preservatives applied on papers sheet to extend chicken meat shelf-life without affecting the flavor
Epicardial fat thickness : relationship with plasma visfatin and plasminogen activator inhibitor-1 levels in visceral obesity
No full textBackground and aim: Epicardial fat (EF), a true visceral. adipose tissue (VAT) deposited around the heart, is considered as possible cardiovascular risk indicator, in view of its ability to produce and release several inflammatory adipo-cytokines. It is still not known whether increased cardiac adiposity is related to increased inflammatory adipo-cytokines in obesity. The aim of this study was to evaluate whether echocardiographic EF thickness, an indicator of cardiac adiposity, is related to circulating levels of inflammatory adipo-cytokines such as visfatin and plasminogen activator inhibitor-1 (PAI-1) in visceral obesity.
Methods and results: EF thickness (measured by echocardiography), visfatin, PAI-1 antigen and some inflammatory markers were studied in 42 women, 27 of them severely obese (OB) (BMI 43.5 +/- 4.8 kg/m(2)) but with no apparent complications, and 15 normal-weight controls. Abdominal VAT in the OB was assessed by computed tomography. OB had thicker EF and higher visfatin and PAI-1 antigen concentrations than controls (P < 0.0001). EF thickness, log-visfatin and log-PAI-1 antigen concentrations directly correlated with VAT (P < 0.0001). Log-visfatin and log-PAI-1 antigen were correlated with EF thickness even after adjusting for indices of fat distribution (P < 0.01 and P < 0.001 respectively). Moreover, when dividing 013 on the basis of median EF thickness, women with greater EF thickness had more VAT and higher adipo-cytokine concentrations and inflammatory markers.
Conclusions: This study suggests that EF thickness, an indicator of cardiac adiposity, may be significantly related to inflammatory adipo-cytokines in visceral-obese patients. This suggests EF might be used as an easy and reliable marker of visceral adiposity and inflammation and as a cardiovascular risk indicator
Nutritional characterization of a fermented beverage from donkey milk
No full textThe present work is part of the Tool4MEDLife project (PRIMA program), which aims to in-crease awareness about the Mediterranean diet thanks to the production of innovative foods and educational toolkits. Donkey milk, due to its potential hypoallergenic properties, has been sug-gested as a good alternative for feeding young children affected by cow milk protein allergy (CMPA) when it is not possible to breastfeed. Furthermore, thanks to the presence of nutraceu-tical molecules with antioxidant, anti inflammatory, antimicrobial, antiviral, and antitumor activities, donkey milk is interesting also for elderly people. Considering the high quality char-acteristics associated with fermented milk, the aim of this work was the production of ferment-ed donkey milk by selected Lactic Acid Bacteria (LAB) able to synthesize folates (vitamin B9). The final product was also fortified with vitamin D3 and calcium. The levels of folates of natu-ral origin represent an optimal alternative to synthetic folate-fortified products, which have limited bioavailability, and possibly lead to the accumulation of unmetabolized folic acid. Five fresh pasteurized donkey milk samples, added with vitamin D3, calcium carbonate, Streptococ-cus thermophilus, Lactobacillus delbrueckii ssp. bulgaricus and Lactobacillus plantarum IMC 509 (Synbiotec), were fermented at a constant temperature of 38-40°C for 5 hours. Folate con-tent on the final product was determined by RP HPLC (Agilent 1260 Infinity LC system), using a column C18 HiQSil HS, 5 μm, 4.6 mm i.d., 250 mm (Kya Tech Corporation, Tokyo, Japan).
The fermentation process led to the production of a fermented beverage with a final pH value of 4.4. The determination of folates by RP HPLC indicated mainly the presence of tetrahydro-folate (5.3 ± 0.081 M) which is a form of folate with high bioavailability. Other water soluble vitamins found in the final fermented donkey milk were vitamin C (110.16 ± 13.5 M), nicotin-ic acid, and nicotinamide (52.7 ± 0.05 M and 7.36 ± 0.15 M respectively), and also vitamin B12 (1.69 ± 0.022 M). Comparing the above results with the water soluble vitamin content of donkey milk present in the literature, it can be noticed that the vitamin content found in the fermented donkey milk beverage is considerably higher. These preliminary results indicated that the LABs used in these experiments are very promising to produce fermented donkey milk with enhanced nutraceutical properties.
Research supported by: PRIMA, Partnership for Research and Innovation in the Mediterranean Area supported by the European Union - Section 2, Tool4MEDLife Project - PRIMA22_00088 - CUP: J13C23000150002
Chemical, sensory and biological characteristics of selected monovarietal extra virgin olive oils
No full textThe present study deals with the chemical, biological and sensory characterization of monovarietal extra virgin olive oils (EVOOs) obtained from cultivar grown in Marche region (Italy). EVOO is a food product having interesting beneficial properties, as evidenced by scientific literature [1]. One of the key features contributing to these properties are phenolic substances, which are related to the healthy, sensory and stability properties of EVOOs. They have been also related to the prebiotic activity of the oil [2]. Also volatile substances greatly contribute to the overall quality of EVOO and they are produced in chemical and biochemical pathways whose outcome depends on several factors, one of the most important of which, is the olives health state, and thus the microorganisms present. This study aims to investigate the relations between the chemical characteristics of monovarietal EVOOs mainly related to the overall quality and to correlate them with sensorial properties, prebiotic activity and yeasts characterizing the oils. Because of the influences of yeasts on the final EVOO quality, the high-throughput sequencing of internal transcribed spacers amplicons was employed to study the yeast biodiversity associated to the monovarietal EVOOs. Significant differences in taxa abundance among samples were obtained.
Regarding prebiotic activity, it has been investigated by a semi-continuous fermentation system inoculated with a pool of human faeces under anaerobic conditions, to mime a colonic human fermentation [3]. Bifidobacteria, lactobacilli and clostridia and short chain fatty acids have been monitored using RT-PCR and gas-chromatography respectively, during 24h fermentation of each previously digested EVOO. Preliminary results will be presented and discussed.
[1]. G. Caramia, A. Gori, E. Valli, L. Cerretani Virgin olive oil in preventive medicine: from legend to epigenetics European Journal of Lipid Science and Technology 2012; 114, 375–388.
[2]. Cardona F., Andrés-Lacuevac C., Tulipania S., Tinahonesb F.J., Queipo-Ortuñoa M.I..Benefits of polyphenols on gut microbiota and implications in human health. Journal of Nutritional Biochemistry 2013; 24, 1415–1422.
[3]. Zampa A., Silvi S., Servili M., Montedoro G., Orpianesi C., Cresci A. In vitro modulatory effects of colonic microflora by olive oil iridoids. Microbial Ecology in Health and Disease, 2006; 18, 147-153
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