Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 3 de 3
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Food Prot ; 72(2): 415-20, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19350990

RESUMO

Previously there was no available information on the levels of indicator bacteria and the prevalence of pathogens in fresh produce grown in Alberta, Canada. Baseline information on the occurrence and levels of Escherichia coli and the prevalence of foodborne pathogens in selected produce items available to consumers from farmers' and public markets in two large urban centers and surrounding areas in Alberta was obtained. A total of 10 large markets with between 1 and 12 produce vendors and 26 small markets with between 1 and 6 produce vendors were sampled from 21 June to 7 October 2007. Lettuce (128 samples), spinach (59 samples), tomatoes (120 samples), carrots (206 samples), green onions (129 samples), and strawberries (31 samples) were analyzed for E. coli, Salmonella, E. coli O157:H7, and Campylobacter spp. Lettuce, spinach, green onion, and strawberry samples were also tested for the presence of Cryptosporidium spp. Information on whether produce was grown using organic or conventional practices was obtained from the produce vendors. E. coli was isolated from 8.2% of the samples that included lettuce, spinach, carrots, and green onions. The bacterial counts ranged from <0.48 to >3.04 Log most probable number per g. E. coli was not isolated from tomatoes or strawberries. The percentage of positive samples ranged from 4.4% for carrots to 27.1% for spinach. Salmonella, E. coli O157:H7, and Campylobacter spp. were not isolated from any of the samples. Cryptosporidium was identified by PCR in one sample of spinach (0.6% of the samples).


Assuntos
Agricultura/métodos , Contaminação de Alimentos/análise , Microbiologia de Alimentos , Parasitologia de Alimentos , Verduras/microbiologia , Alberta , Animais , Campylobacter/crescimento & desenvolvimento , Campylobacter/isolamento & purificação , Contagem de Colônia Microbiana , Qualidade de Produtos para o Consumidor , Cryptosporidium , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Escherichia coli O157/crescimento & desenvolvimento , Escherichia coli O157/isolamento & purificação , Manipulação de Alimentos/métodos , Humanos , Prevalência , Salmonella/crescimento & desenvolvimento , Salmonella/isolamento & purificação , Verduras/parasitologia , Verduras/normas
2.
J Food Prot ; 70(5): 1080-7, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17536664

RESUMO

Conventional culture methods have traditionally been considered the "gold standards" for the isolation and identification of foodborne pathogens. However, culture methods are labor-intensive and time-consuming. We have developed a real-time PCR assay for the detection of Salmonella in a variety of food and food-animal matrices. The real-time PCR assay incorporates both primers and hybridization probes based on the sequence of the Salmonella invA gene and uses fluorescent resonance energy transfer technology to ensure highly sensitive and specific results. This method correctly classified 51 laboratory isolates of Salmonella and 28 non-Salmonella strains. The method was also validated with a large number of field samples that consisted of porcine feces and cecal contents, pork carcasses, bovine feces and beef carcasses, poultry cecal contents and carcasses, equine feces, animal feeds, and various food products. The samples (3388) were preenriched in buffered peptone water and then selectively enriched in tetrathionate and Rappaport-Vassiliadis broths. Aliquots of the selective enrichment broths were combined for DNA extraction and analysis by the real-time PCR assay. When compared with the culture method, the diagnostic sensitivity of the PCR assay for the various matrices ranged from 97.1 to 100.0%, and the diagnostic specificity ranged from 91.3 to 100.0%. Kappa values ranged from 0.87 to 1.00, indicating excellent agreement of the real-time PCR assay to the culture method. The reduction in time and labor makes this highly sensitive and specific real-time PCR assay an excellent alternative to conventional culture methods for surveillance and research studies to improve food safety.


Assuntos
Contaminação de Alimentos/análise , Microbiologia de Alimentos , Reação em Cadeia da Polimerase/métodos , Salmonella/isolamento & purificação , Pele/microbiologia , Ração Animal/microbiologia , Animais , Bovinos/microbiologia , Contagem de Colônia Microbiana/métodos , Qualidade de Produtos para o Consumidor , Sondas de DNA , Fluorescência , Cavalos/microbiologia , Humanos , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase/normas , Aves Domésticas/microbiologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Suínos/microbiologia , Fatores de Tempo
3.
J Food Prot ; 69(9): 2176-82, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16995521

RESUMO

A total of 800 meat and poultry products were purchased from the retail marketplace in Edmonton, Alberta, Canada. The products consisted of raw ground beef, chicken legs, pork chops, and ready-to-eat fermented sausage, roast beef, processed turkey breast, chicken wieners, and beef wieners. The samples were analyzed to determine the prevalence of Shiga toxin-producing Escherichia coli, Salmonella, Campylobacter spp., and Listeria monocytogenes. Shiga toxin-producing E. coli 022: H8 was found in one raw ground beef sample. Salmonella and Campylobacter were found in 30 and 62% of raw chicken legs, respectively. L. monocytogenes was found in 52% of raw ground beef, 34% of raw chicken legs, 24% of raw pork chops, 4% of fermented sausages, 3% of processed turkey breast, 5% of beef wieners, and 3% of chicken wieners. The occurrence of pathogens in this study is similar to that in retail products in many other international locales.


Assuntos
Qualidade de Produtos para o Consumidor , Contaminação de Alimentos/análise , Produtos da Carne/microbiologia , Carne/microbiologia , Produtos Avícolas/microbiologia , Alberta , Animais , Campylobacter/isolamento & purificação , Bovinos , Galinhas , Comércio/normas , Escherichia coli/isolamento & purificação , Microbiologia de Alimentos , Humanos , Listeria monocytogenes/isolamento & purificação , Salmonella/isolamento & purificação , Suínos , Perus
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...