1. |
- Allende, Ana, et al.
(author)
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Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 2: Aminoglycosides/aminocyclitols: apramycin, paromomycin, neomycin and spectinomycin
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of apramycin, paromomycin, neomycin and spectinomycin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC for these antimicrobials, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for apramycin and neomycin, whilst for paromomycin and spectinomycin, no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these four antimicrobials.
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2. |
- Boqvist, Sofia, et al.
(author)
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Escherichia coli O157:H7 reduction in hamburgers with regard to premature browning of minced beef, colour score and method for determining doneness
- 2015
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In: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 215, s. 109-116
-
Journal article (peer-reviewed)abstract
- This study investigated the effect of premature browning (PMB) on the survival of Escherichia coli O157:H7 in beef hamburgers after cooking with respect to interior colour of the hamburger and recommendations to cook hamburgers to a core temperature of 71 degrees C. Assessment of doneness by visual inspection or measurement of internal temperature was compared in terms of survival and the increased relative risk of illness due to PMB was estimated. At the last consume-by-day, hamburgers made from minced meat packaged in 80/20 O-2/CO2 (MAP hamburger) and from meat minced at retail packaged in atmospheric condition (control hamburger) were inoculated with a gfp-tagged strain of E. coli O157:H7 (E. coli O157:H7gfp+). Hamburgers were cooked for different times during assessment of the core temperature every 30 s and cut in halves after cooking. Doneness was evaluated based on visual judgement of the internal colour using a score chart (C-score) from 'uncooked' (score 1) to 'tan with no evidence of pink' (score 5). An alternative five point score chart (TCC-score) including texture of the meat, clarity of meat juice and internal colour was also developed. Enumeration of viable E. coli O157:H7gfp+ in cooked hamburgers was based on fluorescent colonies recovered from plates. Results showed that MAP hamburgers developed PMB when compared with controls (P = 0.0003) and that the shortest cooking time for the highest C-score was 6 and 11 min for MAP and control hamburgers, respectively. The mean temperature in the MAP hamburger was then 60.3 degrees C. The TCC-score reduced the difference between MAP and control hamburgers. It was also shown that the survival of E. coli O157:H7gfp+ was highest in MAP hamburgers. The predicted absolute risks for illness were highest for MAP hamburgers for all C-scores and the relative risk associated with PMB increased with doneness. For a C-score of 4 (slightly pink) the predicted relative risk for illness was 300 times higher for MAP hamburger than for controls. A variable pathogen reduction was observed when cooking hamburgers to temperatures of 70-76 degrees C (the 5th and 95th percentile range was around 33 log CFU). The lower reductions, at the 5th percentile, may, depending on initial contamination levels, not be enough to ensure sufficient and safe inactivation of E. coli O157:H7. Efforts to inform consumers about PMB in minced meat packaged in high oxygen packages (>= 60% O-2) are needed with the aim to make consumers use thermometers correctly or at least not determine doneness based only on meat colour. (C) 2015 Elsevier B.V. All rights reserved.
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3. |
- Hjelmervik, Trond Ove R., et al.
(author)
-
The influence of the NOD Nss1/Idd5 loci on sialadenitis and gene expression in salivary glands of congenic mice
- 2007
-
In: Arthritis Research and Therapy. - : Springer Science and Business Media LLC. - 1478-6362 .- 1478-6354. ; 9:5
-
Journal article (peer-reviewed)abstract
- The nonobese diabetic ( NOD) Nss1 and Idd5 loci have been associated with sialadenitis development in mice. In this study the NOD Nss1 and Idd5 loci were backcrossed onto the healthy control strain B10. Q by using the speed congenic breeding strategy, resulting in three congenic strains: B10. Q. Nss1, B10. Q. Nss1/Idd5 heterozygous and B10. Q. Nss1/Idd5 homozygous. We investigated the effects of the Nss1 and Idd5 loci on sialadenitis and gene expression in NOD congenic mice. One submandibular salivary gland from each mouse was used for histological analysis of sialadenitis, whereas the contralateral salivary gland was used for gene expression profiling with the Applied Biosystems Mouse Genome Survey chip v. 1.0. The results were validated using quantitative reverse transcriptase PCR. The NOD Nss1 and Idd5 loci had clear influence on the onset and progression of sialadenitis in congenic mice. Double congenic mice exhibited the most severe phenotype. We successfully identified several genes that are located in the NOD congenic regions to be differentially expressed between the congenic strains and the control strain. Several of these were found to be co-regulated, such as Stat1, complement component C1q genes and Tlr12. Also, a vast contingency of interferon-regulated genes ( such as Ltb, Irf7 and Irf8) and cytokine and chemokine genes ( such as Ccr7 and Ccl19) were differentially expressed between the congenic strains and the control strain. Over-representation of inflammatory signalling pathways was observed among the differentially expressed genes. We have found that the introgression of the NOD loci Nss1 and Idd5 on a healthy background caused sialadenitis in NOD congenic mouse strains, and we propose that genes within these loci are important factors in the pathogenesis. Furthermore, gene expression profiling has revealed several differentially expressed genes within and outside the NOD loci that are similar to genes found to be differentially expressed in patients with Sjogren's syndrome, and as such are interesting candidates for investigation to enhance our understanding of disease mechanisms and to develop future therapies.
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4. |
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5. |
- Johansson, Åsa, et al.
(author)
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The genetic control of sialadenitis versus arthritis in a NOD.QxB10.Q F2 cross.
- 2002
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In: European Journal of Immunology. - 1521-4141 .- 0014-2980. ; 32:1, s. 243-250
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Journal article (peer-reviewed)abstract
- The non-obese diabetic (NOD) mouse spontaneously develops diabetes and sialadenitis. The sialadenitis is characterized by histopathological changes in salivary glands and functional deficit similar to Sjögren's syndrome. In humans, Sjögren's syndrome could be associated with other connective tissue disorders, such as rheumatoid arthritis. In the present study the genetic control of sialadenitis in mice was compared to that of arthritis. We have previously reported a NOD locus, identified in an F2 cross with the H2(q) congenic NOD (NOD.Q) and C57BL/10.Q (B10.Q) strains, that promoted susceptibility to collagen-induced arthritis. The sialadenitis in NOD.Q showed a similar histological phenotype as in NOD, whereas no submandibular gland infiltration was found in B10.Q. The development of sialadenitis was independent of immunization with type II collagen and established arthritis. To identify the genetic control of sialadenitis, a gene segregation experiment was performed on an (NOD.QxB10.Q)F2 cross and genetic mapping of 353 F2 mice revealed one significant locus associated with sialadenitis on chromosome 4, LOD score 4.7. The NOD.Q allele-mediated susceptibility under a recessive inheritance pattern. The genetic control of sialadenitis seemed to be unique in comparison to diabetes and arthritis, as no loci associated with these diseases have been identified at the same location.
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6. |
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7. |
- Koutso111umanis, Konstantinos, et al.
(author)
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Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 4: β-Lactams: amoxicillin and penicillin V
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of amoxicillin and penicillin V in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for amoxicillin, whilst for penicillin V no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these two antimicrobials.
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8. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 1: Methodology, general data gaps and uncertainties
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The European Commission requested EFSA to assess, in collaboration with EMA, the specific concentrations of antimicrobials resulting from cross-contamination in non-target feed for food-producing animals below which there would not be an effect on the emergence of, and/or selection for, resistance in microbial agents relevant for human and animal health, as well as the levels of the antimicrobials which could have a growth promotion/increase yield effect. The assessment was performed for 24 antimicrobial active substances, as specified in the mandate. This scientific opinion describes the methodology used, and the main associated data gaps and uncertainties. To estimate the antimicrobial levels in the non-target feed that would not result in emergence of, and/or selection for, resistance, a model was developed. This ‘Feed Antimicrobial Resistance Selection Concentration’ (FARSC) model is based on the minimal selective concentration (MSC), or the predicted MSC (PMSC) if MSC for the most susceptible bacterial species is unavailable, the fraction of antimicrobial dose available for exposure to microorganisms in the large intestine or rumen (considering pharmacokinetic parameters), the daily faecal output or rumen volume and the daily feed intake. Currently, lack of data prevents the establishment of PMSC and/or FARSC for several antimicrobials and animal species. To address growth promotion, data from an extensive literature search were used. Specific assessments of the different substances grouped by antimicrobial classes are addressed in separate scientific opinions. General conclusions and recommendations were made.
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9. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 10: Quinolones: flumequine and oxolinic acid
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of flumequine and oxolinic acid in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data are available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. No suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these antimicrobials.
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10. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 11: Sulfonamides
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of sulfonamides in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data are available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were identified for three sulfonamides: sulfamethazine, sulfathiazole and sulfamerazine. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these antimicrobials.
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11. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 12: Tetracyclines: tetracycline, chlortetracycline, oxytetracycline, and doxycycline
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of tetracycline, chlortetracycline, oxytetracycline and doxycycline in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for these four tetracyclines was estimated. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tetracycline, chlortetracycline, oxytetracycline, whilst for doxycycline no suitable data for the assessment were available. Uncertainties and data gaps associated with the levels reported were addressed. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for these antimicrobials.
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12. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 13: Diaminopyrimidines: trimethoprim
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of trimethoprim in non-target feed for food-producing animals below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for trimethoprim was estimated. Uncertainties and data gaps associated to the levels reported were addressed. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. No suitable data for the assessment were available. It was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC for trimethoprim.
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13. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 3: Amprolium
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of amprolium in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC for amprolium, it was not possible to conclude the assessment. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels of amprolium in feed that showed to have an effect on growth promotion/increased yield were reported. The lack of antibacterial activity at clinically relevant concentrations for amprolium suggests that further studies relating to bacterial resistance are not a priority.
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14. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 5: Lincosamides: lincomycin
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of lincomycin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels of lincomycin in feed that showed to have an effect on growth promotion/increased yield were reported. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for lincomycin.
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15. |
- Koutsoumanis, Konstantinos, et al.
(author)
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Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 6: Macrolides: tilmicosin, tylosin and tylvalosin
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of tilmicosin, tylosin and tylvalosin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tilmicosin and tylosin, whilst for tylvalosin no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these three antimicrobials.
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16. |
- Koutsoumanis, Konstantinos, et al.
(author)
-
Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 7: Amphenicols: florfenicol and thiamphenicol
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of florfenicol and thiamphenicol in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield, were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. The FARSC for florfenicol was estimated. However, due to the lack of data, the calculation of the FARSC for thiamphenicol was not possible until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for florfenicol, whilst for thiamphenicol no suitable data for the assessment were available. Uncertainties and data gaps associated to the levels reported were addressed. For florfenicol, it was recommended to perform further studies to supply more diverse and complete data related to the requirements for calculation of the FARSC, whereas for thiamphenicol, the recommendation was to generate the data required to fill the gaps which prevented the FARSC calculation.
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17. |
- Koutsoumanis, Konstantinos, et al.
(author)
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Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 8: Pleuromutilins: tiamulin and valnemulin
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of tiamulin and valnemulin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels in feed that showed to have an effect on growth promotion/increased yield were reported for tiamulin, while for valnemulin no suitable data for the assessment were available. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these two antimicrobials.
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18. |
- Koutsoumanis, Konstantinos, et al.
(author)
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Maximum levels of cross-contamination for 24 antimicrobial active substances in non-target feed. Part 9: Polymyxins: colistin
- 2021
-
In: EFSA Journal. - : Wiley. - 1831-4732. ; 19:10
-
Journal article (peer-reviewed)abstract
- The specific concentrations of colistin in non-target feed for food-producing animals, below which there would not be an effect on the emergence of, and/or selection for, resistance in bacteria relevant for human and animal health, as well as the specific antimicrobial concentrations in feed which have an effect in terms of growth promotion/increased yield were assessed by EFSA in collaboration with EMA. Details of the methodology used for this assessment, associated data gaps and uncertainties, are presented in a separate document. To address antimicrobial resistance, the Feed Antimicrobial Resistance Selection Concentration (FARSC) model developed specifically for the assessment was applied. However, due to the lack of data on the parameters required to calculate the FARSC, it was not possible to conclude the assessment until further experimental data become available. To address growth promotion, data from scientific publications obtained from an extensive literature review were used. Levels of colistin in feed that showed to have an effect on growth promotion/increased yield were reported. It was recommended to carry out studies to generate the data that are required to fill the gaps which prevented the calculation of the FARSC for these antimicrobials.
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19. |
- Lindqvist, Roland
(author)
-
A BAYESIAN APPROACH TO THE EVALUATION OF RISK-BASED MICROBIOLOGICAL CRITERIA FOR CAMPYLOBACTER IN BROILER MEAT
- 2015
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In: Annals of Applied Statistics. - 1932-6157 .- 1941-7330. ; 9, s. 1415-1432
-
Journal article (peer-reviewed)abstract
- Shifting from traditional hazard-based food safety management toward risk-based management requires statistical methods for evaluating intermediate targets in food production, such as microbiological criteria (MC), in terms of their effects on human risk of illness. A fully risk-based evaluation of MC involves several uncertainties that are related to both the underlying Quantitative Microbiological Risk Assessment (QMRA) model and the production-specific sample data on the prevalence and concentrations of microbes in production batches. We used Bayesian modeling for statistical inference and evidence synthesis of two sample data sets. Thus, parameter uncertainty was represented by a joint posterior distribution, which we then used to predict the risk and to evaluate the criteria for acceptance of production batches. We also applied the Bayesian model to compare alternative criteria, accounting for the statistical uncertainty of parameters, conditional on the data sets. Comparison of the posterior mean relative risk, E(RR vertical bar data) = E(P(illness vertical bar criterion is met)/ P (illness)vertical bar data), and relative posterior risk, RPR = P(illness vertical bar data, criterion is met)/ P (illness vertical bar data), showed very similar results, but computing is more efficient for RPR. Based on the sample data, together with the QMRA model, one could achieve a relative risk of 0.4 by insisting that the default criterion be fulfilled for acceptance of each batch.
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20. |
- Lindqvist, Roland
(author)
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Public health burden due to infections by verocytotoxin-producing Escherichia coli (VTEC) and Campylobacter spp. as estimated by cost of illness and different approaches to model disability-adjusted life years
- 2012
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In: Scandinavian Journal of Public Health. - : SAGE Publications. - 1403-4948 .- 1651-1905. ; 40, s. 294-302
-
Journal article (peer-reviewed)abstract
- Aims: To estimate disability-adjusted life years (DALY) and cost of illness (COI) associated with the gastrointestinal bacterial pathogens Campylobacter and verocytotoxin-producing Escherichia coli (VTEC) in Sweden and to investigate the impact of variability in health outcomes, data availability, and different assumptions about underreporting on DALY. Methods: Data from the Swedish notification system, public databases, and the literature were used to estimate COI and DALY. DALY was modelled using a deterministic and a stochastic approach, the latter describing variation in health outcomes between individuals. Effects of different assumptions about underreporting of gastroenteritis were evaluated in separate scenarios. Results: COI and DALY were greater for Campylobacter than for VTEC. Years of life lost due to haemolytic uraemic syndrome and years lived with gastroenteritis constituted most of DALY for VTEC and Campylobacter, respectively. Productivity losses due to gastroenteritis constituted the main cost associated with both pathogens. Degree of underreporting had a greater impact on DALY for Campylobacter, due to higher estimated incidence of gastroenteritis associated with campylobacteriosis. Conclusions: Pathogen-specific health outcomes and data quality may influence the preferred modelling approach. There was a fair agreement between modelling approaches, but the stochastic model reflected the contribution of some rare health outcomes not captured in the deterministic model. Health outcomes excluded due to lack of data lead to an underestimation of the total burden associated with the pathogens. Increased knowledge, especially on the degree of underreporting and the contribution of the pathogens to sequelae, is needed to further improve public health burden estimates for these pathogens in Sweden.
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21. |
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22. |
- Lindqvist, Roland
(author)
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Risk-based microbiological criteria for Campylobacter in broiler meat: A comparison of two approaches
- 2015
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In: Food Control. - : Elsevier BV. - 0956-7135 .- 1873-7129. ; 53, s. 177-184
-
Journal article (peer-reviewed)abstract
- Risk-based microbiological criteria can offer a tool to control Campylobacter in the broiler meat production chain. Recently two approaches have been applied to derive such criteria and to analyse their potential impact in terms of human health risk reduction: the risk-based version of the established microbiological criteria approach, that applies a microbiological limit (ML) for sample data, and the Danish "case-by- case" risk assessment approach, that applies a limit for the relative risk estimate (relative risk limit, RRL) based on sample data. In this study, data sets from Sweden and Denmark are used to compare the performance of the two approaches in terms of efficiency, i.e. the balance between the residual risk after implementation of the criterion and the percentage of non-complying batches, and the attending uncertainty. The analysis shows that the two approaches are equally efficient, and suggests that the RRL criterion is attended with less uncertainty. The two approaches are compared and their advantages and disadvantages are discussed. Given the uncertainties attending the results of the analysis, more research in terms of data collection, risk assessment and uncertainty analysis would be needed to develop these risk-based criteria further. (C) 2015 Elsevier Ltd. All rights reserved.
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23. |
- Lindqvist, Roland, et al.
(author)
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Specific Growth Rate Determines the Sensitivity of Escherichia coli to Lactic Acid Stress: Implications for Predictive Microbiology
- 2014
-
In: BioMed Research International. - : Hindawi Limited. - 2314-6133 .- 2314-6141. ; , s. 1-8
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Journal article (peer-reviewed)abstract
- This study tested the hypothesis that sensitivity of Escherichia coli to lactic acid at concentrations relevant for fermented sausages ( pH 4.6, 150 mM lactic acid, a(w) = 0.92, temperature = 20 or 27 degrees C) increases with increasing growth rate. For E. coli strain 683 cultured in TSB in chemostat or batch, subsequent inactivation rates when exposed to lactic acid stress increased with increasing growth rate at harvest. A linear relationship between growth rate at harvest and inactivation rate was found to describe both batch and chemostat cultures. The maximum difference in T-90, the estimated times for a one-log reduction, was 10 hours between bacteria harvested during the first 3 hours of batch culture, that is, at different growth rates. A 10-hour difference in T-90 would correspond to measuring inactivation at 33 degrees C or 45 degrees C instead of 37 degrees C based on relationships between temperature and inactivation. At similar harvest growth rates, inactivation rates were lower for bacteria cultured at 37 degrees C than at 15-20 degrees C. As demonstrated for E. coli 683, culture conditions leading to variable growth rates may contribute to variable lactic acid inactivation rates. Findings emphasize the use and reporting of standardised culture conditions and can have implications for the interpretation of data when developing inactivation models.
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24. |
- Lindqvist, Roland
(author)
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Time to growth and inactivation of three STEC outbreak strains under conditions relevant for fermented sausages
- 2011
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In: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 145, s. 49-56
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Journal article (peer-reviewed)abstract
- Published models predicting growth and survival capabilities of shiga-toxin-producing Escherichia coil (STEC) under a(w) and lactic acid stress were validated by performing experiments with fermented sausage associated outbreak strains. Strain variation in inactivation and time to growth (TIC) were investigated for strains representing three serotypes (0103, 0111, and 0157). The TIC and growth boundaries of each strain were compared with predictions of a model for generic acid adapted E. coli and survival with predictions of two inactivation models. In addition, the influence of strain variation on the performance of the inactivation models, in terms of bias and accuracy factors, was illustrated. Strains with induced acid tolerance were used in broths containing 50 or 110 mM total lactic acid. The concentration of undissociated lactic acid (HLac) was adjusted by setting the pH-value, and water activity (0.900 to 0.995 depending on experiment) was adjusted by adding NaCl. The survival capabilities of the outbreak strains were good compared to the model predictions. The average bias factors of inactivation model predictions were within a factor of 2.2 depending on the strain used to validate the model indicating that inactivation rates of outbreak strains were slower than predicted. However, the observed rates were similar to the rates of a previously studied acid tolerant generic E. coil strain. Similarly, the time to growth of two of the strains (0103 and 0157) was comparable with model predictions, whereas the growth capability of the third strain (0111) was lower than predicted. These results suggest that the properties of the most tolerant sausage outbreak strains are comparable to tolerant generic E. coli strains, which imply that suitable non-pathogenic E. coli strains are valid surrogates for fermented sausage outbreak strains. The relative sensitivity of strains depended on the environmental parameters and the response evaluated. The strain with the smallest log reduction at 20 C was 0157, whereas it was strain 0103 at 8 degrees C. Under conditions unfavorable for growth, the time to growth was much shorter for strains 0103 and O157 than for strain O111, whereas differences between strains were negligible under conditions favorable for growth. Depending on the response variable and the specific application the limitation of not addressing strain variation may lead to biased, fail-dangerous, predictions. Thus, solutions on how to best address strain variation in the development and validation of predictive models are needed. (c) 2010 Elsevier B.V. All rights reserved.
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25. |
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26. |
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27. |
- Quinto, Emiliano J., et al.
(author)
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Predicting the concentration of verotoxin-producing Escherichia coli bacteria during processing and storage of fermented raw-meat sausages
- 2014
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In: Applied and Environmental Microbiology. - 0099-2240 .- 1098-5336. ; 80:9, s. 2715-2727
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Journal article (peer-reviewed)abstract
- A model to predict the population density of verotoxigenic Escherichia coli (VTEC) throughout the elaboration and storage of fermented raw-meat sausages (FRMS) was developed. Probabilistic and kinetic measurement data sets collected from publicly available resources were completed with new measurements when required and used to quantify the dependence of VTEC growth and inactivation on the temperature, pH, water activity (aw), and concentration of lactic acid. Predictions were compared with observations in VTEC-contaminated FRMS manufactured in a pilot plant. Slight differences in the reduction of VTEC were predicted according to the fermentation temperature, 24 or 34°C, with greater inactivation at the highest temperature. The greatest reduction was observed during storage at high temperatures. A population decrease greater than 6 decimal logarithmic units was observed after 66 days of storage at 25°C, while a reduction of only ca. 1 logarithmic unit was detected at 12°C. The performance of our model and other modeling approaches was evaluated throughout the processing of dry and semidry FRMS. The greatest inactivation of VTEC was predicted in dry FRMS with long drying periods, while the smallest reduction was predicted in semidry FMRS with short drying periods. The model is implemented in a computing tool, E. coli SafeFerment (EcSF), freely available from http://www.ifr.ac.uk/safety/EcoliSafeFerment. EcSF integrates growth, probability of growth, and thermal and nonthermal inactivation models to predict the VTEC concentration throughout FRMS manufacturing and storage under constant or fluctuating environmental conditions. © 2014, American Society for Microbiology.
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28. |
- Rosengren, Åsa, et al.
(author)
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Occurrence of foodborne pathogens and characterization of Staphylococcus aureus in cheese produced on farm-dairies
- 2010
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In: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 144, s. 263-269
-
Journal article (peer-reviewed)abstract
- The objective of this study was to address knowledge gaps identified in an earlier risk assessment of Staphylococcus aureus and raw milk cheese. A survey of fresh and short-time ripened cheeses produced on farm-dairies in Sweden was conducted to investigate the occurrence and levels of S. aureus, Listeria monocytogenes and Escherichia coil, to characterize S. aureus isolates with special emphasis on enterotoxin genes, antibiotic resistance, bio-typing and genetic variation, and to collect information related to production practices. In general, the hygienic quality of farm-dairy cheeses appeared to be of an acceptable microbiological quality, e.g. L monocytogenes and staphylococcal enterotoxin were not detected in cheese samples. However, E. colt and enterotoxigenic S. aureus were frequently found in raw milk cheeses and sometimes at levels that are of concern, especially in fresh cheese. Interestingly, levels in raw milk fresh cheese were significantly lower when starter cultures were used. Up to five S. aureus colonies per cheese, if possible, were characterized and about 70% of isolates carried one or more enterotoxin genes, most common were sec and sea. The Ovine biotype (73%) was most common among isolates from goat milk cheese and the Human biotype (60%) from cow milk cheese. Of all isolates, 39% showed decreased susceptibility to penicillin, but the proportion of isolates from cows' cheese (66%) compared to isolates from goats' cheese (27%) was significantly higher. S. aureus isolates with different properties were detected in cheese from the same farm and, sometimes even the same cheese. Isolates with the same pulsed-field gel electrophoresis (PFGE)-pattern were detected on geographically distant dairies. This indicates that multiple sources and routes of contamination are important. To improve the safety of these products efforts to raise awareness of the importance of hygiene barriers and raw milk quality as well as improved process control can be suggested, e.g. use of starter cultures and monitoring of fermentation with a pH-meter. For future safety assessments, a better understanding of factors determining toxin production in these cheeses is needed. (C) 2010 Elsevier B.V. All rights reserved.
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29. |
- Rosengren, Åsa, et al.
(author)
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The effect of undissociated lactic acid on Staphylococcus aureus growth and enterotoxin A production
- 2013
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In: International Journal of Food Microbiology. - : Elsevier BV. - 0168-1605 .- 1879-3460. ; 162, s. 159-166
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Journal article (peer-reviewed)abstract
- In summary, ranges of time-to-growth, growth rates, lag times and enterotoxin A production rates of S. aureus in the presence of HLac were estimated. The results can be used together with process data to indicate the range and magnitude of growth and enterotoxin A production during initial stages of cheese production. (C) 2013 Elsevier B.V. All rights reserved.
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30. |
- Sand, Salomon, et al.
(author)
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Dose-Related Severity Sequence, and Risk-Based Integration, of Chemically Induced Health Effects
- 2018
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In: Toxicological Sciences. - : OXFORD UNIV PRESS. - 1096-6080 .- 1096-0929. ; 165:1, s. 74-89
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Journal article (peer-reviewed)abstract
- Risk assessment of chemical hazards is typically based on single critical health effects. This work aims to expand the current approach by characterizing the dose-related sequence of the development of multiple (lower- to higher-order) toxicological health effects caused by a chemical. To this end a "reference point profile" is defined as the relation between benchmark doses for considered health effects, and a standardized severity score determined for these effects. For a given dose of a chemical or mixture the probability for exceeding the reference point profile, thereby provoking lower- to higher-order effects, can be assessed. The overall impact at the same dose can also be derived by integrating contributions across all health effects following severity-weighting. In its generalized form the new impact metric relates to the probability of response for the most severe health effects. Reference points (points of departure) corresponding to defined levels of response can also be estimated. The proposed concept, which is evaluated for dioxin-like chemicals, provides an alternative for characterizing the low-dose region below the reference point for a severe effect like cancer. The shape and variability of the reference point profile add new dimensions to risk assessment, which for example extends the characterization of chemical potency, and the concept of acceptable effect sizes for individual health effects. Based on the present data the method shows high stability at low doses/responses, and is also robust to differences in severity categorization of effects. In conclusion, the novel method proposed enables risk-based integration of multiple dose-related health effects. It provides a first step towards a more comprehensive characterization of chemical toxicity, and suggests a potential for improved low-dose risk assessment.
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31. |
- Schelin, Jenny, et al.
(author)
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The formation of Staphylococcus aureus enterotoxin in food environments and advances in risk assessment.
- 2011
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In: Virulence. - : Informa UK Limited. - 2150-5608 .- 2150-5594. ; 2:6, s. 580-592
-
Research review (peer-reviewed)abstract
- The recent finding that the formation of staphylococcal enterotoxins in food is very different from that in cultures of pure Staphylococcus aureus sheds new light on, and brings into question, traditional microbial risk assessment methods based on planktonic liquid cultures. In fact, most bacteria in food appear to be associated with surfaces or tissues in various ways, and interaction with other bacteria through molecular signaling is prevalent. Nowadays it is well established that there are significant differences in the behavior of bacteria in the planktonic state and immobilized bacteria found in multicellular communities. Thus, in order to improve the production of high-quality, microbiologically safe food for human consumption, in situ data on enterotoxin formation in food environments are required to complement existing knowledge on the growth and survivability of S. aureus. This review focuses on enterotoxigenic S. aureus and describes recent findings related to enterotoxin formation in food environments, and ways in which risk assessment can take into account virulence behavior. An improved understanding of how environmental factors affect the expression of enterotoxins in foods will enable us to formulate new strategies for improved food safety.
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32. |
- Thisted Lambertz, Susanne, et al.
(author)
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A combined culture and PCR method for detection of pathogenic Yersinia enterocolitica in food
- 2000
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In: International Journal of Food Microbiology. - 0168-1605 .- 1879-3460. ; 57:1-2, s. 63-73
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Journal article (peer-reviewed)abstract
- A combined method based on traditional culturing, buoyant density centrifugation, (BDC), and polymerase chain reaction (PCR) techniques for detection and identification of pathogenic Y. enterocolitica in food was developed and evaluated. An internal control, which was added in each PCR-tube and co-amplified by the same primer pair as the pathogen, monitored false-negative PCR results. The sample preparation step, BDC, was used to remove PCR inhibiting food substances and to concentrate the Y. enterocolitica cells. Single PCR with a chromosomal gene (ail) as target was chosen for screening the samples. The method was tested on naturally and artificially contaminated food samples. In three different food samples, processed meat (brawn), unprocessed beef and minced pork, inoculated with 10 cfu pathogenic Y. enterocolitica per gram, Y. enterocolitica was detected and cultural bacteria indicated within 18 h of enrichment.
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33. |
- Thisted Lambertz, Susanne, et al.
(author)
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Subtyping of Listeria monocytogenes isolates recovered from retail ready-to-eat foods, processing plants and listeriosis patients in Sweden 2010
- 2013
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In: International Journal of Food Microbiology. - Amsterdam, Netherlands : Elsevier. - 0168-1605 .- 1879-3460. ; 166, s. 186-192
-
Journal article (peer-reviewed)abstract
- Identification and prioritisation of food safety interventions requires an understanding of the relationship be- tween food, pathogens and cases. Such understanding can be gained through different approaches, e.g. microbial subtyping to attribute cases of foodborne disease to food vehicles or other sources of illness. In this study, Listeria monocytogenes isolates (n = 166) from (i) three categories of ready-to-eat (RTE) foods, (ii) food processing plant environments, and (iii) human listeriosis cases, all sampled during 2010 in Sweden, were subtyped. In addition, 121 isolates from human listeriosis cases, collected 2005–2009, were subtyped. Subtyping consisted of both serotyping (conventional method and PCR) and genotyping using pulsed-field gel electrophoresis (PFGE). Serotype 1/2a dominated in all three groups of isolates (range 73–96%). Eighteen percent of the human isolates (2010) belonged to serotype 4b, but only 1.4% of the food isolates. The food isolates differentiated into 19 pulsotypes (ID = 0.843), the human isolates collected 2010 into 31 pulsotypes (ID = 0.950) and the processing plant isolates into 22 pulsotypes (ID = 0.991). Six of the pulsotypes were shared between the food and human isolates. These pulsotypes comprised 42% of the human isolates and 59% of the food isolates. For some processing plants, there was suggested persistence of one or more specific L. monocytogenes strains, as indicated by repetitive isolation of the same pulsotype from food. This study indicated the presence of L. monocytogenes in the processing plant environment as a likely source of contamination of gravad and cold-smoked fish, and this food category as an important source of human exposure to the pathogen
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