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1.
Int J Food Microbiol ; 298: 1-10, 2019 Jun 02.
Artículo en Inglés | MEDLINE | ID: mdl-30889473

RESUMEN

Fresh betel leaves (Piper betle L.), imported into the UK are a traditional ready-to-eat food consumed by Asian populations. We report here the consolidation of routinely collected data to model the public health risks from consumption of this food. Amongst 2110 samples collected at Border Inspection, wholesale, catering or retail, Salmonella was detected in 488 (23%) of samples tested between 2011 and 2017 and was the most commonly Salmonella-contaminated ready-to-eat food examined by Public Health England during this period. Using data from multiple samples (usually 5) tested per consignment sampled at Border Inspection, contamination levels were calculated by most probable number: seasonal, temporal and country specific differences were detected. Quantitative contamination data was used to estimate the levels present at retail, and a ß-Poisson dose response model the probability of illness was calculated. Using data for products imported from India, the probability of acquiring infection following a single exposure (comprising of a single leaf) was estimated to be between 0.00003 (January-March) and 0.0001 (July-September). Using British Asian population data for individuals over 30 years of age in England in 2011, two estimates of consumption were modelled as 2.1 and 12.8 million servings per annum. Results from the model estimated 160 cases (range 102 to 242) and 960 cases (range 612 to 1456) per year in England for the two consumption estimates and equated to 34 (range 22 to 51) and 204 (range 130 to 310) salmonellosis cases per year reported to national surveillance. Salmonella from 475 of the contaminated samples were further characterised which showed a heterogeneous population structure with 46 S. enterica subsp. Enterica serovars, together with S. enterica subs diarizonae and salamae identified. Isolates from individual consignments were diverse and close genetic relationships between independent isolates were very rare except from within an individual consignment. There were no outbreaks detected as associated with betel leaf consumption. However analysis by whole genome sequencing of the 2014-17 data identified two cases where the clinical isolate had <5 single nucleotide polymorphism differences to isolates from betel leaves which is indicative of a likely epidemiological link and common source of contamination. Due to the diversity of the Salmonella contaminating this product, associations between salmonellosis cases and betel leaf consumption will appear sporadic and unlikely to be detected by current surveillance strategies based on outbreak detection.


Asunto(s)
Microbiología de Alimentos , Modelos Estadísticos , Piper betle/microbiología , Hojas de la Planta/microbiología , Salud Pública/estadística & datos numéricos , Salmonella/fisiología , Adulto , Inglaterra/epidemiología , Humanos , Intoxicación Alimentaria por Salmonella/prevención & control , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/prevención & control , Infecciones por Salmonella/transmisión
2.
Epidemiol Infect ; 145(13): 2727-2734, 2017 10.
Artículo en Inglés | MEDLINE | ID: mdl-28770691

RESUMEN

In August to October 2012, a nationwide outbreak of Salmonella enteritidis phase type (PT) 1B with 53 cases occurred in Finland. Hypothesis generating interviews pointed toward ready-to-eat chicken salad from a Finnish company and at the same time Estonian authorities informed of a S. enteritidis PT 1B outbreak linked to chicken wrap prepared at an Estonian restaurant. We found that chicken salad was associated with the infection (odds ratio (OR) 16·1, 95% confidence interval (CI) 1·7-148·7 for consumption and OR 17·5. 95% CI 4·0-76·0 for purchase). The frozen pre-cooked chicken cubes used in Finnish salad and in Estonian wraps were traced back to a production plant in China. Great Britain made two Rapid Alert Systems for Food and Feed notifications on chicken cubes imported to the UK from the same Chinese production plant. Microbiological investigation confirmed that the patient isolates in Estonia and in Finland were indistinguishable from the strains isolated from chicken cubes in Estonia and in the UK. We recommend that despite certificates for tested Salmonella, food items should be analyzed when Salmonella contamination in outbreak investigations is suspected. In outbreak investigations, electronically implemented case-case study saves time, effort, and money compared with case-control study.


Asunto(s)
Brotes de Enfermedades , Microbiología de Alimentos , Alimentos Congelados/microbiología , Carne/microbiología , Intoxicación Alimentaria por Salmonella/epidemiología , Salmonella enteritidis/fisiología , Adolescente , Adulto , Anciano , Animales , Estudios de Casos y Controles , Pollos/microbiología , China , Estonia , Femenino , Finlandia/epidemiología , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Intoxicación Alimentaria por Salmonella/microbiología , Salmonella enteritidis/clasificación , Salmonella enteritidis/aislamiento & purificación , Reino Unido , Adulto Joven
3.
Epidemiol Infect ; 145(7): 1500-1509, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28236815

RESUMEN

This observational study aims to investigate the microbiological quality of commercially prepared lightly cooked foods with a major component of food of animal origin and collected as would be served to a consumer. A total of 356 samples were collected from catering (92%), retail (7%) or producers (1%) and all were independent of known incidents of foodborne illness. Using standard methods, all samples were tested for: the presence of Campylobacter spp. and Salmonella spp. and enumerated for levels of, Bacillus spp. including B. cereus, Clostridium perfringens, Listeria spp. including L. monocytogenes, Staphylococcus aureus, Escherichia coli, Enterobacteriacea and aerobic colony count (ACC). Results were interpreted as unsatisfactory, borderline or satisfactory according to the Health Protection Agency guidelines for assessing the microbiological safety of ready-to-eat foods placed on the market. Amongst all samples, 70% were classified as satisfactory, 18% were borderline and 12% were of unsatisfactory microbiological quality. Amongst the unsatisfactory samples, six (2%) were potentially injurious to health due to the presence of: Salmonella spp. (one duck breast); Campylobacter spp. (two duck breast and one chicken liver pâté); L. monocytogenes at 4·3 × 103 cfu (colony-forming units)/g (one duck confit with foie gras ballotin) and C. perfringens at 2·5 × 105 cfu/g (one chicken liver pâté). The remaining unsatisfactory samples were due to high levels of indicator E. coli, Enterobacteriaceae or ACC.


Asunto(s)
Bacterias/aislamiento & purificación , Culinaria , Microbiología de Alimentos , Carne/microbiología , Inglaterra , Microbiología de Alimentos/estadística & datos numéricos , Humanos , Productos de la Carne/microbiología
4.
Epidemiol Infect ; 145(2): 289-298, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27780484

RESUMEN

Since April 2015, whole genome sequencing (WGS) has been the routine test for Salmonella identification, surveillance and outbreak investigation at the national reference laboratory in England and Wales. In May 2015, an outbreak of Salmonella Enteritidis cases was detected using WGS data and investigated. UK cases were interviewed to obtain a food history and links between suppliers were mapped to produce a food chain network for chicken eggs. The association between the food chain network and the phylogeny was explored using a network comparison approach. Food and environmental samples were taken from premises linked to cases and tested for Salmonella. Within the outbreak single nucleotide polymorphism defined cluster, 136 cases were identified in the UK and 18 in Spain. One isolate from a food containing chicken eggs was within the outbreak cluster. There was a significant association between the chicken egg food chain of UK cases and phylogeny of outbreak isolates. This is the first published Salmonella outbreak to be prospectively detected using WGS. This outbreak in the UK was linked with contemporaneous cases in Spain by WGS. We conclude that UK and Spanish cases were exposed to a common source of Salmonella-contaminated chicken eggs.


Asunto(s)
Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/epidemiología , Genoma Bacteriano , Secuenciación de Nucleótidos de Alto Rendimiento , Infecciones por Salmonella/epidemiología , Salmonella enteritidis/clasificación , Salmonella enteritidis/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Pollos , Niño , Preescolar , Análisis por Conglomerados , Huevos/microbiología , Femenino , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Lactante , Masculino , Carne/microbiología , Persona de Mediana Edad , Epidemiología Molecular , Polimorfismo de Nucleótido Simple , Infecciones por Salmonella/microbiología , Salmonella enteritidis/aislamiento & purificación , España/epidemiología , Encuestas y Cuestionarios , Reino Unido/epidemiología , Adulto Joven
5.
Lett Appl Microbiol ; 63(5): 335-339, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27561893

RESUMEN

Since 2010, human salmonellosis outbreaks in the UK have been detected as associated with the consumption of duck eggs. Little data are available on the rate of occurrence of Salmonella in duck eggs. The aim of this study was to investigate the occurrence of Salmonella spp. in duck eggs on sale and from catering in England during 2011, particularly those from small-scale production. All samples were collected independently of human salmonellosis outbreak investigations. Composite samples of 6-10 eggs (shells and contents were examined separately) were examined for the presence of Salmonella spp. using the ISO 6579:2002 method. Salmonella spp. was recovered from two of 145 samples (1·4%). In one sample, Salmonella Typhimurium DT 8 was isolated from the shells while Salm. Typhimurium DT 8 and Salm. Typhimurium DT30 were isolated from the contents. Salmonella Typhimurium DT8 was isolated from the egg shells only in the second contaminated sample. This study provides baseline data for risk assessors, regulators and the food industry and may be helpful in communicating risks associated with the consumption of this product as well as evaluating risk management options to control food safety including vaccination of ducks. SIGNIFICANCE AND IMPACT OF THE STUDY: Human salmonellosis outbreaks in England and Northern Ireland due to Salmonella enterica serovar Typhimurium definitive phage type (DT) 8 have been identified as associated with the consumption of duck eggs since 2010. This study has shown that Salmonella spp. was detected in 1·4% of ducks egg samples providing baseline data for risk assessors, regulators and the food industry. This may be helpful in communicating risks associated with the consumption of this product as well as evaluating risk management options to control food safety including vaccination of ducks.


Asunto(s)
Patos/microbiología , Huevos/microbiología , Microbiología de Alimentos , Intoxicación Alimentaria por Salmonella/epidemiología , Infecciones por Salmonella/epidemiología , Salmonella typhimurium/aislamiento & purificación , Animales , Brotes de Enfermedades , Cáscara de Huevo/microbiología , Inglaterra/epidemiología , Inocuidad de los Alimentos , Humanos , Irlanda del Norte/epidemiología
6.
Eur J Clin Microbiol Infect Dis ; 35(5): 741-6, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26864044

RESUMEN

The aim of the present work was to study the epidemiology of Salmonella enterica serovar Enteritidis (S. Enteritidis) in Greece, comparing all the food and food animal isolates during a 3-year period with clinical isolates. Submission of the generated data to the PulseNet Europe database was carried out in order to study the population structure of this particular serovar and indicate possible connections with European strains. One hundred and sixty-eight (168) S. Enteritidis strains of human, animal, and food origin, isolated during the period 2008-2010 in Greece, were studied. Strains were characterized by phenotypic (antibiotic resistance) and molecular [pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST)] methods. PFGE revealed 39 XbaI, 48 BlnI, and 80 XbaI-BlnI distinct pulsotypes, suggesting several clones circulating through the food chain and multiple sources of transmission. Submission to the PulseNet Europe database indicated that PFGE profile SENTXB.0001, the most common PFGE profile in Europe, was also predominant in Greece (33.3 %). MLST showed that all the strains studied shared the same sequence type (ST11), representing the most common ST in Europe. High rates of resistance to nalidixic acid were observed among human and poultry isolates (~25 %), indicating the potential fluoroquinolone treatment failure. Our data suggest that strains originating from multiple reservoirs circulated in Greece through the food chain during the study period. Predominant profiles in Greece were common to PulseNet Europe profiles, indicating similarities between the S. Enteritidis populations in Greece and Europe.


Asunto(s)
Microbiología de Alimentos , Salmonelosis Animal/epidemiología , Salmonelosis Animal/microbiología , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Salmonella enteritidis/aislamiento & purificación , Animales , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Electroforesis en Gel de Campo Pulsado , Grecia/epidemiología , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación de Secuencias Multilocus , Salmonella enteritidis/clasificación , Salmonella enteritidis/efectos de los fármacos , Salmonella enteritidis/genética
7.
Lett Appl Microbiol ; 62(2): 126-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26661563

RESUMEN

UNLABELLED: A total of 554 samples of bean sprouts or other sprouted seeds were collected at retail sale and submitted to nine Official Control Laboratories in England and Northern Ireland during January to March 2011. Samples (100 g) were tested for the presence of Salmonella using the EN ISO 6579:2002 method. Products labelled as ready-to-eat comprised 23% of the samples and 61% were labelled as raw or to-cook: the remaining 12% had no indication if the food was intended as ready-to-eat or ready-to-cook, and 4% were not recorded. Salmonella spp. were detected from four samples of mung-bean sprouts (0·7% of all the 554 samples) and all four isolates were confirmed as Salmonella enterica serovar Abaetetuba (11 : k : 1,5). Two of the samples where Salmonella was detected were sold as ready-to-eat (labelled 'rinse and serve' only): The remaining two were from samples labelled as ready-to-cook. SIGNIFICANCE AND IMPACT OF THE STUDY: Consumption of sprouted seeds have been associated with infections from a range of foodborne pathogens, particularly Salmonella and shigatoxin producing Escherichia coli (STEC). However, there is limited data (including that from EU monitoring) on foodborne pathogens in samples of this food type which are not associated with outbreaks of infection. Out of 554 raw and ready-to-eat bean sprouts and sprouted seeds sampled at retail, Salmonella spp. was detected from four samples. This study illustrated the potential of this product to be contaminated with a human pathogen and the importance of considering the intended use and preparation of specific food in assessing microbiological risks.


Asunto(s)
Fabaceae/microbiología , Microbiología de Alimentos , Salmonella enterica/aislamiento & purificación , Plantones/microbiología , Brotes de Enfermedades , Inglaterra , Humanos , Irlanda del Norte , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/prevención & control
9.
J Appl Microbiol ; 119(3): 827-33, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26010515

RESUMEN

AIMS: Fresh herbs have been associated with a number of outbreaks in recent years, in the United Kingdom and elsewhere. A study of fresh herbs was carried out to assess their microbiological safety in relation to Salmonella contamination and levels of Escherichia coli. METHODS AND RESULTS: Between January and March 2014, 774 samples of ready-to-eat, fresh, whole-leaf herbs were collected from retail premises in the United Kingdom. Overall, Salmonella was detected in nine samples (1·2%). Of these, five were curry leaves. Other herbs contaminated with Salmonella were basil (two samples), walleria (1) and coriander (1). Escherichia coli was detected in 13% of samples, with 11% containing unsatisfactory levels (≥10(2) g(-1)). CONCLUSIONS: Whilst 88% of samples in this study were of an acceptable microbiological quality, the presence of Salmonella and/or elevated E. coli levels in 12% is a cause for concern. Curry leaves, in particular, had significantly higher rates of contamination with both Salmonella and E. coli than other herbs. SIGNIFICANCE AND IMPACT OF THE STUDY: This study highlights the potential public health risk associated with the consumption of certain ready-to-eat fresh herbs, and the need for good hygiene practices and effective decontamination procedures during the growth, harvesting and subsequent handling of these products.


Asunto(s)
Escherichia coli/aislamiento & purificación , Contaminación de Alimentos/análisis , Hojas de la Planta/microbiología , Plantas Medicinales/microbiología , Salmonella/aislamiento & purificación , Seguridad de Productos para el Consumidor , Escherichia coli/genética , Manipulación de Alimentos/métodos , Humanos , Salmonella/genética , Reino Unido
10.
Clin Microbiol Infect ; 21(2): 149.e1-4, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25658552

RESUMEN

All 120 strains of Salmonella enterica serovar Hadar isolated during 2007-2010 in Greece were characterized by phenotypic and molecular methods. High rates of resistance to nalidixic acid (92%) and low levels of ciprofloxacin resistance (88%) were observed. Pulsenet-pulsed field gel electrophoresis profile SHADXB.0001 was predominant in Greece (58%) as in Europe but PT1, a rare phage type in Europe, was frequent in Greece (56%). The SHADXB.0001 and PT1 clone (38%) were found in humans, animals and food of animal origin with R-type ApSpTNxpCp being predominant (25%). The data indicate that this clone (possibly endemic) was circulating through the food chain in Greece during the study period.


Asunto(s)
Microbiología de Alimentos , Salmonelosis Animal/epidemiología , Infecciones por Salmonella/epidemiología , Salmonella enterica/aislamiento & purificación , Serogrupo , Animales , Antibacterianos/farmacología , Tipificación de Bacteriófagos , Farmacorresistencia Bacteriana , Electroforesis en Gel de Campo Pulsado , Genotipo , Grecia/epidemiología , Humanos , Pruebas de Sensibilidad Microbiana , Tipificación Molecular , Fenotipo , Infecciones por Salmonella/microbiología , Salmonelosis Animal/microbiología , Salmonella enterica/clasificación , Salmonella enterica/efectos de los fármacos , Salmonella enterica/genética
11.
Science ; 341(6153): 1514-7, 2013 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-24030491

RESUMEN

The global epidemic of multidrug-resistant Salmonella Typhimurium DT104 provides an important example, both in terms of the agent and its resistance, of a widely disseminated zoonotic pathogen. Here, with an unprecedented national collection of isolates collected contemporaneously from humans and animals and including a sample of internationally derived isolates, we have used whole-genome sequencing to dissect the phylogenetic associations of the bacterium and its antimicrobial resistance genes through the course of an epidemic. Contrary to current tenets supporting a single homogeneous epidemic, we demonstrate that the bacterium and its resistance genes were largely maintained within animal and human populations separately and that there was limited transmission, in either direction. We also show considerable variation in the resistance profiles, in contrast to the largely stable bacterial core genome, which emphasizes the critical importance of integrated genotypic data sets in understanding the ecology of bacterial zoonoses and antimicrobial resistance.


Asunto(s)
Farmacorresistencia Bacteriana Múltiple/genética , Interacciones Huésped-Patógeno , Salmonelosis Animal/microbiología , Infecciones por Salmonella/microbiología , Salmonella typhimurium/clasificación , Zoonosis/microbiología , Animales , Epidemias , Genoma Bacteriano , Humanos , Datos de Secuencia Molecular , Filogenia , Infecciones por Salmonella/epidemiología , Salmonelosis Animal/epidemiología , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética
12.
Euro Surveill ; 17(37)2012 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-22995432

RESUMEN

Difficulties in accurately identifying serovar 4,[5],12:i:- as monophasic variants of Salmonella enterica serovar Typhimurium mean there is confusion in the reporting of serovars Typhimurium and 4,[5],12:i:-. To gain insight into the prevalence and diversity of these monophasic variants in England and Wales, screening for fljB, hin and the serovar 4,[5],12:i:- DT193-associated genomic island was conducted on 609 S. enterica isolates designated as definitive phage type (DT) 193, and 142 isolates serologically-defined as monophasic variants of serovar Typhimurium but belonging to phage types other than DT193. All latter 142 isolates were subtyped by multilocus variable-number tandem repeat analysis (MLVA). MLVA was also applied to 70 DT193 serologically-defined monophasic variant isolates. Results indicate that serovar 4,[5],12:i:- accounted for 108 of 209 (52%) of DT193 isolates with available serological data and 99 of 142 (70%) monophasic variant isolates belonging to other phage types. Of 609 DT193 isolates, 463 (76%) lacked fljB and hin. Moreover, genetically-related isolates of DTs 120, 191, 191a, 195, phage types U311 and U323, and reacts but does not conform (RDNC) and untypable (UT) strains were also lacking either hin and/or fljB. Of note, the serovar 4,[5],12:i:- DT193-associated genomic island was identified in not only 458 of 463 (99%) monophasic DT193 isolates, but also 25 of 139 (18%) biphasic DT193 isolates and 56 of 76 (74%) monophasic variants of other phage types. Accurate monitoring of the emergence of serovar 4,[5],12:i:- isolates is important to ascertain the public health impact of these strains; since 2012 the Health Protection Agency's Salmonella Reference Unit has therefore begun determining full antigenic structures of all presumptive O:4 isolates in addition to routinely performing phage typing for identification of variants of serovar Typhimurium.


Asunto(s)
Tipificación de Bacteriófagos , Infecciones por Salmonella/epidemiología , Salmonella enterica/genética , Salmonella enterica/aislamiento & purificación , Salmonella typhimurium/genética , Serotipificación/métodos , Inglaterra/epidemiología , Islas Genómicas , Humanos , Tipificación de Secuencias Multilocus , Prevalencia , Infecciones por Salmonella/diagnóstico , Infecciones por Salmonella/microbiología , Salmonella typhimurium/aislamiento & purificación , Secuencias Repetidas en Tándem , Gales/epidemiología
13.
Epidemiol Infect ; 140(1): 146-9, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21470442

RESUMEN

Salmonella enterica serovar Typhimurium definitive phage type (DT) 8 is uncommon in humans in the UK. In July 2010, the Health Protection Agency reported an excess isolation rate of pan-susceptible S. Typhimurium DT8 in England and Northern Ireland. By the end of October, this amounted to 81 laboratory-confirmed human cases for all regions of England and Northern Ireland in 2010, an increase of 26% and 41% on 2009 and 2008, respectively. Descriptive epidemiological investigation found a strong association with infection and consumption of duck eggs. Duck eggs contaminated with S. Typhimurium DT8 were collected from a patient's home and also at farms in the duck-egg supply chain. Although duck eggs form a small part of total UK eggs sales, there has been significant growth in sales in recent years. This is the first known outbreak of salmonellosis linked to duck eggs in the UK since 1949 and highlighted the impact of a changing food source and market on the re-emergence of salmonellosis linked to duck eggs. Control measures by the duck-egg industry should be improved along with a continued need to remind the public and commercial caterers of the potential high risks of contracting salmonellosis from duck eggs.


Asunto(s)
Huevos/microbiología , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/microbiología , Salmonella typhimurium/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Brotes de Enfermedades/estadística & datos numéricos , Patos/microbiología , Inglaterra/epidemiología , Femenino , Inocuidad de los Alimentos , Humanos , Lactante , Masculino , Persona de Mediana Edad , Irlanda del Norte/epidemiología , Vigilancia de la Población , Intoxicación Alimentaria por Salmonella/prevención & control , Fagos de Salmonella , Salmonella typhimurium/genética
14.
Euro Surveill ; 16(32)2011 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-21871223

RESUMEN

Salmonella enterica serovar (S.) Enteritidis is an important cause of food-borne infection in Europe and the United States. Further subtyping of isolates is necessary to support epidemiological data for the detection of outbreaks and identification of the vehicle of infection. Multilocus variable-number tandem-repeat analysis (MLVA) is reportedly more discriminatory and produces data that are easier to share via databases than other molecular subtyping methods. However, lack of standardisation of the methodology and interpretive criteria for data analysis has meant that comparison of data between laboratories can be problematic. On the basis of MLVA profiles of 298 S. Enteritidis isolates received at the Health Protection Agency's Salmonella Reference Unit and sequence analysis of selected isolates, we propose a MLVA scheme for S. Enteritidis based on five loci (SENTR4, SENTR5, SENTR6, SENTR7 and SE-3) that have been selected from previously published S. Enteritidis MLVA schemes. A panel of reference strains has been developed that can be used by laboratories to normalise their raw fragment data to actual fragment sizes. We also provide recommendations for analysing and interpreting MLVA data. We urge laboratories to consider implementing these guidelines, thereby allowing direct comparison of data between laboratories irrespective of the platform used for fragment analysis, to facilitate international surveillance and investigation of international outbreaks.


Asunto(s)
Dermatoglifia del ADN/métodos , ADN Bacteriano/genética , Repeticiones de Minisatélite , Salmonella enteritidis/clasificación , Salmonella enteritidis/genética , Serotipificación/normas , Secuencia de Bases , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Humanos , Estándares de Referencia , Reproducibilidad de los Resultados , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/genética , Salmonella enteritidis/aislamiento & purificación , Serotipificación/métodos
15.
Epidemiol Infect ; 139(12): 1936-44, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21255477

RESUMEN

In March 2008, the Health Protection Agency in England conducted a retrospective case-control study to investigate the cause of 179 cases of the newly recognized, fully antimicrobial-sensitive Salmonella Typhimurium PT U320. Forty-three symptomatic laboratory-confirmed case-patients and 84 asymptomatic location-matched controls were interviewed by telephone about exposures in the 3 days prior to illness or interview. Multivariate logistic analysis indicated consumption of pre-packaged egg sandwiches (odds ratio 3·29, 95% confidence interval 1·19-9·09) was independently associated with illness. Eight of the 15 case-patients who consumed egg sandwiches did so from retail chain A (53·3%) whereas none of the eight controls consumed similar sandwiches (χ2=7·20, P≤0·01). A review of the pre-packaged egg sandwich ingredients suggested this outbreak was probably caused by exposure to an ingredient common to pre-packaged sandwiches and prepared salads but we established a definitive epidemiological link with only the former. Short shelf-life, product diversity and investigation lag hinder epidemiological investigations of such popular products, providing continued challenges for food safety enforcement of freshly prepared produce.


Asunto(s)
Brotes de Enfermedades , Huevos/envenenamiento , Comida Rápida/microbiología , Intoxicación Alimentaria por Salmonella/epidemiología , Salmonella typhimurium , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Tipificación de Bacteriófagos , Estudios de Casos y Controles , Niño , Preescolar , Comida Rápida/envenenamiento , Femenino , Embalaje de Alimentos , Humanos , Lactante , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Estudios Retrospectivos , Intoxicación Alimentaria por Salmonella/etiología , Salmonella typhimurium/clasificación , Reino Unido/epidemiología , Verduras/microbiología , Adulto Joven
16.
Epidemiol Infect ; 139(8): 1254-61, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20943001

RESUMEN

In December 2008 an increase of tetracycline-resistant Salmonella Typhimurium definitive phage-type 191a (DT191a) was identified in England and Wales by the reference laboratory. This was confirmed to have a phage-typing pattern that had not previously been seen. Strong statistical evidence for an association between illness and keeping reptiles was demonstrated by a matched case-case study (mOR 16·82, 95% CI 2·78-∞). Questionnaires revealed an association with frozen reptile feeder mice, and mice representing 80% of the UK supply lines were tested for the presence of Salmonella. DT191a was found in three pools of sampled mice, which were traced back to a single supplier in the USA. Imports from this supplier were halted, and tighter regulations are now in place. A leaflet detailing how to prevent contracting Salmonella from pet reptiles has been published as well as updated advice on the Health Protection Agency's website.


Asunto(s)
Enfermedades Transmitidas por los Alimentos/veterinaria , Mascotas , Reptiles , Salmonelosis Animal/transmisión , Infecciones por Salmonella/epidemiología , Salmonella typhimurium/aislamiento & purificación , Adolescente , Adulto , Anciano , Animales , Tipificación de Bacteriófagos , Estudios de Casos y Controles , Niño , Preescolar , Inglaterra/epidemiología , Femenino , Humanos , Lactante , Masculino , Ratones , Persona de Mediana Edad , Infecciones por Salmonella/transmisión , Salmonella typhimurium/clasificación , Encuestas y Cuestionarios , Gales/epidemiología , Adulto Joven
17.
Epidemiol Infect ; 139(8): 1272-80, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20950515

RESUMEN

We investigated an international outbreak of Salmonella Agona with a distinct PFGE pattern associated with an Irish Food company (company X) producing pre-cooked meat products sold in various food outlet chains in Europe. The outbreak was first detected in Ireland. We undertook national and international case-finding, food traceback and microbiological investigation of human, food and environmental samples. We undertook a matched case-control study on Irish cases. In total, 163 cases in seven European countries were laboratory-confirmed. Consumption of food from food outlet chains supplied by company X was significantly associated with being a confirmed case (mOR 18·3, 95% CI 2·2-149·2) in the case-control study. The outbreak strain was isolated from the company's pre-cooked meat products and production premises. Sufficient evidence was gathered to infer the vehicles of infection and sources of the outbreak and to justify the control measures taken, which were plant closure and food recall.


Asunto(s)
Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/epidemiología , Carne/microbiología , Infecciones por Salmonella/epidemiología , Salmonella enterica/aislamiento & purificación , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Niño , Preescolar , Electroforesis en Gel de Campo Pulsado , Microbiología Ambiental , Europa (Continente)/epidemiología , Femenino , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Tipificación Molecular , Infecciones por Salmonella/microbiología , Salmonella enterica/clasificación , Serotipificación , Adulto Joven
18.
J Food Prot ; 73(3): 574-8, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20202348

RESUMEN

Salmonella contamination of pooled raw shelled egg mix (RSEM) used as an ingredient in lightly cooked or uncooked foods and high-risk kitchen hygiene practices in United Kingdom food service establishments using RSEM were investigated. Samples were collected from 934 premises. Salmonella was found in 1 (0.13%) of 764 RSEM samples, 2 (0.3%) of 726 samples from surfaces where ready-to-eat foods were prepared, and 7 (1.3%) of 550 cleaning cloths. Poor RSEM storage and handling practices were highlighted. Workers in 40% of the premises sampled failed to use designated utensils when RSEM was added to other ingredients, workers in 17% of the premises did not clean surfaces and utensils thoroughly after use with RSEM and before preparing other foods, only 42% of workers washed and dried their hands after handling eggs or RSEM, workers in 41% of the premises did not store RSEM at refrigeration temperature before use, and workers in 8% of the premises added RSEM to cooked rice at the end of cooking when preparing egg fried rice. Take-away premises, especially those serving Chinese cuisine, were least likely to have a documented food safety management system and awareness of the key food safety points concerning the use of RSEM compared with other food service premises (P < 0.0001). Food service businesses using RSEM must be aware of the continuing hazard from Salmonella, must adopt appropriate control measures, and must follow advice provided by national food agencies to reduce the risk of Salmonella infection.


Asunto(s)
Huevos/microbiología , Contaminación de Alimentos/análisis , Manipulación de Alimentos/métodos , Servicios de Alimentación/normas , Salmonella/crecimiento & desarrollo , Animales , Seguridad de Productos para el Consumidor , Cáscara de Huevo/microbiología , Contaminación de Equipos , Microbiología de Alimentos , Desinfección de las Manos , Humanos , Higiene , Medición de Riesgo , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/etiología , Reino Unido
19.
Food Microbiol ; 27(2): 243-9, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20141942

RESUMEN

From 2359 specialty meats (continental sausages, cured/fermented, dried meats) sampled from markets and specialty food shops, 98.9% of samples were of satisfactory or acceptable microbiological quality. However, 16 (0.7%) were unsatisfactory as a result of Escherichia coli, Staphylococcus aureus or Listeria spp. contamination (>or=10(2) CFU/g), and nine (0.4%) were unacceptable due to presence of Salmonella spp. or Listeria monocytogenes (>10(2) CFU/g). Meats with unacceptable levels of L. monocytogenes were within shelf life (range: 8-143 days remaining). Nine different subtypes of L. monocytogenes were detected with sero/AFLP type 1/2c VII predominating (37%), although this subtype was not overrepresented in any particular meat type (P > 0.05). Ninety-six percent of continental sausages and cured/fermented products were stored at <8 degrees C at premises, including seven of the nine unacceptable samples. These nine meats were all pre-packed prior to supply to retail premises (OR = 0.1 P = 0.003) indicating that contamination with bacterial pathogens occurred earlier in the production chain. Most samples (72.7%, 8/11) with unsatisfactory levels of E. coli were sliced on request, suggesting cross-contamination at point of sale. This study highlights the importance of ensuring that products do not become contaminated before final packaging, that storage conditions are controlled, and that durability dates are an accurate indication of the shelf life of the product so as to minimise the potential for L. monocytogenes to be present at levels hazardous to health at the point of sale.


Asunto(s)
Microbiología de Alimentos , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Salmonella/aislamiento & purificación , Escherichia coli/aislamiento & purificación , Contaminación de Alimentos/prevención & control , Manipulación de Alimentos/métodos , Embalaje de Alimentos , Listeria monocytogenes/clasificación , Productos de la Carne/clasificación , Salmonella/clasificación , Reino Unido
20.
Food Microbiol ; 27(1): 171-4, 2010 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19913709

RESUMEN

Consumption of nut kernels has shown an upward trend due to people's increasing tendency to eat healthy snacks. The purpose of this survey was to establish the microbiological safety of retail edible nut kernel samples of different varieties. Overall Salmonella spp. and Escherichia coli were detected from 0.1% and 0.8% of 2886 edible nut kernels, respectively. S. Senftenberg and S. Tennessee were detected from two pre-packed samples of Brazil nuts (0.4%) and S. Anatum from a pre-packed mixed nuts sample (0.9%; mix: almonds, Brazils, cashews, peanuts, walnuts) indicating a risk to health. The levels of Salmonella ranged from <0.01 to 0.23/g. E. coli at unsatisfactory levels (150/g) was present in another pre-packed Brazils nuts sample (0.2%). E. coli was additionally found at lower levels (range: 3.6-43/g) in Brazils (1.9%), macadamia (1.5%), pistachios (1.1%), walnuts (0.7%), peanuts (0.7%), hazels (0.5%), cashews (0.4%), and almonds (0.3%). Levels of E. coli did not correlate with the presence of Salmonella. The batches contaminated with Salmonella were recalled and Food Standards Agency food alerts were issued to advise against the consumption of the affected products. The presence of Salmonella is unacceptable in ready-to-eat foods and follows that the need for applying good agricultural and hygiene practices and effective decontamination procedures during the production of edible kernels cannot be overemphasized.


Asunto(s)
Seguridad de Productos para el Consumidor , Contaminación de Alimentos/análisis , Nueces/microbiología , Salmonella/aislamiento & purificación , Recolección de Datos , Contaminación de Alimentos/estadística & datos numéricos , Reino Unido
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