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1.
Int J Food Microbiol ; 312: 108358, 2020 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-31655356

RESUMEN

Meat products are commonly regarded as one of the main sources of human listeriosis caused by Listeria monocytogenes. The objective of this study was to estimate the prevalence of L. monocytogenes in a range of meat products from 24 different Chinese regions by using meta-analysis of literature data and a novel sensitivity analysis approach. A total of 112 publications from five databases, published between 1 January 2007 and 31 December 2017, were systematically selected for relevance and covered meat products sampled between 2000 and 2016. Estimated by the random-effects model, the pooled prevalence of L. monocytogenes was 8.5% (95% CI: 7.1%-10.3%) in raw meats and 3.2% (95% CI: 2.7%-3.9%) in ready-to-eat (RTE) meats. The prevalence differed from high to low among raw meats including prefabricated raw meats 12.6% (95% CI: 6.9%-21.7%), fresh pork 11.4% (95% CI: 8.6%-14.9%), fresh beef 9.1% (95% CI: 6.3%-13.0%), fresh poultry 7.2% (95% CI:4.9%-10.4%), frozen raw meats 7.2% (95% CI: 5.7%-9.0%), and fresh mutton 5.4% (95% CI: 2.5%-11.0%). A higher L. monocytogenes prevalence level was shown in the meat products from central and northeastern China provincial regions. The entropy-based sensitivity analysis utilized in the meta-analysis indicated that the sampling period and location were two critical factors influencing the prevalence level of L. monocytogenes in meat products. A better understanding of differences in prevalence levels per geographic region and between meat product sources may allow the competent authorities, industry, and other relevant stakeholders to tailor their interventions to control the occurrence of L. monocytogenes in meat products effectively.


Asunto(s)
Contaminación de Alimentos/análisis , Microbiología de Alimentos , Listeria monocytogenes/aislamiento & purificación , Productos de la Carne/microbiología , Aves de Corral/microbiología , Animales , Bovinos , China , Humanos , Listeriosis/epidemiología , Prevalencia , Ovinos , Porcinos
2.
Food Microbiol ; 85: 103280, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31500706

RESUMEN

Listeria monocytogenes causes severe diseases in humans, including febrile gastroenteritis and systemic infections that has a high mortality despite antibiotic treatment. This pathogen may cause massive outbreaks associated to the consumption of contaminated food products, which highlight its importance in public health. In the last decade, L. monocytogenes has emerged as a foodborne pathogen of major importance in Chile. A previous work showed that in Chile during 2008 and 2009, L. monocytogenes serotypes 1/2a, 1/2b and 4b were the most frequently identified in food and clinical strains. Here we report the molecular characterization of L. monocytogenes strains isolated from 2008 to 2017 in the country. Our results indicate that serotypes 1/2a, 1/2b and 4b continue to be the most commonly found in food products. In addition, we identify persistent and widespread PFGE subtypes. This study reports ten years of epidemiological surveillance ofL. monocytogenes in Chile.


Asunto(s)
Monitoreo Epidemiológico , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/genética , Listeriosis/epidemiología , Chile/epidemiología , Recuento de Colonia Microbiana , ADN Bacteriano/genética , Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/microbiología , Gastroenteritis/epidemiología , Gastroenteritis/microbiología , Variación Genética , Humanos , Listeria monocytogenes/patogenicidad , Productos de la Carne/microbiología , Epidemiología Molecular , Salud Pública , Serogrupo , Serotipificación , Factores de Virulencia/genética
3.
Lett Appl Microbiol ; 69(6): 392-398, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31562639

RESUMEN

Four cases of listeriosis in a hospital (A) in New Zealand were identified in 2012. Pulsed-field gel electrophoresis (PFGE) used at the time identified four pulsotypes amongst the clinical isolates. Two of the pulsotypes matched to Listeria monocytogenes isolates obtained from ready-to-eat (RTE) meat samples from a RTE producer tested during a nationwide microbiological survey the month prior. The outbreak investigation confirmed that the RTE producer had supplied product to the hospital and additional testing confirmed the presence of L.  monocytogenes in RTE meats from the hospital kitchen. Two further listeriosis cases presented in another hospital (B) with one clinical isolate identified as the same pulsotype as identified for one case in hospital A, but the epidemiology information concluded that the clinical cases from hospital B were not linked to the outbreak. Retrospective whole-genome sequencing confirmed that epidemiologically linked isolates belonging to three different genotypes for clinical cases from hospital A and RTE meats samples from the hospital kitchen differed by 0-1 core-genome locus or single nucleotide polymorphisms (SNP). The use of core-genome multilocus sequence typing and SNP analysis provided a greater degree of discrimination between isolates compared to PFGE. SIGNIFICANCE AND IMPACT OF THE STUDY: This study describes a listeriosis outbreak associated with a hospital in New Zealand and attributed to contaminated ready-to-eat (RTE) meat supplied to the hospital by a single producer. Retrospective whole-genome sequence analysis of outbreak isolates was found to provide a greater degree of discrimination between isolates compared to pulsed-field gel electrophoresis and supported the conclusions made at the time of the outbreak. The multiple genotypes identified from clinical cases and the RTE meats obtained during the outbreak highlight the importance of epidemiological concordance alongside genotyping.


Asunto(s)
Infección Hospitalaria/microbiología , Listeria monocytogenes/genética , Listeriosis/epidemiología , Productos de la Carne/microbiología , Carne/microbiología , Brotes de Enfermedades , Electroforesis en Gel de Campo Pulsado , Microbiología de Alimentos , Genoma Bacteriano/genética , Genotipo , Humanos , Listeria monocytogenes/clasificación , Listeria monocytogenes/aislamiento & purificación , Listeriosis/microbiología , Tipificación de Secuencias Multilocus , Nueva Zelanda/epidemiología , Polimorfismo de Nucleótido Simple/genética , Estudios Retrospectivos , Secuenciación Completa del Genoma
4.
Lett Appl Microbiol ; 69(4): 230-236, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31381169

RESUMEN

This study evaluated the survival responses of Listeria monocytogenes strains (individually and mixed) in a soft lactic cheese following acid and salt stress exposures. The Weibull and log-linear with tail models were used to predict the survival responses of the pathogen in the cheese stored at 4°C for 15 days. Both models showed a good prediction accuracy for stressed L. monocytogenes cells (Af = 1·00) and higher prediction errors (Af = 1·12-1·14) for nonstressed cells. The inactivation rates (δ (d) and kmax (d-1 )) were significantly lower (P < 0·05) for cells subjected to stress exposure indicating the enhanced tolerance to food stress. However, while enhanced tolerance appeared to be the main effect of stress pre-exposure, in one susceptible strain (69), stress exposure led to higher rates of inactivation. When introduced into the food as mixed strains, one strain out-lived others and remained as the sole survivor. Such strains that perhaps have a predilection for the food environment can provide more cautious estimates of kinetic parameters for predicting L. monocytogenes responses in foods especially if their stress-hardened tolerant cells are used. SIGNIFICANCE AND IMPACT OF THE STUDY: The ability to predict the growth and survival of Listeria monocytogenes in contaminated RTE foods is essential for listeriosis risk assessment. The results of this study provided valuable information on the kinetic parameters of survival of some L. monocytogenes strains found within the South African food environment. In addition to showing differences in the survival responses among strains, the study also showed the importance of the pre-contamination state of the cells in influencing survival kinetics.


Asunto(s)
Queso/microbiología , Ácido Láctico/farmacología , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/epidemiología , Cloruro de Sodio/farmacología , Queso/análisis , Microbiología de Alimentos , Medición de Riesgo , Tolerancia a la Sal/fisiología , Sudáfrica/epidemiología
5.
Emerg Infect Dis ; 25(8): 1461-1468, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31310227

RESUMEN

We investigated an outbreak of listeriosis detected by whole-genome multilocus sequence typing and associated with packaged leafy green salads. Nineteen cases were identified in the United States during July 5, 2015-January 31, 2016; isolates from case-patients were closely related (median difference 3 alleles, range 0-16 alleles). Of 16 case-patients interviewed, all reported salad consumption. Of 9 case-patients who recalled brand information, all reported brands processed at a common US facility. The Public Health Agency of Canada simultaneously investigated 14 cases of listeriosis associated with this outbreak. Isolates from the processing facility, packaged leafy green salads, and 9 case-patients from Canada were closely related to US clinical isolates (median difference 3 alleles, range 0-16 alleles). This investigation led to a recall of packaged leafy green salads made at the processing facility. Additional research is needed to identify best practices and effective policies to reduce the likelihood of Listeria monocytogenes contamination of fresh produce.


Asunto(s)
Brotes de Enfermedades , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Listeria , Listeriosis/epidemiología , Listeriosis/microbiología , /microbiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Canadá/epidemiología , Niño , Preescolar , Notificación de Enfermedades , Femenino , Genoma Bacteriano , Geografía Médica , Humanos , Listeria/clasificación , Listeria/genética , Listeria/aislamiento & purificación , Listeriosis/transmisión , Masculino , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Embarazo , Vigilancia en Salud Pública , Estaciones del Año , Estados Unidos/epidemiología , Adulto Joven
6.
Forensic Sci Int ; 302: 109869, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31302416

RESUMEN

A common objective in microbial forensic investigations is to identify the origin of a recovered pathogenic bacterium by DNA sequencing. However, there is currently no consensus about how degrees of belief in such origin hypotheses should be quantified, interpreted, and communicated to wider audiences. To fill this gap, we have developed a concept based on calculating probabilistic evidential values for microbial forensic hypotheses. The likelihood-ratio method underpinning this concept is widely used in other forensic fields, such as human DNA matching, where results are readily interpretable and have been successfully communicated in juridical hearings. The concept was applied to two case scenarios of interest in microbial forensics: (1) identifying source cultures among series of very similar cultures generated by parallel serial passage of the Tier 1 pathogen Francisella tularensis, and (2) finding the production facilities of strains isolated in a real disease outbreak caused by the human pathogen Listeria monocytogenes. Evidence values for the studied hypotheses were computed based on signatures derived from whole genome sequencing data, including deep-sequenced low-frequency variants and structural variants such as duplications and deletions acquired during serial passages. In the F. tularensis case study, we were able to correctly assign fictive evidence samples to the correct culture batches of origin on the basis of structural variant data. By setting up relevant hypotheses and using data on cultivated batch sources to define the reference populations under each hypothesis, evidential values could be calculated. The results show that extremely similar strains can be separated on the basis of amplified mutational patterns identified by high-throughput sequencing. In the L. monocytogenes scenario, analyses of whole genome sequence data conclusively assigned the clinical samples to specific sources of origin, and conclusions were formulated to facilitate communication of the findings. Taken together, these findings demonstrate the potential of using bacterial whole genome sequencing data, including data on both low frequency SNP signatures and structural variants, to calculate evidence values that facilitate interpretation and communication of the results. The concept could be applied in diverse scenarios, including both epidemiological and forensic source tracking of bacterial infectious disease outbreaks.


Asunto(s)
Trazado de Contacto/métodos , Francisella tularensis/genética , Genoma Bacteriano , Funciones de Verosimilitud , Listeria monocytogenes/genética , Secuenciación Completa del Genoma , Brotes de Enfermedades , Enfermedades Transmitidas por los Alimentos/microbiología , Genética Forense/métodos , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Listeriosis/epidemiología , Filogenia , Polimorfismo de Nucleótido Simple , Tularemia/epidemiología
7.
Obstet Gynecol Surv ; 74(6): 362-368, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31216045

RESUMEN

Importance: Listeriosis is a rare foodborne condition that can cause serious health consequences in neonates and pregnant women. Listeria monocytogenes can be vertically transmitted to the fetus, resulting in adverse maternal, fetal, and neonatal outcomes. In this review, we summarize what is currently known about listeriosis in pregnancy and review the current management and treatment recommendations. Objective: To summarize the clinical and relevant evidence available regarding listeriosis in pregnancy and educate providers on common clinical symptoms, sequelae, and appropriate treatment guidelines. Evidence Acquisition: A PubMed review was conducted using search terms "pregnancy" OR "Listeria" OR "Maternal Listeriosis," and "Neonatal Listeriosis." The search included review articles, original research articles, and guidelines on diagnosis and management of listeriosis in pregnancy. The search was limited to the English language and publications between 1988 and July 2018. Conclusions: Listeriosis in pregnancy can result in severe adverse maternal, fetal, and neonatal outcomes including miscarriage, preterm labor, fetal death, and neonatal meningitis and sepsis. Early treatment has been shown to improve fetal and neonatal outcomes; therefore, prevention with education and early diagnosis prompting treatment will improve overall outcomes. Relevance: The incidence of listeriosis is expected to rise in the coming years due to changes in the US population, with increasing numbers of older Americans and Hispanic individuals, both of whom are at higher risk. Pregnant women contract listeriosis at a rate that is 16- to 18-fold greater than the general population. Given the expected increased rise in incidence and increased susceptibility of pregnant women, understanding the common clinical symptoms, maternal and fetal sequelae, and appropriate treatment guidelines is essential.


Asunto(s)
Muerte Fetal/etiología , Listeriosis/complicaciones , Listeriosis/tratamiento farmacológico , Complicaciones Infecciosas del Embarazo/tratamiento farmacológico , Femenino , Humanos , Recién Nacido , Listeria monocytogenes , Listeriosis/diagnóstico , Listeriosis/epidemiología , Embarazo , Complicaciones Infecciosas del Embarazo/diagnóstico , Complicaciones Infecciosas del Embarazo/epidemiología , Complicaciones Infecciosas del Embarazo/microbiología , Evaluación de Síntomas
8.
Int J Food Microbiol ; 304: 97-105, 2019 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-31176965

RESUMEN

Listeria monocytogenes causes severe consequences especially for persons belonging to risk groups. Finland is among the countries with highest number of listeriosis cases in the European Union. Although most reported cases appear to be sporadic and the maximum bacterial concentration of 100 cfu/g is not usually exceeded at retail, cold smoked and salt-cured fish products have been noted as those products with great risk especially for the elderly. In order to investigate the listeriosis risk more carefully, an exposure assessment was developed, and laboratory results for cold smoked and salt-cured salmon products were exploited. L. monocytogenes exposure was modeled for consumers in two age groups, the elderly population as a risk group and the working-age population as a reference. Incidence was assessed by estimating bacterial growth in the food products at three temperatures. Bayesian estimation of the risk was based on bacterial occurrence and product consumption data and epidemiological population data. The model builds on a two-state Markov chain describing repeated consumption on consecutive days. The cumulative exposure is probabilistically governed by the daily decreasing likelihood of continued consumption and the increasing bacterial concentrations due to growth. The population risk was then predicted with a Poisson distribution accounting for the daily probabilities of purchasing a contaminated product and the cumulative total probability of infection from its use. According to the model presented in this article, elderly Finns are at a greater risk of acquiring listeriosis than healthy adults. The risk for the elderly does not fully diminish even if the products have been stored at the recommended temperature (between 0 and 3 °C). It can be concluded that the stage after retail, i.e. food handling and storage by consumer or professional kitchens, is essential to protection against listeriosis. The estimation model provides means for assessing the joint impacts of these effects.


Asunto(s)
Manipulación de Alimentos/métodos , Enfermedades Transmitidas por los Alimentos/epidemiología , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/epidemiología , Salmón/microbiología , Alimentos Marinos/microbiología , Anciano , Animales , Teorema de Bayes , Seguridad de Productos para el Consumidor , Finlandia/epidemiología , Explotaciones Pesqueras , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Medición de Riesgo , Humo , Cloruro de Sodio , Temperatura Ambiental
9.
Int J Infect Dis ; 84: 48-53, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31051276

RESUMEN

BACKGROUND: The purpose of this study was to identify global trends in Listeria monocytogenes epidemiology using ProMED reports. ProMED is a publicly available, global outbreak reporting system that uses both informal and formal sources. In the context of Listeria, ProMED reports on atypical findings such as higher than average case counts, events from unusual sources, and multinational outbreaks. METHODS: Keywords "Listeria" and "listeriosis" were utilized in the ProMED search engine covering the years 1996-2018. Issue date, countries involved, source, suspected and confirmed case counts, and fatalities were extracted. Data unique to each event, including commentary by content experts, were evaluated. When multiple reports regarding the same outbreak or recall were obtained, the last report pertaining to that outbreak was utilized. Rates of Listeria events over time were compared using a normal approximation to the Poisson distribution; p < 0.05 was considered to be statistically significant. RESULTS: From 1996 through 2018, 123 Listeria events were identified in the ProMED database. Eighty-one events (65%) were associated with two or more human cases (outbreak events), 13 events (11%) were associated with only one human case (sporadic cases), and 29 events (24%) were precautionary food product recalls due to the presence of bacterial contamination without associated human cases. The implicated food vehicle was identified in 69 (85%) outbreak events and in 10 (77%) sporadic case events. Listeria contaminated foods were identified in all precautionary recall events. Overall, 28 events (23%) implicated novel food vehicles/sources. Events associated with novel food vehicles increased over the study period (p < 0.02), as did international events with more than one country involved (p < 0.02). Ten reports (8%) described hospital-acquired events. CONCLUSIONS: This study demonstrates the use of publicly available data to document Listeria epidemiological trends, particularly in settings where foodborne disease surveillance is weak or non-existent. Over the last decade, an increasing number of events have been associated with foods not traditionally recognized as vehicles for Listeria transmission, and a rise in international events was noted. Informing high-risk individuals such as pregnant women and immunocompromised individuals of safe food handling practices is warranted. To ensure timely recall of contaminated food products, open data sharing and communication across borders is critical. Changes in food production and distribution, and improved diagnostics may have contributed to the observed changes.


Asunto(s)
Brotes de Enfermedades , Listeriosis/epidemiología , Femenino , Manipulación de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Humanos , Listeria monocytogenes , Masculino , Embarazo
10.
Pesqui. vet. bras ; 39(5): 299-303, May 2019. graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1012749

RESUMEN

ABSTRACT: Listeriosis is a disease that affects several animal species, including humans, and has three different forms of presentation: encephalic, reproductive, or septicemic. The nervous form is caused mainly by the bacterium Listeria monocytogenes. In Brazil, this disease has already been described in sheep, goats, and cattle. There are no reports of the disease in buffaloes in Brazil and worldwide. The objective of this study was to describe an outbreak of listeric meningoencephalitis in buffaloes in the state of Pará, Brazil. The outbreak occurred in a property located in the municipality of Bujaru, in the eastern Amazon, from May to July 2016. In a herd of 47 buffaloes, three animals (Cases 1, 2 and 3), aged <40 days, presented a neurological condition with locomotion difficulty characterized by paralysis of the four limbs, hypoesthesia, lateral recumbency, and death. Morbidity was 6.38% and lethality was 100%. At necropsy, no significant macroscopic lesions were found. Samples of the central nervous system were collected, fixed in 10% buffered formalin, and routinely processed for histopathological analysis. The main microscopic changes observed were unilateral microabscesses in the brainstem composed predominantly of mononuclear cells, with fewer polymorphonuclear cells, and perivascular cuffs composed mostly of mononuclear cells and few neutrophils. Samples of Cases 1 and 2 revealed Gram-positive bacteria in the areas of necrosis by the Gram's stain technique. Samples of Case 1 were positive in immunohistochemistry for L. monocytogenes. Diagnosis of the nervous form of listeriosis was based on epidemiological data, clinical profile, and immunostaining for Listeria monocytogenes. Results showed that listeriosis should be considered in the differential diagnosis in buffaloes with nervous signs.


RESUMO: A listeriose é uma doença que afeta várias espécies animais, incluindo o homem, e possui três formas diferentes de apresentação: nervosa, abortiva ou septicêmica. A forma nervosa é causada principalmente pela bactéria Listeria monocytogenes. No Brasil a doença já foi descrita em bovinos, ovinos e caprinos, mas não foram encontrados relatos desta doença em búfalos no Brasil e no mundo. O objetivo deste trabalho foi descrever um surto de listeriose nervosa em búfalos no estado do Pará, Brasil. O surto ocorreu de maio a julho de 2016, em uma propriedade localizada no município de Bujaru, na Amazônia Oriental. Três bubalinos de um total de 47 animais (Casos 1, 2 e 3), menores de 40 dias, apresentaram um quadro clínico neurológico caracterizado por dificuldade de locomoção, paralisia dos quatro membros, diminuição da sensibilidade cutânea, decúbito lateral e morte. A morbidade foi de 6,38% e a letalidade de 100%. Na necropsia não foram encontradas lesões macroscópicas significativas. Amostras do sistema nervoso central foram coletadas e fixadas em formalina tamponada a 10% e processadas rotineiramente para análise histopatológica. As principais alterações microscópicas observadas foram microabscessos unilaterais no tronco encefálico, compostos predominantemente por células mononucleares, com menor número de polimorfonucleares, e manguitos perivasculares compostos predominantemente por células mononucleares e poucos neutrófilos. Amostras dos Casos 1 e 2 revelaram bactérias Gram positivas nas áreas de necrose na técnica de Gram. Amostras do Caso 1 resultaram positivas na imuno-histoquímica para L. monocytogenes. O diagnóstico da forma nervosa da listeriose foi baseado nos dados epidemiológicos, no quadro clínico patológico e na imunomarcação para Listeria monocytogenes. Os resultados demostram que a listeriose deve ser considerada no diagnóstico diferencial em bubalinos com sinais nervosos.


Asunto(s)
Animales , Búfalos/anomalías , Listeriosis/epidemiología , Enfermedades del Sistema Nervioso/veterinaria , Listeria monocytogenes
11.
PLoS One ; 14(2): e0213039, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30818354

RESUMEN

Food safety risk assessments and large-scale epidemiological investigations have the potential to provide better and new types of information when whole genome sequence (WGS) data are effectively integrated. Today, the NCBI Pathogen Detection database WGS collections have grown significantly through improvements in technology, coordination, and collaboration, such as the GenomeTrakr and PulseNet networks. However, high-quality genomic data is not often coupled with high-quality epidemiological or food chain metadata. We have created a set of tools for cleaning, curation, integration, analysis and visualization of microbial genome sequencing data. It has been tested using Salmonella enterica and Listeria monocytogenes data sets provided by NCBI Pathogen Detection (160,000 sequenced isolates in 2018). GenomeGraphR presents foodborne pathogen WGS data and associated curated metadata in a user-friendly interface that allows a user to query a variety of research questions such as, transmission sources and dynamics, global reach, and persistence of genotypes associated with contamination in the food supply and foodborne illness across time or space. The application is freely available (https://fda-riskmodels.foodrisk.org/genomegraphr/).


Asunto(s)
Microbiología de Alimentos , Inocuidad de los Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Secuenciación Completa del Genoma/estadística & datos numéricos , Bases de Datos Genéticas , Enfermedades Transmitidas por los Alimentos/epidemiología , Genoma Bacteriano , Humanos , Internet , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Listeriosis/microbiología , Metadatos , Epidemiología Molecular , Polimorfismo de Nucleótido Simple , Medición de Riesgo , Intoxicación Alimentaria por Salmonella/epidemiología , Intoxicación Alimentaria por Salmonella/microbiología , Salmonella enterica/genética , Programas Informáticos , Interfaz Usuario-Computador
12.
Emerg Microbes Infect ; 8(1): 17-28, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30866756

RESUMEN

An outbreak with a remarkable Listeria monocytogenes clone causing 163 cases of non-invasive listeriosis occurred in Germany in 2015. Core genome multi locus sequence typing grouped non-invasive outbreak isolates and isolates obtained from related food samples into a single cluster, but clearly separated genetically close isolates obtained from invasive listeriosis cases. A comparative genomic approach identified a premature stop codon in the chiB gene, encoding one of the two L. monocytogenes chitinases, which clustered with disease outcome. Correction of this premature stop codon in one representative gastroenteritis outbreak isolate restored chitinase production, but effects in infection experiments were not found. While the exact role of chitinases in virulence of L. monocytogenes is still not fully understood, our results now clearly show that ChiB-derived activity is not required to establish L. monocytogenes gastroenteritis in humans. This limits a possible role of ChiB in human listeriosis to later steps of the infection.


Asunto(s)
Quitinasas/genética , Brotes de Enfermedades , Gastroenteritis/microbiología , Listeria monocytogenes/clasificación , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Adolescente , Adulto , Proteínas Bacterianas/genética , Técnicas de Tipificación Bacteriana , Células CACO-2 , Niño , Preescolar , Codón de Terminación , Femenino , Microbiología de Alimentos , Gastroenteritis/epidemiología , Genómica , Alemania/epidemiología , Células HeLa , Células Hep G2 , Humanos , Lactante , Listeria monocytogenes/enzimología , Listeria monocytogenes/patogenicidad , Masculino , Persona de Mediana Edad , Tipificación de Secuencias Multilocus , Filogenia , Factores de Virulencia/genética , Adulto Joven
13.
J Food Prot ; 82(1): 30-38, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30702931

RESUMEN

This article describes the identification and investigation of two extended outbreaks of listeriosis in which crabmeat was identified as the vehicle of infection. Comparing contemporary and retrospective typing data of Listeria monocytogenes isolates from clinical cases and from food and food processing environments allowed the detection of cases going back several years. This information, combined with the analysis of routinely collected enhanced surveillance data, helped to direct the investigation and identify the vehicle of infection. Retrospective whole genome sequencing (WGS) analysis of isolates provided robust microbiological evidence of links between cases, foods, and the environments in which they were produced and demonstrated that for some cases and foods, identified by fluorescent amplified fragment length polymorphism, the molecular typing method in routine use at the time, were not part of the outbreak. WGS analysis also showed that the strains causing illness had persisted in two food production environments for many years and in one producer had evolved into two strains over a period of around 8 years. This article demonstrates the value of reviewing L. monocytogenes typing data from clinical cases together with that from foods as a means of identifying potential vehicles and sources of infection in outbreaks of listeriosis. It illustrates the importance of reviewing retrospective L. monocytogenes typing alongside enhanced surveillance data to characterize extended outbreaks and inform control measures. Also, this article highlights the advantages of WGS analysis for strain discrimination and clarification of evolutionary relationships that refine outbreak investigations and improve our understanding of L. monocytogenes in the food chain.


Asunto(s)
Braquiuros/microbiología , Listeria monocytogenes , Listeriosis , Mariscos/microbiología , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Animales , Brotes de Enfermedades , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Genoma Bacteriano , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Listeriosis/microbiología , Epidemiología Molecular , Tipificación de Secuencias Multilocus , Estudios Retrospectivos , Secuenciación Completa del Genoma
14.
Emerg Infect Dis ; 25(3): 581-584, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30789125

RESUMEN

In an investigation of a listeriosis outbreak in Ontario, Canada, during November 2015-June 2016, pasteurized chocolate milk was identified as the source. Because listeriosis outbreaks associated with pasteurized milk are rare in North America, these findings highlight that dairy products can be contaminated after pasteurization.


Asunto(s)
Chocolate , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/epidemiología , Enfermedades Transmitidas por los Alimentos/microbiología , Listeria monocytogenes , Listeriosis/epidemiología , Listeriosis/microbiología , Leche , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Niño , Preescolar , Brotes de Enfermedades , Femenino , Contaminación de Alimentos , Humanos , Lactante , Listeria monocytogenes/clasificación , Listeria monocytogenes/genética , Listeria monocytogenes/aislamiento & purificación , Masculino , Persona de Mediana Edad , Ontario/epidemiología , Pasteurización , Adulto Joven
16.
J Food Prot ; 82(2): 344-357, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30688537

RESUMEN

Listeria monocytogenes is the cause of listeriosis, an important foodborne disease. Contaminated ready-to-eat foods are common sources of L. monocytogenes, yet no global estimates exist for prevalence and levels in high-risk ready-to-eat foods. Our objective was to estimate the prevalence and levels of L. monocytogenes in deli meat, soft cheese, and packaged salad. We searched Medline, Web of Science, Agricola, Conference Proceedings Citation Index-Science, Science.gov, ScienceResearch.com , and OpenGREY for studies on L. monocytogenes prevalence and/or levels, with no restriction on publication date. We used a priori study selection, data extraction, and risk of biases processes. Results were synthesized with random-effects meta-analyses and meta-regressions to evaluate heterogeneity between studies. We included in the review 100 studies with a sample size restriction of ≥100, and we estimated L. monocytogenes prevalence in deli meat at 2.9% (95% confidence interval [CI], 2.3 to 3.6%), in soft cheese at 2.4% (95% CI, 1.6 to 3.6%), and in packaged salad at 2.0% (95% CI, 1.2 to 3.1%). High heterogeneity was present in all food groups, and meta-regressions did not reveal consistent explanations for heterogeneity. Pathogen level was not reported consistently or in the format required for synthesis, so meta-analyses of this variable were not performed. The high heterogeneity between studies indicates that use of global summary prevalence estimates for risk assessments are not advisable, but awareness of risk and the heterogeneity of the risk is relevant for education and further risk assessment.


Asunto(s)
Queso , Contaminación de Alimentos/análisis , Listeria monocytogenes , Productos de la Carne , Queso/microbiología , Microbiología de Alimentos , Humanos , Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Listeriosis/prevención & control , Carne , Productos de la Carne/microbiología , Prevalencia , /microbiología
17.
Int J Infect Dis ; 81: 17-24, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30641204

RESUMEN

OBJECTIVE: The aim of this study was to conduct a systematic review to better understand the epidemiological and clinical characteristics of listeriosis patients in mainland China. METHODS: The six most widely used Chinese and English language databases were searched. The records of patients with listeriosis in mainland China reported during the years 2011-2017 were extracted. The clinical data of patients and information on clinical isolates of Listeria were collected and analyzed. RESULTS: In total, 136 records were identified, reporting 562 patients with listeriosis. The number of patients was much higher than that reported in the previous decade. The 227 non-perinatal listeriosis patients included had a mortality rate of 23.78%. Of the 231 perinatal listeriosis patients, 32.68% resulted in abortion and/or newborn death. All listeriosis cases were reported as being sporadic. The listeriosis was traced to infection via a meat product in only three patients, while 33.12% were healthcare-associated infections. CONCLUSIONS: The number of patients with listeriosis in mainland China may have been underestimated previously. Perinatal cases in mainland China account for a much higher proportion than is usually described. Considering the high number of listeriosis patients in China, a comprehensive monitoring system for Listeria is urgently needed.


Asunto(s)
Listeria monocytogenes/aislamiento & purificación , Listeriosis/epidemiología , Listeriosis/microbiología , China/epidemiología , Humanos
18.
Microb Genom ; 5(1)2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30648944

RESUMEN

The persuasiveness of genomic evidence has pressured scientific agencies to supplement or replace well-established methodologies to inform public health and food safety decision-making. This study of 52 epidemiologically defined Listeria monocytogenes isolates, collected between 1981 and 2011, including nine outbreaks, was undertaken (1) to characterize their phylogenetic relationship at finished genome-level resolution, (2) to elucidate the underlying genetic diversity within an endemic subtype, CC8, and (3) to re-evaluate the genetic relationship and epidemiology of a CC8-delimited outbreak in Canada in 2008. Genomes representing Canadian Listeria outbreaks between 1981 and 2010 were closed and manually annotated. Single nucleotide variants (SNVs) and horizontally acquired traits were used to generate phylogenomic models. Phylogenomic relationships were congruent with classical subtyping and epidemiology, except for CC8 outbreaks, wherein the distribution of SNV and prophages revealed multiple co-evolving lineages. Chronophyletic reconstruction of CC8 evolution indicates that prophage-related genetic changes among CC8 strains manifest as PFGE subtype reversions, obscuring the relationship between CC8 isolates, and complicating the public health interpretation of subtyping data, even at maximum genome resolution. The size of the shared genome interrogated did not change the genetic relationship measured between highly related isolates near the tips of the phylogenetic tree, illustrating the robustness of these approaches for routine public health applications where the focus is recent ancestry. The possibility exists for temporally and epidemiologically distinct events to appear related even at maximum genome resolution, highlighting the continued importance of epidemiological evidence.


Asunto(s)
Bases de Datos de Ácidos Nucleicos , Genoma Bacteriano , Listeria monocytogenes/genética , Listeriosis/genética , Filogenia , Profagos/genética , Análisis de Secuencia de ADN , Canadá , ADN Bacteriano/genética , Brotes de Enfermedades , Humanos , Listeriosis/epidemiología
19.
J Sci Food Agric ; 99(6): 2931-2938, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30471122

RESUMEN

BACKGROUND: To estimate the public health risk related to cooked meat in bulk products contaminated with Listeria monocytogenes, a generic Bayesian network (BN) risk-assessment model was developed to simulate influencing factors and processes of products from the industry level to the consumer level. To quantify the model, parameter values of prior distributions were acquired from the literature, websites, and expert opinions. Using the Markov chain Monte Carlo (MCMC) simulation approach, posterior probability distributions were calculated according to the incorporated evidence, which allowed us to predict various risks affected by processing variability from production to consumption. RESULTS: The average risks of listeriosis from consuming cooked meat in bulk products are 8.40 × 10-7 , 2.58 × 10-8 , 8.24 × 10-7 , and 1.05 × 10-6 per meal for children, young people, elderly people, and pregnant women, respectively. The estimated mean number of listeriosis cases is 5 per 100 000 people per year in China. CONCLUSION: Although only a conceptual BN model is given, it manifests the principles and characteristics of mathematical methods. The BN model can also provide significant benefits for quantitative risk assessment by incorporating all available data and by updating beliefs. © 2018 Society of Chemical Industry.


Asunto(s)
Listeria monocytogenes/aislamiento & purificación , Carne/microbiología , Adolescente , Adulto , Anciano , Animales , Teorema de Bayes , Niño , Preescolar , China/epidemiología , Seguridad de Productos para el Consumidor , Femenino , Contaminación de Alimentos/análisis , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/crecimiento & desarrollo , Listeriosis/epidemiología , Listeriosis/microbiología , Masculino , Carne/análisis , Persona de Mediana Edad , Porcinos , Adulto Joven
20.
Clin Microbiol Infect ; 25(2): 252.e1-252.e4, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30195066

RESUMEN

OBJECTIVES: To investigate the contribution to virulence of the surface protein internalin B (InlB) in the Listeria monocytogenes lineage I strain F2365, which caused a deadly listeriosis outbreak in California in 1985. METHODS: The F2365 strain displays a point mutation that hampers expression of InlB. We rescued the expression of InlB in the L. monocytogenes lineage I strain F2365 by introducing a point mutation in the codon 34 (TAA to CAA). We investigated its importance for bacterial virulence using in vitro cell infection systems and a murine intravenous infection model. RESULTS: In HeLa and JEG-3 cells, the F2365 InlB+ strain expressing InlB was ≈9-fold and ≈1.5-fold more invasive than F2365, respectively. In livers and spleens of infected mice at 72 hours after infection, bacterial counts for F2365 InlB+ were significantly higher compared to the F2365 strain (≈1 log more), and histopathologic assessment showed that the F2365 strain displayed a reduced number of necrotic foci compared to the F2365 InlB+ strain (Mann-Whitney test). CONCLUSIONS: InlB plays a critical role during infection of nonpregnant animals by a L. monocytogenes strain from lineage I. A spontaneous mutation in InlB could have prevented more severe human morbidity and mortality during the 1985 California listeriosis outbreak.


Asunto(s)
Proteínas Bacterianas/metabolismo , Listeria monocytogenes/patogenicidad , Listeriosis/microbiología , Proteínas de la Membrana/metabolismo , Animales , Proteínas Bacterianas/genética , Línea Celular , Epidemias , Regulación Bacteriana de la Expresión Génica , Humanos , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo , Listeriosis/epidemiología , Hígado/microbiología , Proteínas de la Membrana/genética , Ratones , Mutación Puntual , Bazo/microbiología , Virulencia
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