Progress 11/01/15 to 10/20/20
Outputs
Target Audience:The target audiences reached during the reporting period include the international representatives of the food industry, researchers and students from multiple disciplines (e.g., food science, food safety, microbiology, plant pathology, agricultural engineering, epidemiology, veterinary medicine, statistics, and public health) as well as representatives of government bodies and regulatory agencies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The following training and professional development opportunities have been provided: Texas A&M AgriLife Extension and Research Center: Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trial testing UV and SA water treatments in growing of spinach. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. Texas Tech University: Dr. Nightingale mentored April Englishbey (PhD student) and Joshua Jenkins and Douglas Thomas (undergraduate students) in processing of field samples and their microbiological testing. Cornell University: Dr. Ivanek mentored Dr. Wendy Beauvais, Alexandra Belias (PhD student) and Michelle Wemette (graduate, DVM student) in statistical analyses of controlled trials. Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The results of the study were disseminated at an international conference that gathered members of the food industry, academia and government bodies (including, USDA, FDA, CDC, FAO, and WHO). Specifically, Dr. Ivanek presented study findings at the Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition - Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA. Also, preliminary study findings were disseminated via a trade journal for growers in the South Texas. Finally, results have been described in a PhD dissertation. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized as a major route of produce contamination at the pre-harvest level. This project evaluated effectiveness of existing and new control strategies, the ultraviolet radiation treatment and sulfuric acid-based fertilizer treatment, to reduce microbial hazards in fresh produce attributed to irrigation water, as affected by irrigation method, weather conditions and produce commodity (spinach and cantaloupe). Researchers from Texas A&M Agrilife conducted several controlled intervention trials in open produce fields and collected nearly 3,500 samplesof water, produce and soil swabs. Researchers from Texas Tech University conducted microbiological testing of the samples. Finally, researchers from Cornell University conducted statistical analyses of all collected data and conducted additional supporting laboratory experiments. Our results show that both the ultraviolet radiation and sulphuric acid-based fertilizer are effective treatments for reducing levels of E. coli in surface irrigation water. In some irrigation cycles, treatment appeared to have a measurable effect on the levels of contamination on fresh produce. However, our results also indicate that it is possible for an increase in E. coli to occur in produce fields post irrigation, which appears to be associated with temperature and precipitation. These results are of value for both produce growers and regulating bodies as implementation of the irrigation water portion of the Produce Safety Rule in the Food Safety Modernization Act is imminent.The results have been reported in a manuscript (Beauvais et al., submitted) and in a PhD dissertation (Englishbey, 2019). Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. We conducted four controlled intervention trials to test water treatment strategies to reduce microbial hazards in fresh produce attributed to irrigation water. Two trials were in cantaloupes in the summers of 2016 and 2017 and two in spinach during the winter seasons 2016-2017 and 2017-2018. In each trial we compared three water treatments: an ultraviolet radiation treatment, a novel sulfuric acid-based fertilizer (9-0-0-12, monourea) treatment, a no treatment control. Surface water naturally contaminated with Salmonella and spiked with Rifampicin resistant (RifR) Escherichia coli was used for irrigation in both furrow and drip irrigation systems. In total, we collected, processed and analysed almost 3,500 samples over 4 trials, however, trial 1 was eventually excluded from the final statistical analysis because of improvements in sample collection and processing methods applied after that trial. Thus, the number of samples included in the final statistical analysis was 2,768 in total; including water from irrigation tanks (502), irrigation water from the field (503), cantaloupe (234), spinach (1,079) and soil swab (360) samples. Overall, the analysis of data revealed that both the ultraviolet radiation and sulphuric acid-based fertilizer treatments significantly reduced RifR E. coli levels in irrigation water (both at the tank and the field levels). Eighty-five percent cent of ultraviolet radiation-treated tank water samples and 76% of sulphuric acid-based fertilizer-treated tank water samples had a RifR E. coli count below the detection limit of 1 Log10 CFU/mL, whereas samples before treatment had a mean count of 3.3 Log10 CFU/mL. The odds of produce contamination differed by the produce commodity and were affected to a lesser degree by the irrigation method and water treatment. Salmonella was detected in spinach (0.3%), tank water (1.8%) and field water (2.8%) samples. Sulphuric acid-based fertilizer appeared to be less effective at eliminating Salmonella from irrigation water than the ultraviolet radiation treatment. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The data from the controlled intervention trials described in Objective 1 were used to determine the trend in odds of contamination over the days post irrigation and the rate of RifR E. coli die-off on harvested produce (cantaloupes and spinach) post last irrigation before harvest. For this purpose, we collected produce and soil swab samples just before and up to 15 times after the last irrigation. Weather data were recorded daily over the whole period. Statistical analyses revealed that there was an overall decrease in the odds of contamination over the days post-irrigation when the first cut of spinach was harvested. However, there was an increase in the odds of contamination over the days post-irrigation in the cantaloupe trial and in the spinach trail when the second cut (regrowth) of spinach was harvested. In the spinach trials, higher minimum temperature five days prior to sampling was associated with a decrease in the odds of detecting RifR E. coli in spinach (second cut) and higher minimum temperature one day prior to sampling was associated with a decrease in the odds of detecting RifR E. coli in soil. In the cantaloupe trial, a higher precipitation four days prior to sampling was associated with a decrease in the odds of detection of RifR E. coli in the soil. (3) Develop Good Agricultural Practices for management of irrigation. A non-parametric approach, classification and regression tree analysis, was used to evaluate the final parametric statistical models developed to evaluate the effectiveness of water treatment strategies (Objective 1) and microbial die-off on produce post last irrigation before harvest (Objective 2) in order to interpret the results and produce user-friendly decision trees for produce growers. The produced decision trees confirmed the results of parametric methods and revealed and visualized interactions between significant risk factors. The senior members of the project team held a 2-day working meeting to discuss all study findings and the best ways to communicate the findings to the produce growers. During the meeting the investigators drafted a lay-person summary of study findings for produce growers to serve as GAPs guidelines and strategies for reduction of irrigation-induced contamination of produce.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Ivanek, R. Microbial safety of fresh produce the role of surface waters and weather. Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Anciso. J, and J. Enciso. Recent produce safety management research for agricultural irrigation water. Ag Mag Journal. Issue 29, May 8, 2019. pp 6-7.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2019
Citation:
April K. Englishbey: Evaluation of Antimicrobial Interventions to Reduce Escherichia coli in Surface Irrigation Water and Produce Growers Perceptions of the Food Safety Modernization Act Produce Safety Rule. PhD Dissertation, Texas Tech University. 2019.
|
Progress 11/01/15 to 10/31/19
Outputs
Target Audience:The target audiences reached during the reporting period include the international representatives of the food industry, researchers and students from multiple disciplines (e.g., food science, food safety, microbiology, plant pathology, agricultural engineering, epidemiology, veterinary medicine, statistics, and public health) as well as representatives of government bodies and regulatory agencies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The following training and professional development opportunities have been provided: Texas A&M AgriLife Extension and Research Center: Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trial testing UV and SA water treatments in growing of spinach. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. Texas Tech University: Dr. Nightingale mentored April Englishbey (PhD student) and Joshua Jenkins and Douglas Thomas (undergraduate students) in processing of field samples and their microbiological testing. Cornell University: Dr. Ivanek mentored Dr. Wendy Beauvais, Alexandra Belias (PhD student) and Michelle Wemette (graduate, DVM student) in statistical analyses of controlled trials. Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The results of the study were disseminated at an international conference that gathered members of the food industry, academia and government bodies (including, USDA, FDA, CDC, FAO, and WHO). Specifically, Dr. Ivanek presented study findings at the Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition - Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA. Also, preliminary study findings were disseminated via a trade journal for growers in the South Texas. Finally, results have been described in a PhD dissertation. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized as a major route of produce contamination at the pre-harvest level. This project evaluated effectiveness of existing and new control strategies, the ultraviolet radiation treatment and sulfuric acid-based fertilizer treatment, to reduce microbial hazards in fresh produce attributed to irrigation water, as affected by irrigation method, weather conditions and produce commodity (spinach and cantaloupe). Researchers from Texas A&M Agrilife conducted several controlled intervention trials in open produce fields and collected nearly 3,500 samplesof water, produce and soil swabs. Researchers from Texas Tech University conducted microbiological testing of the samples. Finally, researchers from Cornell University conducted statistical analyses of all collected data and conducted additional supporting laboratory experiments. Our results show that both the ultraviolet radiation and sulphuric acid-based fertilizer are effective treatments for reducing levels of E. coli in surface irrigation water. In some irrigation cycles, treatment appeared to have a measurable effect on the levels of contamination on fresh produce. However, our results also indicate that it is possible for an increase in E. coli to occur in produce fields post irrigation, which appears to be associated with temperature and precipitation. These results are of value for both produce growers and regulating bodies as implementation of the irrigation water portion of the Produce Safety Rule in the Food Safety Modernization Act is imminent.The results have been reported in a manuscript (Beauvais et al., submitted) and in a PhD dissertation (Englishbey, 2019). Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. We conducted four controlled intervention trials to test water treatment strategies to reduce microbial hazards in fresh produce attributed to irrigation water. Two trials were in cantaloupes in the summers of 2016 and 2017 and two in spinach during the winter seasons 2016-2017 and 2017-2018. In each trial we compared three water treatments: an ultraviolet radiation treatment, a novel sulfuric acid-based fertilizer (9-0-0-12, monourea) treatment, a no treatment control. Surface water naturally contaminated with Salmonella and spiked with Rifampicin resistant (RifR) Escherichia coli was used for irrigation in both furrow and drip irrigation systems. In total, we collected, processed and analysed almost 3,500 samples over 4 trials, however, trial 1 was eventually excluded from the final statistical analysis because of improvements in sample collection and processing methods applied after that trial. Thus, the number of samples included in the final statistical analysis was 2,768 in total; including water from irrigation tanks (502), irrigation water from the field (503), cantaloupe (234), spinach (1,079) and soil swab (360) samples. Overall, the analysis of data revealed that both the ultraviolet radiation and sulphuric acid-based fertilizer treatments significantly reduced RifR E. coli levels in irrigation water (both at the tank and the field levels). Eighty-five percent cent of ultraviolet radiation-treated tank water samples and 76% of sulphuric acid-based fertilizer-treated tank water samples had a RifR E. coli count below the detection limit of 1 Log10 CFU/mL, whereas samples before treatment had a mean count of 3.3 Log10 CFU/mL. The odds of produce contamination differed by the produce commodity and were affected to a lesser degree by the irrigation method and water treatment. Salmonella was detected in spinach (0.3%), tank water (1.8%) and field water (2.8%) samples. Sulphuric acid-based fertilizer appeared to be less effective at eliminating Salmonella from irrigation water than the ultraviolet radiation treatment. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The data from the controlled intervention trials described in Objective 1 were used to determine the trend in odds of contamination over the days post irrigation and the rate of RifR E. coli die-off on harvested produce (cantaloupes and spinach) post last irrigation before harvest. For this purpose, we collected produce and soil swab samples just before and up to 15 times after the last irrigation. Weather data were recorded daily over the whole period. Statistical analyses revealed that there was an overall decrease in the odds of contamination over the days post-irrigation when the first cut of spinach was harvested. However, there was an increase in the odds of contamination over the days post-irrigation in the cantaloupe trial and in the spinach trail when the second cut (regrowth) of spinach was harvested. In the spinach trials, higher minimum temperature five days prior to sampling was associated with a decrease in the odds of detecting RifR E. coli in spinach (second cut) and higher minimum temperature one day prior to sampling was associated with a decrease in the odds of detecting RifR E. coli in soil. In the cantaloupe trial, a higher precipitation four days prior to sampling was associated with a decrease in the odds of detection of RifR E. coli in the soil. (3) Develop Good Agricultural Practices for management of irrigation. A non-parametric approach, classification and regression tree analysis, was used to evaluate the final parametric statistical models developed to evaluate the effectiveness of water treatment strategies (Objective 1) and microbial die-off on produce post last irrigation before harvest (Objective 2) in order to interpret the results and produce user-friendly decision trees for produce growers. The produced decision trees confirmed the results of parametric methods and revealed and visualized interactions between significant risk factors. The senior members of the project team held a 2-day working meeting to discuss all study findings and the best ways to communicate the findings to the produce growers. During the meeting the investigators drafted a lay-person summary of study findings for produce growers to serve as GAPs guidelines and strategies for reduction of irrigation-induced contamination of produce.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Ivanek, R. Microbial safety of fresh produce the role of surface waters and weather. Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Anciso. J, and J. Enciso. Recent produce safety management research for agricultural irrigation water. Ag Mag Journal. Issue 29, May 8, 2019. pp 6-7.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2019
Citation:
April K. Englishbey: Evaluation of Antimicrobial Interventions to Reduce Escherichia coli in Surface Irrigation Water and Produce Growers Perceptions of the Food Safety Modernization Act Produce Safety Rule. PhD Dissertation, Texas Tech University. 2019.
|
Progress 11/01/18 to 10/31/19
Outputs
Target Audience:The target audiences reached during the reporting period include the international representatives of the food industry, researchers and students from multiple disciplines (e.g., food science, food safety, microbiology, plant pathology, agricultural engineering, epidemiology, veterinary medicine, statistics, and public health) as well as representatives of government bodies and regulatory agencies. Changes/Problems:Preliminary statistical analysis revealed that the electronic database of microbial test results was compromised during data manipulation. This required a time-consuming manual checking of data from the laboratory records for almost 3,500 tested samples and re-recording all data into a new master electronic database before repeating all statistical analyses causing a delay. What opportunities for training and professional development has the project provided?The following training and professional development opportunities have been provided: Texas A&M AgriLife Extension and Research Center: Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trial testing UV and SA water treatments in growing of spinach. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. Texas Tech University: Dr. Nightingale mentored April Englishbey (PhD student) and Joshua Jenkins and Douglas Thomas (undergraduate students) in processing of field samples and their microbiological testing. Cornell University: Dr. Ivanek mentored Dr. Wendy Beauvais, Alexandra Belias (PhD student) and Michelle Wemette (graduate, DVM student) in statistical analyses of controlled trials. Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The results of the study were disseminated at an international conference that gathered members of the food industry, academia and government bodies (including, USDA, FDA, CDC, FAO, and WHO). Specifically, Dr. Ivanek presented study findings at the Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition - Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA. Also, preliminary study findings were disseminated via a trade journal for growers in the South Texas. Finally, results have been described in a PhD dissertation. What do you plan to do during the next reporting period to accomplish the goals?We will translate into Spanish the developed guidelines for Good Agricultural Practices for management of irrigation with surface waters and complete the process of manuscript peer-review.
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized as a major route of produce contamination at the pre-harvest level. This project evaluated effectiveness of two treatments to reduce microbial hazards in fresh produce attributed to irrigation with surface water, while controlling for the effects of irrigation method (drip or furrow) and weather conditions. The two treatments are ultra violet (UV) radiation and a novel treatment, which takes advantage of the widespread use of sulfuric acid-based fertilizers (SA) in produce growing. In the previous reporting periods, we conducted four controlled intervention trials testing these treatments in cantaloupes and spinach. During the current reporting period we completed statistical analysis of the data and drafted a lay summary of study findings for produce growers to serve as Good Agricultural Practices (GAPs) guidelines and strategies for reduction of irrigation-induced contamination of produce. Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. We conducted four controlled intervention trials: two in cantaloupes in the summers of 2016 and 2017 and two in spinach during the winter seasons 2016-2017 and 2017-2018, at the Texas A&M Agrilife Research and Extension Center (Weslaco, TX). Three water treatments: a NO treatment control, UV radiation treatment and a novel SA fertilizer treatment (based on monourea with 12% sulfur (9-0-0-12)), were compared in a split-plot intervention trial; surface water naturally contaminated with Salmonella and spiked with Rifampicin resistant (RifR) E. coli (at a concentration of approximately 3.3 Log10 CFU/mL) was used for irrigation in both furrow and drip irrigation systems. In total, over the 4 controlled trials we collected and processed nearly 3,500 samples of water, soil swabs and produce and tested them for the presence and serotype of Salmonella and the contamination level of RifR E. coli. However, because of improvements in experimental design and sampling made after the first trial, only trials 2-4 were subjected to the final statistical analyses reported here and are reported in an associated manuscript (Beauvais et al., submitted) and in a PhD dissertation (Englishbey, 2019). Statistical analysis indicated that UV treatment was highly effective at reducing the counts of RifR E. coli in tank water; 85% of UV-treated tank water samples had a count below the detection limit of 1 Log10 CFU/mL compared to the mean count of 3.3 Log10 CFU/mL in water before treatment. Similarly, SA treatment was highly effective at reducing the counts of RifR E. coli in tank water; 76% of SA-treated tank water samples had a count below the detection limit. Comparing UV treated plots with control plots we observed a reduction in the proportion of RifR E. coli contaminated soil and produce samples in both the spinach and cantaloupe trials. There was also some evidence of a reduction in the proportion of RifR E. coli positive produce samples comparing SA treated plots with controls on spinach regrowth (second cut) after irrigation but no statistical difference on the first cut of spinach. Based on the final multivariable models, in the spinach trials, higher minimum temperature several days prior to sampling was associated with a decrease in the logodds of detecting RifR E. coli in spinach and higher minimum temperature a day prior to sampling was associated with a decrease in the logodds of detecting RifR E. coli in soil. Irrigation type (furrow or drip) was not a significant predictor of RifR E. coli contamination status in soil or produce samples. Salmonella was detected in water and produce samples in the spinach trials only. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The data from the controlled intervention trials described in Objective 1 were used to determine the trend in odds of contamination over the days post irrigation and the rate of RifR E. coli die-off on harvested produce (cantaloupes and spinach) post last irrigation before harvest. The trends in Log10 CFU/sample over time since irrigation varied considerably. We observed a statistically significant increase in both the proportion of samples in which RifR E. coli was detected and an increase in contamination level among positive samples during the cantaloupe trial as well as following the irrigation of spinach in which spinach regrowth (2nd cut) was harvested. However, we also observed a statistically significant decrease in the proportion of samples in which RifR E. coli was detected and a decrease in contamination level following the irrigation in spinach trials where the 1st cut of spinach was harvested. A manuscript describing the results was submitted for peer review (Beauvais et al., submitted) . (3) Develop Good Agricultural Practices for management of irrigation. We evaluated the final parametric statistical models developed in Objectives 1 and 2 using a non-parametric classification and regression tree analysis. To this end we identified and interpreted interactions among predictors in the final models and produced user-friendly decision trees for produce growers (Beauvais et al., submitted). The senior members of the project team (Drs. Worobo, Encisco, Ancisco, Nightingale, and Ivanek and project members from Dr. Ivanek's group) held a 2-day meeting in spring of 2019 to discuss all study findings. As part of the meeting the investigators drafted a lay-person summary of study findings for produce growers to serve as GAPs guidelines and strategies for reduction of irrigation-induced contamination of produce and treatments with SA and UV.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Ivanek, R. Microbial safety of fresh produce the role of surface waters and weather. Global Water and Food Safety Summit (Nov 19-21, 2019), organized by the Joint Institute for Food Safety and Applied Nutrition Center for Food Safety and Security Systems (JIFSAN-CFS3), College Park, MD, USA.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Anciso. J, and J. Enciso. Recent produce safety management research for agricultural irrigation water. Ag Mag Journal. Issue 29, May 8, 2019. pp 6-7.
- Type:
Theses/Dissertations
Status:
Accepted
Year Published:
2019
Citation:
April K. Englishbey: Evaluation of Antimicrobial Interventions to Reduce Escherichia coli in Surface Irrigation Water and Produce Growers Perceptions of the Food Safety Modernization Act Produce Safety Rule. PhD Dissertation, Texas Tech University. 2019.
|
Progress 11/01/17 to 10/31/18
Outputs
Target Audience:The target audiences reached during the reporting period include the representatives of the food industry, researchers and students from multiple disciplines (e.g., food science, food safety, microbiology, plant pathology, agricultural engineering, epidemiology, veterinary medicine, and public health) as well as representatives of regulatory agencies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The following training and professional development opportunities have been provided: Texas A&M AgriLife Extension and Research Center: Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trial testing UV and SA water treatments in growing of spinach. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. Texas Tech University: Dr. Nightingale mentored April Englishbey (PhD student) and Joshua Jenkins and Douglas Thomas (undergraduate students) in processing of field samples and their microbiological testing. Cornell University: Dr. Ivanek mentored Drs. Wendy Beauvais and Claire Zoellner (postdocs) and Michelle Wemette (graduate, DVM student) in statistical analyses of controlled trials. Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The preliminary results of the study have been disseminated among members of the food industry, academia and government bodies. Specifically, at the 2018 Annual USDA NIFA Food Safety Project Directors' Meeting, organized in conjunction with the International Association for Food Protection meeting, the results were disseminated among food safety researchers, USDA and FDA representatives and the food industry. Dr. Ivanek also shared preliminary results with a multidisciplinary working group supported by the NSF - National Institute for Mathematical & Biological Synthesis; the group consists of experts in food safety, microbiology, plant pathology, mathematics, risk assessment, epidemiology and plant sciences, as well as representatives of FDA and USDA. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we plan to complete statistical analyses and develop Good Agricultural Practices for management of irrigation.
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized as a major route of produce contamination at the pre-harvest level. This project aims to evaluate effectiveness of control strategies to reduce microbial hazards in fresh produce attributed to irrigation water, as affected by irrigation method and weather conditions in two produce commodities (spinach and cantaloupe). In the previous reporting period, we conducted two controlled intervention trials in cantaloupes and one in spinach. During the current reporting period we conducted the final planned spinach trial. The goal of the trials was to determine effectiveness of the FSMA mitigation options based on microbial die-off and test the effectiveness of two strategies for treatment of surface water to keep generic Escherichia coli levels under the regulatory thresholds. The two treatments are ultra violet (UV) radiation and a novel treatment, which takes advantage of the widespread use of sulfuric acid-based fertilizers (SA) in produce growing. The preliminary results indicated that, compared to the no-treatment (NO) control, both UV and SA treatments were effective in reducing contamination of water with inoculated Rifampicin-Resistant (RifR) E. coli, and the microbial reduction was evident both in the tank water just before irrigation and in the irrigation water in the produce field. Furthermore, there were large differences in the odds of contamination between the two evaluated produce commodities (cantaloupes and spinach), irrigation systems and seasons. Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. We conducted four controlled intervention trials: two in cantaloupes in the summers of 2016 and 2017 and two in spinach during the winter seasons 2016-2017 and 2017-2018, at the Texas A&M Agrilife Research and Extension Center (Weslaco, TX). Three water treatments: a NO treatment control, UV radiation treatment and a novel SA fertilizer treatment (based on 9-0-0-12 (monourea)), were compared in a split-plot intervention trial; surface water naturally contaminated with E. coli and Salmonella and spiked with RifR E. coli (at a targeted concentration of 1 x 10^5 log10 CFU/ml) was used for irrigation in both furrow and drip irrigation systems. Four or five irrigations with spiked water were conducted per trial. On the day of irrigation, we collected samples of surface water at the tank level (before and after the point of water treatment) and at the field level (from the irrigation water in the field). Additionally, before and after the 4th and 5th irrigation, we collected soil swab (boot sock) samples and produce samples (cantaloupes or spinach) through a repeated and spatially explicit scheme. In total, we collected and processed 3,409 samples: 645 samples of tank irrigation water, 647 samples of field irrigation water, 535 cantaloupes, 1,079 spinach and 503 soil swabs. Microbiological testing of samples was conducted at Texas Tech University, Lubbock, TX and it included enumeration of coliforms, generic E. coli and RifR E. coli, and detection and serotyping of Salmonella. Additionally, at Cornell University (Ithaca, NY) we evaluated pH and turbidity of water samples and conducted a comparative assessment of the effect of UV treatment on RifR E. coli and a cocktail of pathogens. Weather data have been recorded by the Texas A&M Agrilife and are being processed for statistical analysis at Cornell. Statistical analyses of the probability and level of microbial contamination in tank water is being conducted at Texas Tech, while contamination of field water, produce and soil swab samples is being conducted at Cornell. Salmonella was detected in 3 of 1,079 samples of spinach (0.3%), 0 of 535 samples of cantaloupe (0 %), 0 of 503 soil swabs (0%), 9 of 645 samples of the tank water (1.4%) and 14 of 647 samples of water collected in the field post irrigation (2.2%). The following Salmonella serotypes were identified: Baildon, Braenderup, Saintpaul, II 912, Javiana, Montevideo, Typhimurium. For the purpose of this report we will focus on preliminary analysis of RifR E. coli in 3 of 4 trials (excluding the 1st trial growing cantaloupes). Preliminary analysis of tank water before and after treatment from a total of 18 irrigations indicated that UV and SA treatments were similarly effective. Both UV and SA treatments reduced concentrations of RifR E. coli by a median of 3.3 log10 CFU/ml compared to levels before treatment. We also evaluated the odds ratios (ORs) of contamination. The odds of contamination in water samples collected from the field after irrigation were strongly and similarly affected by UV and SA treatments and the irrigation method (furrow vs drip). For example, compared to the NO-treatment plots the odds of contamination with RifR E. coli in the field water samples were significantly lower in UV (OR=0.0001) and SA (OR=0.0007) plots. Also, the odds of contamination were significantly higher in furrow plots compared to the drip plots (OR=28.7). Field water samples in plots with UV and SA treatments had approximately 3 log10 CFU/ml lower concentrations of RifR compared to the NO treatment control plots. The odds of produce sample contamination with RifR E. coli were lower in spinach vs. cantaloupe samples (RifR E. coli crude OR=0.10). The odds of cantaloupe contamination with RifR E. coli were lower in UV plots compared to the NO-treatment plots (OR=0.31, p=0.02). There were no significant treatment effects on the odds of spinach contamination, possibly affected by the low prevalence of contamination. A large degree of variability was observed in the level of microbial contamination in produce over time. Overall, both UV and SA treatments were effective in reducing contamination of water with RifR E. coli. The odds of produce contamination differed by the produce commodity and were affected to a lesser degree by the irrigation method and water treatment. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The data from the controlled intervention trials described in Objective 1 are being used to determine the trend in odds of contamination over the days post irrigation and the rate of RifR E. coli die-off on harvested produce (cantaloupes and spinach) post last irrigation before harvest. For this purpose, we collected produce and soil swab samples just before and up to 15 times after the last irrigation for a total of 535 cantaloupe, 1,079 spinach and 503 soil swab samples, and we enumerated native and RifR E. coli. Weather data were recorded daily over the whole period. In the spinach trial year 1, there was an overall decrease in the odds of contamination over the days post-irrigation. However, in year 2, there was an increase in the odds of contamination over the days post-irrigation in both spinach and cantaloupe trials. Environmental UV radiation levels on the day of sampling and average wind speed three days previous to sampling were significantly associated with the odds of contamination after controlling for the effects of treatment group, produce type, year, irrigation type, irrigation number and days post-irrigation, however the differences between trials and the differences in the trend in odds of contamination over the days post-irrigation remained significant, even after accounting for these weather variables. RifR E. coli was found on produce on 15 days post-irrigation (the last day of sampling) and in soil swabs on 10 days post-irrigation (the last day of sampling). In addition, the presence of RifR E. coli on produce and soil just prior to irrigation suggests that the RifR E. coli persisted throughout the previous irrigation. (3) Develop Good Agricultural Practices for management of irrigation. Nothing to report for the current reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2018
Citation:
Beauvais, W, A.K. Englishbey, C.M. Marconi, J. Usaga, A. Rodriguez, E. Serna, R.W. Worobo, K.K. Nightingale, J.M. Enciso, J.R. Anciso, R. Ivanek. The effects of irrigation water treatments on Escherichia coli presence on produce: a controlled trial. USDA NIFA Food Safety Program Project Directors Meeting, July 7, 2018 in Salt Lake City, Utah. Poster presentation.
|
Progress 11/01/16 to 10/31/17
Outputs
Target Audience:The target audiences reached during the reporting period include representatives of regulatory agencies as well as researchers and students from multiple disciplines, including food safety, microbiology, plant pathology, agricultural engineering, epidemiology, and public health. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?The following training and professional development opportunities have been provided during the reporting period: Texas A&M AgriLife Extension and Research Center: Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trail testing UV and SA water treatments in growing of cantaloupes. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. Texas Tech University: Dr. Nightingale mentored April Englishbey (PhD student) and Joshua Jenkins and Douglas Thomas (undergraduate students) in processing of field samples and their microbiological testing. Cornell University: Dr. Ivanek mentored Dr. Wendy Beauvais (postdoc) in statistical analyses of controlled trials, while Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The preliminary results of the study have been disseminated among members of academia and government bodies. Specifically, at the 2017 Annual USDA NIFA Food Safety Project Directors' Meeting the results were disseminated among food safety researchers and USDA representatives. Dr. Ivanek also shared preliminary results with a multidisciplinary working group supported by the NSF - National Institute for Mathematical & Biological Synthesis; the group consists of experts in food safety, microbiology, plant pathology, mathematics, risk assessment, epidemiology and plant sciences, as well as representatives of FDA and USDA. Finally, Dr. Ivanek presented the preliminary results at the retreat of the Cornell's Center for Infection & Pathobiology that also included experts in foodborne disease agents. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we plan to conduct the last (4th) planned intervention trial, continue statistical analyses and develop Good Agricultural Practices for management of irrigation.
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized as a major route of produce contamination at pre-harvest. The current project aims to evaluate effectiveness of control strategies to reduce microbial hazards in fresh produce attributed to irrigation water, as affected by irrigation method, produce commodity and weather conditions. In the previous reporting period we conducted a controlled intervention trial in cantaloupes. During the current reporting period we conducted two additional trials, one in cantaloupes and one in spinach. The goal of the trials was to determine effectiveness of the Food Safety Modernization Act (FSMA) mitigation options based on microbial die-off and test the effectiveness of two strategies for treatment of surface water to keep generic Escherichia coli levels under the regulatory thresholds. The two treatments are ultra violet (UV) radiation and a novel treatment, which takes advantage of the widespread use of sulfuric acid-based fertilizers (SA-fertilizer) in produce growing. The preliminary results of analyses of the three controlled trials conducted thus far indicated that, compared to the no-treatment ("NO") control, both UV and SA treatments were effective in reducing contamination of water with (i) native generic E. coli that naturally occurred in water used for irrigation and (ii) inoculated Rifampicin-Resistant (RifR) E. coli, and the microbial reduction was evident both in the tank water just before irrigation and in the irrigation water in the produce field. The preliminary results also revealed large differences in the odds of contamination between the two evaluated produce commodities (cantaloupes and spinach). In the next reporting period, an additional trial will be conducted in spinach to further support comparisons between produce commodities and seasons. Data compiled from all four planned trials will be further analysed in the last year of the project to determine the effectiveness of the two water treatments in reducing contamination of harvested produce and to estimate the rate of E. coli die-off on produce post irrigation, while accounting for the effect of weather conditions. Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. Thus far we conducted three controlled intervention trials: in cantaloupes in summers of 2016 and 2017 and in spinach in the winter season 2016/2017, at Texas A&M Agrilife Research and Extension Center, Weslaco, TX. Three water treatments: a NO-treatment control, UV-radiation treatment and a novel SA-fertilizer treatment (based on 9-0-0-12 (monourea)), were compared in a split-plot intervention trial; surface water naturally contaminated with Salmonella and spiked with RifR E. coli (at concentration of 1 x 10^5 log10 CFU/ml) was used for irrigation in both furrow and drip irrigation systems. Four or five irrigations with spiked water were conducted per trial. On the day of irrigation, we collected samples of surface water at the tank level (before and after the point of water treatment) and at the field level (from the irrigation water in the field). Additionally, before and after the 4th and 5th irrigation, we collected soil swab samples and produce samples (cantaloupes or spinach) through a repeated and spatially explicit scheme. In total, thus far we collected and processed 1,431 samples: 489 samples of tank irrigation water, 485 samples of field irrigation water, 535 cantaloupes, 539 spinach and 383 soil swabs. Microbiological testing of samples was conducted at Texas Tech University, Lubbock, TX and it included enumeration of coliforms, generic E. coli and RifR E. coli, and detection of Salmonella. Additionally, at Cornell University we evaluated pH and turbidity of water samples and conducted a comparative assessment of the effect of UV treatment on RifR and a cocktail of pathogens. Preliminary statistical analyses of the probability and level of microbial contamination in water, produce and soil swab samples were conducted at Cornell University. Salmonella was detected in the spinach trial in 3 of 540 samples of spinach (0.6%), 3 of 180 samples of the tank water (2%) and 7 of 180 samples of water collected in the field post irrigation (4%). There were no Salmonella positive samples in either of the two cantaloupe trials. Preliminary analysis of tank water before and after treatment from a total of 13 irrigations indicated that UV and SA treatments were similarly effective. UV treatment reduced concentrations of RifR E. coli, native E. coli and Coliforms between 0.6 and 2.6 log10 CFU/ml compared to the before treatment levels. Similarly, SA treatment reduced concentrations of RifR E. coli, native E. coli and Coliforms between 0.5 and 2.5 log10 CFU/ml. We also evaluated the odds ratios (ORs) of contamination. The odds of contamination in water samples collected from the field after irrigation were strongly and similarly affected by UV and SA treatments and the irrigation method (furrow vs drip). For example, compared to the NO-treatment plots the odds of contamination with RifR E. coli in the field water samples were significantly lower in UV (OR=0.0001) and SA (OR=0.0002) plots. Also, the odds of contamination were significantly higher in furrow plots compared to the drip plots (OR=9.6). Field water samples in plots with UV and SA treatments had approximately 3 log10 CFU/ml lower concentrations of RifR and native E. coli compared to the NO treatment control plots. The odds of produce sample contamination with RifR E. coli and native E. coli were lower in spinach compared to cantaloupe samples (RifR E. coli OR=0.04; native E. coli OR=0.02) and the odds of contamination with RifR E. coli were lower in UV plots compared to the NO-treatment plots (OR=0.28). Also, spinach was contaminated with slightly lower levels of RifR and native E. coli compared to cantaloupes. A large degree of variability was observed in the level of microbial contamination in produce over time. In the next reporting period we will evaluate whether the variability could be explained by the weather conditions. In conclusion, the preliminary results indicated that both UV and SA treatments were effective in reducing contamination of water with native and RifR E. coli. The odds of produce contamination differed by the produce commodity and were affected to a lesser degree by the irrigation method and water treatment. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The controlled intervention trails described in Objective 1 will be used to determine the rate of E. coli die-off on harvested produce (cantaloupes and spinach) post last irrigation before harvest. For this purpose, we collected produce and soil swab samples just before and up to 15 times after the last irrigation for a total of 535 cantaloupe, 539 spinach and 383 soil swab samples, and we enumerated native and RifR E. coli. Weather data were recorded daily over the whole period. In year 3 of the project, after completion of the final planned intervention trial in spinach, we will estimate the die-off rates of native and RifR E. coli after controlling for the effect of weather. (3) Develop Good Agricultural Practices for management of irrigation. Nothing to report for the current reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Ivanek, R., C. M. Marconi, R. W. Worobo, K. K. Nightingale, J. R. Anciso, J. M. Enciso, Englishbey, A. K. Dissemination and the fate of foodborne pathogens and indicators on produce post irrigation with surface water: an intervention trial. 2017 Center for Infection & Pathobiology retreat, April 28-29, 2017 at Greek Peak, NY.
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2017
Citation:
Ivanek, R., A. K. Englishbey, C. M. Marconi, J. Usaga, A. Rodriguez, E. Serna, R. W. Worobo, K. K. Nightingale, J. M. Enciso, J. R. Anciso. Foodborne pathogens and indicators on cantaloupes and spinach post irrigation with surface water: an intervention trial. USDA NIFA Food Safety Project Directors Meeting, July 8, 2017, Tampa, FL.
|
Progress 11/01/15 to 10/31/16
Outputs
Target Audience:The target audiences reached during the reporting period include researchers, students and representatives of regulatory agencies. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Multiple training and professional development opportunities have been provided during the reporting period: At Texas A&M AgriLife Extension and Research Center, Cristina Marconi (research assistant), Alfredo Rodriguez (agricultural research technician II), Eduardo Serna (extension assistant), Uriel Cholula (technician II), Micah Cantu (agricultural researcher worker) and Inez Vela (technician I) were mentored by Drs. Anciso and Enciso in the set-up and execution of a controlled intervention trail testing UV and SA water treatments in growing of cantaloupes. Also, Inez Vela was trained by Dr. Enciso in measuring UV radiation using a remote sensor and in datalogger programming to collect weather data. Finally, Cristina Marconi and Alfredo Rodriguez received training in Good Laboratory Practices (GLP): improving field records and quality assurance; understanding the GLP Compliance Statement. At Texas Tech University, Dr. Nightingale mentored April Englishbey (PhD student) and Luis Jimenez (undergraduate student) in processing of field samples and their microbiological testing. At Cornell University, Dr. Ivanek mentored Dr. Wendy Beauvais (postdoc) in statistical analyses of controlled trials, while Dr. Worobo mentored John Churey (research support specialist II) and Dr. Jessie Usaga (visiting professor) in UV treatment of surface water spiked with a cocktail of pathogens. How have the results been disseminated to communities of interest?The preliminary results of the study have been disseminated among researchers and government officials attending the USDA NIFA Food Safety Project Directors' Meeting and within a working group of the NSF - National Institute for Mathematical & Biological Synthesis (of which Ivanek is one of the PIs) that develops mathematical models of produce contamination at pre-harvest. What do you plan to do during the next reporting period to accomplish the goals?In the next reporting period, we plan to conduct the first of the two planned intervention trials in spinach and the second of the two planned intervention trials in cantaloupes.
Impacts
What was accomplished under these goals?
Impact: Irrigation water has been recognized by the US FDA Food Safety Modernization Act (FSMA) as a major route of produce contamination at pre-harvest. The current project addresses a critical research need to evaluate effectiveness of control strategies to reduce microbial hazards in irrigation water, as affected by irrigation method, produce commodity and weather conditions. Specifically, during the current reporting period we conducted a controlled intervention trial in cantaloupes to determine effectiveness of FSMA mitigation options based on microbial die-off and test the effectiveness of two strategies for treatment of surface water to keep generic Escherichia coli levels under the regulatory thresholds. The two treatments are ultra violet (UV) radiation and a novel treatment, which takes advantage of the widespread use of sulfuric acid based fertilizers (SA-fertilizer) in produce growing. The preliminary results indicated that, compared to the no-treatment control, both UV and SA treatments were effective in reducing contamination of water with (i) native generic E. coli that naturally occurred in water used for irrigation and (ii) inoculated Rifampicin-Resistant (RifR) E. coli, and the microbial reduction was evident both in the tank water just before irrigation and in the irrigation water in the produce field. The trial will be repeated in cantaloupes in year 2 of the project to determine if results are repeatable over different seasons. Furthermore, 2 additional trials will be conducted in spinach to allow comparisons between produce commodities. Data compiled from all four planned trials will be analysed in the last year of the project to determine the effectiveness of the two water treatments in reducing contamination of harvested produce and to estimate the rate of E. coli die-off on produce post irrigation. Meanwhile, the preliminary results for the current reporting period support that both UV and SA treatments are effective in reducing microbial hazards in irrigation water. Objectives: (1) Conduct intervention trials to test effectiveness of irrigation water treatments in reducing produce contamination at harvest. In summer of 2016, we conducted a controlled intervention trial in cantaloupes at Texas A&M Agrilife Research and Extension Center, Weslaco, TX. Three water treatments: a no-treatment control, UV-radiation treatment and a novel SA-fertilizer treatment (based on 9-0-0-12 (monourea)), were compared in a split-plot intervention trial; surface water naturally contaminated with Salmonella and spiked with RifR E. coli (at concentration of 1 x 10^5 log10 CFU/ml) was used for irrigation in both furrow and drip irrigation systems. In each of the 4 irrigations with spiked water, samples of surface water (before and after the point of treatment and during irrigation) were collected. Additionally, before and after the 4th irrigation, we collected soil (swab) samples and cantaloupes through a repeated and spatially explicit scheme. In total we collected 167 samples of tank irrigation water, 162 samples of field irrigation water, 301 cantaloupes and 143 soil swabs. Microbiological testing of samples was conducted at Texas Tech University, Lubbock, TX and it included enumeration of coliforms, generic E. coli and RifR E. coli, and detection of Salmonella. Statistical analyses of the probability and level of microbial contamination in water samples were conducted using random effect generalized linear models at Cornell University. Salmonella was not detected in any of the collected samples. Preliminary analysis of tank water from 4 irrigations indicated that UV and SA treatments were similarly effective (e.g., the UV treatment reduced concentration of RifR and native E. coli by 1.9 (SE=0.4) log10 CFU/ml and 3.3 (SE=0.32) log10 CFU/ml, respectively). The odds of contamination with RifR and native E. coli in irrigation water collected from the field were approximately 50 times lower in plots where water was treated with UV or SA compared to no-treatment plots. The achieved reductions in contamination level in field samples of irrigation water were similar in plots irrigated with UV-treated and SA-treated water (e.g., the UV treatment reduced concentration of RifR and native E. coli by 2.24 (SE=0.29) and 3.16 (SE=0.21) log10 CFU/ml, respectively). The odds of contamination with coliforms were approximately 14 times higher in furrow compared to drip plots and at least 7 times higher in the middle or end of a row compared to the beginning of a row. Similarly, water samples collected in plots with furrow irrigation on average had approximately 1.5 log10 CFU/ml more coliforms than samples collected from plots with drip irrigation, and samples collected in the middle or end of a row had around 1 log10 CFU/ml more coliforms compared to the beginning of a row. In conclusion, the preliminary results indicated that both UV and SA treatments were effective in reducing contamination of water with native and RifR E. coli. Effectiveness of UV and SA treatments on the contamination of harvested cantaloupes will be conducted in the last year of the project after data are available from all 4 planned intervention trials. (2) Estimate irrigation-induced dissemination of indicators and pathogens on produce at harvest and the rate of indicator die-off on produce post-irrigation. The controlled intervention trail conducted to evaluate the effectiveness of UV and SA treatments, described in Objective 1, served an additional purpose, namely to determine the rate of E. coli die-off on harvested cantaloupes post last irrigation. For this purpose we collected cantaloupes and soil swabs just before and 7-8 times after the last irrigation for a total of 301 cantaloupes and 143 soil swabs and we enumerated native and RifR E. coli. Weather data were recorded daily over the whole period. Estimation of the die-off rate of native and RifR E. coli will commence in year 3 of the project after we obtain data from the additional 3 intervention trials in cantaloupes and spinach. Due to the standardized study designs planned for all 4 trials proposed in this project, the dataset compiled during the current reporting period will help elucidate how much of the commodity-specific contamination prevalence and level at harvest is attributed to the microbial quality of irrigation water and the lag time since last irrigation, as opposed to being attributed to other factors, such as irrigation system, weather and season. (3) Develop Good Agricultural Practices for management of irrigation. Nothing to report for the current reporting period.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
Englishbey, A. K., C. M. Marconi, R. W. Worobo, K. K. Nightingale, J. R. Anciso, J. M. Enciso, R. Ivanek@. Dissemination and the fate of foodborne pathogens and indicators on produce post irrigation with surface water: an intervention trial. USDA NIFA Food Safety Project Directors Meeting, July 30, 2016, St Louis, MO.
|
|