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Euro Surveill ; 24(10)2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30862336


We describe detection in the United Kingdom (UK) of the drug-resistant Neisseria gonorrhoeae FC428 clone, with ceftriaxone resistance and intermediate azithromycin resistance. Two female patients developed infection following contact with UK-resident men from the same sexual network linked to travel to Ibiza, Spain. One case failed treatment with ceftriaxone, and azithromycin and gentamicin, before successful treatment with ertapenem. Both isolates had indistinguishable whole-genome sequences. Urgent action is essential to contain this drug-resistant strain.

Euro Surveill ; 23(26)2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29970217


Public Health England was alerted to a national outbreak of Shiga toxin-producing Escherichia coli O157 PT34 in July 2016. Early investigations suggested that the likely source was a salad item consumed outside of the home. A number of cases reported consuming meals at a staff canteen (Venue A) and a garden café (Venue B). Both venues shared a common salad supplier. An investigation was undertaken to measure associations between salad items and illness using an 'ingredient-based analysis'. A retrospective case-control study was conducted using an online questionnaire to collect information on menu items consumed at each venue. Chefs at both venues were interviewed to identify ingredients contained within each menu item. Both venues were pooled together for multivariable analysis measuring associations at the ingredient level. Among 203 responses, 24 cases were identified (13 confirmed, two probable and nine possible). Case onsets ranged between 7 and 25 June 2016. Multivariable analysis identified strong evidence that only baby mixed-leaf salad from the common supplier was a vehicle of infection (adjusted odds ratio = 13.1; 95% confidence interval: 1.6-106.5). Identifying the specific salad ingredient associated with illness was made possible by using an ingredient-based analysis. We recommend the increased use of ingredient-based analyses.

Brotes de Enfermedades , Infecciones por Escherichia coli/epidemiología , Escherichia coli O157/aislamiento & purificación , Enfermedades Transmitidas por los Alimentos/epidemiología , Lechuga/microbiología , Toxina Shiga/aislamiento & purificación , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Niño , Preescolar , Brotes de Enfermedades/estadística & datos numéricos , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/microbiología , Femenino , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Reino Unido/epidemiología , Adulto Joven
Epidemiol Infect ; 146(11): 1452-1460, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29961436


Since April 2014 all presumptive Salmonella isolates received by Public Health England (PHE) have been characterised using whole genome sequencing (WGS) and the genomic data generated used to identify clusters of infection. To inform the implementation and development of a national gastrointestinal infection surveillance system based on WGS we have retrospectively identified genetically related clusters of Salmonella Enteritidis and Salmonella Typhimurium infection over a one year period and determined the distribution of these clusters by PHE operational levels. Using a constrained WGS cluster definition based on single nucleotide polymorphism distance, case frequency and temporal spread we demonstrate that the majority of clusters spread to multiple PHE operational levels. The greatest investigative burden is on national level staff investigating small, geographically dispersed clusters. We also demonstrate that WGS identifies long-running, slowly developing clusters that may previously have remained undetected. This analysis also indicates likely increased workload for local health protection teams and will require an operational strategy to balance limited human resources with the public health importance of investigating small, geographically contained clusters of highly related cases. While there are operational challenges to its implementation, integrated cluster detection based on WGS from local to international level will provide further improvements in the identification of, response to and control of clusters of Salmonella spp. with public health significance.

Infecciones por Salmonella/epidemiología , Salmonella enteritidis/aislamiento & purificación , Salmonella typhimurium/aislamiento & purificación , Secuenciación Completa del Genoma , Análisis por Conglomerados , Inglaterra/epidemiología , Humanos , Análisis Multivariante , Polimorfismo de Nucleótido Simple , Análisis de Regresión , Estudios Retrospectivos , Infecciones por Salmonella/microbiología , Salmonella enteritidis/genética , Salmonella typhimurium/genética
Euro Surveill ; 23(18)2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29741151


We investigated a large outbreak of Escherichia coli O157 in the United Kingdom (UK) with 165 cases between 31 May and 29 July 2016. No linked cases were reported in other countries. Cases were predominately female (n = 128) and adult (n = 150), 66 attended hospital and nine had features of haemorrhagic uraemic syndrome. A series of epidemiological studies (case-control, case-case, ingredients-based and venue-based studies) and supply chain investigations implicated mixed salad leaves from Supplier A as the likely outbreak vehicle. Whole genome sequencing (WGS) indicated a link with strains from the Mediterranean and informed the outbreak control team to request that Supplier A cease distributing salad leaves imported from Italy. Microbiological tests of samples of salad leaves from Supplier A were negative. We were unable to confirm the source of contamination or the contaminated constituent leaf although our evidence pointed to red batavia received from Italy as the most likely vehicle. Variations in Shiga toxin-producing E.coli surveillance and diagnosis may have prevented detection of cases outside the UK and highlights a need for greater standardisation. WGS was useful in targeting investigations, but greater coverage across Europe is needed to maximise its potential.

Brotes de Enfermedades , Infecciones por Escherichia coli/epidemiología , Escherichia coli O157/aislamiento & purificación , Enfermedades Transmitidas por los Alimentos/epidemiología , Genoma Bacteriano/genética , Lechuga/microbiología , Escherichia coli Shiga-Toxigénica/aislamiento & purificación , Adulto , Animales , Estudios de Casos y Controles , ADN Bacteriano/genética , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/genética , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Vigilancia de Guardia , Escherichia coli Shiga-Toxigénica/genética , Reino Unido/epidemiología , Secuenciación Completa del Genoma
Phys Rev Lett ; 120(9): 095901, 2018 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-29547334


Heat dissipation in integrated nanoscale devices is a major issue that requires the development of nanoscale temperature probes. Here, we report the implementation of a method that combines electron energy gain and loss spectroscopy to provide a direct measurement of the local temperature in the nanoenvironment. Loss and gain peaks corresponding to an optical-phonon mode in boron nitride were measured from room temperature to ∼1600 K. Both loss and gain peaks exhibit a shift towards lower energies as the sample is heated up. First-principles calculations of the temperature-induced phonon frequency shifts provide insights into the origin of this effect and confirm the experimental data. The experiments and theory presented here open the doors to the study of anharmonic effects in materials by directly probing phonons in the electron microscope.

Microsc Microanal ; 20(2): 452-61, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24618013


Insight into dynamic electrochemical processes can be obtained with in situ electrochemical-scanning/transmission electron microscopy (ec-S/TEM), a technique that utilizes microfluidic electrochemical cells to characterize electrochemical processes with S/TEM imaging, diffraction, or spectroscopy. The microfluidic electrochemical cell is composed of microfabricated devices with glassy carbon and platinum microband electrodes in a three-electrode cell configuration. To establish the validity of this method for quantitative in situ electrochemistry research, cyclic voltammetry (CV), choronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) were performed using a standard one electron transfer redox couple [Fe(CN)6]3-/4--based electrolyte. Established relationships of the electrode geometry and microfluidic conditions were fitted with CV and chronoamperometic measurements of analyte diffusion coefficients and were found to agree with well-accepted values that are on the order of 10-5 cm2/s. Influence of the electron beam on electrochemical measurements was found to be negligible during CV scans where the current profile varied only within a few nA with the electron beam on and off, which is well within the hysteresis between multiple CV scans. The combination of experimental results provides a validation that quantitative electrochemistry experiments can be performed with these small-scale microfluidic electrochemical cells provided that accurate geometrical electrode configurations, diffusion boundary layers, and microfluidic conditions are accounted for.