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1.
J Med Internet Res ; 26: e51952, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38771622

RESUMO

BACKGROUND: Electronic health record-based clinical decision support (CDS) tools can facilitate the adoption of evidence into practice. Yet, the impact of CDS beyond single-site implementation is often limited by dissemination and implementation barriers related to site- and user-specific variation in workflows and behaviors. The translation of evidence-based CDS from initial development to implementation in heterogeneous environments requires a framework that assures careful balancing of fidelity to core functional elements with adaptations to ensure compatibility with new contexts. OBJECTIVE: This study aims to develop and apply a framework to guide tailoring and implementing CDS across diverse clinical settings. METHODS: In preparation for a multisite trial implementing CDS for pediatric overweight or obesity in primary care, we developed the User-Centered Framework for Implementation of Technology (UFIT), a framework that integrates principles from user-centered design (UCD), human factors/ergonomics theories, and implementation science to guide both CDS adaptation and tailoring of related implementation strategies. Our transdisciplinary study team conducted semistructured interviews with pediatric primary care clinicians and a diverse group of stakeholders from 3 health systems in the northeastern, midwestern, and southeastern United States to inform and apply the framework for our formative evaluation. RESULTS: We conducted 41 qualitative interviews with primary care clinicians (n=21) and other stakeholders (n=20). Our workflow analysis found 3 primary ways in which clinicians interact with the electronic health record during primary care well-child visits identifying opportunities for decision support. Additionally, we identified differences in practice patterns across contexts necessitating a multiprong design approach to support a variety of workflows, user needs, preferences, and implementation strategies. CONCLUSIONS: UFIT integrates theories and guidance from UCD, human factors/ergonomics, and implementation science to promote fit with local contexts for optimal outcomes. The components of UFIT were used to guide the development of Improving Pediatric Obesity Practice Using Prompts, an integrated package comprising CDS for obesity or overweight treatment with tailored implementation strategies. TRIAL REGISTRATION: ClinicalTrials.gov NCT05627011; https://clinicaltrials.gov/study/NCT05627011.


Assuntos
Sistemas de Apoio a Decisões Clínicas , Humanos , Criança , Design Centrado no Usuário , Registros Eletrônicos de Saúde , Atenção Primária à Saúde
2.
Int J Tuberc Lung Dis ; 27(4): 248-283, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-37035971

RESUMO

TB affects around 10.6 million people each year and there are now around 155 million TB survivors. TB and its treatments can lead to permanently impaired health and wellbeing. In 2019, representatives of TB affected communities attending the '1st International Post-Tuberculosis Symposium´ called for the development of clinical guidance on these issues. This clinical statement on post-TB health and wellbeing responds to this call and builds on the work of the symposium, which brought together TB survivors, healthcare professionals and researchers. Our document offers expert opinion and, where possible, evidence-based guidance to aid clinicians in the diagnosis and management of post-TB conditions and research in this field. It covers all aspects of post-TB, including economic, social and psychological wellbeing, post TB lung disease (PTLD), cardiovascular and pericardial disease, neurological disability, effects in adolescents and children, and future research needs.


Assuntos
Tuberculose , Criança , Adolescente , Humanos , Tuberculose/diagnóstico , Tuberculose/epidemiologia , Tuberculose/terapia , Pessoal de Saúde
3.
Acad Pediatr ; 23(7): 1376-1384, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36933616

RESUMO

OBJECTIVE: To identify factors associated with participation in group well-child care (GWCC), wherein families share preventive health care visits. METHODS: We extracted electronic health record data of mother-infant dyads with infants born 2013-18 at Yale New Haven Hospital and followed at the primary care center. Using chi-square analysis and multivariate logistic regression, we examined the extent to which 1) maternal/infant characteristics and recruitment timing were associated with GWCC initiation and continued engagement and 2) initiation was associated with primary care visits. RESULTS: Of 2046 eligible mother-infant dyads, 11.6% initiated GWCC. The odds of initiation were higher among mothers with Spanish versus English primary language (odds ratio: 2.36 [95% confidence interval: 1.52-3.66]), with 1 child versus ≥ 3 children (1.58 [1.13-2.22]), and of non-Hispanic Black versus non-Hispanic White infants (2.72 [1.39-5.32]). Initiation was lower among infants born in 2016 (0.53 [0.32-0.88]) and 2018 (0.29 [0.17-0.52]) versus 2013. Among GWCC initiators with follow-up data (n = 217), continued engagement (n = 132, 60.8%) was positively associated with maternal age of 20-29 years (2.85 [1.10-7.34]) and > 30 years (3.46 [1.15-10.43]) compared with< 20 years, and mothers with 1 child versus ≥ 3 (2.28 [1.04-4.98]). GWCC initiators, versus non-initiators, had 5.06 times higher adjusted odds of attending > 9 primary care appointments in the first 18 months (95% confidence interval: 3.74-6.85). CONCLUSIONS: As evidence builds on health and social benefits of GWCC, recruitment efforts may gain from considering multi-level socio-economic, demographic, and cultural factors associated with GWCC participation. Higher participation among systemically marginalized groups may present unique opportunities for family-based health promotion to mitigate health inequities.

4.
Cancer Biother Radiopharm ; 37(1): 11-16, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35021863

RESUMO

Background: Liver metastases from uveal melanoma carry a very poor prognosis. Hepatic artery infusions with Yttrium-90 (90Y) resin microspheres have some activity in this disease, and radiation and immunotherapy may be synergistic. The primary objective of this study was to determine the safety and tolerability of sequential 90Y resin microspheres and immunotherapy with ipilimumab and nivolumab in metastatic uveal melanoma. Materials and Methods: Twenty-six patients with uveal melanoma with hepatic metastases were entered into a pilot study. Treatment consisted of two infusions of 90Y resin microspheres, one to each lobe of the liver, followed in 2-4 weeks by immunotherapy with ipilimumab and nivolumab every 3 weeks for four doses, then maintenance immunotherapy with nivolumab alone. Results: Initial dosing of both 90Y and immunotherapy resulted in excessive toxicity. With decreasing the dosage of 90Y to limit the normal liver dose to 35Gy and lowering the ipilimumab dose to 1 mg/kg, the toxicity was tolerable, with no apparent change in efficacy. There was one complete and four confirmed partial responses, for an objective response rate of 20% and a disease control rate of 68%. The median progression-free survival was 5.5 months (95% confidence interval [CI]: 1.3-9.7 months), with a median overall survival of 15 months (95% CI: 9.7-20.1 months). Conclusions: With dose reductions, sequential therapy with 90Y and immunotherapy with ipilimumab and nivolumab is safe and tolerable, and has activity in metastatic uveal melanoma. These results justify a controlled trial to demonstrate whether 90Y resin microspheres add to the utility of combination immunotherapy in this disease. Clinical Trial Registration number: NCT02913417.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Nivolumabe , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Humanos , Imunoterapia , Ipilimumab/efeitos adversos , Fígado , Melanoma , Microesferas , Nivolumabe/efeitos adversos , Projetos Piloto , Neoplasias Uveais , Radioisótopos de Ítrio
5.
Appl Environ Microbiol ; 86(6)2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-31900309

RESUMO

Changes with time of a population of Bacillus weihenstephanensis KBAB4 and Bacillus licheniformis AD978 dormant spores into germinated spores and vegetative cells were followed by flow cytometry, at pH ranges of 4.7 to 7.4 and temperatures of 10°C to 37°C for B. weihenstephanensis and 18°C to 59°C for B. licheniformis Incubation conditions lower than optimal temperatures or pH led to lower proportions of dormant spores able to germinate and extended time of germination, a lower proportion of germinated spores able to outgrow, an extension of their times of outgrowth, and an increase of the heterogeneity of spore outgrowth time. A model based on the strain growth limits was proposed to quantify the impact of incubation temperature and pH on the passage through each physiological stage. The heat treatment temperature or time acted independently on spore recovery. Indeed, a treatment at 85°C for 12 min or at 95°C for 2 min did not have the same impact on spore germination and outgrowth kinetics of B. weihenstephanensis despite the fact that they both led to a 10-fold reduction of the population. Moreover, acidic sporulation pH increased the time of outgrowth 1.2-fold and lowered the proportion of spores able to germinate and outgrow 1.4-fold. Interestingly, we showed by proteomic analysis that some proteins involved in germination and outgrowth were detected at a lower abundance in spores produced at pH 5.5 than in those produced at pH 7.0, maybe at the origin of germination and outgrowth behavior of spores produced at suboptimal pH.IMPORTANCE Sporulation and incubation conditions have an impact on the numbers of spores able to recover after exposure to sublethal heat treatment. Using flow cytometry, we were able to follow at a single-cell level the changes in the physiological states of heat-stressed spores of Bacillus spp. and to discriminate between dormant spores, germinated spores, and outgrowing vegetative cells. We developed original mathematical models that describe (i) the changes with time of the proportion of cells in their different states during germination and outgrowth and (ii) the influence of temperature and pH on the kinetics of spore recovery using the growth limits of the tested strains as model parameters. We think that these models better predict spore recovery after a sublethal heat treatment, a common situation in food processing and a concern for food preservation and safety.


Assuntos
Bacillus licheniformis/crescimento & desenvolvimento , Bacillus/crescimento & desenvolvimento , Esporos Bacterianos/crescimento & desenvolvimento , Temperatura Alta , Modelos Teóricos
6.
Int J Food Microbiol ; 278: 81-87, 2018 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-29709833

RESUMO

The recovery at a range of incubation temperatures and pH of spores of Bacillus weihenstephanensis KBAB4 exposed to a peracetic acid-based disinfectant (PABD) or to pulsed light was estimated. Spores of B. weihenstephanensis were produced at 30 °C and pH 7.00, at 30 °C and pH 5.50, or at 12 °C and pH 7.00. The spores were treated with a commercial peracetic acid-based disinfectant at 80 mg·mL-1 for 0 to 200 min at 18 °C or by pulsed light at fluences ranging between 0.4 and 2.3 J·cm-2 for pulsed light treatment. After each treatment, the spores were incubated on nutrient agar at 12 °C, 30 °C or 37 °C, or at pH 5.10, 6.00 or 7.40. Incubation temperature during recovery had a significant impact only near the recovery limits, beyond which surviving spores previously exposed to a PABD or to pulsed light were not able to form colonies. In contrast, a decrease in pH of the recovery nutrient agar had a progressive impact on the ability of spores to form colonies. The time to first log reduction after PABD treatment was 29.5 ±â€¯0.7 min with recovery at pH 7.40, and was tremendously shortened 5.1 ±â€¯0.2 min with recovery at pH 5.10. Concerning the fluence necessary for the first log reduction, it was 1.5 times higher when the spores were recovered at pH 6.00 compared to a recovery at pH 5.10. The impact of recovery temperature and pH can be described with a mathematical model using cardinal temperature and pH as parameters. These effects of temperature and pH on recovery of Bacillus weihenstephanensis spores exposed to a disinfectant combining peracetic acid and hydrogen peroxide, or pulsed light are similar, although these treatments are of different natures. Sporulation temperature or pH did not impact resistance to the peracetic acid-based disinfectant or pulsed light.


Assuntos
Bacillus/crescimento & desenvolvimento , Desinfetantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Ácido Peracético/farmacologia , Esporos Bacterianos/crescimento & desenvolvimento , Temperatura Alta , Concentração de Íons de Hidrogênio , Esporos Bacterianos/efeitos dos fármacos , Esterilização/métodos
7.
Dysphagia ; 32(6): 759-766, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28687869

RESUMO

Tongue strength is routinely evaluated in clinical swallowing evaluations since lingual weakness is an established contributor to dysphagia. Tongue strength may be clinically quantified by the maximum isometric tongue pressure (MIP) generated by the tongue against the palate; however, wide ranges in normal performance remain to be fully explained. Although orthodontic theory has long suggested a relation between lingual function and oral cavity dimensions, little attention has been given to the potential influence of oral and palatal structure(s) on healthy variance in MIP generation. Therefore, anterior and posterior tongue strength measures and oropalatal dimensions were obtained across 147 healthy adults (aged 18-88 years). Age was confirmed as a significant, independent predictor explaining approximately 10.2% of the variance in anterior tongue strength, but not a significant predictor of posterior tongue strength. However, oropalatal dimensions predicted anterior tongue strength with over three times the predictive power of age alone (p < .001). Significant models for anterior tongue strength (R 2 = .457) and posterior tongue strength (R 2 = .283) included a combination of demographic predictors (i.e., age and/or gender) and oropalatal dimensions. Palatal width, estimated tongue volume, and gender were significant predictors of posterior tongue strength (p < .001). Therefore, oropalatal dimensions may warrant consideration when accurately differentiating between pathological lingual weakness and healthy individual difference.


Assuntos
Deglutição/fisiologia , Língua/anatomia & histologia , Língua/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos de Deglutição/etiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Pressão , Adulto Jovem
8.
J Appl Microbiol ; 121(6): 1568-1579, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27618523

RESUMO

AIM: Hydrosols are hydrodistillation products used in food and cosmetic industries, perfumery, pharmacy and aromatherapy. The ability of preservatives to control previously reported bacterial proliferation and spoilage was evaluated. All tested preservatives were authorized for food and cosmetic application. METHODS AND RESULTS: Major pathogens of concern for foods and cosmetics were poorly able to grow in rose and orange blossom hydrosols when inoculated and incubated at 30°C. Commercial antimicrobials, such as isothiazolinone, chlorphenesin and paraben solutions, benzyl alcohol and sodium benzoate at pH = 5·0, controlled the growth of Pseudomonas and Burkholderia sp. strains representative of the natural microbiota of both hydrosols for >90 days at 30°C, only at concentrations close to the authorized limits. Concentrations of some of the tested preservatives that controlled growth at 5°C were lower than at 30°C. CONCLUSION: Pathogenic micro-organisms likely represent a low risk in rose flower and orange blossom hydrosol. However, the oligotrophic character of hydrosols and the antimicrobial properties of their essential oils do not prevent microbiological spoilage by the naturally present microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY: In the absence of aseptic conditions and microbial inactivation process, only preservatives can stabilize hydrosols for a several-month storage. Several effective preservatives have been identified.


Assuntos
Antibacterianos/farmacologia , Citrus/microbiologia , Cosméticos , Conservantes de Alimentos/farmacologia , Rosa/microbiologia , Burkholderia/efeitos dos fármacos , Citrus/química , Pseudomonas/efeitos dos fármacos , Rosa/química , Compostos Orgânicos Voláteis/química
9.
Appl Environ Microbiol ; 81(2): 562-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25381235

RESUMO

The apparent heat resistance of spores of Bacillus weihenstephanensis and Bacillus licheniformis was measured and expressed as the time to first decimal reduction (δ value) at a given recovery temperature and pH. Spores of B. weihenstephanensis were produced at 30°C and 12°C, and spores of B. licheniformis were produced at 45°C and 20°C. B. weihenstephanensis spores were then heat treated at 85°C, 90°C, and 95°C, and B. licheniformis spores were heat treated at 95°C, 100°C, and 105°C. Heat-treated spores were grown on nutrient agar at a range of temperatures (4°C to 40°C for B. weihenstephanensis and 15°C to 60°C for B. licheniformis) or a range of pHs (between pH 4.5 and pH 9.5 for both strains). The recovery temperature had a slight effect on the apparent heat resistance, except very near recovery boundaries. In contrast, a decrease in the recovery pH had a progressive impact on apparent heat resistance. A model describing the heat resistance and the ability to recover according to the sporulation temperature, temperature of treatment, and recovery temperature and pH was proposed. This model derived from secondary mathematical models for growth prediction. Previously published cardinal temperature and pH values were used as input parameters. The fitting of the model with apparent heat resistance data obtained for a wide range of spore treatment and recovery conditions was highly satisfactory.


Assuntos
Bacillus/crescimento & desenvolvimento , Esporos Bacterianos/crescimento & desenvolvimento , Bacillus/efeitos dos fármacos , Bacillus/efeitos da radiação , Concentração de Íons de Hidrogênio , Modelos Teóricos , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/efeitos da radiação , Temperatura
10.
J Speech Lang Hear Res ; 55(3): 960-72, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22232400

RESUMO

PURPOSE: In the present study, the authors investigated lingual propulsive pressures generated in the normal swallow by the anterior and posterior lingual segments for various consistencies and maximum isometric tasks. METHOD: Lingual pressures for saliva, thin, and honey-thick liquid boluses were measured via the Iowa Oral Performance Instrument (IOPI Medical, Carnation, WA) at both anteromedian and posteromedian lingual segments of 62 healthy participants, ages 18-34 years (30 men, 32 women). RESULTS: A repeated-measures analysis of variance revealed that all lingual swallowing pressures were significantly greater at the anteromedian segment than at the posteromedian segment. Gender was not a significant factor; however, women exhibited greater swallowing pressures across all conditions. Lingual pressures increased as bolus viscosity increased. No significant interactions existed. Analysis of a subset of 30 participants revealed that men exhibited greater maximal isometric pressure at the anteromedian segment than women, with no significant gender difference at the posteromedian segment. A significantly higher percentage of maximum isometric tongue pressure was exerted by the posteromedian tongue than by the anteromedian tongue. CONCLUSION: Findings suggest that greater amplitudes of lingual pressures are generated during normal swallowing at the anteromedian lingual segment; however, a greater percentage of maximum isometric tongue pressure was exerted by the posteromedian lingual segment, suggesting increased effort by the posterior tongue during bolus propulsion.


Assuntos
Deglutição/fisiologia , Ingestão de Alimentos/fisiologia , Contração Isométrica/fisiologia , Língua/fisiologia , Adolescente , Adulto , Fenômenos Biomecânicos , Transtornos de Deglutição/fisiopatologia , Feminino , Humanos , Masculino , Pressão , Valores de Referência , Adulto Jovem
11.
Int J Food Microbiol ; 146(1): 57-62, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21354646

RESUMO

While bacterial spores are mostly produced in a continuous process, this study reports a two-step sporulation methodology. Even though spore heat resistance of numerous spore-forming bacteria is known to be dependent on sporulation conditions, this approach enables the distinction between the vegetative cell growth phase in nutrient broth and the sporulation phase in specific buffer. This study aims at investigating whether the conditions of growth of the vegetative cells, prior to sporulation, could affect spore heat resistance. For that purpose, wet-heat resistance of Bacillus weihenstephanensis KBAB4 spores, produced via a two-step sporulation process, was determined from vegetative cells harvested at four different stages of the growth kinetics, i.e. early exponential phase, late exponential phase, transition phase or early stationary phase. To assess the impact of the temperature on spore heat resistance, sporulation was performed at 10 °C, 20 °C and 30 °C from cells grown during a continuous or a discontinuous temperature process, differentiating or not the growth and sporulation temperatures. Induction of sporulation seems possible for a large range of growth stages. Final spore concentration was not significantly affected by the vegetative cell growth stage while it was by the temperature during growing and sporulation steps. The sporulation temperature influences the heat resistance of B. weihenstephanensis KBAB4 spores much more than growth temperature prior to sporulation. Spores produced at 10 °C were up to 3 times less heat resistant than spores produced at 30 °C.


Assuntos
Bacillus/fisiologia , Temperatura Alta , Esporos Bacterianos/crescimento & desenvolvimento , Bacillus/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Cinética
12.
Int J Food Microbiol ; 128(1): 165-73, 2008 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-18805600

RESUMO

The natural contamination of foods with a bacterial pathogen frequently consists of a mixture of strains with their own characteristics of survival, growth potential and virulence. Quantitative Microbial Risk Assessment (QMRA) must account for this genetic diversity to reflect the variability of the pathogen risk and to identify the genetic groups present at key stages of the food pathway. To describe the transmission dynamics of a heterogeneous population of B. cereus, we developed an exposure model that covers a food processing chain from "farm to table". The studied food was a cooked, pasteurised and chilled courgette purée used as an example of Refrigerated Processed Food of Extended Durability (REPFED). The B. cereus population consists of a continuum of genetic groups ranging from mesophilic and highly heat resistant, to psychrotrophic and moderately-heat resistant ones. At each step in a processing chain comprising cooking, blending, mixing with ingredients providing a secondary contamination, pasteurisation and chilling for several weeks, the prevalence of contaminated units (batches or packages) and the spore load within the units was determined for each genetic group, as well as their proportion to the total B. cereus population in the units. The model predicted that all packages contain mesophilic groups just after partitioning. The addition of mesophilic strains by the ingredients during the process of the courgette purée was an important contribution. At the end of the domestic storage, the model predicted a dominance of the mesophilic groups, while only some psychrotrophic groups were present.


Assuntos
Bacillus cereus/crescimento & desenvolvimento , Bacillus cereus/genética , Contaminação de Alimentos/análise , Manipulação de Alimentos/métodos , Variação Genética , Medição de Risco , Bacillus cereus/classificação , Bacillus cereus/patogenicidade , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Microbiologia de Alimentos , Cinética , Modelos Biológicos , Método de Monte Carlo , Filogenia , Valor Preditivo dos Testes , Especificidade da Espécie
13.
J Appl Microbiol ; 105(4): 1081-90, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18498350

RESUMO

AIMS: Our aim was to assess the diversity of the nutrient germination response of Bacillus cereus spores. METHODS AND RESULTS: B. cereus spore germination was monitored by decrease in optical density using a Bioscreen C analyser in response to the major germinant substances inosine and l-alanine. Spores of a set of 12 strains taken to illustrate the diversity of the B. cereus group showed ranging germination capacities. Two strains never germinated in the presence of l-alanine, at any of the germinant concentrations tested. Both the extent and rate of spore germination were affected by low pH and high NaCl concentration, but differently according to the strain. CONCLUSIONS: A broad diversity was observed in nutrient-triggered spore germination among the members of the B. cereus group. Spore germination of some strains occurred at low concentrations of inosine or l-alanine, suggesting high receptor sensitivity to germinants. The activity of these receptors was also affected by pH or high NaCl concentration. SIGNIFICANCE AND IMPACT OF THE STUDY: The greater ability of some strains to germinate in response to l-alanine and inosine is one criterion among others for B. cereus strain selection in food processing or storage studies, before confirmation in complex food or laboratory media. The diversity in response to germinants found among the B. cereus strains suggests a differential expression and (or) absence of some germination genes involved in the response, mainly to l-alanine.


Assuntos
Alanina/farmacologia , Bacillus cereus/fisiologia , Microbiologia de Alimentos , Inosina/farmacologia , Bacillus cereus/efeitos dos fármacos , Técnicas Bacteriológicas , Concentração de Íons de Hidrogênio , Cloreto de Sódio/farmacologia , Especificidade da Espécie , Esporos Bacterianos/efeitos dos fármacos , Esporos Bacterianos/fisiologia
14.
J Appl Microbiol ; 104(4): 1221-7, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17976173

RESUMO

AIMS: To investigate the effect of glycine betaine (GB) on the survival of Listeria monocytogenes on leaf surfaces under low relative humidity (RH). METHODS AND RESULTS: The addition of GB (> or = 25 mmol l(-1)) improved the survival of L. monocytogenes under low RH on parsley leaves, thus suggesting that GB can improve the tolerance of L. monocytogenes to desiccation. Ten times less GB was needed to improve L. monocytogenes survival under low RH on nonbiological surfaces compared with parsley leaves, suggesting that, on the leaf surface, L. monocytogenes may have to compete for the available GB with autochthonous bacteria and/or the plant itself. Wild type and mutants carrying deletions in the three GB uptake systems, BetL, Gbu and OpuC, behaved similarly with and without added GB on parsley leaves (P > 0.05). In addition, preaccumulation of GB, triggered by osmotic stress prior to inoculation, failed to improve survival under low RH compared with osmotic stress without GB accumulation. CONCLUSIONS: Exogenous GB had a protective effect on L. monocytogenes cells from desiccation during survival on parsley leaves. This effect was independent of intracellular GB accumulation by the known uptake systems. SIGNIFICANCE AND IMPACT OF THE STUDY: Presence of GB could improve the survival of L. monocytogenes to desiccation on leaf surfaces and nonbiological surfaces.


Assuntos
Betaína/farmacologia , Microbiologia de Alimentos , Listeria monocytogenes/fisiologia , Proteínas de Membrana Transportadoras/metabolismo , Técnicas Bacteriológicas , Betaína/metabolismo , Transporte Biológico , Transporte Biológico Ativo , Contagem de Colônia Microbiana , Meios de Cultura , Dessecação , Listeria monocytogenes/efeitos dos fármacos , Listeriose/transmissão , Viabilidade Microbiana , Pressão Osmótica , Petroselinum/microbiologia , Folhas de Planta/microbiologia , Virulência
15.
J Appl Microbiol ; 103(5): 1568-75, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17953568

RESUMO

AIMS: To determine the effects of porcine bile (PB) on Bacillus cereus vegetative cells and Haemolysin BL (HBL) enterotoxin production in reconstituted small intestine media (IM). METHODS AND RESULTS: The effects of PB on the growth of B. cereus vegetative cells in reconstituted IM at PB concentrations ranging between 0 and 3.0 g l(-1) were examined. Four gastric media (GM) named GM-J broth (JB), GM-chicken, GM-milk and GM-pea were prepared by mixing equal volumes of a gastric electrolyte solution containing pepsin with JB, chicken, semi-skimmed milk and pea soup, respectively. Bacillus cereus was inoculated at approx. 2 x 10(4) CFU ml(-1) into each GM at pH 5.0 for 30 min at 37 degrees C, then mixed to the same volume of double-strength JB (IM) and PB to give concentrations of between 0 and 3.0 g of PB per litre at pH 6.5 and incubated at 37 degrees C. The diarrhoeal B. cereus strain F4430/73 grew in IM-JB, IM-chicken and IM-milk at PB concentrations of up to 0.6, 1.5 and 1.2 g l(-1), respectively. Growth was observed in IM-pea at all concentrations tested. The highest PB concentrations allowing a 3 log B. cereus increase in IM-JB, IM-chicken, IM-milk and IM-pea after a 7-10 h incubation period were 0.3, 0.9, 0.9 and 3.0 g l(-1), respectively. The effect of PB on B. cereus cells was strongest in IM-JB, followed by IM-chicken, IM-milk and IM-pea. Haemolysin BL enterotoxin was detectable in IM-chicken, IM-whole milk, IM-semi-skimmed milk and IM-pea up to PB concentrations of only 0.6, 0.6, 0.3 and 0.9 g l(-1), respectively. The diarrhoeal B. cereus strain F4433/73 behaved similarly to B. cereus strain F4430/73, whereas the food strain TZ415 was markedly more susceptible to bile. CONCLUSIONS: The tolerance of B. cereus cells to PB strongly depends on the type of food contained in the IM. Bile tolerance is also subject to strain variation. SIGNIFICANCE AND IMPACT OF THE STUDY: The probability that B. cereus cells will grow in the small intestine, produce toxins and cause diarrhoea is likely to depend on the food they are ingested with, on the bile tolerance of the B. cereus strain, and on bile concentration.


Assuntos
Infecções por Bacillaceae/microbiologia , Bacillus cereus/fisiologia , Proteínas de Bactérias/biossíntese , Ácidos e Sais Biliares/farmacologia , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/microbiologia , Proteínas Hemolisinas/biossíntese , Animais , Bacillus cereus/efeitos dos fármacos , Proteínas de Bactérias/análise , Técnicas Bacteriológicas , Contagem de Colônia Microbiana , Proteínas Hemolisinas/análise , Humanos , Concentração de Íons de Hidrogênio , Intestino Delgado/microbiologia , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Suínos
16.
J Appl Microbiol ; 103(5): 1821-7, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17953592

RESUMO

AIMS: To investigate the population dynamics of Listeria monocytogenes and Listeria innocua on the aerial surfaces of parsley. METHODS AND RESULTS: Under 100% relative humidity (RH) in laboratory and regardless of the inoculum tested (10(3)-10(8) CFU per leaf), counts of L. monocytogenes EGDe, LO28, LmP60 and L. innocua CIP 80-12 tended towards approx. 10(5) CFU per leaf. Under low RH, Listeria spp. populations declined regardless to the inoculum size (10(4)-10(8) CFU per leaf). L. innocua CIP 80-12 survived slightly better than L. monocytogenes in the laboratory and was used in field cultures. Under field cultures, counts of L. innocua decreased more rapidly than in the laboratory, representing a decrease of 9 log(10) in 2 days in field conditions compared to a decrease of 4.5 log(10) in 8 days in the laboratory. Counts of L. innocua on tunnel parsley cultures were always higher (at least by 100 times) than those on unprotected parsley culture. CONCLUSIONS: Even with a high inoculum and under protected conditions (i.e. plastic tunnels), population of L. monocytogenes on the surface of parsley on the field would decrease by several log(10) scales within 2 days. SIGNIFICANCE AND IMPACT OF THE STUDY: Direct contamination of aerial surfaces of parsley with L. monocytogenes (i.e. through contaminated irrigation water) will not lead to contaminated produce unless it occurs very shortly before harvest.


Assuntos
Microbiologia de Alimentos , Listeria/crescimento & desenvolvimento , Petroselinum/microbiologia , Folhas de Planta/microbiologia , Técnicas Bacteriológicas , Contagem de Colônia Microbiana , Umidade , Listeria monocytogenes/crescimento & desenvolvimento , Viabilidade Microbiana , Fatores de Tempo , Microbiologia da Água
17.
J Appl Microbiol ; 103(4): 1272-81, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17897231

RESUMO

AIMS: To investigate the presence of viable but non-culturable Listeria monocytogenes during survival on parsley leaves under low relative humidity (RH) and to evaluate the ability of L. monocytogenes to recover from VBNC to culturable state under satured humidity. METHODS AND RESULTS: Under low RH (47-69%) on parsley leaves, the initial number of L. monocytogenes populations counted on non selective media (10(9) L. monocytogenes per leaf on TSA) was reduced by 6 log10 scales in 15 days, whereas number of viable L. monocytogenes counted under the microscope was reduced by 3-4 log10 scales, indicating the presence of VBNC cells. This was demonstrated on three L. monocytogenes strains (EGDe, Bug 1995 and LmP60). Changing from low to 100% RH permitted an increase of the culturable counts of L. monocytogenes and this growth was observed only when residual culturable cells were present. Moreover, VBNC L. monocytogenes inoculated on parsley leaves did not become culturable after incubation under 100% RH. CONCLUSIONS: Dry conditions induced VBNC L. monocytogenes on parsley leaves but these VBNC were likely unable to recover culturability after transfer to satured humidity. SIGNIFICANCE AND IMPACT OF STUDY: Enumeration on culture media presumably under-estimates the number of viable L. monocytogenes on fresh produce after exposure to low RH.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/isolamento & purificação , Petroselinum/microbiologia , Folhas de Planta/microbiologia , Técnicas Bacteriológicas , Umidade , Listeria monocytogenes/crescimento & desenvolvimento
18.
Percept Mot Skills ; 98(3 Pt 2): 1359-62, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15291227

RESUMO

The accurate identification of 30 words and 15 sentences spoken by native English, Taiwanese, and Spanish speakers was compared for 16 persons with and 16 persons without dementia. Statistically significant differences for words and sentences occurred between groups of listeners.


Assuntos
Demência/diagnóstico , Emigração e Imigração , Idioma , Vocabulário , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos
19.
J Appl Microbiol ; 97(1): 214-9, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15186458

RESUMO

AIMS: To determine the fate of Bacillus cereus spores or vegetative cells in simulated gastric medium. METHODS AND RESULTS: The effects of acidity on the survival of B. cereus in a medium simulating human stomach content was followed on spores at pH 1.0-5.2, and on vegetative cells at pH 2.5-5.7. Gastric media (GM) were prepared by mixing equal volumes of a gastric electrolyte solution with J broth (JB), half-skim milk, pea soup and chicken. At pH 1.0 and 1.4, the number of spores slightly decreased in GM-JB and GM-pea soup and remained stable in GM-milk and GM-chicken. A rapid marked decrease (always higher than 2.0 log CFU ml(-1) in 2 h) in vegetative cell counts was observed at pH below 4.2, 4.0, 3.6 and 3.5 in GM-chicken, GM-JB, GM-milk and GM-pea soup, respectively. Between pH 5.0 and 5.3, B. cereus growth was observed in GM-JB (1.2 log CFU ml(-1) increase after 4 h) and in GM-pea soup (1.8 log CFU ml(-1) increase after 4 h). CONCLUSIONS: Bacillus cereus spores are very much more resistant to gastric acidity than vegetative cells. This resistance strongly depends on the type of food present in the GM. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results suggest that the probability that viable B. cereus cells enter the small intestine, where they can cause diarrhoea, strongly depends on the form of the ingested cells (spores or vegetative cells), on what food they are ingested with, and on the level of stomach acidity.


Assuntos
Bacillus cereus/fisiologia , Microbiologia de Alimentos , Ácido Gástrico , Técnicas Bacteriológicas , Humanos , Concentração de Íons de Hidrogênio , Modelos Biológicos , Esporos Bacterianos
20.
Percept Mot Skills ; 97(1): 11-20, 2003 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-14604018

RESUMO

This pilot study concerned the intelligibility of accented speech for listeners of different ages. 72 native speakers of English, representing three age groups (20-39, 40-59, 60 and older) listened to words and sentences produced by native speakers of English, Taiwanese, and Spanish. Listeners transcribed words and sentences. Listeners also rated speakers' comprehensibility, i.e., listeners' perceptions of difficulty in understanding utterances, and accentedness, i.e., how strong a speaker's foreign accent is perceived to be. On intelligibility measures, older adults had significantly greater difficulty in understanding individuals with accented speech than the other two age groups. Listeners, regardless of age, were more likely to provide correct responses if they perceived the speaker easier to understand. Ratings of comprehensibility were highly correlated with ratings of accentedness.


Assuntos
Idioma , Inteligibilidade da Fala , Percepção da Fala , Adulto , Fatores Etários , Idoso , Envelhecimento , Cultura , Feminino , Humanos , Julgamento , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Testes de Discriminação da Fala
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