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1.
N Engl J Med ; 381(26): 2569-2580, 2019 12 26.
Artigo em Inglês | MEDLINE | ID: mdl-31881145

RESUMO

Rapid advances in DNA sequencing technology ("next-generation sequencing") have inspired optimism about the potential of human genomics for "precision medicine." Meanwhile, pathogen genomics is already delivering "precision public health" through more effective investigations of outbreaks of foodborne illnesses, better-targeted tuberculosis control, and more timely and granular influenza surveillance to inform the selection of vaccine strains. In this article, we describe how public health agencies have been adopting pathogen genomics to improve their effectiveness in almost all domains of infectious disease. This momentum is likely to continue, given the ongoing development in sequencing and sequencing-related technologies.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Influenza Humana/epidemiologia , Saúde Pública , Tuberculose/epidemiologia , Animais , Bactérias/genética , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/parasitologia , Humanos , Influenza Humana/diagnóstico , Influenza Humana/microbiologia , Metagenômica , Parasitos/genética , Tuberculose/diagnóstico , Vírus/genética
2.
Int J Food Microbiol ; 309: 108332, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31494483

RESUMO

Vibrio parahaemolyticus is a major food-borne pathogen. V. parahaemolyticus infections are associated with various serotypes; to date, 71 K-serogroups of V. parahaemolyticus have been determined based on capsular polysaccharide (CPS) diversity. In this study, the capsular polysaccharide gene clusters (CPSgcs) of 55 K-serogroups were identified by whole-genome sequencing and analysis. These CPSgcs exhibit a high level of genetic diversity. A microsphere-based suspension array (MSA) was established for the detection and identification of 55 V. parahaemolyticus K-serogroups based on CPSgc-specific genes. To evaluate our array, a double-blind test with 120 clinical isolates was carried out. In addition, an in silico K-serotyping system was established based on V. parahaemolyticus CPSgc-specific genes. This system was then used to examine 845 publicly available V. parahaemolyticus genomes; the results demonstrated that 813 isolates belong to one of 43 K-serogroups. Taken together, these results demonstrate that the molecular system developed in this study is suitable for rapid serotyping of V. parahaemolyticus isolates from environmental and clinical samples. In addition, the system could be applied to epidemiological investigations of this important food-borne pathogen.


Assuntos
Cápsulas Bacterianas/genética , Doenças Transmitidas por Alimentos/diagnóstico , Polissacarídeos Bacterianos/genética , Sorotipagem/métodos , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/imunologia , Cápsulas Bacterianas/imunologia , Método Duplo-Cego , Doenças Transmitidas por Alimentos/microbiologia , Humanos , Família Multigênica/genética , Polissacarídeos Bacterianos/imunologia , Sorogrupo , Vibrioses/diagnóstico , Vibrio parahaemolyticus/classificação
3.
Przegl Epidemiol ; 73(2): 239-248, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31385681

RESUMO

INTRODUCTION: Tick-borne encephalitis (TBE) virus remains one of the main etiological agents of central nervous system infections in Europe. The disease occurs endemically in Central and Eastern Europe, Southern part of Russia and Scandinavia. Between 2000 and 2015 there were 3 662 registered TBE cases in Poland and approximately 45% of them were reported in Podlaskie voivodeship. TBE typically develops as a result of being bitten by infected tick, however, it can also be a consequence of ingestion of unpasteurized milk from viremic animal. OBJECTIVES: The aim of the article was to underline to the importance of TBE virus transmission via alimentary route and clinical description of four patients who developed TBE as a result of raw goat milk consumption. MATERIAL AND METHODS: A retrospective analysis of documentation of four patients hospitalized in Observational-Infectious Department of Independent Public Healthcare Centre in Hajnówka and Department of Infectious Diseases and Neuroinfections at the Medical University of Bialystok from June 10th 2017 to July 11th 2017 due to alimentary TBE. RESULTS: Patients were between 24 and 36 years of age. They have consumed goat milk from the same source. None of the patients have been vaccinated against TBE virus. In all patients typical biphasic disease course with the presence of prodromal and neurological phase was observed. TBE was confirmed by demonstration of anti-TBE antibodies in serum and/or cerebrospinal fluid of patients. CONCLUSIONS: Diagnosis of TBE should be considered in every case of encephalitis in endemic areas. Due to the risk of TBE infection after consumption of unpasteurized milk from livestock, it is crucial to raise awareness of general population and farm owners about the possibility of TBE infection via alimentary route.


Assuntos
Surtos de Doenças , Encefalite Transmitida por Carrapatos/epidemiologia , Doenças Transmitidas por Alimentos/epidemiologia , Adulto , Animais , Encefalite Transmitida por Carrapatos/sangue , Encefalite Transmitida por Carrapatos/diagnóstico , Encefalite Transmitida por Carrapatos/transmissão , Doenças Transmitidas por Alimentos/sangue , Doenças Transmitidas por Alimentos/diagnóstico , Cabras , Humanos , Masculino , Leite , Polônia , Estudos Retrospectivos , Adulto Jovem
4.
Analyst ; 144(19): 5766-5774, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31436781

RESUMO

We present a centrifugal microfluidic device which is combined with a solution-loading cartridge for fully automatic molecular diagnostics of foodborne pathogens. The proposed device could perform all processes of molecular diagnostics including bead-based DNA extraction, isothermal DNA amplification and colorimetric amplicon detection. In particular, the 3D-printed solution-loading cartridge was incorporated into the device to enhance the sample handling capacity and eliminate laborious steps such as pipetting for sample loading and sealing the top of the device. The cartridge could store four kinds of essential solutions (a sample solution, a washing solution, an elution solution, and a loop-mediated isothermal amplification (LAMP) cocktail) for pathogen detection, and the designated solutions were automatically released into the microdevice in a consecutive order by rotation. Since one unit of a device contains 20 reaction chambers, 18 kinds of pathogens plus two controls can be simultaneously detected in one test. As a proof-of-concept, we targeted four kinds of foodborne pathogens (Escherichia coli O157:H7, Salmonella typhimurium, Vibrio parahaemolyticus and Listeria monocytogenes) and successfully verified them, demonstrating that the centrifugal microdevice could be combined with a 3D printed solution-loading cartridge to achieve fully automated lab-on-a-chip-based molecular diagnostics. The entire process was completed in 65 min, and the limit of detection of the assay was 100 bacterial cells. The employment of the solution-loading cartridge successfully replaced the laborious and error-prone manual loading processes, which realized true automation of molecular diagnostics. This device could have promise in the fields of lab-on-a-chip and point-of-care molecular diagnostics.


Assuntos
DNA Bacteriano/análise , Doenças Transmitidas por Alimentos/microbiologia , Dispositivos Lab-On-A-Chip , Técnicas de Diagnóstico Molecular/métodos , Bactérias/genética , Bactérias/isolamento & purificação , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Centrifugação , Colorimetria , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Amplificação de Ácido Nucleico/métodos , Impressão Tridimensional , Estudo de Prova de Conceito
5.
Artigo em Inglês | MEDLINE | ID: mdl-31295907

RESUMO

Prompt investigation of food poisoning outbreak are essential, as it usually involves a short incubation period. Utilizing the advancement in mobile technology, a mobile application named MyMAFI (My Mobile Apps for Field Investigation) was developed with the aim to be an alternative and better tool for current practices of field investigation of food poisoning outbreak. A randomized cross-over trial with two arms and two treatment periods was conducted to assess the effectiveness of the newly developed mobile application as compared to the standard paper-based format approach. Thirty-six public health inspectors from all districts in Kelantan participated in this study and they were randomized into two equal sized groups. Group A started the trial as control group using the paper-format investigation form via simulated outbreaks and group B used the mobile application. After a one-month 'washout period', the group was crossed over. The primary outcome measured was the time taken to complete the outbreak investigation. The treatment effects, the period effects and the period-by-treatment interaction were analyzed using Pkcross command in Stata software. There was a significant treatment effect with mean square 21840.5 and its corresponding F statistic 4.47 (p-value = 0.038), which indicated that the mobile application had significantly improve the reporting timeliness. The results also showed that there was a significant period effect (p-value = 0.025); however, the treatment by period interaction was not significant (p-value = 0.830). The newly developed mobile application-MyMAFI-can improve the timeliness in reporting for investigation of food poisoning outbreak.


Assuntos
Surtos de Doenças , Doenças Transmitidas por Alimentos/epidemiologia , Aplicativos Móveis , Vigilância em Saúde Pública/métodos , Adulto , Idoso , Estudos Cross-Over , Feminino , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/etiologia , Humanos , Malásia/epidemiologia , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
6.
Toxicol Lett ; 314: 75-81, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31284020

RESUMO

Aflatoxin is a fungal secondary metabolite with high toxicity that is capable of contaminating various types of food crops. It has been identified as a Group 1 human carcinogen by the International Agency for Research on Cancer. Chronic aflatoxin exposure has caused worldwide concern as a matter of public food safety. Peanuts and peanut products are the major sources of aflatoxin exposure. Therefore, some reduction interventions have been developed to minimize contamination throughout the peanut production chain. The purpose of this study is to estimate the efficacy of interventions in reducing the health impact of hepatocellular carcinoma caused by aflatoxin contamination in peanuts. The estimated total Disability-Adjusted Life Years (DALYs) were calculated using FDA-iRISK software. Six aflatoxin reduction strategies were evaluated, including good agricultural practice (GAP), biocontrol, Purdue Improved Crop Storage packaging, basic processing, ozonolysis, and ultraviolet irradiation. The results indicated that basic processing could prevent huge public health loss of 4,079.7-21,833 total DALYs per year. In addition, GAP and biocontrol were both found to be effective strategies in the farm field. Meanwhile, the other three interventions had limited effectiveness in reducing total DALYs. In conclusion, this study could help farmers, processing plants, and government policy makers to alleviate aflatoxin contamination issues in the peanut production chain.


Assuntos
Aflatoxinas/efeitos adversos , Arachis/microbiologia , Carcinoma Hepatocelular/prevenção & controle , Produtos Agrícolas/microbiologia , Exposição Dietética/efeitos adversos , Exposição Dietética/prevenção & controle , Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/prevenção & controle , Neoplasias Hepáticas/prevenção & controle , Anos de Vida Ajustados por Qualidade de Vida , Agentes de Controle Biológico , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/epidemiologia , Efeitos Psicossociais da Doença , Avaliação da Deficiência , Manipulação de Alimentos/métodos , Armazenamento de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/epidemiologia , Humanos , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/epidemiologia , Ozônio/química , Fatores de Proteção , Medição de Risco , Fatores de Risco , Fatores de Tempo , Raios Ultravioleta
8.
BMC Res Notes ; 12(1): 399, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31300042

RESUMO

OBJECTIVE: Food borne diseases are predominant in all parts of the world especially in urban areas and are the main source for food borne illness. The aim of this study is to assess sanitation status and its determinants among food establishments in Adwa town, North Ethiopia from March to June 2017. RESULTS: A total of 391 (95.4%) subjects were included in this study. Around 53.3% of food establishments in the study area were in a poor sanitary status. Presence of trained managers on hygiene and sanitation (AOR = 2.6, 95% CI 1.7-4.1); inspection by regulatory personnel (AOR = 1.95, 95% CI 1.36-22.4) and being licensed (AOR = 1.2 95% CI 1.11-2.51) were associated factors which affect sanitary status sanitary of the establishments. The overall sanitary status of the establishments in the study area was found unhygienic. Managers should gain trainings on food hygiene and sanitation to follow and improve the sanitary status of the establishments.


Assuntos
Manipulação de Alimentos/normas , Doenças Transmitidas por Alimentos/diagnóstico , Desinfecção das Mãos/normas , Saneamento/normas , Adulto , Idoso , Estudos Transversais , Etiópia/epidemiologia , Feminino , Alimentos/normas , Alimentos/estatística & dados numéricos , Manipulação de Alimentos/métodos , Manipulação de Alimentos/estatística & dados numéricos , Serviços de Alimentação/legislação & jurisprudência , Serviços de Alimentação/normas , Serviços de Alimentação/estatística & dados numéricos , Doenças Transmitidas por Alimentos/epidemiologia , Desinfecção das Mãos/métodos , Humanos , Higiene/normas , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Saneamento/estatística & dados numéricos , Inquéritos e Questionários , População Urbana/estatística & dados numéricos
9.
Biosens Bioelectron ; 135: 120-128, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31004922

RESUMO

This study presents a slidable paper-embedded plastic microdevice fully integrated with DNA extraction, loop-mediated isothermal amplification (LAMP), and colorimetric detection functionalities. The developed microdevice consists of three layers that allow a sliding movement to mix the sample and reagents for DNA purification, amplification, and detection in a sequential manner. An FTA card was employed in the main chamber for DNA extraction and purification from intact bacterial cells. Subsequently, LAMP reagents and fuchsin-stored chambers were pulled toward the main chambers for DNA amplifications at 65 °C. After 30 min, the detection reagents-stored chambers were then moved to main chambers for result analysis. For the detection of LAMP amplicons, a novel colorimetric fuchsin-based method was employed. The wide applicability of the integrated microdevice was demonstrated by successfully screening three major foodborne pathogens, namely Salmonella spp., Staphylococcus aureus, and Escherichia coli O157:H7 in food, enabling highly sensitive detection of 3.0 × 101 CFU/sample of Gram-negative bacteria (Salmonella spp. and Escherichia coli O157:H7) and 3.0 × 102 CFU/sample of Gram-positive bacteria (Staphylococcus aureus) within 75 min. The portable and integrated microdevice presented in this study holds significant promise for point-of-care applications to accurately and rapidly diagnose and control diseases.


Assuntos
Escherichia coli O157/isolamento & purificação , Doenças Transmitidas por Alimentos/microbiologia , Testes Imediatos , Salmonella/isolamento & purificação , Staphylococcus aureus/isolamento & purificação , Técnicas Biossensoriais/instrumentação , DNA Bacteriano/análise , DNA Bacteriano/genética , Desenho de Equipamento , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Escherichia coli O157/genética , Doenças Transmitidas por Alimentos/diagnóstico , Humanos , Dispositivos Lab-On-A-Chip , Limite de Detecção , Técnicas de Amplificação de Ácido Nucleico/instrumentação , Papel , Plásticos , Salmonella/genética , Infecções por Salmonella/diagnóstico , Infecções por Salmonella/microbiologia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética
10.
Biosens Bioelectron ; 135: 137-144, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31005765

RESUMO

Foodborne illnesses are a major contributor to misery and health challenges in both rich and poor nations. Illnesses from pathogens such as Escherichia coli and Cryptosporidium parvum oocysts account for most of the cases of diarrhea in the world. Many standard methods exist for detecting these pathogens in water. However, these standard methods do not readily translate to the detection of the same pathogens in food. Detection techniques for pathogens in food are often inadequate, due to their inability to completely separate pathogens from food matrices. In this paper, we present a technique to separate and detect both Escherichia coli cells and Cryptosporidium parvum oocysts that have been embedded in ground meat. We achieve this objective by combining enzymatic digestion of the meat, hydrodynamic cavitation to disassemble pathogens from the meat, immunomagnetic separation to purify meat samples and indirect electrochemical detection of the target pathogens. Our use of hydrodynamic cavitation to separate pathogens is compared against an industry standard separation technique. Results indicate that the use of hydrodynamic cavitation amplifies the detection capabilities of our sensing technique and is overall comparable to or better than conventional stomacher sample preparation.


Assuntos
Cryptosporidium parvum/isolamento & purificação , Escherichia coli O157/isolamento & purificação , Análise de Alimentos/métodos , Carne Vermelha/microbiologia , Animais , Técnicas Biossensoriais/economia , Técnicas Biossensoriais/métodos , Bovinos , Criptosporidiose/diagnóstico , Criptosporidiose/microbiologia , Infecções por Escherichia coli/diagnóstico , Infecções por Escherichia coli/microbiologia , Análise de Alimentos/economia , Contaminação de Alimentos/análise , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/microbiologia , Hidrodinâmica , Separação Imunomagnética/economia , Separação Imunomagnética/métodos , Fatores de Tempo
11.
Anaerobe ; 56: 49-50, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30763675

RESUMO

Botulism type C was suspected in a 46-year old man after consumption of sick poultry from a flock where botulism type C was confirmed. The patient developed characteristic signs of botulism, but investigation of biological samples did not confirm the presence of Clostridium botulinum or botulinum toxin. Despite having classical botulism symptoms, the man recovered very quickly. This raises the question of botulism transmission to humans by ingestion of contaminated poultry.


Assuntos
Botulismo/transmissão , Clostridium botulinum tipo C/isolamento & purificação , Surtos de Doenças , Transmissão de Doença Infecciosa , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/patologia , Animais , Botulismo/diagnóstico , Botulismo/patologia , Guiana Francesa/epidemiologia , Humanos , Aves Domésticas
12.
J Microbiol Methods ; 157: 117-122, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30641093

RESUMO

Although rapid detection kits continue to be developed and used, the classical culture method is still accepted as a gold standard. Therefore accelerating the classical culture methods safely is important for the detection of Campylobacter. The aim of this study is to design and compare a novel developed medium with other confirmed media in naturally and experimentally contaminated food matrices. Besides classical culture methods, it is subjected to qPCR and FISH methods. In this study, Campylobacter counts are investigated in spiked milk, chicken breast meat, cumin, minced beef meat, celery and tomato puree. Also to evaluate the enrichment medium in naturally contaminated samples, Campylobacter detection is performed in 20 chicken neck skin samples obtained from different sales points. The study showed that the novel broth provides a faster detectable number of Campylobacter. It was found to provide detectable Campylobacter counts after eight hours of inoculation. The results have shown that there is a significant increase on Campylobacter count in the detection performed using the spiked foods. Furthermore, the entire natural contaminated chicken neck skin samples are found to be positive the same as the other mediums. As a result of the study, in the classic culture methods, designed enrichment medium is faster than the currently used enrichment mediums. It is an important point of view to develop fast and reliable diagnostic methods for assuring adequate public health.


Assuntos
Infecções por Campylobacter/diagnóstico , Campylobacter/crescimento & desenvolvimento , Carne/microbiologia , Leite/microbiologia , Verduras/microbiologia , Animais , Campylobacter/isolamento & purificação , Bovinos , Galinhas , Contagem de Colônia Microbiana , Meios de Cultura , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/microbiologia , Hibridização in Situ Fluorescente , Reação em Cadeia da Polimerase em Tempo Real
13.
Acta Biomed ; 89(4): 590-592, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30657109

RESUMO

The gastro enteric toxic effects of the barbel eggs have been described up to two centuries ago, but deliberate or serendipitous ingestion of this fish product still occur, often eliciting a gastrointestinal syndrome usually known as barbel cholera. Barbel cholera is a self-limited gastrointestinal diarrheic syndrome that develops 2 to 4 hours after ingestion of the eggs, lasting up to 12-36 hours, nearly always complicated by vomiting and severe abdominal pain. The disease is usually self-limited, and the prognosis is thus benign even without hospitalization and medical treatment. Rarely, however, barbel cholera may be complicated by massive diarrhea, and the patients can develop bradycardia, oligo-anuria, and eventually hypovolemic shock. In this article we describe a rare case of barbel cholera, highlighting both the diagnostic difficulties in identifying it, and the importance of obtain an accurate history, focused on recently ingested food, thus addressing the clinical management on supportive treatment, expecting symptoms' improvement usually within 36 hours.


Assuntos
Cólera/diagnóstico , Cólera/etiologia , Cyprinidae , Doenças Transmitidas por Alimentos/diagnóstico , Doenças Transmitidas por Alimentos/etiologia , Adulto , Animais , Feminino , Humanos
14.
Forensic Sci Med Pathol ; 15(1): 102-105, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30293223

RESUMO

Sodium nitrite is used as a coloring agent or preservative in food, as well as an antimicrobial agent in meat and fish and some cheeses. In high amounts it can be toxic for humans, causing methemoglobinemia. This is an unusual and potentially fatal condition in which hemoglobin is oxidized to methemoglobin (MHb), reducing the amount of oxygen that is released from hemoglobin, similar to carbon monoxide poisoning. MHb levels of 70% are generally lethal, but the existence of underlying anemia, acidosis, respiratory compromise, and cardiac disease may exacerbate the toxicity of MHb. We present a case of poisoning with sodium nitrite in three family members after eating homemade sausages given to them by their neighbor who was a butcher. According to the findings of the veterinary inspectorate in charge of food control in this case, the concentration of sodium nitrite in the homemade sausages was about 3.5 g per 1 kg of meat, almost 30 times higher than allowed according to legislation. In this case report, a 70-year-old man died about 7 h after consuming the meal, while two women, 53 and 67 years of age, respectively, were admitted to a toxicology clinic the following day due to food poisoning, with the maximum concentration of MHb in blood of 33.7 and 20.4%, respectively. They were discharged 3 days later. The autopsy of the deceased man showed sodium nitrite poisoning with a relatively low concentration of MHb in his blood - 9.87%. Death was attributed to the exacerbation of hypertensive and ischemic heart disease, resulting from accidental sodium nitrite poisoning. The presented cases illustrate the necessity of close cooperation between the authorities, medical staff, veterinary inspectorate, and forensic pathologists in determining the source of poisoning, the cause of death of the victim, and preventing the outbreak of poisoning among a greater number of consumers.


Assuntos
Conservantes de Alimentos/envenenamento , Doenças Transmitidas por Alimentos/diagnóstico , Nitrito de Sódio/envenenamento , Acidentes Domésticos , Idoso , Feminino , Humanos , Hipertensão/complicações , Masculino , Produtos da Carne/envenenamento , Metemoglobinemia/etiologia , Pessoa de Meia-Idade , Isquemia Miocárdica/complicações
16.
Methods Mol Biol ; 1918: 21-33, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30580396

RESUMO

The use of direct nucleic acid amplification of pathogens from food matrices has the potential to reduce time to results over DNA extraction-based approaches as well as traditional culture-based approaches. Here we describe protocols for assay design and experiments for direct amplification of foodborne pathogens in food sample matrices using loop-mediated isothermal amplification (LAMP) and polymerase chain reaction (PCR). The examples provided include the detection Escherichia coli in milk samples and Salmonella in pork meat samples. This protocol includes relevant reagents and methods including obtaining target sequences, assay design, sample processing, and amplification. These methods, though used for specific example matrices, could be applied to many other foodborne pathogens and sample types.


Assuntos
Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Técnicas de Amplificação de Ácido Nucleico , Animais , DNA Bacteriano , Escherichia coli/genética , Doenças Transmitidas por Alimentos/diagnóstico , Humanos , Reação em Cadeia da Polimerase , Salmonella/genética , Sensibilidade e Especificidade
17.
Methods Mol Biol ; 1918: 35-45, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30580397

RESUMO

Foodborne pathogens continue to be a major health issue worldwide. Culture-dependent methodologies are still considered the gold-standard to perform pathogen detection and quantification. These methods present several drawbacks, such as being time-consuming and labor-intensive. The implementation of real-time PCR has allowed to overcome these limitations and even reduce costs associated with the analyses, due to the possibility of simultaneously and accurately detecting several pathogens in one single assay, with results comparable to those obtained by classical approaches. In this chapter a protocol for the simultaneous detection of two of the most important foodborne pathogens, Salmonella spp. and Listeria monocytogenes, is described.


Assuntos
Infecções Bacterianas/microbiologia , DNA Bacteriano , Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , Reação em Cadeia da Polimerase Multiplex , Reação em Cadeia da Polimerase em Tempo Real , Infecções Bacterianas/diagnóstico , Doenças Transmitidas por Alimentos/diagnóstico , Humanos , Salmonella/genética , Sensibilidade e Especificidade
18.
Methods Mol Biol ; 1918: 129-137, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30580404

RESUMO

One strategy bacteria use to acclimate to changing environmental conditions is modulation of gene expression. Alterations in gene expression are indicative of activation or repression of certain physiological responses. In order to understand which genetic responses are utilized to cope with various environmental conditions by analyzing transcriptomes, obtaining RNA of high quality, yield, and integrity is paramount. Here, we describe an acid phenol-chloroform method employed to extract RNA from laboratory grown cell cultures, as well as cultures inoculated onto complex matrices such as lettuce and cold-smoked salmon. The method results in high-quality RNA, which can be used for various downstream processes such as cDNA library construction, RNA sequencing, real-time quantitative PCR, and northern analysis. Extraction of RNA from bacterial foodborne pathogens in conjunction with transcriptome sequencing is a useful technique to elucidate pathogens' transcriptional responses.


Assuntos
Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/microbiologia , RNA Bacteriano/isolamento & purificação , Contaminação de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Sequenciamento de Nucleotídeos em Larga Escala , Análise de Sequência de RNA
19.
Methods Mol Biol ; 1918: 139-147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30580405

RESUMO

Proteomics was applied here to study Listeria monocytogenes response to gastrointestinal stress. It separated extracted proteins by their isoelectric point (pI) in the first dimension followed by separation by molecular weight in the second dimension on a polyacrylamide gel. L. monocytogenes was grown in an appropriate culture medium after which it was transferred to a simulated cheese medium for 2 h. Bacteria were exposed to gastric stress using artificial saliva and gastric fluid for 5 min and 2 h, respectively. After each step samples were taken for protein extraction and a two-dimensional electrophoresis approach. Proteins were separated on 18 cm Immobiline DryStrip gels with a pH range of 4-7 and the protein pattern analyzed.


Assuntos
Bactérias , Eletroforese em Gel Bidimensional , Doenças Transmitidas por Alimentos/microbiologia , Gastroenterite/microbiologia , Bactérias/genética , Bactérias/metabolismo , Eletroforese em Gel Bidimensional/métodos , Contaminação de Alimentos , Doenças Transmitidas por Alimentos/diagnóstico , Gastroenterite/diagnóstico , Listeria monocytogenes/genética , Listeria monocytogenes/metabolismo
20.
Methods Mol Biol ; 1918: 149-164, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30580406

RESUMO

Metabolomics is one of the more recently developed "omics" that measures low molecular weight (typically < 1500 Da) compounds in biological samples. Metabolomics has been widely explored in environmental, clinical, and industrial biotechnology applications. However, its application to the area of food safety has been limited but preliminary work has demonstrated its value. This chapter describes an untargeted (nontargeted) metabolomics workflow using gas chromatography coupled to mass spectrometry (GC-MS) for characterizing three globally important foodborne pathogens, Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica, from selective enrichment liquid culture media. The workflow involves a detailed description of food spiking experiments followed by procedures for extraction of polar metabolites from media, analyzing the extracts using GC-MS and, finally, chemometric data analysis using the software "SIMCA" to identify potential pathogen-specific biomarkers.


Assuntos
Biomarcadores , Doenças Transmitidas por Alimentos/etiologia , Metabolômica/métodos , Interpretação Estatística de Dados , Microbiologia de Alimentos/métodos , Doenças Transmitidas por Alimentos/diagnóstico , Cromatografia Gasosa-Espectrometria de Massas , Humanos
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