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Arie H Havelaar - One of the best experts on this subject based on the ideXlab platform.
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explanatory variables associated with campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
Journal of Food Protection, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:This study aimed at identifying explanatory variables that were associated with Campylobacter and Escherichia coli concentrations throughout processing in two commercial broiler Slaughterhouses. Quantative data on Campylobacter and E. coli along the processing line were collected. Moreover, information on batch characteristics, Slaughterhouse practices, process performance, and environmental variables was collected through questionnaires, observations, and measurements, resulting in data on 19 potential explanatory variables. Analysis was conducted separately in each Slaughterhouse to identify which variables were related to changes in concentrations of Campylobacter and E. coli during the processing steps: scalding, defeathering, evisceration, and chilling. Associations with explanatory variables were different in the Slaughterhouses studied. In the first Slaughterhouse, there was only one significant association: poorer uniformity of the weight of carcasses within a batch with less decrease in E. coli concentrations after defeathering. In the second Slaughterhouse, significant statistical associations were found with variables, including age, uniformity, average weight of carcasses, Campylobacter concentrations in excreta and ceca, and E. coli concentrations in excreta. Bacterial concentrations in excreta and ceca were found to be the most prominent variables, because they were associated with concentration on carcasses at various processing points. Although the Slaughterhouses produced specific products and had different batch characteristics and processing parameters, the effect of the significant variables was not always the same for each Slaughterhouse. Therefore, each Slaughterhouse needs to determine its particular relevant measures for hygiene control and process management. This identification could be supported by monitoring changes in bacterial concentrations during processing in individual Slaughterhouses. In addition, the possibility that management and food handling practices in Slaughterhouses contribute to the differences in bacterial contamination between Slaughterhouses needs further investigation.
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influence of food handlers compliance with procedures of poultry carcasses contamination a case study concerning evisceration in broiler Slaughterhouses
Food Control, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Arie H Havelaar, L J A Lipman, Sri Aika Sura Barus, Pieternel A LuningAbstract:Campylobacter remains the most commonly reported zoonotic agent worldwide. Reducing the concentration of Campylobacter on chicken meat is seen as the most efficient strategy to diminish the number of human campylobacteriosis cases. Analysis of risk factors related to characteristics of broiler batches and processing conditions could, however, not fully explain differences in impact of processing on contamination levels between Slaughterhouses. Our study aimed at investigating whether compliance of food handlers with procedures on setting and controlling evisceration process parameters could explain differences in microbial concentrations on carcasses between Slaughterhouses. The study was conducted in two commercial broiler chicken Slaughterhouses. Analysis of documentation provided insight in the adequacy of procedures, and observational studies revealed insight in compliance with procedures by using a set of criteria for evisceration control. The frequency of carcasses with visible faecal contamination was counted and Escherichia coli concentrations on carcasses classified based on visible contamination was analysed. E. coli was found to be a valid indicator for Campylobacter during evisceration. Food handlers' knowledge, attitude and practices related to evisceration control tasks were analysed based on a validated questionnaire. Documentation analysis revealed obvious differences in the procedures between Slaughterhouses. The observation study revealed that in the Slaughterhouse with advanced procedures, the food handlers more often complied with these procedures and a lower frequency of carcasses with visible faecal contamination was observed. Carcasses contaminated with visible faecal spots, even at a low level, carried significantly higher concentrations of E. coli than visibly clean carcasses. Food handlers in both Slaughterhouses revealed a good knowledge level. The attitude of food handlers differed between Slaughterhouses. In one Slaughterhouse, where food handlers complied more frequently with procedures their attitude was at a good level, and practices at good and moderate levels. In the other Slaughterhouse the attitude of food handlers was at moderate level and practices at moderate and poor levels. In conclusion, the results from our case study suggest that management factors like availability of adequate monitoring procedures and food handlers' compliance with these procedures may influence the bacterial concentrations on carcasses. Our study demonstrated that compliance with procedures differed between Slaughterhouses, and might be associated with faecal contamination of carcasses and thus with higher bacterial concentrations. These results suggest that managerial improvements, supervising and motivating food handlers could be an important control point. To validate the observed relation between compliance with procedures and contamination of carcasses, an intervention study is needed.
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reduction of extended spectrum β lactamase and ampc β lactamase producing escherichia coli through processing in two broiler chicken Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Betty G M Gortemaker, Arie H Havelaar, Apostolos Liakopoulos, Cindy Dierikx, Heike SchmittAbstract:Whilst broilers are recognised as a reservoir of extended-spectrum-β-lactamase (ESBL)- and AmpC-β-lactamase (AmpC)-producing Escherichia coli, there is currently limited knowledge on the effect of slaughtering on its concentrations on poultry meat. The aim of this study was to establish the concentration of ESBL/AmpC producing E. coli on broiler chicken carcasses through processing. In addition the changes in ESBL/AmpC producing E. coli concentrations were compared with generic E. coli and Campylobacter. In two Slaughterhouses, the surface of the whole carcasses was sampled after 5 processing steps: bleeding, scalding, defeathering, evisceration and chilling. In total, 17 batches were sampled in two different Slaughterhouses during the summers of 2012 and 2013. ESBL/AmpC producing E. coli was enumerated on MacConkey agar with 1mg/l cefotaxime, and the ESBL/AmpC phenotypes and genotypes were characterised. The ESBL/AmpC producing E. coli concentrations varied significantly between the incoming batches in both Slaughterhouses. The concentrations on broiler chicken carcasses were significantly reduced during processing. In Slaughterhouse 1, all subsequent processing steps reduced the concentrations except evisceration which led to a slight increase that was statistically not significant. The changes in concentration between processing steps were relatively similar for all sampled batches in this Slaughterhouse. In contrast, changes varied between batches in Slaughterhouse 2, and the overall reduction through processing was higher in Slaughterhouse 2. Changes in ESBL/AmpC producing E. coli along the processing line were similar to changes in generic E. coli in both Slaughterhouses. The effect of defeathering differed between ESBL/AmpC producing E. coli and Campylobacter. ESBL/AmpC producing E. coli decreased after defeathering, whereas Campylobacter concentrations increased. The genotypes of ESBL/AmpC producing E. coli (blaCTX-M-1, blaSHV-12, blaCMY-2, blaTEM-52c, blaTEM-52cvar) from both Slaughterhouses match typical poultry genotypes. Their distribution differed between batches and changed throughout processing for some batches. The concentration levels found after chilling were between 10(2) and 10(5)CFU/carcass. To conclude, changes in ESBL/AmpC producing E. coli concentrations on broiler chicken carcasses during processing are influenced by batch and Slaughterhouse, pointing to the role of both primary production and process control for reducing ESBL/AmpC producing E. coli levels in final products. Due to similar changes upon processing, E. coli can be used as a process indicator of ESBL/AmpC producing E. coli, because the processing steps had similar impact on both organisms. Cross contamination may potentially explain shifts in genotypes within some batches through the processing.
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a comparison of fluctuations of campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Maarten Schipper, Betty G M Gortemaker, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:The causes of differences in Campylobacter and Escherichia coli concentrations on broiler chicken carcasses after chilling between Slaughterhouses are not fully identified. Therefore, it is a challenge for Slaughterhouses to comply with Process Hygiene Criteria for broiler meat. The aim of the study was to identify which processing steps contribute to increases or decreases in Campylobacter and E. coli concentrations within and between two Slaughterhouses. Identifying the processing steps with variable performance could explain the differences in bacterial concentrations after chilling between Slaughterhouses. Thermotolerant Campylobacter and E. coli concentrations on carcasses during broiler processing were measured during the summer period in 21 trials after bleeding, scalding, defeathering, evisceration and chilling. In two Slaughterhouses with comparable Campylobacter and E. coli concentrations in the incoming batches (after bleeding), the mean log10 concentrations are found to be significantly different after chilling. Campylobacter concentrations decreased by 1.40 log10 in Slaughterhouse 1 and by 1.86 log10 in Slaughterhouse 2, whereas E. coli decreased by 2.19 log10 in Slaughterhouse 1 and by 2.84 log10 in Slaughterhouse 2. Higher concentrations of Campylobacter and E. coli on carcasses after chilling were observed in Slaughterhouse 1 in which an increase in concentrations was observed after evisceration. The effect of processing on Campylobacter and E. coli concentrations in Slaughterhouse 1 did not differ between batches. In Slaughterhouse 2, the effect of processing on the concentrations of both bacteria varied over batches. Changes in E. coli concentration levels during processing were similar to Campylobacter except for defeathering. E. coli concentration significantly decreased after defeathering in both Slaughterhouses, whereas Campylobacter increased in Slaughterhouse 2 and in Slaughterhouse 1 no significant changes were observed. The patterns of increases and decreases in bacterial concentrations during processing are specific for each Slaughterhouse. Inhomogeneous patterns potentially explain the differences in concentrations after chilling between Slaughterhouses. Critical processing steps should be validated in each Slaughterhouse by longitudinal studies and potentially based on E. coli. E. coli has a potential to be used as an indicator of processing hygiene, because the impact of most of the studied processing steps was similar as for Campylobacter.
Ewa Pacholewicz - One of the best experts on this subject based on the ideXlab platform.
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explanatory variables associated with campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
Journal of Food Protection, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:This study aimed at identifying explanatory variables that were associated with Campylobacter and Escherichia coli concentrations throughout processing in two commercial broiler Slaughterhouses. Quantative data on Campylobacter and E. coli along the processing line were collected. Moreover, information on batch characteristics, Slaughterhouse practices, process performance, and environmental variables was collected through questionnaires, observations, and measurements, resulting in data on 19 potential explanatory variables. Analysis was conducted separately in each Slaughterhouse to identify which variables were related to changes in concentrations of Campylobacter and E. coli during the processing steps: scalding, defeathering, evisceration, and chilling. Associations with explanatory variables were different in the Slaughterhouses studied. In the first Slaughterhouse, there was only one significant association: poorer uniformity of the weight of carcasses within a batch with less decrease in E. coli concentrations after defeathering. In the second Slaughterhouse, significant statistical associations were found with variables, including age, uniformity, average weight of carcasses, Campylobacter concentrations in excreta and ceca, and E. coli concentrations in excreta. Bacterial concentrations in excreta and ceca were found to be the most prominent variables, because they were associated with concentration on carcasses at various processing points. Although the Slaughterhouses produced specific products and had different batch characteristics and processing parameters, the effect of the significant variables was not always the same for each Slaughterhouse. Therefore, each Slaughterhouse needs to determine its particular relevant measures for hygiene control and process management. This identification could be supported by monitoring changes in bacterial concentrations during processing in individual Slaughterhouses. In addition, the possibility that management and food handling practices in Slaughterhouses contribute to the differences in bacterial contamination between Slaughterhouses needs further investigation.
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influence of food handlers compliance with procedures of poultry carcasses contamination a case study concerning evisceration in broiler Slaughterhouses
Food Control, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Arie H Havelaar, L J A Lipman, Sri Aika Sura Barus, Pieternel A LuningAbstract:Campylobacter remains the most commonly reported zoonotic agent worldwide. Reducing the concentration of Campylobacter on chicken meat is seen as the most efficient strategy to diminish the number of human campylobacteriosis cases. Analysis of risk factors related to characteristics of broiler batches and processing conditions could, however, not fully explain differences in impact of processing on contamination levels between Slaughterhouses. Our study aimed at investigating whether compliance of food handlers with procedures on setting and controlling evisceration process parameters could explain differences in microbial concentrations on carcasses between Slaughterhouses. The study was conducted in two commercial broiler chicken Slaughterhouses. Analysis of documentation provided insight in the adequacy of procedures, and observational studies revealed insight in compliance with procedures by using a set of criteria for evisceration control. The frequency of carcasses with visible faecal contamination was counted and Escherichia coli concentrations on carcasses classified based on visible contamination was analysed. E. coli was found to be a valid indicator for Campylobacter during evisceration. Food handlers' knowledge, attitude and practices related to evisceration control tasks were analysed based on a validated questionnaire. Documentation analysis revealed obvious differences in the procedures between Slaughterhouses. The observation study revealed that in the Slaughterhouse with advanced procedures, the food handlers more often complied with these procedures and a lower frequency of carcasses with visible faecal contamination was observed. Carcasses contaminated with visible faecal spots, even at a low level, carried significantly higher concentrations of E. coli than visibly clean carcasses. Food handlers in both Slaughterhouses revealed a good knowledge level. The attitude of food handlers differed between Slaughterhouses. In one Slaughterhouse, where food handlers complied more frequently with procedures their attitude was at a good level, and practices at good and moderate levels. In the other Slaughterhouse the attitude of food handlers was at moderate level and practices at moderate and poor levels. In conclusion, the results from our case study suggest that management factors like availability of adequate monitoring procedures and food handlers' compliance with these procedures may influence the bacterial concentrations on carcasses. Our study demonstrated that compliance with procedures differed between Slaughterhouses, and might be associated with faecal contamination of carcasses and thus with higher bacterial concentrations. These results suggest that managerial improvements, supervising and motivating food handlers could be an important control point. To validate the observed relation between compliance with procedures and contamination of carcasses, an intervention study is needed.
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reduction of extended spectrum β lactamase and ampc β lactamase producing escherichia coli through processing in two broiler chicken Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Betty G M Gortemaker, Arie H Havelaar, Apostolos Liakopoulos, Cindy Dierikx, Heike SchmittAbstract:Whilst broilers are recognised as a reservoir of extended-spectrum-β-lactamase (ESBL)- and AmpC-β-lactamase (AmpC)-producing Escherichia coli, there is currently limited knowledge on the effect of slaughtering on its concentrations on poultry meat. The aim of this study was to establish the concentration of ESBL/AmpC producing E. coli on broiler chicken carcasses through processing. In addition the changes in ESBL/AmpC producing E. coli concentrations were compared with generic E. coli and Campylobacter. In two Slaughterhouses, the surface of the whole carcasses was sampled after 5 processing steps: bleeding, scalding, defeathering, evisceration and chilling. In total, 17 batches were sampled in two different Slaughterhouses during the summers of 2012 and 2013. ESBL/AmpC producing E. coli was enumerated on MacConkey agar with 1mg/l cefotaxime, and the ESBL/AmpC phenotypes and genotypes were characterised. The ESBL/AmpC producing E. coli concentrations varied significantly between the incoming batches in both Slaughterhouses. The concentrations on broiler chicken carcasses were significantly reduced during processing. In Slaughterhouse 1, all subsequent processing steps reduced the concentrations except evisceration which led to a slight increase that was statistically not significant. The changes in concentration between processing steps were relatively similar for all sampled batches in this Slaughterhouse. In contrast, changes varied between batches in Slaughterhouse 2, and the overall reduction through processing was higher in Slaughterhouse 2. Changes in ESBL/AmpC producing E. coli along the processing line were similar to changes in generic E. coli in both Slaughterhouses. The effect of defeathering differed between ESBL/AmpC producing E. coli and Campylobacter. ESBL/AmpC producing E. coli decreased after defeathering, whereas Campylobacter concentrations increased. The genotypes of ESBL/AmpC producing E. coli (blaCTX-M-1, blaSHV-12, blaCMY-2, blaTEM-52c, blaTEM-52cvar) from both Slaughterhouses match typical poultry genotypes. Their distribution differed between batches and changed throughout processing for some batches. The concentration levels found after chilling were between 10(2) and 10(5)CFU/carcass. To conclude, changes in ESBL/AmpC producing E. coli concentrations on broiler chicken carcasses during processing are influenced by batch and Slaughterhouse, pointing to the role of both primary production and process control for reducing ESBL/AmpC producing E. coli levels in final products. Due to similar changes upon processing, E. coli can be used as a process indicator of ESBL/AmpC producing E. coli, because the processing steps had similar impact on both organisms. Cross contamination may potentially explain shifts in genotypes within some batches through the processing.
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a comparison of fluctuations of campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Maarten Schipper, Betty G M Gortemaker, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:The causes of differences in Campylobacter and Escherichia coli concentrations on broiler chicken carcasses after chilling between Slaughterhouses are not fully identified. Therefore, it is a challenge for Slaughterhouses to comply with Process Hygiene Criteria for broiler meat. The aim of the study was to identify which processing steps contribute to increases or decreases in Campylobacter and E. coli concentrations within and between two Slaughterhouses. Identifying the processing steps with variable performance could explain the differences in bacterial concentrations after chilling between Slaughterhouses. Thermotolerant Campylobacter and E. coli concentrations on carcasses during broiler processing were measured during the summer period in 21 trials after bleeding, scalding, defeathering, evisceration and chilling. In two Slaughterhouses with comparable Campylobacter and E. coli concentrations in the incoming batches (after bleeding), the mean log10 concentrations are found to be significantly different after chilling. Campylobacter concentrations decreased by 1.40 log10 in Slaughterhouse 1 and by 1.86 log10 in Slaughterhouse 2, whereas E. coli decreased by 2.19 log10 in Slaughterhouse 1 and by 2.84 log10 in Slaughterhouse 2. Higher concentrations of Campylobacter and E. coli on carcasses after chilling were observed in Slaughterhouse 1 in which an increase in concentrations was observed after evisceration. The effect of processing on Campylobacter and E. coli concentrations in Slaughterhouse 1 did not differ between batches. In Slaughterhouse 2, the effect of processing on the concentrations of both bacteria varied over batches. Changes in E. coli concentration levels during processing were similar to Campylobacter except for defeathering. E. coli concentration significantly decreased after defeathering in both Slaughterhouses, whereas Campylobacter increased in Slaughterhouse 2 and in Slaughterhouse 1 no significant changes were observed. The patterns of increases and decreases in bacterial concentrations during processing are specific for each Slaughterhouse. Inhomogeneous patterns potentially explain the differences in concentrations after chilling between Slaughterhouses. Critical processing steps should be validated in each Slaughterhouse by longitudinal studies and potentially based on E. coli. E. coli has a potential to be used as an indicator of processing hygiene, because the impact of most of the studied processing steps was similar as for Campylobacter.
Hannu Korkeala - One of the best experts on this subject based on the ideXlab platform.
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bayesian modelling to identify the risk factors for yersinia enterocolitica contamination of pork carcasses and pluck sets in Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: M J Vilar, Riikka Laukkanenninios, Sonja Virtanen, Hannu KorkealaAbstract:The probability of contamination by pathogenic Yersinia enterocolitica of carcasses and pluck sets at Slaughterhouse was determined by means of a Bayesian analysis. Prior information of the prevalence of Y. enterocolitica in faeces and the seroprevalence of Yersinia in serum of pigs collected at farms were obtained from previous studies and introduced in the models as beta prior informative distributions. Samples of intestinal content, tonsils, and swabs of carcasses and pluck set surfaces were collected at Slaughterhouses. The posterior probabilities, odds ratio (OR) and their probability interval (PI) were calculated by means of a generalized linear model constructed in WinBugs. Occurrence of Y. enterocolitica in intestinal content (OR: 35.6, 95%PI 2.8-8285), tonsils (OR: 38.4, 95%PI 5.0-854), and pluck set (OR: 16.6, 95%PI 1.9-1111) was a risk for the contamination of pork carcasses, and an increased risk of contaminated pluck set was observed when Y. enterocolitica was isolated in intestinal content (OR: 40.6, 95%PI 2.1-10510) and tonsils (OR: 17.6, 95%PI 3.4-230.6). This increased risk indicated a potential cross-contamination at the Slaughterhouse.
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transmission of yersinia pseudotuberculosis in the pork production chain from farm to Slaughterhouse
Applied and Environmental Microbiology, 2008Co-Authors: Riikka Laukkanen, Pilar Ortiz Martinez, Kirsimaarit Siekkinen, Jukka Ranta, Riitta Maijala, Hannu KorkealaAbstract:The transmission of Yersinia pseudotuberculosis in the pork production chain was followed from farm to Slaughterhouse by studying the same 364 pigs from different production systems at farm and Slaughterhouse levels. In all, 1,785 samples were collected, and the isolated Y. pseudotuberculosis strains were analyzed by pulsed-field gel electrophoresis. The results of microbial sampling were combined with data from an on-farm observation and questionnaire study to elucidate the associations between farm factors and the prevalence of Y. pseudotuberculosis. Following the same pigs in the production chain from farm to Slaughterhouse, we were able to show similar Y. pseudotuberculosis genotypes in live animals, pluck sets (containing tongue, tonsils, esophagus, trachea, heart, lungs, diaphragm, liver, and kidneys), and carcasses and to conclude that Y. pseudotuberculosis contamination originates from the farms, is transported to Slaughterhouses with pigs, and transfers to pluck sets and carcasses in the slaughter process. The study also showed that the high prevalence of Y. pseudotuberculosis in live pigs predisposes carcasses and pluck sets to contamination. When production types and capacities were compared, the prevalence of Y. pseudotuberculosis was higher in organic production than in conventional production and on conventional farms with high rather than low production capacity. We were also able to associate specific farm factors with the prevalence of Y. pseudotuberculosis by using a questionnaire and on-farm observations. On farms, contact with pest animals and the outside environment and a rise in the number of pigs on the farm appear to increase the prevalence of Y. pseudotuberculosis.
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prevalence and characterization of pathogenic yersinia enterocolitica in pig tonsils from different Slaughterhouses
Food Microbiology, 2000Co-Authors: Maria Fredrikssonahomaa, Johanna Bjorkroth, Sebastian Hielm, Hannu KorkealaAbstract:The prevalence of yadA-positive Yersinia enterocolitica was determined in 185 pig tonsils from nine Slaughterhouses using both the PCR and culture method. The mean prevalence was 37%, varying from 13% to 45% when both PCR and culture-positive results were included. Of the 52 PCR-positive tonsil samples, 20 were culture-negative, while of the 48 culture-positive, 16 were PCR-negative. Using the culture method, Y. enterocolitica belonging to the bioserotype 4/O:3 was found in 61 tonsils, of which 48 were yadA-positive. Type 4/O:3 was the only pathogenic bioserotype found in this study. Most of the yadA-positive samples (85%) were recovered already after overnight enrichment. A total of 61 isolates, including 13 yadA-negative isolates from different samples, were characterized with PFGE. UsingNotI and XbaI, 20 and 17 PFGE patterns were obtained, respectively. Although the patterns were not identical, most of them played only minor deviations. A total of 26 pulsotypes, defined by combination of the various NotI andXbaI digestion profiles, were observed. Two to eight different pulsotypes were observed in each Slaughterhouse, The most common pulsotypes, 1a and 4g, were found in 36% and 20% of the tonsils, respectively and these pulsotypes were widely distributed to most of the Slaughterhouses. The pulsotype 1a was identified in eight out of nine Slaughterhouses and the pulsotype 4g in seven Slaughterhouses.
Arno Swart - One of the best experts on this subject based on the ideXlab platform.
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explanatory variables associated with campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
Journal of Food Protection, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:This study aimed at identifying explanatory variables that were associated with Campylobacter and Escherichia coli concentrations throughout processing in two commercial broiler Slaughterhouses. Quantative data on Campylobacter and E. coli along the processing line were collected. Moreover, information on batch characteristics, Slaughterhouse practices, process performance, and environmental variables was collected through questionnaires, observations, and measurements, resulting in data on 19 potential explanatory variables. Analysis was conducted separately in each Slaughterhouse to identify which variables were related to changes in concentrations of Campylobacter and E. coli during the processing steps: scalding, defeathering, evisceration, and chilling. Associations with explanatory variables were different in the Slaughterhouses studied. In the first Slaughterhouse, there was only one significant association: poorer uniformity of the weight of carcasses within a batch with less decrease in E. coli concentrations after defeathering. In the second Slaughterhouse, significant statistical associations were found with variables, including age, uniformity, average weight of carcasses, Campylobacter concentrations in excreta and ceca, and E. coli concentrations in excreta. Bacterial concentrations in excreta and ceca were found to be the most prominent variables, because they were associated with concentration on carcasses at various processing points. Although the Slaughterhouses produced specific products and had different batch characteristics and processing parameters, the effect of the significant variables was not always the same for each Slaughterhouse. Therefore, each Slaughterhouse needs to determine its particular relevant measures for hygiene control and process management. This identification could be supported by monitoring changes in bacterial concentrations during processing in individual Slaughterhouses. In addition, the possibility that management and food handling practices in Slaughterhouses contribute to the differences in bacterial contamination between Slaughterhouses needs further investigation.
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influence of food handlers compliance with procedures of poultry carcasses contamination a case study concerning evisceration in broiler Slaughterhouses
Food Control, 2016Co-Authors: Ewa Pacholewicz, Arno Swart, Arie H Havelaar, L J A Lipman, Sri Aika Sura Barus, Pieternel A LuningAbstract:Campylobacter remains the most commonly reported zoonotic agent worldwide. Reducing the concentration of Campylobacter on chicken meat is seen as the most efficient strategy to diminish the number of human campylobacteriosis cases. Analysis of risk factors related to characteristics of broiler batches and processing conditions could, however, not fully explain differences in impact of processing on contamination levels between Slaughterhouses. Our study aimed at investigating whether compliance of food handlers with procedures on setting and controlling evisceration process parameters could explain differences in microbial concentrations on carcasses between Slaughterhouses. The study was conducted in two commercial broiler chicken Slaughterhouses. Analysis of documentation provided insight in the adequacy of procedures, and observational studies revealed insight in compliance with procedures by using a set of criteria for evisceration control. The frequency of carcasses with visible faecal contamination was counted and Escherichia coli concentrations on carcasses classified based on visible contamination was analysed. E. coli was found to be a valid indicator for Campylobacter during evisceration. Food handlers' knowledge, attitude and practices related to evisceration control tasks were analysed based on a validated questionnaire. Documentation analysis revealed obvious differences in the procedures between Slaughterhouses. The observation study revealed that in the Slaughterhouse with advanced procedures, the food handlers more often complied with these procedures and a lower frequency of carcasses with visible faecal contamination was observed. Carcasses contaminated with visible faecal spots, even at a low level, carried significantly higher concentrations of E. coli than visibly clean carcasses. Food handlers in both Slaughterhouses revealed a good knowledge level. The attitude of food handlers differed between Slaughterhouses. In one Slaughterhouse, where food handlers complied more frequently with procedures their attitude was at a good level, and practices at good and moderate levels. In the other Slaughterhouse the attitude of food handlers was at moderate level and practices at moderate and poor levels. In conclusion, the results from our case study suggest that management factors like availability of adequate monitoring procedures and food handlers' compliance with these procedures may influence the bacterial concentrations on carcasses. Our study demonstrated that compliance with procedures differed between Slaughterhouses, and might be associated with faecal contamination of carcasses and thus with higher bacterial concentrations. These results suggest that managerial improvements, supervising and motivating food handlers could be an important control point. To validate the observed relation between compliance with procedures and contamination of carcasses, an intervention study is needed.
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Modeling of Salmonella Contamination in the Pig Slaughterhouse
Risk analysis : an official publication of the Society for Risk Analysis, 2016Co-Authors: Arno Swart, Eric G. Evers, R. L. L. Simons, M. SwanenburgAbstract:In this article we present a model for Salmonella contamination of pig carcasses in the Slaughterhouse. This model forms part of a larger QMRA (quantitative microbial risk assessment) on Salmonella in slaughter and breeder pigs, which uses a generic model framework that can be parameterized for European member states, to describe the entire chain from farm-to-consumption and the resultant human illness. We focus on model construction, giving mathematical formulae to describe Salmonella concentrations on individual pigs and slaughter equipment at different stages of the slaughter process. Variability among individual pigs and over Slaughterhouses is incorporated using statistical distributions, and simulated by Monte Carlo iteration. We present the results over the various slaughter stages and show that such a framework is especially suitable to investigate the effect of various interventions. In this article we present the results of the Slaughterhouse module for two case study member states. The model outcome represents an increase in average prevalence of Salmonella contamination and Salmonella numbers at dehairing and a decrease of Salmonella numbers at scalding. These results show good agreement when compared to several other QMRAs and microbiological studies.
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reduction of extended spectrum β lactamase and ampc β lactamase producing escherichia coli through processing in two broiler chicken Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Betty G M Gortemaker, Arie H Havelaar, Apostolos Liakopoulos, Cindy Dierikx, Heike SchmittAbstract:Whilst broilers are recognised as a reservoir of extended-spectrum-β-lactamase (ESBL)- and AmpC-β-lactamase (AmpC)-producing Escherichia coli, there is currently limited knowledge on the effect of slaughtering on its concentrations on poultry meat. The aim of this study was to establish the concentration of ESBL/AmpC producing E. coli on broiler chicken carcasses through processing. In addition the changes in ESBL/AmpC producing E. coli concentrations were compared with generic E. coli and Campylobacter. In two Slaughterhouses, the surface of the whole carcasses was sampled after 5 processing steps: bleeding, scalding, defeathering, evisceration and chilling. In total, 17 batches were sampled in two different Slaughterhouses during the summers of 2012 and 2013. ESBL/AmpC producing E. coli was enumerated on MacConkey agar with 1mg/l cefotaxime, and the ESBL/AmpC phenotypes and genotypes were characterised. The ESBL/AmpC producing E. coli concentrations varied significantly between the incoming batches in both Slaughterhouses. The concentrations on broiler chicken carcasses were significantly reduced during processing. In Slaughterhouse 1, all subsequent processing steps reduced the concentrations except evisceration which led to a slight increase that was statistically not significant. The changes in concentration between processing steps were relatively similar for all sampled batches in this Slaughterhouse. In contrast, changes varied between batches in Slaughterhouse 2, and the overall reduction through processing was higher in Slaughterhouse 2. Changes in ESBL/AmpC producing E. coli along the processing line were similar to changes in generic E. coli in both Slaughterhouses. The effect of defeathering differed between ESBL/AmpC producing E. coli and Campylobacter. ESBL/AmpC producing E. coli decreased after defeathering, whereas Campylobacter concentrations increased. The genotypes of ESBL/AmpC producing E. coli (blaCTX-M-1, blaSHV-12, blaCMY-2, blaTEM-52c, blaTEM-52cvar) from both Slaughterhouses match typical poultry genotypes. Their distribution differed between batches and changed throughout processing for some batches. The concentration levels found after chilling were between 10(2) and 10(5)CFU/carcass. To conclude, changes in ESBL/AmpC producing E. coli concentrations on broiler chicken carcasses during processing are influenced by batch and Slaughterhouse, pointing to the role of both primary production and process control for reducing ESBL/AmpC producing E. coli levels in final products. Due to similar changes upon processing, E. coli can be used as a process indicator of ESBL/AmpC producing E. coli, because the processing steps had similar impact on both organisms. Cross contamination may potentially explain shifts in genotypes within some batches through the processing.
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a comparison of fluctuations of campylobacter and escherichia coli concentrations on broiler chicken carcasses during processing in two Slaughterhouses
International Journal of Food Microbiology, 2015Co-Authors: Ewa Pacholewicz, Arno Swart, Maarten Schipper, Betty G M Gortemaker, Jaap A Wagenaar, Arie H Havelaar, L J A LipmanAbstract:The causes of differences in Campylobacter and Escherichia coli concentrations on broiler chicken carcasses after chilling between Slaughterhouses are not fully identified. Therefore, it is a challenge for Slaughterhouses to comply with Process Hygiene Criteria for broiler meat. The aim of the study was to identify which processing steps contribute to increases or decreases in Campylobacter and E. coli concentrations within and between two Slaughterhouses. Identifying the processing steps with variable performance could explain the differences in bacterial concentrations after chilling between Slaughterhouses. Thermotolerant Campylobacter and E. coli concentrations on carcasses during broiler processing were measured during the summer period in 21 trials after bleeding, scalding, defeathering, evisceration and chilling. In two Slaughterhouses with comparable Campylobacter and E. coli concentrations in the incoming batches (after bleeding), the mean log10 concentrations are found to be significantly different after chilling. Campylobacter concentrations decreased by 1.40 log10 in Slaughterhouse 1 and by 1.86 log10 in Slaughterhouse 2, whereas E. coli decreased by 2.19 log10 in Slaughterhouse 1 and by 2.84 log10 in Slaughterhouse 2. Higher concentrations of Campylobacter and E. coli on carcasses after chilling were observed in Slaughterhouse 1 in which an increase in concentrations was observed after evisceration. The effect of processing on Campylobacter and E. coli concentrations in Slaughterhouse 1 did not differ between batches. In Slaughterhouse 2, the effect of processing on the concentrations of both bacteria varied over batches. Changes in E. coli concentration levels during processing were similar to Campylobacter except for defeathering. E. coli concentration significantly decreased after defeathering in both Slaughterhouses, whereas Campylobacter increased in Slaughterhouse 2 and in Slaughterhouse 1 no significant changes were observed. The patterns of increases and decreases in bacterial concentrations during processing are specific for each Slaughterhouse. Inhomogeneous patterns potentially explain the differences in concentrations after chilling between Slaughterhouses. Critical processing steps should be validated in each Slaughterhouse by longitudinal studies and potentially based on E. coli. E. coli has a potential to be used as an indicator of processing hygiene, because the impact of most of the studied processing steps was similar as for Campylobacter.
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phenotypic and molecular typing of salmonella strains reveals different contamination sources in two commercial pig Slaughterhouses
Applied and Environmental Microbiology, 2004Co-Authors: Nadine Botteldoorn, Lieve Herman, Nancy Rijpens, Marc HeyndrickxAbstract:This study aimed to define the origin of Salmonella contamination on swine carcasses and the distribution of Salmonella serotypes in two commercial Slaughterhouses during normal activity. Salmonellae were isolated from carcasses, from colons and mesenteric lymph nodes of individual pigs, and from the Slaughterhouse environment. All strains were serotyped; Salmonella enterica serotype Typhimurium and Salmonella enterica serotype Derby isolates were additionally typed beyond the serotype level by pulsed-field gel electrophoresis (PFGE) and antibiotic resistance profiling (ARP); and a subset of 31 serotype Typhimurium strains were additionally phage typed. PFGE and ARP had the same discriminative possibility. Phage typing in combination with PFGE could give extra information for some strains. In one Slaughterhouse, 21% of the carcasses were contaminated, reflecting a correlation with the delivery of infected pigs. Carcass contamination did not result only from infection of the corresponding pig; only 25% of the positive carcasses were contaminated with the same serotype or genotype found in the corresponding feces or mesenteric lymph nodes. In the other Slaughterhouse, 70% of the carcasses were contaminated, and only in 4% was the same genotype or serotype detected as in the feces of the corresponding pigs. The other positive carcasses in both Slaughterhouses were contaminated by genotypes present in the feces or lymph nodes of pigs slaughtered earlier that day or from dispersed sources in the environment. In Slaughterhouses, complex contamination cycles may be present, resulting in the isolation of many different genotypes circulating in the environment due to the supply of positive animals and in the contamination of carcasses, probably through aerosols.
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Salmonella on pig carcasses: positive pigs and cross contamination in the Slaughterhouse
Journal of applied microbiology, 2003Co-Authors: Nadine Botteldoorn, Marc Heyndrickx, Koen Grijspeerdt, Nancy Rijpens, Lieve HermanAbstract:N . B O T T E L D O O R N , M . H E Y N D R I C K X , N . R I J P E N S , K . G R I J S P E E R D T A N D L . H E R M A N . 2003. Aims: The purpose of this study was to investigate the prevalence of Salmonella in pigs at the moment of slaughter and in the Slaughterhouse environment. Methods and Results: In total, five different commercial Slaughterhouses were sampled during eight Slaughterhouse visits. Carcass swabs, colon content and mesenteric lymph nodes were taken to reflect the animal status and from the Slaughterhouse environmental samples were taken. Salmonella was isolated from 37% of the carcass samples as a mean value. High variations were noticed between different Slaughterhouses (between 0 and 70%) and sampling days in the same abattoir (between 3 and 52%). A correlation was found between the carcass contamination and the status of the delivered animals (P ¼ 0AE01675). Cross contamination was estimated to account for 29% of the positive carcasses. The Slaughterhouse environment was highly contaminated; before starting the slaughtering activities 25% of the samples were positive on average. The most prevalent serotypes isolated at the Slaughterhouse environment and from the colon content were S. Typhimurium, S. Livingstone and S. Derby. On carcasses S. Typhimurium was predominately isolated (71%). The biggest variability of serotypes was found in the mesenteric lymph nodes. Serologically 56AE3% of the pigs were found positive for Salmonella using a cut-off level of the optical density percentage higher than 10 (O.D.% ‡ 10). While on individual pig level the correlation between the bacteriological and serological data was poor, because of recent Salmonella infections, a better correlation was found at the herd level on the moment of slaughtering. Conclusion: A high degree of carcass contamination is noticed after slaughtering. This contamination resulted from the delivery of Salmonella-positive pigs and cross-contamination from the Slaughterhouse environment. Significance and Impact of the Study: In pigs, Salmonella carriage is high, but it is obvious that Slaughterhouse hygiene is a determinative factor for managing carcass contamination.
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Routes for salmonella contamination of poultry meat: Epidemiological study from hatchery to Slaughterhouse
Epidemiology and Infection, 2002Co-Authors: Marc Heyndrickx, D. Vandekerchove, I. Rollier, Lieve Herman, Koen Grijspeerdt, Lieven De ZutterAbstract:SUMMARY Data were collected on the prevalence of salmonella at different stages during the life cycle of 18 broiler flocks on different farms as well as during slaughter in different poultry Slaughterhouses. For the isolation of salmonella, the highest sensitivity (93n9 %) was obtained by enrichment in the semi-solid agar Diasalm. The ' overshoe method ' utilizing several pairs of overshoes provided the highest sensitivity for determining the salmonella status of the broilers during rearing. A clear decrease of the relative importance of the first production stages was demonstrated for the salmonella contamination of the end product, whereas horizontal transmission of salmonella to broilers during rearing and to broiler carcasses in the Slaughterhouse was shown to be the main determinative factor. Ten of the 18 flocks received a salmonella positive status with the highest shedding occurring during the first 2 weeks of rearing. The shedding of the animals was significantly negatively influenced by the use of subtherapeutic or therapeutic doses of antibiotics. The intake of portable material in the broiler house was identified as the most important risk factor for horizontal transmission. Significant associations were found between the contamination level of a flock and hygiene of the broiler house, feed and water in the broiler house and both animal and non-animal material sampled in the environment. No correlation was found between contamination during the rearing period and contamination found after slaughtering. The presence of faecal material in the transport crates and predominantly the identity of the Slaughterhouse seemed to be the determining factors for carcass quality. Improved hygiene management during transport of broilers and in some Slaughterhouses could significantly reduce the risk of salmonella contamination of poultry meat.
