| 1. |
- Darlison, Julia, et al.
(författare)
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Plant species affects establishment of Escherichia coli O157:H7 gfp+ on leafy vegetables
- 2019
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Ingår i: Journal of Applied Microbiology. - : Oxford University Press (OUP). - 1364-5072 .- 1365-2672. ; 127, s. 292-305
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Tidskriftsartikel (refereegranskat)abstract
- Aims Greenhouse trials were conducted with different cultivars of baby leaf spinach, rocket and Swiss chard and inoculation of Escherichia coli O157:H7 gfp+, to determine whether plant species and cultivar have an impact on the establishment of this strain. Methods and Results Three cultivars each of spinach, rocket and Swiss chard were spray inoculated with E. coli O157:H7 gfp+ at doses of log 7 CFU per ml. Due to the different lengths of growing period spinach and Swiss chard were spray inoculated three times and rocket five times, with final inoculation performed 3 days prior to harvest. After a growing period of 26-33 days, E. coli O157:H7 gfp+ was recovered from the leaf surface in mean populations between log 1 and 6 CFU per gram. The lowest occurrence of E. coli O157:H7 gfp+ was found on rocket leaves and the highest on spinach. There was no significant difference in the establishment of E. coli O157:H7 gfp+ between cultivars, but there were differences between plant species. Indigenous phyllosphere bacteria were pure cultured and identified with 16S rRNA gene sequencing. Conclusions Despite the same high inoculation dose of E. coli O157:H7 gfp+ on leaves, the establishment rate differed between plant species. However, plant cultivar did not affect establishment. Pantoea agglomerans dominated the identified bacterial isolates. Significance and Impact of the Study As previous studies are inconclusive on choice of model plant species and cultivar, we studied whether plant species or cultivar determines the fate of E. coli O157:H7 gfp+ on leafy vegetables. The findings indicate that plant species is a key determinant in the establishment of E. coli O157:H7 gfp+.
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| 2. |
- Vågsholm, Ivar
(författare)
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Scientific Opinion on the risk posed by Shiga toxin-producing Escherichia coli (STEC) and other pathogenic bacteria in seeds and sprouted seeds
- 2011
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Sprouted seeds are young seedlings obtained from the germination of seeds. They are ready-to-eat foods which have caused large outbreaks. The bacterial pathogens most frequently associated with illness due to contaminated sprouted seeds are Salmonella and to a lesser extent STEC. Bacillus cereus, Listeria monocytogenes, Staphylococcus aureus and Yersinia enterocolitica have also been transmitted by sprouted seeds, albeit very rarely. Dry seed contaminated with bacterial pathogens has been identified as the most likely initial source of sprout-associated outbreaks; although other routes of contamination (e.g. during production due to poor practices) may also occur. In some outbreaks, contamination of seeds with as low as 4 Salmonella per kg was sufficient for the sprouts to cause disease. Seeds purchased by sprouts producers are usually not grown specifically for this purpose. They may be contaminated during production, harvest, storage and transport, and there may be difficulties in traceability of seeds from production to sprouting. Bacterial pathogens on seeds may survive for long periods during seed storage. There is so far no guarantee of a bactericidal step which is able to control contamination of seeds with bacterial foodborne pathogens acquired prior to germination. Due to the high humidity and the favourable temperature during sprouting, bacterial pathogens present on dry seeds can multiply on the sprouts. Contamination with pathogenic bacteria must be minimized by identification of seed crops intended for sprouted seeds production before planting, and application of GAP, GHP, GMP, HACCP principles at all steps of the production chain. The relevance of decontamination treatments of seeds and of microbiological criteria is also discussed
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| 3. |
- Vågsholm, Ivar
(författare)
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Statement on technical assistance related to the EFSA opinion on transformation of Animal By-Products into biogas and compost
- 2009
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 7
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Tidskriftsartikel (refereegranskat)abstract
- EFSA’s Scientific Panel on Biological Hazards (BIOHAZ) was asked by the European Commission to clarify i) whether additional testing for Clostridium perfringens of the end product obtained from biogas and compost transformation of Animal By-Products (ABPs) would respond to the concerns expressed in the EFSA 2005 opinion on "the safety vis-à-vis biological risks of biogas and compost treatment standards of animal by-products" and, should this was not be the case, ii) to indicate if additional testing, according to the model of method 7 of the ABP Regulation, for another pathogen than Clostridium perfringens would respond to the recommendations laid down in the abovementioned opinion. Considering that digestion residues and compost are intended to be applied on land, that land naturally contains bacterial spores and that Clostridium perfringens is ubiquitous, the BIOHAZ Panel concluded that the absence of Clostridium perfringens is not necessary. The BIOHAZ Panel also concluded that end product testing does not respond to the recommendations given in the previous EFSA opinion, which concerns the validation of the efficacy of a process
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| 4. |
- Alsanius, Beatrix, et al.
(författare)
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Green wheel : om målkonflikten rörande tunga batteridrivna vägtransporter och mikrobiella faror samt hållbarhet av bladgrönsaker
- 2022
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Rapport (populärvet., debatt m.m.)abstract
- Låg självförsörjningsgrad, centralisering av marknaden, samt mycket varierande klimatförhållanden i Sverige som hindrar lokalproduktion av vegetabilier, detta är tre viktiga anledningar varför det svenska livsmedelssystemet är beroende av transporter. För att nå målet för ett "hållbart livsmedelssystem" måste transporter övergå till andra än fossila energikällor. Transporter av varor som är beroende av en kylkedja kräver inte bara energi för själva transporten, utan också för att hålla temperaturen på en nivå som inte äventyrar livsmedelssäkerhet och produktens hållbarhet. Maximitemperatur under transport av temperaturkänsliga matvaror har varit ett återkommande ämne i många brancher. I föreliggande rapport ställde vi oss frågan vilken betydelse temperaturskillnaden mellan 4 och 8 C under transport av bladgrönsaker har för tre mycket generaliserade körscenarion (200, 400 och 900 km) ur ett kvalitets- och livsmedelsäkerhetsperspektiv, med den psykrofila patogenen Listeria monocytogenes som modell. Studien utgår från två laddningskapaciteter för batterier (150 resp. 350 kW). Vi visar att laddningsinfrastrukturen är den mest avgörande faktorn som påverkar produkthållbarhet och livsmedelssäkerhet. Risk för nedsatt kvalitet och i synnerhet livsmedelsäkerhet ökar avsevärd med långa körtider vid en temperatur av 8 C i lastutrymmet.
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| 5. |
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| 6. |
- Hartmann, Rahel, et al.
(författare)
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Impact of the source of organic manure on persistence of E. coli O157:H7 gfp+ in rocket (Diplotaxis tenuifolia) and Swiss chard (Beta vulgaris cicla)
- 2017
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Ingår i: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 81, s. 200-210
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Tidskriftsartikel (refereegranskat)abstract
- The influence of organic nitrogen sources on the establishment of E. coil 0157:H7 and the occurrence of other potentially human pathogenic bacteria on baby leaf salads was evaluated. Greenhouse-grown rocket and Swiss chard were spray-inoculated with gfp-tagged E. coil 0157:H7 twice a week from when their first true leaves reached a length of 2 cm until three days before harvest. Analysis of nitrogen content in leaves revealed differences between treatments. Untreated plants had the lowest values, followed by plants fertilized with pig hair pellets and chicken manure. The same pattern was seen for the growth medium at the day of harvest. The applied strain showed similar establishment (measured using culture-dependent methods) irrespective of treatment, but Swiss chard hosted significantly more E. coli 0157:H7 than rocket. Differences in the risk of infection were found for the crops, with plants fertilized with pig hair pellets showing a slightly higher risk. No relationship was found for total nitrogen content in leaves and colonization with E. coli 0157:H7 gfp+. Isolating dominant Enterobacteriaceae from leaves, some strains showed conformity to bacterial species that have previously been identified to influence the establishment of E. coli 0157:H7 in the phyllosphere. In this study, no inhibitory effects were observed in vitro.Colonies showing matching characteristics for Listeria spp. and Salmonella spp. were detected up to 5.5 and 5 log CFU g(-1) fresh weight, respectively. However, presumptive Listeria spp. and Salmonella spp. could not be confirmed by sequencing of the 16S rRNA gene. (C) 2017 Elsevier Ltd. All rights reserved.
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| 7. |
- Söderqvist, Karin, et al.
(författare)
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Fate of Listeria monocytogenes, Pathogenic Yersinia enterocolitica, and Escherichia coli O157:H7 gfpþ in Ready-to-Eat Salad during Cold Storage: What Is the Risk to Consumers?
- 2017
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Ingår i: Journal of Food Protection. - 0362-028X. ; 80, s. 204-212
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we investigated the fate of Listeria monocytogenes, pathogenic Yersinia enterocolitica, and Escherichia coli O157:H7 gfp(+) inoculated in low numbers into ready-to-eat baby spinach and mixed-ingredient salad (baby spinach with chicken meat). Samples were stored at recommended maximum refrigerator temperature (8 degrees C in Sweden) or at an abuse temperature (15 degrees C) for up to 7 days. Mixed-ingredient salad supported considerable growth when stored at 15 degrees C during shelf life (3 days), with populations of L. monocytogenes, pathogenic Y. enterocolitica, and E. coli O157:H7 gfp(+) increasing from less than 2.0 log CFU/g on day 0 to 7.0, 4.0, and 5.6 log CFU/g, respectively. However, when mixed-ingredient salad was stored at 8 degrees C during shelf life, only L. monocytogenes increased significantly, reaching 3.0 log CFU/g within 3 days. In plain baby spinach, only pathogenic Y. enterocolitica populations increased significantly during storage for 7 days, and this was exclusively at an abuse temperature (15 degrees C). Thus, mixing ready-to-eat leafy vegetables with chicken meat strongly influenced levels of inoculated strains during storage. To explore the food safety implications of these findings, bacterial numbers were translated into risks of infection by modeling. The risk of listeriosis (measured as probability of infection) was 16 times higher when consuming a mixed ingredient salad stored at 8 degrees C at the end of shelf life, or 200,000 times higher when stored at 15 degrees C, compared with when consuming it on the day of inoculation. This indicates that efforts should focus on preventing temperature abuse during storage to mitigate the risk of listeriosis. The storage conditions recommended for mixed-ingredient salads in Sweden (maximum 8 degrees C for 3 days) did not prevent growth of L. monocytogenes in baby spinach mixed with chicken meat. Manufacturers preparing these salads should be aware of this, and recommended storage temperature should be revised downwards to reduce the risk of foodborne disease.
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| 8. |
- Vågsholm, Ivar
(författare)
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Scientific Opinion on an update on the present knowledge on the occurrence and control of foodborne viruses
- 2011
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- A review of the biology, epidemiology, diagnosis and public health importance of foodborne viruses was performed. Data needs to support a risk assessment were also identified. In addition possible control options and their anticipated impact to prevent or reduce the number of foodborne viral human infections were identified, including the scientific reasons for and against the establishment of food safety criteria and process hygiene criteria for viruses for certain food categories. Food may be contaminated by virus during all stages of the food supply chain, and transmission can occur by consumption of food contaminated during the production process (primary production, or during further processing), or contaminated by infected food handlers. Transmission of zoonotic viruses (e.g. HEV) can also occur by consumption of products of animal origin. Viruses do not multiply in foods, but may persist for extended periods of time as infectious particles in the environment, or in foods. At the EU-level it is unknown how much viral disease can be attributed to foodborne spread. The relative contribution of different sources (shellfish, fresh produce, food handler including asymptomatic shedders, food handling environment) to foodborne illness has not been determined. The Panel recommends focusing controls on preventive measures to avoid viral contamination rather than trying to remove/inactivate these viruses from food. Also, it is recommended to introduce a microbiological criteria for viruses in bivalve molluscs, unless they are labelled “to be cooked before consumption”. The criteria could be used by food business operators to validate their control options. Furthermore, it is recommended to refine the regulatory standards and monitoring approaches in order to improve public health protection. Introduction of virus microbiological criteria for classification of bivalve molluscs production areas should be considered. A virus monitoring programme for compliance with these criteria should be risk based according to the findings of a sanitary survey
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| 9. |
- Vågsholm, Ivar
(författare)
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Scientific Opinion on assessment of epidemiological data in relation to the health risks resulting from the presence of parasites in wild caught fish from fishing grounds in the Baltic Sea
- 2011
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- For fishery products caught from fishing grounds in the Baltic Sea, four groups of viable parasites present possible health risks, Anisakis simplex (sensu stricto), Contracaecum osculatum (sensu stricto), Pseudoterranova decipiens (sensu stricto) and Diphyllobothrium spp. Since A. simplex and Pseudoterranova decipiens have been found in fishery products in International Council for the Exploration of the Sea (ICES) subdivisions 22, 23, 24, 25, 26, public health risks due to the presence of these parasites cannot be excluded in any fishery products caught from these areas. Migrating fish from areas where A. simplex, and to a lesser degree P. decipiens, occur may carry these parasites and reach the northern Baltic, therefore, public health risks due to parasites in all migrating fish (including salmon) in Baltic Sea cannot be excluded. C. osculatum occurs in fish throughout all areas of the Baltic Sea. However, at present it is not possible to assess the public health importance of viable C. osculatum larvae in fishery products. Diphyllobothrium spp. occurs in fish species in brackish waters of Baltic Sea. Hence all freshwater fish as well as migrating fish, including sea trout and whitefish, are of public health importance if consumed raw, since they may carry viable parasites. More research is needed to elucidate the importance of C. osculatum from fish as a source of human infection, including pathogenicity of this parasite and the anatomic distribution of the parasite in edible parts of the fish. In order to definitively identify species of anisakids, genetic/molecular methods should be more widely applied to material from all hosts of the Baltic Sea. Surveillance of anisakiasis and other parasitic infections in the human population in Baltic Sea countries should be improved
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| 10. |
- Vågsholm, Ivar
(författare)
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Scientific Opinion on the evaluation of a new processing method for ABP Category 2 materials of fish origin
- 2011
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Ingår i: EFSA Journal. - : Wiley. - 1831-4732. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- A new method for the treatment and disposal of Category 2 animal by-products (ABP’s) of fish origin according to Regulation (EC) 1774/2002 was assessed for the inactivation of the relevant biological hazards. It is proposed that the method will be used for the treatment of Category 2 fish material obtained from aquaculture plants. The proposed process technology consists of grinding fish raw material followed by acidification and heat treatment. The main steps of the proposed process are the mixing with formic acid, the storage for at least 24 hours at pH < 4, the heat treatment of the fish silage at a temperature ≥85°C for at least 25 minutes. It was concluded that, based on the results of the laboratory experiments, the risk related to pathogens present in fish ABPs from aquaculture would be adequately reduced by the proposed process, if the requirements of the HACCP plan are achieved. However, since there was no validation of the process in an existing plant, it is not possible to conclude on the feasibility of the given HACCP plan. It was further recommended that the full scale equipment should be designed in a way to permit validation by exposure to representative test organisms
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