Consulta: creatorFacets:"Landgraf,Mariza"
Registros recuperados: 10
Data/hora: 02/06/2024 13:31:48

Biochemical characteristics of typical and atypical Staphylococcus aureus in mastitic milk and environmental samples of Brazilian dairy farms
Provedor de dados: Brazilian Journal of Microbiology
Autores: Silva,Wladimir Padilha da; Destro,Maria Teresa; Landgraf,Mariza; Franco,Bernadette D.G.M.
This study reports results on the biochemical characteristics of 274 Staphylococcus aureus strains isolated from mastitic milk, hands of milkmen and milking machines. Features included colony morphology on Baird Parker agar (BPA), catalase, coagulase and thermonuclease tests. API-Staph (bioMérieux, France) was used as reference identification system. 39.4% of the colonies on BPA identified as S.aureus were atypical. They were more frequent in milk samples (94.4%). All S.aureus strains were coagulase positive but intensity of the test varied according to the source: environmental strains were 3+ or 4+, while 17.1% of strains isolated from milk presented only 1+ or 2+ results. The majority of atypical S.aureus strains presented a 4+ coagulase result. 2.2% of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Staphylococcus aureus; Atypical S.aureus; Coagulase; Thermonuclease; API-Staph; Baird-Parker agar; Milk; Mastitis; Environmental samples.
Ano: 2000
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822000000200008

Inactivation of Escherichia coli O157:H7 in hamburgers by gamma irradiation
Provedor de dados: Brazilian Journal of Microbiology
Autores: Chirinos,Rodolfo R.O.; Vizeu,Dirceu M.; Destro,Maria Teresa; Franco,Bernadette D.G.M.; Landgraf,Mariza.
Escherichia coli O157:H7 causes bloody diarrhoea, haemorrhagic colitis and life-threatening complications like haemolytic uremic syndrome and thrombotic thrombocitopenic purpura. Among foods associated with outbreaks caused by this pathogen, hamburger is the most common one. The aim of this research was to determine the radiation dose to reduce the population of E. coli O157:H7 in hamburgers to non-detectable levels in order to render a safer product. Hamburgers, inoculated with Escherichia coli O157:H7, were exposed to gamma radiation (60Co) treatment, with doses ranging from 0 to 0.7 kGy. The average temperature during the process was 5.6ºC. Non-inoculated hamburgers were submitted to sensory evaluation after being exposed to irradiation doses of 0.8 kGy...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hamburger; Patties; Escherichia coli O157:H7; Food irradiation; Gamma radiation.
Ano: 2002
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822002000100011

Characterization of class 1 integrons and antibiotic resistance genes in multidrug-resistant Salmonella enterica isolates from foodstuff and related sources
Provedor de dados: Brazilian Journal of Microbiology
Autores: Ribeiro,Vinicius B.; Lincopan,Nilton; Landgraf,Mariza; Franco,Bernadete D.G.M.; Destro,Maria T.
In recent years, an increase in the occurrence of antimicrobial resistance among Salmonella enterica has been observed in several countries, which is worrisome because S. enterica is one of the most common causes of human gastroenteritis worldwide. The aim of this study was to characterize class 1 integrons and antibiotic resistance genotypes in Salmonella enterica isolates recovered from foodstuff and related sources. Nineteen multidrug-resistant (MDR) Salmonella enterica isolates were recovered. Higher resistance rates to tetracycline (90%), streptomycin (80%), sulfamethoxazole-trimethoprim (80%), ampicillin (60%) and nalidixic acid (70%) were related to the presence of the tetA, aadA, sul1/sul2, blaTEM-1 genes, and a codon mutation at position 83 of the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Salmonella; Multidrug-resistant; Class 1 integrons; Foodstuff; Brazil.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822011000200033

Bacteriocinogenic Lactococcus lactis subsp: lactis DF04Mi isolated from goat milk: Evaluation of the probiotic potential
Provedor de dados: Brazilian Journal of Microbiology
Autores: Furtado,Danielle N.; Todorov,Svetoslav D.; Landgraf,Mariza; Destro,Maria T.; Franco,Bernadette D.G.M.
Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its probiotic potential. Lc. lactis DF4Mi was resistant to acidic pH and oxbile, presented co-aggregation with Listeria monocytogenes, and was not affected by several drugs from different generic groups, being sensitive to most tested antibiotics. These properties indicate that this Lc. lactis strain can be used for enhancement of dairy foods safety and quality, in combination with potential probiotic properties.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteriocin; Probiotic; Lc. lactis subsp. lactis; Biopreservation; Goat milk.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000300038

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: characterization of the bacteriocin
Provedor de dados: Brazilian Journal of Microbiology
Autores: Furtado,Danielle N.; Todorov,Svetoslav D.; Landgraf,Mariza; Destro,Maria T.; Franco,Bernadette D.G.M.
Lactic acid bacteria capable of producing bacteriocins and presenting probiotic potential open innovative technological applications in the dairy industry. In this study, a bacteriocinogenic strain (Lactococcus lactis subsp. lactis DF4Mi) was isolated from goat milk, and studied for its antimicrobial activity. The bacteriocin presented a broad spectrum of activity, was sensitive to proteolytic enzymes, resistant to heat and pH extremes, and not affected by the presence of SDS, Tween 20, Tween 80, EDTA or NaCl. Bacteriocin production was dependent on the components of the culture media, especially nitrogen source and salts. When tested by PCR, the bacteriocin gene presented 100% homology to nisin Z gene. These properties indicate that this L. lactis subsp....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteriocin; Probiotic; Lc. lactis subsp; Lactis; Biopreservation; Goat milk.
Ano: 2014
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822014000400052

Behaviour of L. monocytogenes in sliced, vacuum-packed mortadella
Provedor de dados: Brazilian Journal of Microbiology
Autores: Bersot,Luciano dos Santos; Gillio,Cíntia; Tavolaro,Paula; Landgraf,Mariza; Franco,Bernadette Dora Gombossy de Melo; Destro,Maria Teresa.
This study evaluated the growth of naturally occurring L. monocytogenes in sliced, vacuum-packed mortadella samples during storage at 5ºC until the expiration date. Tukey's test indicated that counts of L. monocytogenes on 0, 10, 20, 30 and 40 days of storage were significantly different (p&lt;0.05), indicating growth during shelf life. In three trials, the mean increase was 1.72 log cycles. Vacuum packing and storage under refrigeration were not effective in controlling the growth of L. monocytogenes in sliced mortadella, indicating that good manufacturing practices and implemented HACCP programs are essential to assure safety of this product.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Listeria monocytogenes; Growth; Sliced mortadella; Vacuum-packing.
Ano: 2008
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822008000300020

Performance of two ready-to-use systems for enumeration of aerobic mesophilic microorganisms in frozen goat milk
Provedor de dados: Brazilian Journal of Microbiology
Autores: Tavolaro,Paula; Ferrati,Analí Ramazotti; Destro,Maria Teresa; Landgraf,Mariza; Franco,Bernadette Dora Gombossy de Melo.
Enumeration of aerobic microorganisms in Brazilian pasteurized bovine milk using PetrifilmTM AC and SimplateTM TPC was shown to be influenced by the nature of autochthonous microbiota. This study was conducted to assess if the same occurs in pasteurized goat milk. Pasteurized frozen goat milk (n=62) was purchased in retail stores in São Paulo, SP, Brazil, and submitted to mesophilic aerobic counts using PetrifilmTM AC and SimplateTM TPC, comparing results with those of conventional pour-plates. Correlation indexes above 0.90 were ranked "excellent"; those between 0.80 and 0.89, "good", those from 0.79 to 0.50, "fair", and those below 0.50, "poor". Correlation indexes for PetrifilmTM AC counts were "good", but "poor" using SimplateTM TPC. Comparison of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Rapid methods; Ready-to-use systems; Goat milk; PetrifilmTM AC; SimplateTM TPC.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822005000300017

Microbiology of organic and conventionally grown fresh produce
Provedor de dados: Brazilian Journal of Microbiology
Autores: Maffei,Daniele F.; Batalha,Erika Y.; Landgraf,Mariza; Schaffner,Donald W.; Franco,Bernadette D.G.M.
ABSTRACT Fresh produce is a generalized term for a group of farm-produced crops, including fruits and vegetables. Organic agriculture has been on the rise and attracting the attention of the food production sector, since it uses eco-agricultural principles that are ostensibly environmentally-friendly and provides products potentially free from the residues of agrochemicals. Organic farming practices such as the use of animal manure can however increase the risk of contamination by enteric pathogenic microorganisms and may consequently pose health risks. A number of scientific studies conducted in different countries have compared the microbiological quality of produce samples from organic and conventional production and results are contradictory. While...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Fresh produce; Foodborne diseases; Organic agriculture; Pathogens.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822016000500099

Bacteriocinogenic Lactococcus lactis subsp. lactis DF04Mi isolated from goat milk: Application in the control of Listeria monocytogenes in fresh Minas-type goat cheese
Provedor de dados: Brazilian Journal of Microbiology
Autores: Furtado,Danielle N.; Todorov,Svetoslav D.; Landgraf,Mariza; Destro,Maria T.; Franco,Bernadette D.G.M.
Listeria monocytogenes is a pathogen frequently found in dairy products. Its control in fresh cheeses is difficult, due to the psychrotrophic properties and salt tolerance. Bacteriocinogenic lactic acid bacteria (LAB) with proven in vitro antilisterial activity can be an innovative technological approach but their application needs to be evaluated by means of in situ tests. In this study, a novel bacteriocinogenic Lactococcus lactis strain (Lc. lactis DF4Mi), isolated from raw goat milk, was tested for control of growth of L. monocytogenes in artificially contaminated fresh Minas type goat cheese during storage under refrigeration. A bacteriostatic effect was achieved, and counts after 10 days were 3 log lower than in control cheeses with no added LAB....
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteriocin; Lc. lactis subsp. lactis; Biopreservation; Fresh cheese; Goat cheese.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822015000100201

SENSORY ASPECTS AND REDUCTION OF Salmonella IN IRRADIATED EGG POWDER
Provedor de dados: Ciência e Agrotecnologia
Autores: Froehlich,Ângela; Franco,Bernadette Dora Gombossy de Melo; Destro,Maria Teresa; Landgraf,Mariza.
ABSTRACTEggs and their products have been implicated in food-borne disease outbreaks due to contamination with SalmonellaEnteritidis. Irradiation, as a food preservation technology, could minimize such contamination. The aim of this study was to determine the effects of irradiation in powdered egg yolk, egg white, and whole egg samples spiked with Salmonella Enteritidis. The powdered egg samples were exposed to doses of 0.5, 1.0, 1.0, 2.0, 2.5, 3.0, 3.5, or 4.0 kGy irradiation. Odors and tastes of raw and cooked non-inoculated, irradiated samples, and non-irradiated samples, were analyzed by a trained panel. A dose of 2.0 kGy resulted in slight to moderate changes in powdered egg yolk samples, compared to non-irradiated controls, while minimal differences...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteria; Elimination; Powder food.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542015000500506