Factors affecting cell population density during enrichment and subsequent molecular detection of Salmonella enterica and Escherichia coli O157:H7 on lettuce contaminated during field production

López-Velasco, Gabriela; Tomás‐Callejas, Alejandro; Sbodio, Adrian; Pham, Xuan Ngoc; Wei, Polly; Diribsa, D.; Suslow, Trevor

doi:10.1016/j.foodcont.2015.01.041

Cited by 20 publications

(14 citation statements)

References 60 publications

(86 reference statements)

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“…Among these pathogens, Salmonella spp, Listeria monocytogenes and Escherichia coli O157:H7 are the most important. E. coli O157:H7 has been associated with outbreaks involving lettuce, spinach, culinary herbs and other fresh products [3]. According to Shekarforoush and co-workers [4] E. coli is *Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of microencapsulation of the UFV-AREG1 bacteriophage in alginate-Ca microcapsules using microfluidic devices

Boggione

Batalha

Gontijo

et al. 2017

Colloids and Surfaces B: Biointerfaces

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A B S TR A C TThe indiscriminate use of antibiotics and the emergence of resistant microorganisms have become a major challenge for the food industry. The purpose of this work was to microencapsulate the bacteriophage UFV-AREG1 in a calcium alginate matrix using microfluidic devices and to study the viability and efficiency of retention. The microcapsules were added to gel of propylene glycol for use as an antimicrobial in the food industry. The technique showed the number of the phage encapsulation, yielding drops with an average 100-250 µm of diameter, 82.1 ± 2% retention efficiency and stability in the gel matrix for 21 days. The gel added to the microencapsulated phage showed efficiency (not detectable on the surface) in reducing bacterial contamination on the surface at a similar level to antimicrobial chemicals (alcohol 70%). Therefore, it was possible to microencapsulate bacteriophages in alginate-Ca and apply the microcapsules in gels for use as sanitizers in the food industry.

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Section: Introductionmentioning

confidence: 99%

Evaluation of microencapsulation of the UFV-AREG1 bacteriophage in alginate-Ca microcapsules using microfluidic devices

Boggione

Batalha

Gontijo

et al. 2017

Colloids and Surfaces B: Biointerfaces

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“…Nevertheless, even when outbreaks have been traced back to a farm, documenting the actual source of contamination has been rare given the time lag between the time at which the crop was harvested and the time at which the outbreaks are detected and epidemiologically investigated. Consequently, to estimate the risk associated with several of these potential contamination sources, research has examined them under controlled conditions in either growth chamber or field systems in an effort to understand the level and fate of that contamination on leafy greens of which lettuce or spinach crops have been the primary focus . In addition to those investigations, growth chamber studies have also assisted in assessing the role of a number of other variables that could affect the ability of pathogens to survive or be internalized into lettuce or spinach tissues.…”

Section: Introductionmentioning

confidence: 99%

“…Consequently, to estimate the risk associated with several of these potential contamination sources, research has examined them under controlled conditions in either growth chamber or field systems in an effort to understand the level and fate of that contamination on leafy greens of which lettuce or spinach crops have been the primary focus. [5][6][7][8][9][10] In addition to those investigations, growth chamber studies have also assisted in assessing the role of a number of other variables that could affect the ability of pathogens to survive or be internalized into lettuce or spinach tissues. For example, a number of reports would suggest that solar radiation/ultraviolet (UV) light 11 and desiccation 12 would be the primary agents responsible for the rapid rate of decline seen when plants are initially exposed to high pathogen populations.…”

Section: Introductionmentioning

confidence: 99%

Survival and internalization of Salmonella and Escherichia coli O157:H7 sprayed onto different cabbage cultivars during cultivation in growth chambers

et al. 2019

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BACKGROUND Cabbage may become contaminated with enteric pathogens during cultivation. Using multiple cabbage cultivars at two maturity stages (small plants or plants with small heads) in growth chamber studies, the fate (internalization or surface survival) of Salmonella and Escherichia coli O157:H7 (0157) were examined in conjunction with any potential relationships to the plant's antimicrobial content. RESULTS Internalized Salmonella was detected in cabbage within 24 h with prevalence ranging from 62% (16 of 26) for the ‘Super Red 80’ cultivar to 92% (24 of 26) for the ‘Red Dynasty’ cultivar. Surface survival of pathogens on small cabbage plants over nine days was significantly affected by cultivar with both pathogens surviving the most on the ‘Farao’ cultivar and Salmonella and O157 surviving the least on the ‘Super Red 80’ and ‘Capture’ cultivars, respectively (P < 0.05). Survival of O157 was slightly higher on cabbage heads for O157 than small plants suggesting that the maturity stage may affect this pathogen's fate. An inverse relationship existed between antimicrobial levels and the pathogen's surface survival on cabbage heads (P < 0.05). CONCLUSIONS The fate of pathogens varied with the cabbage cultivar in growth chamber studies highlighting the potential to explore cultivar in field studies to reduce the risk of microbiological contamination in this crop. © 2019 Society of Chemical Industry

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“…Essas técnicas tradicionais de microbiologia envolvem etapas de cultura onerosas e bastante trabalhosas, necessitando de até sete dias para a confirmação dos resultados, pois são necessárias as etapas de pré-enriquecimento, enriquecimento seletivo, plaqueamento seletivo diferencial e confirmação bioquímica e sorológica. Essas etapas servem para aumentar a recuperação das células nos alimentos que possuem microbiota competitiva, células em número reduzido ou injuriadas (Havelaar et al 2010, Lopez-Velasco et al 2015. Além disso, a identificação por perfis fenotípicos utilizada nessas metodologias é propensa a erros devido à possibilidade de variabilidade desses perfis, levando a reações falso-negativas, ou ainda ser de difícil ou errônea interpretação (Marin et al 2006, Settanni & Corsetti 2007, Carrique-Mas & Davies 2008, Spanu et al 2011.…”

Section: Introductionunclassified

Identificação por espectrometria de massa MALDI-TOF de Salmonella spp. e Escherichia coli isolados de carcaças bovinas

et al. 2017

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RESUMO.-O objetivo deste trabalho foi introduzir a téc-nica de espectrometria de massa com fonte de ionização e dessorção a laser assistida por matriz e analisador de tempo-de-voo (MALDI-TOF) para incrementar o método tradicional microbiológico na detecção de Salmonella spp. The aim of this study was to introduce matrix-assisted laser desorption/ionization (MAL-DI) time-of-flight (TOF) mass spectrometry to improve the traditional microbiological method for the detection of Salmonella spp. and Escherichia coli in beef carcasses. Two hundred seventy samples from 90 beef carcasses were evaluated. The methodologies described in ISO 6579:2002 and in the Compendium of Methods for the Microbiological Examination of Foods were used for Salmonella spp. and E. coli isolation, respectively. MALDI-TOF analysis were performed on tryptone soya broth suspension isolates or directly from nutrient agar colonies, from the positive, inconclusive or negative biochemically tested samples for Salmonella and E. coli. Mass profiles were acquired on an Autoflex III SmartBeam MALDI-TOF mass spectrometer and the raw spectra were processed using the MALDI Biotyper software (Bruker Daltonics). According to the preliminary identification based on colony morphology and the biochemical reactions, seven isolates were positive for Salmonella spp. Through MALDI Biotyper these seven isolates were also classified as belonging to the genus Salmonella and further identified as S. enterica. Four isolates showing unusual phenotypic characteristics and inconclusive results in biochemical tests for Salmonella were identified as belonging to Citrobacter and Proteus genera after MALDI analysis. Regarding Escherichia coli, 37 were positive for species biochemical testing which MALDI Biotyper confirmed. MALDI-TOF methodology allowed rapid Salmonella spp. and E. coli identity confirmation and may be used to detect these microrganisms within bacterial isolates from beef carcasses.

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Factors affecting cell population density during enrichment and subsequent molecular detection of Salmonella enterica and Escherichia coli O157:H7 on lettuce contaminated during field production

Cited by 20 publications

References 60 publications

Evaluation of microencapsulation of the UFV-AREG1 bacteriophage in alginate-Ca microcapsules using microfluidic devices

Evaluation of microencapsulation of the UFV-AREG1 bacteriophage in alginate-Ca microcapsules using microfluidic devices

Survival and internalization of Salmonella and Escherichia coli O157:H7 sprayed onto different cabbage cultivars during cultivation in growth chambers

Identificação por espectrometria de massa MALDI-TOF de Salmonella spp. e Escherichia coli isolados de carcaças bovinas

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