Cross-contamination in food-contacting surfaces: novel approaches to control food-borne pathogens

Este resumo faz parte de: Book of abstracts of the Meeting of the Institute for Biotechnology and Bioengineering, 2, Braga, Portugal, 2010. A versão completa do livro de atas está disponível em: http://hdl.handle.net/1822/1096

Adhesion and biofilm formation by a Salmonella enterica enteritidis isolate on kitchen bench stones: evaluation of the antibacterial effect of MICROBAN®

Contamination of food processing materials by microorganisms is the basis of the cross-contamination phenomenon and, therefore, is directly associated with the occurrence of severe foodborne diseases. Some approaches have already been made in order to control microbes’ attachment and development on food-contact surfaces, being the incorporation of antimicrobial compounds one of the most promising. In this context, the aim of this work was to assess bacterial adhesion and biofilm formation by Salmonella Enteritidis on kitchen bench stones (materials yet poorly studied but largely used in Mediterranean kitchens) and to compare the results between regular stones (without any antimicrobial added) and stones with Microban® incorporated (with triclosan as active agent). The assays were performed with a clinical isolate of Salmonella Enteritidis and four kitchen bench stones - granite, marble and two kinds of silestone (a material mainly made from quartz and with Microban® incorporated) – cut into squares of 2.0 x 2.0 cm2. Both adhesion and biofilm formation processes were assessed in 6-weel plates, at room temperature (25ºC), with shaking at 120 rpm and using LB as culture medium. Total cell counts of adhered bacteria were accomplished after 2 hours of incubation through epifluorescence microscopy enumeration of cells stained with DAPI, while biofilms biomass was evaluated by cell scraping and CFUs enumeration after a 48 hours growth period. The results revealed that all stones tested are prone to bacterial adhesion and no considerable effect of triclosan was observed in both silestones, indicating that Microban® does not act upon the interactions between the bacterial cells and stones surface. On the other hand, biofilm outcomes point out a possible bacteriostatic activity of this compound since, even though bacterial load in silestones remained high (≈ 7x106 cfu/cm2), significantly higher numbers of bacterial cells were found in granite and marble. In conclusion, given their propensity to bacterial colonization and biofilm growth, all these kitchen bench stones are not suitable for food processing. Moreover, Microban® incorporated in silestones had a poor performance in controlling microbial spread and, therefore, seems to be insufficient to prevent cross-contamination

Essential oils encapsulated in zeolite structures as delivery systems (EODS): an overview

Essential oils (EO) obtained from plants have proven industrial applications in the manufacturing of perfumes and cosmetics, in the production and flavoring of foods and beverages, as therapeutic agents in aromatherapy, and as the active principles or excipients of medicines and pharmaceutics due to their olfactory, physical-chemical, and biological characteristics. On behalf of the new paradigm of a more natural and sustainable lifestyle, EO are rather appealing due to their physical, chemical, and physiological actions in human beings. However, EO are unstable and susceptible to degradation or loss. To tackle this aspect, the encapsulation of EO in microporous structures as zeolites is an attractive solution, since these host materials are cheap and non-toxic to biological environments. This overview provides basic information regarding essential oils, including their recognized benefits and functional properties. Current progress regarding EO encapsulation in zeolite structures is also discussed, highlighting some representative examples of essential oil delivery systems (EODS) based on zeolites for healthcare applications or aromatherapy.The authors are grateful for the national funds provided by the FCT (Foundation for Science and Technology, Portugal) under the projects UIDB/04050/2020 (CBMA) and PTDC/AAGTEC/5269/2014 (FEDER, European Fund for Regional Development)/COM PETE/POCI—Operational Competitiveness and Internationalization Programme under the project POCI-01-0145-FEDER-006958. They are grateful for the financial support provided by the Research Centers CQ/UM through UID/QUI/0686/2020 and Project BioTecNorte (operation NORTE-01-0145-FEDER-000004), supported by the Northern Portugal Regional Operational Programme (NORTE 2020) under the Portugal 2020 Partnership Agreement through the European Regional Development Fund.info:eu-repo/semantics/publishedVersio

Swimming abilities of temperate pelagic fish larvae prove that they may control their dispersion in coastal areas

The Sense Acuity and Behavioral (SAAB) Hypothesis proposes that the swimming capabilities and sensorial acuity of temperate fish larvae allows them to find and swim towards coastal nursery areas, which are crucial for their recruitment. To gather further evidence to support this theory, it is necessary to understand how horizontal swimming capability varies along fish larvae ontogeny. Therefore, we studied the swimming capability of white seabream Diplodus sargus (Linnaeus, 1758) larvae along ontogeny, and their relationship with physiological condition. Thus, critical swimming speed (U-crit) and the distance swam (km) during endurance tests were determined for fish larvae from 15 to 55 days post-hatching (DPH), and their physiological condition (RNA, DNA and protein contents) was assessed. The critical swimming speed of white seabream larvae increased along ontogeny from 1.1 cm s(-1) (15 DPH) to 23 cm s(-1) (50 and 55 DPH), and the distance swam by larvae in the endurance experiments increased from 0.01 km (15 DPH) to 86.5 km (45 DPH). This finding supports one of the premises of the SAAB hypothesis, which proposes that fish larvae can influence their transport and distribution in coastal areas due to their swimming capabilities. The relationship between larvae's physiological condition and swimming capabilities were not evident in this study. Overall, this study provides critical information for understanding the link between population dynamics and connectivity with the management and conservation of fish stocks.Funding Agency Portuguese Foundation for Science and Technology SFRH/BD/104209/2014 Portuguese Foundation for Science and Technology UID/Multi/04326/2019 FCT, under the Transitional Norm DL57/2016/CP[1361]/CT[CT0008 CLIMFISH project-A framework for assess vulnerability of coastal fisheries to climate change in Portuguese coast n2/SAICT/2017-SAICTinfo:eu-repo/semantics/publishedVersio

Monoculture and mixed biofilms of listeria monocytogenes and pseudomonas fluorescens: effect of different culture media and temperatures

Like most microorganisms, Listeria monocytogenes and Pseudomonas fluorescens are able to form biofilms and are rarely found as monoculture biofilms in natural environments. Previous works showed that associations between bacteria from different genus commonly found in food-processing environments may affect their growth, attachment and biofilm formation. This work studied L. monocytogenes and P. fluorescens monoculture and multispecies biofilm formation, and investigated how different culture media and temperatures may influence such bacterial interactions. L. monocytogenes strains assayed were CECT 4031T, 747 and 994 (food isolates), 1559 (environmental isolate) and 1562 (clinical isolate). P. fluorescens strains used were ATCC 27663 and PF7A (food isolate). Each strain was tested for monoculture and mixed culture biofilm formation with each one of the other bacterium’s strains. Assays were performed during three days in 96-weel microtitre plates, at 4ºC, 22ºC and 37ºC. Brain Heart Infusion (BHI) and Skim Milk (SM) were the culture media and biofilm formation was assessed by Crystal Violet staining. Overall results showed that both media and temperature affect biofilm formation, as monoculture and as multispecies biofilms, and confirmed that the influence of different bacterial genus on biofilm formation is dependent on strains. Although a decrease of biomass was observed on multispecies biofilms formed at 22ºC in SM and at 37ºC in BHI, significantly higher OD values were found at 4ºC in both media, and at 22ºC in SM, indicating that the combination of these two bacteria on meat and dairy food processing environments may seriously compromise food safety potentiating higher contamination levels

The role of spirituality in pain, function, and coping in Individuals with chronic pain

Chronic pain is a multidimensional experience associated with psychosocial (e.g., pain-related beliefs and pain coping responses) and spiritual factors. Spirituality is a universal aspect of the human experience that has been hypothesized to impact pain experience via its effects on pain, physical/psychological function, resilience and pain-related beliefs, and pain coping responses. However, research evaluating the associations between measures of spirituality and measures of pain and function in individuals with chronic pain is limited. This study seeks to address this limitation.info:eu-repo/semantics/publishedVersio

Pain diagnosis, pain coping, and function in individuals with chronic musculoskeletal pain

Purpose: Research supports a role for coping responses in adjustment to chronic pain. However, it is likely that some coping responses play a larger role in adjustment to pain for some individuals than others. The identification of the factors that moderate the association between coping responses and pain-related outcomes has important clinical implications. This study sought to determine if musculoskeletal pain diagnosis moderates the associations between eight pain-coping responses and both pain and function. Patients and Methods: A non-probabilistic sample of 323 persons with different chronic musculoskeletal pain conditions completed measures of pain intensity, physical function, psychological function, and pain-coping responses. Results: With only one exception, the frequency of use of pain-coping responses was not associated with pain diagnosis. Statistically significant moderation effects of pain diagnosis on the association between coping and pain outcomes were found for two coping responses: 1) support seeking when predicting pain intensity, and 2) resting when predicting both physical and psychological function. Conclusion: The findings indicate that coping responses tend to play a similar role in patients' pain and function across different musculoskeletal pain conditions, with some important exceptions. If the findings are found to replicate in other samples, they would have important implications for determining when psychosocial pain treatments might (and when they might not) need to be adapted for specific diagnostic groups.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Effect of batch and fed-batch growth modes on biofilm formation by Listeria monocytogenes at different temperatures

The influence of Listeria monocytogenes (L. monocytogenes) biofilm formation feeding conditions (batch and fed-batch) at different temperatures on biofilm biomass and activity was determined. Biofilm biomass and cellular metabolic activity were assessed by Crystal Violet (CV) staining and 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide inner salt (XTT) colorimetric method, respectively. Live/Dead staining was also performed in order to get microscopic visualization of the different biofilms. Results revealed that at refrigeration temperature (4°C) a higher amount of biofilm was produced when batch conditions were applied, while at higher temperatures the fed-batch feeding condition was the most effective on biofilm formation. Moreover, independently of the temperature used, biofilms formed under fed-batch conditions were metabolically more active than those formed in batch mode. In conclusion, this work shows that different growth modes significantly influence L. monocytogenes biofilm formation on abiotic surfaces as well as the metabolic activity of cells within biofilms.Fundação para a Ciência e a Tecnologia (FCT) - PPCDT/AGR/59358/2004, SFRH/ BD/28887/2006, SFRH/BPD/26803/200

Pain-related beliefs, coping, and function: an observational study on the moderating influence of country of origin

Chronic pain is a multidimensional experience and pain treatments targeting psychosocial factors reduce pain and improve function. These treatments often overlook the sociocultural factors that influence pain and the psychological factors associated with function in people with chronic pain. Although preliminary findings suggest that cultural background may influence pain and function via their effects on beliefs and coping, no previous study has directly tested if the country of origin moderates the associations between these psychological factors and pain and function. This study sought to address this knowledge gap. Five hundred sixty-one adults with chronic pain, born and living in the USA (n = 273) or Portugal (n = 288), completed measures of pain, function, pain-related beliefs, and coping. Between-country similarities were found in the endorsement of beliefs related to disability, pain control, and emotion, and in asking for assistance, task persistence, and coping self-statement responses. Portuguese participants reported greater endorsement of harm, medication, solicitude, and medical cure beliefs, more frequent use of relaxation and support seeking, and less frequent use of guarding, resting, and exercising/stretching. In both countries, disability and harm beliefs and guarding responses were associated with worse outcomes; pain control and task persistence were associated with better outcomes. Six country-related small effect-size moderation effects emerged, such that task persistence and guarding are stronger predictors of pain and function in adults from the USA, but pain control, disability, emotion, and medication beliefs are more important in adults from Portugal. Some modifications may be needed when adapting multidisciplinary treatments from one country to another. Perspective: This article examines the similarities and differences in beliefs and coping endorsed by adults with chronic pain from 2 countries, and the potential moderation effects of country on the associations between these variables and pain and function. The findings suggest that some modifications may be needed when culturally customizing psychological pain treatments.info:eu-repo/semantics/acceptedVersio

Applications of the Schwinger Multichannel method with pseudopotentials to electron scattering from polyatomic molecules II: rotational excitation cross sections

This paper reports results for rotational excitation of H2O and H2S molecules by electron impact. It is also a databasis including tables of previously published rotationally resolved cross sections for CH4, SiH4, GeH4, SnH4, PbH4, NH3, PH3, AsH3, SbH3, CF4, CCl4, SiCl4 SiBr4, and SiI4. Our scattering amplitudes were calculated using the Schwinger multichannel method with norm-conserving pseudopotentials and the rotational resolved cross sections were obtained with the help of the adiabatic nuclei rotation approximation. Our results are in good agreement with other theoretical data and experimental results when available.2129Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq