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Ingrid H M Friesema - One of the best experts on this subject based on the ideXlab platform.
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the economic burden of a Salmonella thompson outbreak caused by smoked salmon in the netherlands 2012 2013
European Journal of Public Health, 2016Co-Authors: Anita W M Suijkerbuijk, W Van Pelt, Martijn Bouwknegt, Mariejosee J Mangen, Paul Bijkerk, Ingrid H M FriesemaAbstract:Background: In 2012, the Netherlands experienced the most extensive food-related outbreak of Salmonella ever recorded. It was caused by smoked salmon contaminated with Salmonella thompson during processing. In total, 1149 cases of salmonellosis were laboratory confirmed and reported to RIVM. Twenty percent of cases was hospitalised and four cases were reported to be fatal. The purpose of this study was to estimate total costs of the Salmonella thompson outbreak. Methods: Data from a case–control study were used to estimate the cost-of-illness of reported cases (i.e. healthcare costs, patient costs and production losses). Outbreak control costs were estimated based on interviews with staff from health authorities. Using the Dutch foodborne disease burden and cost-of-illness model, we estimated the number of underestimated cases and the associated cost-of-illness. Results: The estimated number of cases, including reported and underestimated cases was 21 123. Adjusted for underestimation, the total cost-of-illness would be €6.8 million (95% CI €2.5–€16.7 million) with productivity losses being the main cost driver. Adding outbreak control costs, the total outbreak costs are estimated at €7.5 million. Conclusion: In the Netherlands, measures are taken to reduce Salmonella concentrations in food, but detection of contamination during food processing remains difficult. As shown, Salmonella outbreaks have the potential for a relatively high disease and economic burden for society. Early warning and close cooperation between the industry, health authorities and laboratories is essential for rapid detection, control of outbreaks, and to reduce disease and economic burden.
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large outbreak of Salmonella thompson related to smoked salmon in the netherlands august to december 2012
Eurosurveillance, 2014Co-Authors: Ingrid H M Friesema, Agnetha Hofhuis, M Heck, H Van Den Kerkhof, RICHARD DE JONGE, D Hameryck, K Nagel, G Van Vilsteren, A. De Jong, Pascal BeekAbstract:On 15 August 2012, an increase in the number of Salmonella thompson cases was noticed by the Salmonella surveillance in the Netherlands. A case-control study was performed, followed by a food investigation. In total 1,149 cases were laboratory-confirmed between August and December 2012 of which four elderly (76-91 years) were reported to have died due to the infection. The cause of the outbreak was smoked salmon processed at a single site. The smoked salmon had been continuously contaminated in the processing lines through reusable dishes, which turned out to be porous and had become loaded with bacteria. This is the largest outbreak of salmonellosis ever recorded in the Netherlands. The temporary closure of the processing site and recall of the smoked salmon stopped the outbreak. An estimated four to six million Dutch residents were possibly exposed to the contaminated smoked salmon and an estimated 23,000 persons would have had acute gastroenteritis with S. thompson during this outbreak. This outbreak showed that close collaboration between diagnostic laboratories, regional public health services, the national institute for public health and the food safety authorities is essential in outbreak investigations. .
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outbreak of Salmonella thompson in the netherlands since july 2012
Eurosurveillance, 2012Co-Authors: Ingrid H M Friesema, M Heck, A E De Jong, I Fitz A James, J Van Den Kerkhof, D W Notermans, W Van Pelt, Agnetha HofhuisAbstract:An ongoing outbreak of salmonellosis due to Salmonella thompson is affecting the Netherlands. Between 2 August and 19 October 2012, 866 cases were confirmed. Their median age was 44 years (range: 0-95 years), 63% were female and 36% were hospitalised. A matched case-control study suggested smoked salmon as the vehicle. Salmonella thompson was confirmed in four of nine batches of smoked salmon from one producer. A recall of all concerned smoked salmon products was executed starting end of September. .
Mieke Uyttendaele - One of the best experts on this subject based on the ideXlab platform.
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GeneDisc multiplex-PCR and IMS-chromogenic media for detection of VTEC and Salmonella in lettuce, strawberries and basil
2020Co-Authors: Stefanie Delbeke, Kevin Holvoet, Eric Samuels, Mieke UyttendaeleAbstract:Introduction: VTEC have been increasingly recognized as food borne pathogen, also in fresh produce. Detection methods are primarily focused on E. coli O157:H7, but there is an increasing attention for non-O157 VTEC (1). Adequate detection methods are lacking for non-O157 VTEC, in particular for fresh produce with high levels of competing flora (2). Multiplex PCR methods are recommended for detection of VTEC virulence factors and have potential to detect multiple enteric pathogens or emerging virulence factors (e.g. aggR) in one run. Materials and methods: The aim of the present study is to validate an appropriate approach for high throughput multiscreening for VTEC and Salmonella in fresh produce focusing on the case studies of strawberries, lettuce and basil. Sample replicates were inoculated (1000, 100, 10 cfu/25 g) and analysed after 1 and 5 days storage at 7°C using in parallel GeneDisc Multiplex PCR (stx2, stx1, eae, aggR and Salmonella) and IMS-chromogenic media (CT-SMAC (O157), MAC (O26) and Brilliance Salmonella (Salmonella spp.)). Results and Discussion: Both methods enabled detection of the E. coli O157 and O26 and Salmonella thompson strain at all inoculums if analysed after 24h although, in particular for basil, GeneDisc needed ½ dilution of DNA extract to overcome inhibition and competitive flora troubled reading of chromogenic media. After 5 days cold storage, pathogens were recovered for basil (stored at 10°C) whereas lower inoculums levels were more difficult to detect for strawberries (13/18 for VTEC and 10/18 for Salmonella) and lettuce (16/18 for VTEC and 18/18 for Salmonella). GeneDisc Multiplex PCR was shown to be a suitable screening method for simultaneous sensitive detection of VTEC and Salmonella in fresh produce although overcoming PCR inhibition by DNA dilution was needed in particular after 5 days storage and for the leafy vegetables. IMS combined with chromogenic media was shown to be a cumbersome method in particular for VTEC to differentiate from competing flora in leafy vegetables. When using CHROMagar STEC as chromogenic media (without IMS) better and clearer results were obtained.
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GeneDisc multiplex-PCR and IMS-chromogenic media for detection of VTEC and Salmonella in lettuce, strawberries and basil
2020Co-Authors: Stefanie Delbeke, Kevin Holvoet, Eric Samuels, Mieke UyttendaeleAbstract:Introduction: VTEC have been increasingly recognized as food borne pathogens in fresh produce. Detection methods are primarily focused on E. coli O157:H7, but there is an increasing attention for non-O157 VTEC. Adequate detection methods are lacking for non-O157 VTEC, in particular for fresh produce with high levels of competing flora. Multiplex PCR methods are recommended for detection of VTEC virulence factors and have potential to detect multiple enteric pathogens or emerging virulence factors (e.g. aggR) in one run. Purpose: The aim of the present study is to validate an appropriate approach for high throughput multiscreening for VTEC and Salmonella in fresh produce focusing on the case studies of strawberries, lettuce and basil. Methods: Sample replicates were inoculated (1000, 100, 10 cfu/25 g) and analysed after 1 and 5 days storage at 7°C using in parallel GeneDisc Multiplex PCR (stx2, stx1, eae, aggR and Salmonella) and IMS-chromogenic media. Results: Both methods enabled detection of the E. coli O157 and O26 and Salmonella thompson strain at all inoculums if analysed after 24h. For basil, GeneDisc needed ½ dilution of DNA extract to overcome inhibition and competitive flora troubled reading of chromogenic media. After 5 days cold storage, pathogens were recovered for basil (stored at 10°C) whereas lower inoculums levels were more difficult to detect for strawberries (13/18 for VTEC and 10/18 for Salmonella) and lettuce (16/18 for VTEC and 18/18 for Salmonella). Significance: GeneDisc Multiplex PCR was shown to be a suitable screening method for simultaneous sensitive detection of VTEC and Salmonella in fresh produce although overcoming PCR inhibition by DNA dilution was needed in particular after 5 days storage and for the leafy vegetables. IMS combined with chromogenic media was shown to be a cumbersome method in particular for VTEC to differentiate from competing flora in leafy vegetables.
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Survival of Salmonella and E. coli O157 on strawberries and basil during storage at different temperatures
2020Co-Authors: Stefanie Delbeke, Claudia Titze Hessel, Elien Verguldt, Astrid De Beleyer, Tine Clicque, Jolien Boussemaere, Liesbeth Jacxsens, Mieke UyttendaeleAbstract:Limited information about the survival of Salmonella and E. coli O157 on strawberries and basil is available. As strawberries and basil are often consumed raw, they can pose a potential risk of foodborne illness for consumers. Therefore, the survival of both pathogens was assessed during one week storage at cold and ambient temperatures. Strawberries (100 ± 5 g in a perforated box) and basil leaves (25 g in a closed tray), were inoculated with a mix of 2 strains of E. coli O157 or Salmonella (thompson and Typhimurium) to obtain an initial inoculum of 104 – 105 cfu/g. Strawberries’ samples were stored at 4°C, 10°C, 15°C, and 22°C and basil leaves at 7°C, 15°C and 22°C for 7 days (or less if visual spoilage occurred before or the pathogens dropped below the detection limit i.e. 50 cfu/g). For each temperature/time condition 2 independent storage experiments were performed (study A and B) (with triplicate sampling at defined time points). Samples were analysed by plating on Chromocult agar (+ 50 µg/ml nalidixic acid; E. coli O157) and XLD (Salmonella). In addition, the visual quality was assessed during storage. No growth of E. coli O157 or Salmonella was observed in case of strawberries stored at 4°C, 10°C, 15°C and 22°C. E. coli O157 and Salmonella survived during 7 days at 4°C but with a decrease of 2,5 to 3,8 log units being observed and a final recovery rate from 2 and 5 out of 6 samples respectively. At 10°C, no E. coli O157 was detected anymore after 6 days (0/6), in contrast to Salmonella which could be detected after 7 days in 5/6 samples with a similar decrease as for 4°C (2,5 to 3,9 log units). The numbers of pathogens dropped below the detection limit after 4 and 5 days at 15°C for E. coli O157 and Salmonella in study A respectively, while in study B a reduction of 3,0 to 4,0 log units was observed after 6 days, which was the end of shelf life due to the growth of molds. Storage of strawberries at 22°C resulted in growth of molds from day 2 (A) or 3 (B) whereby a reduction of pathogens was noticed of 1 to 2 log units after 2 days. In contrast, reduction of pathogens below the detection limit was not yet reached after 7 days storage of basil at different temperatures and only at 22°C some samples needed to be discarded due to the growth of molds and quality defects. Storage of basil leaves for 7 days at 7°C resulted in a decline of maximum 1,8 log cfu/g for both pathogens. Similar results were obtained at 15°C for Salmonella, whereas no decline was observed in case of E. coli O157. Also at 22°C restricted increase/decrease (≤ 1 log cfu/g) was observed for both pathogens after 7 days. Thus, avoiding contamination in particular at cultivation (and (post-)harvest) is important as both pathogens survive during storage, washing has only a limited effect and both strawberries and basil are consumed after minimal processing, excluding an inactivation treatment.
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multiplex real time pcr and culture methods for detection of shiga toxin producing escherichia coli and Salmonella thompson in strawberries a lettuce mix and basil
International Journal of Food Microbiology, 2015Co-Authors: Stefanie Delbeke, Siele Ceuppens, Kevin Holvoet, Eric Samuels, Imca Sampers, Mieke UyttendaeleAbstract:Abstract An appropriate approach of high throughput multi-screening was verified for Shiga toxin-producing Escherichia coli (STEC) and Salmonella spp. in strawberries, lettuce and basil. Sample replicates were inoculated with STEC O157 or O26 and Salmonella thompson (ca. 10–70, 100–700 and 1000–7000 cfu/25 g) and analysed after 1 and 5 days of storage (strawberries and lettuce at 7 °C and basil at 10 °C). After 18–24 h of enrichment at 37 °C in buffered peptone water, detection was performed using the GeneDisc multiplex PCR (stx1, stx2, eae and iroB genes) and selective culture media for isolation of STEC (with immunomagnetic separation (IMS)) and Salmonella spp. in parallel. After 1 day, the pathogenic strains were recovered from all samples for all inoculum levels, whereas reduced detection rates of STEC O157 and S. thompson were observed after 5 days of storage in case of strawberries, in particular for the lowest inoculums level, suggesting superior survival potential for STEC O26. Overall, this study indicates the ability of PCR based screening methods for reproducible multi-detection of low numbers (10–70 cfu/25 g) of STEC and Salmonella in this type of foods. However, for the basil samples, PCR needed twofold dilution of the DNA extract to overcome inhibition. It was noted that on several occasions growth of competitive microbiota obstructed finding presumptive colonies on the selective agar media, whereas the use of an additional agar medium such as CHROMagar STEC (without IMS) improved recovery rate of STEC.
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Enteric pathogen survival varies substantially in irrigation water from Belgian lettuce producers.
International Journal of Environmental Research and Public Health, 2014Co-Authors: Inge Van Der Linden, Mieke Uyttendaele, Bart Cottyn, Nick Berkvens, Geertrui Vlaemynck, Marc Heyndrickx, Martine MaesAbstract:It is accepted that irrigation water is a potential carrier of enteric pathogens, such as Salmonella and E. coli O157:H7 and, therefore, a source for contamination of fresh produce. We tested this by comparing irrigation water samples taken from five different greenhouses in Belgium. The water samples were inoculated with four zoonotic strains, two Salmonella and two E. coli O157:H7 strains, and pathogen survival and growth in the water were monitored up till 14 days. The influence of water temperature and chemical water quality was evaluated, and the survival tests were also performed in water samples from which the resident aquatic microbiota had previously been eliminated by filter sterilization. The pathogen’s survival differed greatly in the different irrigation waters. Three water samples contained nutrients to support important growth of the pathogens, and another enabled weaker growth. However, for all, growth was only observed in the samples that did not contain the resident aquatic microbiota. In the original waters with their specific water biota, pathogen levels declined. The same survival tendencies existed in water of 4 °C and 20 °C, although always more expressed at 20 °C. Low water temperatures resulted in longer pathogen survival. Remarkably, the survival capacity of two E. coli 0157:H7 strains differed, while Salmonella thompson and Salmonella Typhimurium behaved similarly. The pathogens were also transferred to detached lettuce leaves, while suspended in two of the water samples or in a buffer. The effect of the water sample on the pathogen’s fitness was also reproduced on the leaves when stored at 100% relative humidity. Inoculation of the suspension in buffer or in one of the water samples enabled epiphytic growth and survival, while the pathogen level in the other water sample decreased once loaded on the leaves. Our results show that irrigation waters from different origin may have a different capacity to transmit enteric pathogens and an important impact on the fitness of the pathogens to sustain and even grow on the leaf surface.
Agnetha Hofhuis - One of the best experts on this subject based on the ideXlab platform.
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large outbreak of Salmonella thompson related to smoked salmon in the netherlands august to december 2012
Eurosurveillance, 2014Co-Authors: Ingrid H M Friesema, Agnetha Hofhuis, M Heck, H Van Den Kerkhof, RICHARD DE JONGE, D Hameryck, K Nagel, G Van Vilsteren, A. De Jong, Pascal BeekAbstract:On 15 August 2012, an increase in the number of Salmonella thompson cases was noticed by the Salmonella surveillance in the Netherlands. A case-control study was performed, followed by a food investigation. In total 1,149 cases were laboratory-confirmed between August and December 2012 of which four elderly (76-91 years) were reported to have died due to the infection. The cause of the outbreak was smoked salmon processed at a single site. The smoked salmon had been continuously contaminated in the processing lines through reusable dishes, which turned out to be porous and had become loaded with bacteria. This is the largest outbreak of salmonellosis ever recorded in the Netherlands. The temporary closure of the processing site and recall of the smoked salmon stopped the outbreak. An estimated four to six million Dutch residents were possibly exposed to the contaminated smoked salmon and an estimated 23,000 persons would have had acute gastroenteritis with S. thompson during this outbreak. This outbreak showed that close collaboration between diagnostic laboratories, regional public health services, the national institute for public health and the food safety authorities is essential in outbreak investigations. .
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outbreak of Salmonella thompson in the netherlands since july 2012
Eurosurveillance, 2012Co-Authors: Ingrid H M Friesema, M Heck, A E De Jong, I Fitz A James, J Van Den Kerkhof, D W Notermans, W Van Pelt, Agnetha HofhuisAbstract:An ongoing outbreak of salmonellosis due to Salmonella thompson is affecting the Netherlands. Between 2 August and 19 October 2012, 866 cases were confirmed. Their median age was 44 years (range: 0-95 years), 63% were female and 36% were hospitalised. A matched case-control study suggested smoked salmon as the vehicle. Salmonella thompson was confirmed in four of nine batches of smoked salmon from one producer. A recall of all concerned smoked salmon products was executed starting end of September. .
Pascal Beek - One of the best experts on this subject based on the ideXlab platform.
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large outbreak of Salmonella thompson related to smoked salmon in the netherlands august to december 2012
Eurosurveillance, 2014Co-Authors: Ingrid H M Friesema, Agnetha Hofhuis, M Heck, H Van Den Kerkhof, RICHARD DE JONGE, D Hameryck, K Nagel, G Van Vilsteren, A. De Jong, Pascal BeekAbstract:On 15 August 2012, an increase in the number of Salmonella thompson cases was noticed by the Salmonella surveillance in the Netherlands. A case-control study was performed, followed by a food investigation. In total 1,149 cases were laboratory-confirmed between August and December 2012 of which four elderly (76-91 years) were reported to have died due to the infection. The cause of the outbreak was smoked salmon processed at a single site. The smoked salmon had been continuously contaminated in the processing lines through reusable dishes, which turned out to be porous and had become loaded with bacteria. This is the largest outbreak of salmonellosis ever recorded in the Netherlands. The temporary closure of the processing site and recall of the smoked salmon stopped the outbreak. An estimated four to six million Dutch residents were possibly exposed to the contaminated smoked salmon and an estimated 23,000 persons would have had acute gastroenteritis with S. thompson during this outbreak. This outbreak showed that close collaboration between diagnostic laboratories, regional public health services, the national institute for public health and the food safety authorities is essential in outbreak investigations. .
M Heck - One of the best experts on this subject based on the ideXlab platform.
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large outbreak of Salmonella thompson related to smoked salmon in the netherlands august to december 2012
Eurosurveillance, 2014Co-Authors: Ingrid H M Friesema, Agnetha Hofhuis, M Heck, H Van Den Kerkhof, RICHARD DE JONGE, D Hameryck, K Nagel, G Van Vilsteren, A. De Jong, Pascal BeekAbstract:On 15 August 2012, an increase in the number of Salmonella thompson cases was noticed by the Salmonella surveillance in the Netherlands. A case-control study was performed, followed by a food investigation. In total 1,149 cases were laboratory-confirmed between August and December 2012 of which four elderly (76-91 years) were reported to have died due to the infection. The cause of the outbreak was smoked salmon processed at a single site. The smoked salmon had been continuously contaminated in the processing lines through reusable dishes, which turned out to be porous and had become loaded with bacteria. This is the largest outbreak of salmonellosis ever recorded in the Netherlands. The temporary closure of the processing site and recall of the smoked salmon stopped the outbreak. An estimated four to six million Dutch residents were possibly exposed to the contaminated smoked salmon and an estimated 23,000 persons would have had acute gastroenteritis with S. thompson during this outbreak. This outbreak showed that close collaboration between diagnostic laboratories, regional public health services, the national institute for public health and the food safety authorities is essential in outbreak investigations. .
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outbreak of Salmonella thompson in the netherlands since july 2012
Eurosurveillance, 2012Co-Authors: Ingrid H M Friesema, M Heck, A E De Jong, I Fitz A James, J Van Den Kerkhof, D W Notermans, W Van Pelt, Agnetha HofhuisAbstract:An ongoing outbreak of salmonellosis due to Salmonella thompson is affecting the Netherlands. Between 2 August and 19 October 2012, 866 cases were confirmed. Their median age was 44 years (range: 0-95 years), 63% were female and 36% were hospitalised. A matched case-control study suggested smoked salmon as the vehicle. Salmonella thompson was confirmed in four of nine batches of smoked salmon from one producer. A recall of all concerned smoked salmon products was executed starting end of September. .
