Removal of virus from hands: a study on the role of washing and drying.

Background: Proper hand hygiene is extremely important to control the transmission of pathogens. Although many studies have been undertaken on the effect of washing and drying on bacterial contamination of hands, studies on viral contamination are scarce.

Aim: To assess the viral load of artificially contaminated hands after washing and after drying.

Impact of different hand-drying methods on surrounding environment: aerosolization of virus and bacteria, and transfer to surfaces.

Background: In recent years, hand drying has been highlighted as a key step in appropriate hand hygiene, as moisture on hands can increase the transfer of micro-organisms from hands to surfaces and vice versa.

Aim: To understand bacterial and viral aerosolization following hand drying, and study the transfer of micro-organisms from hands to surfaces after drying using different methods.

Methods: Groups of five volunteers had their hands pre-washed with soap, rinsed and dried, then inoculated with a concentrated mixture of Pseudomonas fluorescens and MS2 bacteriophage.

Can air purification improve sleep quality? A 2-week randomised-controlled crossover pilot study in healthy adults.

Insufficient quantity and quality of sleep is a public health concern that can be addressed by interventions for improving sleep outcomes. Environmental factors such as poor air quality are a potential target for intervention, particularly in light of associations between air pollution and worse sleep. The aim of this pilot study was to investigate the effects of using an air purifier on sleep outcomes and mood in 30 healthy adults.

Aerosols and Bacteria From Hand Washing and Drying in Indoor Air.

Effective hand drying is an important part of hand hygiene that can reduce the risk of infectious disease transmission through cross-contamination of surfaces by wet hands. However, hand drying methods may also cause aerosolisation of pathogenic microorganisms if they are present in washed hands. This study investigated experimentally the impact of washing hands and different hand drying methods on the concentration and size distribution of aerosols and bacteria in indoor air.

Differential internalin A levels in biofilms of Listeria monocytogenes grown on different surfaces and nutrient conditions.

Listeria monoctyogenes is a foodborne pathogen containing the surface protein, internalin A (InlA). The expression of this protein permits the invasion of L. monocytogenes into intestinal epithelial cells expressing the receptor E-cadherin, thus crossing the intestinal barrier and resulting in listerosis.

Antioxidant properties of sterilized yacon (Smallanthus sonchifolius) tuber flour.

The objective of this research work was to investigate the antioxidant properties of sterilized yacon tuber flour. The results revealed for the first time the high antioxidant activity of sterilized yacon flour. The best extract obtained by boiling 8.

Improved recovery of Listeria monocytogenes from stainless steel and polytetrafluoroethylene surfaces using air/water ablation.

Aims: To develop a gentle ablation technique to recover Listeria monocytogenes biofilms from stainless steel (SS) and polytetrafluoroethylene (PTFE) surfaces by using compressed air and water injection.

Methods And Results: Biofilms were grown for 4, 24 and 48 h or 7 days and a compressed air and water flow at 2, 3 and 4 bars was applied for cell removal. Collected cells were quantified for total/dead by staining with SYTO 9/PI double staining and cultivable populations were determined by plating onto brain heart infusion (BHI) agar, while coupon surfaces also were stained with DAPI to quantify in situ the remaining cells.

Influence of copper surfaces on biofilm formation by Legionella pneumophila in potable water.

Legionella pneumophila is a waterborne pathogen that can cause Legionnaires' disease, a fatal pneumonia, or Pontiac fever, a mild form of disease. Copper is an antimicrobial material used for thousands of years. Its incorporation in several surface materials to control the transmission of pathogens has been gaining importance in the past decade.

Outbreak of Clostridium difficile PCR ribotype 027--the recent experience of a regional hospital.

Background: Clostridium difficile infection (CDI) is the leading cause of healthcare-associated diarrhea, and several outbreaks with increased severity and mortality have been reported. In this study we report a C. difficile PCR ribotype 027 outbreak in Portugal, aiming to contribute to a better knowledge of the epidemiology of this agent in Europe.

Listeria monocytogenes can form biofilms in tap water and enter into the viable but non-cultivable state.

Listeria monocytogenes is a foodborne pathogen that can be transmitted through contaminated raw food or by ready-to-eat products that have been in contact with contaminated surfaces. Tap water (TW) is used to wash produce, as a processed food constituent and to wash processing surfaces and floors. The main aim of this work was to investigate the formation and survival of L.

Evaluation of the antioxidant activity of cell extracts from microalgae.

A growing market for novel antioxidants obtained from non-expensive sources justifies educated screening of microalgae for their potential antioxidant features. Characterization of the antioxidant profile of 18 species of cyanobacteria (prokaryotic microalgae) and 23 species of (eukaryotic) microalgae is accordingly reported in this paper. The total antioxidant capacity, accounted for by both water- and lipid-soluble antioxidants, was evaluated by the (radical cation) ABTS method.

Optimization of ABTS radical cation assay specifically for determination of antioxidant capacity of intracellular extracts of microalgae and cyanobacteria.

A renewed interest in antioxidants has arisen in recent years; microalgae and cyanobacteria are potential sources thereof for use as food/feed ingredients. However, improved methods for comprehensive screening of antioxidant capacity specifically in intracellular extracts of marine microorganisms are required - encompassing lipophilic and hydrophilic compounds simultaneously. The original ABTS method was thus improved, and in particular the procedures of cell disruption and storage were optimized.

Hydrodynamic shear stress to remove Listeria monocytogenes biofilms from stainless steel and polytetrafluoroethylene surfaces.

Aims: To calculate the shear stress needed to remove sessile Listeria monocytogenes cells from stainless steel (SS) and polytetrafluoroethylene (PTFE) surfaces.

Methods And Results: Listeria monocytogenes biofilms were formed on SS and PTFE surfaces. Shear stress was calculated using a radial flow chamber device and cells quantified by staining with 4',6-diamidino-2-phenylindole.

Interaction of Legionella pneumophila and Helicobacter pylori with bacterial species isolated from drinking water biofilms.

Background: It is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission remains unknown but water seems to play an important role. This work aims to study the influence of five microorganisms isolated from drinking water biofilms on the survival and integration of both of these pathogens into biofilms.

Results: Firstly, both pathogens were studied for auto- and co-aggregation with the species isolated from drinking water; subsequently the formation of mono and dual-species biofilms by L.

How three adventitious lactic acid bacteria affect proteolysis and organic acid production in model Portuguese cheeses manufactured from several milk sources and two alternative coagulants.

Model cheeses were manufactured according to a full factorial experimental design to help shed light on the individual and combined roles played by 3 native lactic acid bacteria (Lactococcus lactis ssp. lactis, Lactobacillus brevis, and Lactobacillus plantarum) upon proteolysis and organic acid evolution in cheese. The model cheeses were manufactured according to a generally representative Portuguese artisanal protocol, but the (ubiquitous) adventitious microflora in the cheesemaking milk were removed via sterilization before manufacture; therefore, the specific effects of only those lactic acid bacteria selected were monitored.

Effects of extracts of selected medicinal plants upon hepatic oxidative stress.

Aqueous extracts of a few medicinal plants traditionally used in Portugal have been assayed for their effects upon hepatic oxidative stress in mice. Previous in vitro studies had allowed characterization of agrimony, sage, savory, and raspberry in terms of overall antioxidant capacity and phenolic content. In the present study, the antioxidant effect and safety of these four plants were evaluated in vivo.

Effect of chlorine on incorporation of Helicobacter pylori into drinking water biofilms.

The use of a specific peptide nucleic acid (PNA) probe demonstrated that Helicobacter pylori persisted inside biofilms exposed to low concentrations of chlorine (0.2 and 1.2 mg liter(-1)) for at least 26 days, although no culturable cells were recovered.

Comparison between standard culture and peptide nucleic acid 16S rRNA hybridization quantification to study the influence of physico-chemical parameters on Legionella pneumophila survival in drinking water biofilms.

Legionella pneumophila is a waterborne pathogen that is mainly transmitted by the inhalation of contaminated aerosols. In this article, the influence of several physico-chemical parameters relating to the supply of potable water was studied using a L. pneumophila peptide nucleic acid (PNA) specific probe to quantify total L.

Incorporation of natural uncultivable Legionella pneumophila into potable water biofilms provides a protective niche against chlorination stress.

Legionella pneumophila is a waterborne pathogen that has been isolated sporadically from drinking water distribution systems (DWDS). Resistance to disinfectants is mainly attributed to the association of cells with amoebae, but biofilms are also thought to provide some degree of protection. In the present work, a two-stage chemostat was used to form heterotrophic biofilms from drinking water to study the influence of chlorine on the presence of naturally occurring L.

Incorporation of natural uncultivable Legionella pneumophila into potable water biofilms provides a protective niche against chlorination stress.

Legionella pneumophila is a waterborne pathogen that has been isolated sporadically from drinking water distribution systems (DWDS). Resistance to disinfectants is mainly attributed to the association of cells with amoebae, but biofilms are also thought to provide some degree of protection. In the present work, a two-stage chemostat was used to form heterotrophic biofilms from drinking water to study the influence of chlorine on the presence of naturally occurring L.

Determination of antioxidant capacity using the biological system bacteriophage P22/bacterium Salmonella typhimurium.

Bacteriophage/bacterium systems have been employed in the past in assays for virucidal activity. A novel application of one such system is proposed here for the in vivo determination of antioxidant capacity. It was shown that an antioxidant such as gallic acid can effectively protect against oxidative damage brought about by H2O2-but only within a narrow range of concentrations (i.

Validation of SYTO 9/propidium iodide uptake for rapid detection of viable but noncultivable Legionella pneumophila.

Legionella pneumophila is an ubiquitous environmental microorganism that can cause Legionnaires' disease or Pontiac fever. As a waterborne pathogen, it has been found to be resistant to chlorine disinfection and survive in drinking water systems, leading to potential outbreaks of waterborne disease. In this work, the effect of different concentrations of free chlorine was studied (0.

Persistence of Helicobacter pylori in heterotrophic drinking-water biofilms.

Although the route of transmission of Helicobacter pylori remains unknown, drinking water has been considered a possible transmission vector. It has been shown previously that, in water, biofilms are a protective niche for several pathogens, protecting them from stressful conditions, such as low carbon concentration, shear stress, and less-than-optimal temperatures. In this work, the influence of these three parameters on the persistence and cultivability of H.

Antioxidant activity of sugar molasses, including protective effect against DNA oxidative damage.

Extracts were obtained from molasses, a byproduct of the sugar industry, via a number of chromatographic steps. Their antioxidant capacity was studied, including the inhibitory effect upon DNA oxidative damage; the phenolic compound profile thereof was ascertained as well. Two extracts exhibited significant antioxidant features, expressed by their capacity to decolorize ABTS radical cation and to scavenge hydroxyl free radicals (via deoxyribose assay).

Infusions of Portuguese medicinal plants: Dependence of final antioxidant capacity and phenol content on extraction features.

Background: Aqueous extracts of most medicinal plants traditionally employed in Portugal (at the ratio of 1 g plant: 110 mL water) have been assayed for total antioxidant capacity and phenol content, in order to elucidate their claimed medicinal features.

Results: The antioxidant activity was assessed by the ABTS(•+) method; the ascorbic acid equivalent values ranged from 1.4280 ± 0.