Antibacterial efficacy of polypyrrole in textile applications

This paper describes application and evaluation of polypyrrole as an antibacterial polymer. Polypyrrole was produced embedding two doping agents: chloride and dicyclohexyl sulfosuccinate ions. Stability of the antibacterial efficacy of polypyrrole deposited on cotton fabrics was assessed before and after three different kinds of washing (namely, laundering with anionic and non-ionic detergents and dry-cleaning). Polypyrrole showed excellent antibacterial properties (100 % of bacterial reduction) against Escherichia coli for both doping agents. Treated fabrics were further characterised by scanning electron microscopy, energy dispersive X-ray analysis and infrared spectroscopy. The antibacterial efficacy diminished after launderings with anionic and non-ionic detergents because of two different mechanisms: the neutralisation of positive charges under alkali conditions (dedoping), and a partial removal of polypyrrole by abrasion and surfactant action. After dry-cleaning, polypyrrole embedding chloride and dicyclohexyl sulfosuccinate ions still showed excellent antibacterial efficacy. Moreover, scanning electron microscopy investigations were used to intuitively explain the bactericidal mechanism of polypyrrole on Escherichia coli bacteria.     

PCV2-DNA in formalin-fixed and paraffin embedded lymph nodes of wild boar (Sus scrofa ssp. scrofa): one sampling approach for two laboratory techniques

Superficial inguinal lymph nodes from 72 wild boars examined in a previous immunohistochemical (IHC) study on porcine circovirus type 2 (PCV2) were selected for a PCV2 polymerase chain reaction (PCR) analysis. Four of these lymph nodes were PCV2-IHC strongly positive with PMWS histological lesions (outcome 1), 6 weak to mild PCV2-IHC positive without PMWS histological lesions (outcome 2) and 62 PCV2-IHC negative. Considering IHC the gold standard for diagnosis, the aims of the study were to evaluate the suitability of the PCV2-DNA extraction from formalin-fixed and paraffin-embedded (FFPE) tissue and the sensitivity and specificity of PCR under two IHC interpretations criteria: (A) the sample was considered positive if the result was outcome 1; (B) the sample was considered positive if the result was outcome 1 or 2. Under (A) criteria, sensitivity and specificity of PCR were 100% and 89.7%, respectively; the Cohen''s Kappa coefficient was 0.49. Under (B) criteria, sensitivity and specificity of PCR were 80.0% and 95.2%, respectively; the Cohen''s Kappa coefficient was 0.72. The high Cohen''s Kappa coefficient under the (B) interpretative criteria indicates good agreement between the two methods. In conclusion, 1) DNA extracted from FFPE specimens of wild boar is suitable for PCR and further represents a screening test for PCV2/PCVD (PCV2 Diseases) investigations in wild boar as well; 2) routine histological sampling can also be useful for PCV2 virological studies in wild boar.     

Composition and biological activity of essential oil of Achillea ligustica All. (Asteraceae) naturalized in central Italy: Ideal candidate for anti-cariogenic formulations

Essential oil from flowers (FL) and vegetative parts (VP) of Achillea ligustica (Asteraceae), naturalized after cultivation in central Italy, was investigated by GC–FID and GC–MS. The most abundant components were linalool, viridiflorol, β-pinene, 1,8-cineole and terpinen-4-ol. The antioxidant assays (DPPH and ABTS radical scavenging assays, and β-carotene bleaching test) demonstrated a moderate activity of essential oils. The antimicrobial activity was evaluated by the broth micro-dilution method on 6 microbial strains and showed to be quite strong against the cariogenic Gram-positive Streptococcus mutans, suggesting that this essential oil could be a valid candidate for anti-cariogenic formulations. Moderate cytotoxic activity was observed in assays on four tumour cell lines by MTT assay.     

Copper sulphate forms in piglet diets: Microbiota,intestinal morphology and enteric nervous system glial cells

The objective of this study was to evaluate dietary supplementation with different copper sulphate (CuSO₄) forms on small intestine microanatomy and large intestine microbiota. Ninety weaned piglets were divided into three experimental groups: control diet (CTR), with no added CuSO₄ and diets supplemented with 150 ppm of CuSO₄ in protected (150P) and unprotected form (150UP). After 18 days of dietary treatment, six piglets per treatment were randomly selected and sacrificed. Duodenum villi length and crypt depths were higher (P < 0.001) in the animals fed 150UP than other groups. Glial fibrillary acidic protein (GFAP), a marker for enteric glial cells, was unaffected by dietary treatments. The total bacteria and Enterobacteriaceae bacteria counts were lower (P < 0.05) in cecum of animals fed 150P in comparison with the other two groups. In the colon the Streptococci spp were lower (P < 0.001) in both CuSO₄ supplemented groups than controls. The obtained results revealed a modulation of intestinal structure and microbiota exerted by the studied CuSO₄ dietary supplementation. The present data show that dietary supplementation with 150UP in the first period post‐weaning may assist in restoring the gut morphology, improving duodenal structure.     

Could hypoxia influence basic biological properties and ultrastructural features of adult canine mesenchymal stem /stromal cells?

The aim of the present study was to compare canine adipose tissue mesenchymal stem cells cultured under normoxic (20% O₂) and not severe hypoxic (7% O₂) conditions in terms of marker expression, proliferation rate, differentiation potential and cell morphology. Intra-abdominal fat tissue samples were recovered from 4 dogs and cells isolated from each sample were cultured under hypoxic and normoxic conditions. Proliferation rate and adhesion ability were determined, differentiation towards chondrogenic, osteogenic and adipogenic lineages was induced; the expression of CD44, CD34, DLA-DQA1, DLA-DRA1 was determined by PCR, while flow cytometry analysis for CD90, CD105, CD45 and CD14 was carried out. The morphological study was performed by transmission electron microscopy. Canine AT-MSCs, cultured under different oxygen tensions, maintained their basic biological features. However, under hypoxia, cells were not able to form spheroid aggregates revealing a reduction of their adhesivness. In both conditions, MSCs mainly displayed the same ultrastructural morphology and retained the ability to produce membrane vesicles. Noteworthy, MSCs cultivated under hypoxya revealed a huge shedding of large complex vesicles, containing smaller round-shaped vesicles. In our study, hypoxia partially influences the basic biological properties and the ultrastructural features of canine mesenchymal stem /stromal cells. Further studies are needed to clarify how hypoxia affects EVs production in term of amount and content in order to understand its contribution in tissue regenerative mechanisms and the possible employment in clinical applications. The findings of the present work could be noteworthy for canine as well as for other mammalian species.     

Interaction of phytases with minerals and availability of substrate affect the hydrolysis of inositol phosphates

The stability and activity of phytases in the soil environment may be affected by their sorption on soil particle surfaces and by substrate availability with important consequences for P cycling and nutrient bioavailability. This work evaluated the interaction of phytases with goethite, haematite, kaolinite, montmorillonite and two oxisol clays and investigated how this interaction is affected when myo-inositol hexakisphosphate (InsP₆) was sorbed on the mineral surfaces. phyA histidine acid phosphatases of fungal origin were used and their ability to release orthophosphate from the InsP₆-saturated minerals was evaluated.The phytases showed a high affinity for the mineral surfaces, with a loss of enzyme activity generally being observed over 24 h (up to 95% of the initially added activity). The loss of phytase activity was dependent on the type of mineral, with kaolinite and montmorillonite showing the greatest effect. Retention of enzyme activity was higher with the two oxisol clays, suggesting that the heterogeneous nature of clay surfaces and the presence of endogenous organic matter may limit the inhibition caused by interaction with minerals.In the presence of mineral surfaces saturated with InsP₆, the partitioning of enzyme activity between the solution and the solid phase was shifted more towards the solution phase, presumably due to the mineral surfaces being occupied by the substrate. However, phytases were not able to release any orthophosphate directly from InsP₆-saturated goethite and haematite, and hydrolysed InsP₆ that was desorbed from haematite. Conversely, in the case of kaolinite and of the oxisol clays, where desorption was limited, phytases appeared to be able to hydrolyse a small fraction of the InsP₆ adsorbed on the surfaces. These findings suggest that the bioavailability of P from inositol phosphates is governed to a large extent by the mineral composition of soil and by competitive effects for sorption on reactive surfaces among inositol phosphates and phytases.     

Characterization of a new potential functional ingredient: coffee silverskin

Dietary fiber (DF) is one of the main dietary factors contributing to consumers' well-being. In this work the possibility of using the roasted coffee silverskin (CS), a byproduct of roasted coffee beans, as a DF-rich ingredient has been evaluated. The results of our investigation showed that this material has 60% total DF, with a relevant component (14%) of soluble DF. Although a small amount of free phenol compounds is present in CS, it has a marked antioxidative activity, which can be attributed to the huge amount of Maillard reaction products, the melanoidins. Static batch culture fermentation experiments showed that CS induces preferential growth of bifidobacteria rather than clostridia and Bacteroides spp. CS can be proposed as a new potential functional ingredient in consideration of the high content of soluble DF, the marked antioxidant activity, and the potential prebiotic activity.