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1.
Swiss Med Wkly ; 154: 3706, 2024 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-38642339

RESUMEN

AIM OF THE STUDY: The COVID-19 pandemic has drawn attention to the benefit of wastewater-based epidemiology, particularly when case numbers are underreported. Underreporting may be an issue with mpox, where biological reasons and stigma may prevent patients from getting tested. Therefore, we aimed to assess the validity of wastewater surveillance for monitoring mpox virus DNA in wastewater of a Central European city and its association with official case numbers. METHODS: Wastewater samples were collected between 1 July and 28 August 2022 in the catchment area of Basel, Switzerland, and the number of mpox virus genome copies they contained was determined by real-time quantitative PCR. Logistic regression analyses were used to determine the odds of detectability of mpox virus DNA in wastewater, categorised as detectable or undetectable. Mann-Whitney U tests were used to determine associations between samples that tested positive for the mpox virus and officially reported cases and patients' recorded symptomatic phases. RESULTS: Mpox virus DNA was detected in 15 of 39 wastewater samples. The number of positive wastewater samples was associated with the number of symptomatic cases (odds ratio [OR] = 2.18, 95% confidence interval (CI) = 1.38-3.43, p = 0.001). The number of symptomatic cases differed significantly between days with positive versus negative wastewater results (median = 11 and 8, respectively, p = 0.0024). CONCLUSION: Mpox virus DNA was detectable in wastewater, even when officially reported case numbers were low (0-3 newly reported mpox cases corresponding to 6-12 symptomatic patients). Detectability in wastewater was significantly associated with the number of symptomatic patients within the catchment area. These findings illustrate the value of wastewater-based surveillance systems when assessing the prevalence of emerging and circulating infectious diseases.


Asunto(s)
Mpox , Aguas Residuales , Humanos , Monkeypox virus , Suiza/epidemiología , Pandemias , Monitoreo Epidemiológico Basado en Aguas Residuales , ADN
2.
Front Microbiol ; 14: 1295037, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38075908

RESUMEN

Background: The involvement of non-human-to-human transmission of extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-PE) remains elusive. Foodstuffs may serve as reservoirs for ESBL-PE and contribute to their spread. Aim: We aimed to systematically investigate the presence and spatiotemporal distribution of ESBL-PE in diverse unprocessed foodstuffs of different origin purchased in a central European city. Methods: Chicken and green (herbs, salad, sprouts, vegetables) samples were collected monthly for two consecutive years, from June 2017 to June 2019, from large supermarket chains and small local food retailers, representing all ten postcode areas of the City of Basel (Switzerland), and the kitchen of the University Hospital Basel (Basel, Switzerland). After enrichment, presumptive ESBL-PE were isolated by selective culture methods and identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. ESBL production was confirmed by phenotypic testing. Results: Among 947 food samples, 14.8% were positive for ESBL-PE isolate/s belonging to eight different ESBL-producing bacterial species. Escherichia coli and Serratia fonticola were predominant across samples (9 and 2%, respectively). Higher ESBL-PE prevalence was observed in chicken (25.9%) than in green (3.8%) samples (p < 0.001). Among greens, ESBL-PE were most frequently isolated from sprouts (15.2%). High ESBL-PE species diversity was observed among chicken samples, with E. coli as predominant (17.6%). ESBL-producing Enterobacter cloacae was detected among different greens. Yet, ESBL-producing Klebsiella pneumoniae was predominant in sprouts (12.1%). In total, 20.5% of samples from organic farming and 14.2% of samples from conventionally raised animals harbored an ESBL-producing isolate. Detection of ESBL-PE across samples differed between organic and non-organic when stratified by food source (p < 0.001), particularly among greens (12.5% organic, 2.4% conventional). High proportion of organic chicken samples was positive for ESBL-E. coli (33.3%), while the detection of several species characterized the conventional chicken samples. No significant differences in ESBL-PE frequences were detected between national (13.4%) and international samples (8.0%) (p = 0.122). Instead, differences were observed between regions of food production and countries (p < 0.001). No significant differences were found when comparing the proportion of ESBL-PE positive samples across districts, shop sizes and the hospital kitchen. The percentage of ESBL-PE positive samples did not differ monthly across the two-year sampling period (p = 0.107). Conclusion: Our findings indicate moderate dissemination of ESBL-PE in foodstuffs, especially between chicken products and sprouts. Chicken meat represents a source for several ESBL-producing Enterobacterales, especially E. coli, while greens are more prone to carry ESBL-K. pneumoniae and E. cloacae. We disclose the importance of food type, food production system and production origin when assessing the risk of contamination with different ESBL-PE species.

3.
Front Microbiol ; 14: 1174336, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37250050

RESUMEN

Background: The contribution of community and hospital sources to the transmission of extended-spectrum ß-lactamase producing Enterobacterales (ESBL-PE) remains elusive. Aim: To investigate the extent of community dissemination and the contribution of hospitals to the spread of ESBL-PE by exploring their spatiotemporal distribution in municipal wastewater of the central European city of Basel. Methods: Wastewater samples were collected monthly for two consecutive years throughout Basel, Switzerland, including 21 sites across 10 postcode areas of the city collecting either community wastewater (urban sites, n = 17) or community and hospital wastewater (mixed sites, n = 4). Presumptive ESBL-PE were recovered by selective culture methods. Standard methodologies were applied for species identification, ESBL-confirmation, and quantification. Results: Ninety-five percent (477/504) of samples were positive for ESBL-PE. Among these isolates, Escherichia coli (85%, 1,140/1,334) and Klebsiella pneumoniae (11%, 153/1,334) were most common. They were recovered throughout the sampling period from all postcodes, with E. coli consistently predominating. The proportion of K. pneumoniae isolates was higher in wastewater samples from mixed sites as compared to samples from urban sites, while the proportion of E. coli was higher in samples from urban sites (p = 0.003). Higher numbers of colony forming units (CFUs) were recovered from mixed as compared to urban sites (median 3.2 × 102 vs. 1.6 × 102 CFU/mL). E. coli-counts showed moderate correlation with population size (rho = 0.44), while this correlation was weak for other ESBL-PE (rho = 0.21). Conclusion: ESBL-PE are widely spread in municipal wastewater supporting that community sources are important reservoirs entertaining the spread of ESBL-PE. Hospital-influenced abundance of ESBL-PE appears to be species dependent.

4.
Swiss Med Wkly ; 152: w30202, 2022 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-35822578

RESUMEN

AIMS OF THE STUDY: Wastewater-based epidemiology has contributed significantly to the comprehension of the dynamics of the current COVID-19 pandemic. Its additional value in monitoring SARS-CoV-2 circulation in the population and identifying newly arising variants independently of diagnostic testing is now undisputed. As a proof of concept, we report here correlations between SARS-CoV-2 detection in wastewater and the officially recorded COVID-19 case numbers, as well as the validity of such surveillance to detect emerging variants, exemplified by the detection of the B.1.1.529 variant Omicron in Basel, Switzerland. METHODS: From July 1 to December 31, 2021, wastewater samples were collected six times a week from the inflow of the local wastewater treatment plant that receives wastewater from the catchment area of the city of Basel, Switzerland, comprising 273,075 inhabitants. The number of SARS-CoV-2 RNA copies was determined by reverse transcriptase-quantitative PCR. Spearman's rank correlation coefficients were calculated to determine correlations with the median seven-day incidence of genome copies per litre of wastewater and official case data. To explore delayed correlation effects between the seven-day median number of genome copies/litre wastewater and the median seven-day incidence of SARS-CoV-2 cases, time-lagged Spearman's rank correlation coefficients were calculated for up to 14 days. RNA extracts from daily wastewater samples were used to genotype circulating SARS-CoV-2 variants by next-generation sequencing. RESULTS: The number of daily cases and the median seven-day incidence of SARS-CoV-2 infections in the catchment area showed a high correlation with SARS-CoV-2 measurements in wastewater samples. All correlations between the seven-day median number of genome copies/litre wastewater and the time-lagged median seven-day incidence of SARS-CoV-2 cases were significant (p<0.001) for the investigated lag of up to 14 days. Correlation coefficients declined constantly from the maximum of 0.9395 on day 1 to the minimum of 0.8016 on day 14. The B.1.1.529 variant Omicron was detected in wastewater samples collected on November 21, 2021, before its official acknowledgement in a clinical sample by health authorities. CONCLUSIONS: In this proof-of-concept study, wastewater-based epidemiology proved a reliable and sensitive surveillance approach, complementing routine clinical testing for mapping COVID-19 pandemic dynamics and observing newly circulating SARS-CoV-2 variants.


Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/diagnóstico , COVID-19/epidemiología , Humanos , Pandemias , ARN Viral/genética , SARS-CoV-2/genética , Suiza/epidemiología , Aguas Residuales/análisis
5.
ACS Comb Sci ; 21(10): 675-684, 2019 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-31454226

RESUMEN

Materials exhibiting a giant magnetocaloric effect (GMCE) need to be finely tuned with respect to their magnetic and structural properties, specifically their respective transition temperatures. Co-Mn-Ge and Co-Mn-Ge-Si thin-film materials libraries (MLs) were fabricated and characterized to determine the composition range in which the CoMnGe phase is stable and analyze selected single-phase measurement regions. Phase analysis was performed on these MLs and refined in regard to the CoMnGe single-phase region by synchrotron diffraction experiments. A comparison of the MLs revealed that the CoMnGe (HT) single-phase region gets smaller with the addition of Si and exists for 26.5 at. % < Co < 29.5 at. %, 34 at. % < Mn < 37 at. %, Ge ∼ 35 at. %, and Si ∼ 1.5 at. % in the quaternary ML. The investigation of magnetic and structural transition properties in this region revealed hard-magnetic behavior with Curie temperatures (Tc) between 261 and 274 K and large hysteresis widths with values >100 K for the structural transition. A low Co content was necessary to achieve an overlap of Tc and structural transition temperatures, leading to the most favorable properties for a GMCE to be found in Co26.5Mn37Ge35Si1.5.


Asunto(s)
Cobalto/química , Técnicas Químicas Combinatorias , Germanio/química , Manganeso/química , Silicio/química , Fenómenos Magnéticos , Estructura Molecular
6.
IEEE Trans Neural Syst Rehabil Eng ; 26(6): 1223-1232, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29877847

RESUMEN

The vestibulo-ocular reflex (VOR) is the primary mechanism for stabilizing vision during rapid head movements. We have developed a training technique that typically increases the VOR response a minimum of 15% after 15 mins of training. This technique relies on subjects tracking a visual target that moves as a function of head motion, but at a different speed, so that the VOR is challenged to increase in order to stabilize the retinal image of the target. We have developed a portable device, StableEyes, which implements this technique so that unassisted training can be performed at home by patients with VOR hypofunction. The device consists of a head unit and base unit. The head unit contains inertial sensors to measure the instantaneous 3-D orientation of the head in space at 250 Hz, and an integrated circuit mirror to dynamically control the position of a laser target in space. The base unit consists of a touch screen interface that allows users to calibrate and set the device, in addition to recording compliance. The laser target range is ±12.5°. The device latency is 6 ms with a frequency response stable up to 6 Hz for velocities >80°/s, i.e., head velocities, where the VOR contributes most to visual stability. StableEyes was used to increase the VOR response in 10 normal subjects. In these, the VOR towards the adapting side increased by ~11%, which is comparable to our laboratory findings. The adoption of StableEyes could improve the efficacy of vestibular rehabilitation and its outcomes.


Asunto(s)
Movimientos Oculares/fisiología , Reflejo Vestibuloocular/fisiología , Vestíbulo del Laberinto/fisiología , Adulto , Algoritmos , Movimientos de la Cabeza , Humanos , Rayos Láser , Masculino , Persona de Mediana Edad , Movimientos Sacádicos/fisiología , Interfaz Usuario-Computador , Enfermedades Vestibulares/rehabilitación
7.
Food Chem Toxicol ; 116(Pt B): 100-107, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29626580

RESUMEN

Using a survey approach, the study examined how experts (i.e. food control representatives), producers (i.e. food industry representatives) and consumers prioritized control activities for 28 hazards related to food and other everyday items. The investigated hazards encompassed a wide range of safety issues, including health risks, consumer deception and poor food hygiene behaviour. The participants included 41 experts, 138 producers and 243 consumers from the German- and French-speaking parts of Switzerland. Based on detailed descriptions of the hazards, they were asked to rank these on a score sheet in terms of the perceived importance of monitoring by food control authorities. A between-group comparison of average rankings showed that consumers and experts differed significantly in relation to 17 of the 28 hazards. While the experts assigned higher priority to hazards related to everyday items such as nitrosamine in mascara and chromium VI in leather products, producers and consumers tended to prioritize products related to plant treatment and genetic modification of food and feeds. Producer and consumer rankings of the hazards were highly correlated (r = .96, p < .001). Rankings were also similar among participants from the two cultural regions (i.e. German and French-speaking parts of Switzerland).


Asunto(s)
Seguridad de Productos para el Consumidor , Administración de la Seguridad , Adulto , Femenino , Industria de Alimentos , Humanos , Masculino , Persona de Mediana Edad , Medición de Riesgo , Suiza
8.
BMJ Open ; 8(2): e021823, 2018 02 17.
Artículo en Inglés | MEDLINE | ID: mdl-29455172

RESUMEN

INTRODUCTION: Extended-spectrum beta-lactamases (ESBL)-producing Enterobacteriaceae were first described in relation with hospital-acquired infections. In the 2000s, the epidemiology of ESBL-producing organisms changed as especially ESBL-producing Escherichia coli was increasingly described as an important cause of community-acquired infections, supporting the hypothesis that in more recent years ESBL-producing Enterobacteriaceae have probably been imported into hospitals rather than vice versa. Transmission of ESBL-producing Enterobacteriaceae is complicated by ESBL genes being encoded on self-transmissible plasmids, which can be exchanged among the same and different bacterial species. The aim of this research project is to quantify hospital-wide transmission of ESBL-producing Enterobacteriaceae on both the level of bacterial species and the mobile genetic elements and to determine if hospital-acquired infections caused by ESBL producers are related to strains and mobile genetic elements predominantly circulating in the community or in the healthcare setting. This distinction is critical in prevention since the former emphasises the urgent need to establish or reinforce antibiotic stewardship programmes, and the latter would call for more rigorous infection control. METHODS AND ANALYSIS: This protocol presents an observational study that will be performed at the University Hospital Basel and in the city of Basel, Switzerland. ESBL-producing Enterobacteriaceae will be collected from any specimens obtained by routine clinical practice or by active screening in both inpatient and outpatient settings, as well as from wastewater samples and foodstuffs, both collected monthly over a 12-month period for analyses by whole genome sequencing. Bacterial chromosomal, plasmid and ESBL-gene sequences will be compared within the cohort to determine genetic relatedness and migration between humans and their environment. ETHICS AND DISSEMINATION: This study has been approved by the local ethics committee (Ethikkommission Nordwest-und Zentralschweiz) as a quality control project (Project-ID 2017-00100). The results of this study will be published in peer-reviewed medical journals, communicated to participants, the general public and all relevant stakeholders.


Asunto(s)
Infecciones Comunitarias Adquiridas/transmisión , Infecciones por Enterobacteriaceae/transmisión , Enterobacteriaceae/genética , Enterobacteriaceae/aislamiento & purificación , Secuencias Repetitivas Esparcidas , beta-Lactamasas/genética , Infecciones Comunitarias Adquiridas/microbiología , Infección Hospitalaria , Humanos , Estudios Prospectivos , Proyectos de Investigación , Estudios Retrospectivos , Suiza/epidemiología , Centros de Atención Terciaria , Secuenciación Completa del Genoma , beta-Lactamasas/metabolismo
9.
Risk Anal ; 38(3): 504-524, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28675477

RESUMEN

This study examined how experts and laypeople using both a deliberative and a survey method prioritized 28 hazards related to food and everyday items. To enable them to make deliberative decisions, participants received detailed descriptions of the hazards. The participants prioritized the hazards before and after a group discussion, in which the group's average prioritization was discussed. The rankings of the hazards before and after the group discussion were highly correlated. However, laypeople and experts differed significantly in their rankings for 18 of the 28 hazards. Trust and confidence were important predictors for laypeople's risk rankings. To test the influence of the deliberative method (e.g., providing detailed information about each hazard), data from a second group of laypeople were collected with a no-information survey. This group did not receive specific information about the hazards. The risk rankings of the laypeople who received information were highly correlated with the risk rankings of laypeople who did not receive information. Overall, the results suggest that deliberative methods of risk-ranking or no-information survey methods with no information about hazards provide similar results among laypeople. The conclusion is that government agencies should not only base their risk prioritization on evidence from risk assessments but also need to consider laypeople's hazard rankings. This procedure may result in an efficient and publicly accepted risk management strategy.

10.
Chimia (Aarau) ; 70(5): 334-7, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27198810

RESUMEN

The driving force behind food adulteration is monetary profit and this has remained unchanged for at least the last hundred years. Food adulterations were and still are difficult to uncover because they occur mostly in an unpredictable and unexpected way. Very often food falsifiers take advantage of modern technology in such a way that food adulterations are difficult or sometimes even impossible to detect. Targets for food adulteration were and still are highly priced food items such as spirits, meat, seafood and olive oil. Although difficult to detect, food adulterations were in the past strong driving forces for the development of adequate detection methods in the official food control laboratories and for the enforcement of the food law. A very prominent example in this context is the 'Ravioli scandal' in Switzerland in the late 1970s which showed that cheap second-class meat could be processed into products without being discovered for long time. As a consequence the official food control laboratories in Switzerland were reinforced with more laboratory equipment and technical staff. With the introduction of new detection principles such as DNA-based analytical methods new kinds of food adulteration could and can be uncovered. Analytical methods have their limits and in some cases of food fraud there are no analytical means to detect them. In such cases the examination of trade by checking of accounts is the method of choice.

11.
Opt Lett ; 36(13): 2483-5, 2011 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-21725452

RESUMEN

A diode-pumped actively mode-locked Tm³âº-doped double-clad silica fiber laser providing up to 11.8 W of average output power and pulse widths in mode-locked operation of 38 ps at a repetition rate of 37.88 MHz is reported. Pulse energies of up to 314 nJ were obtained.

12.
Immunology ; 110(2): 269-74, 2003 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-14511241

RESUMEN

Coeliac disease (CD), a gastrointestinal illness characterized by intestinal malabsorption, results from gluten intolerance accompanied with immunological responses towards gliadin, an ethanol-soluble protein fraction of wheat and other cereals. The role of gliadin in eliciting immune responses in CD is still partly unclear; however, the occurrence of anti-gliadin in the sera of patients suffering from CD correlates well with clinical symptoms. In this work we report the construction of isotype-specific, phage-displayed scFv libraries from peripheral blood lymphocytes of a patient with CD and from a healthy control individual. VH and VL chains were amplified by reverse transcription-polymerase chain reaction (RT-PCR) using a set of oligonucleotides recognizing all human variable gene families. The three scFv libraries (IgA, IgG and IgM) were selectively enriched for gliadin-binding phage. After four rounds of affinity selection, polyclonal enrichment of gliadin-binding phage was observed in all libraries from the CD patient but in none from the healthy donor. Phagemid particles generated from single clones were demonstrated to be gliadin-specific, as shown by strongly positive enzyme-linked immunosorbent assay (ELISA) and BiaCore signals. The VH and VL chains from samples of these monoclonal isotype-specific phage were sequenced to identify the most common variable regions used by the immune system to elicit antibody responses against gliadin.


Asunto(s)
Enfermedad Celíaca/inmunología , Gliadina/inmunología , Isotipos de Inmunoglobulinas/biosíntesis , Biblioteca de Péptidos , Secuencia de Aminoácidos , Afinidad de Anticuerpos , Especificidad de Anticuerpos , Secuencia de Bases , Ensayo de Inmunoadsorción Enzimática , Humanos , Fragmentos de Inmunoglobulinas/genética , Fragmentos de Inmunoglobulinas/inmunología , Isotipos de Inmunoglobulinas/genética , Región Variable de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/inmunología , Datos de Secuencia Molecular , Control de Calidad , Resonancia por Plasmón de Superficie
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