Joint project
Plantinfect, Teil I - Colonization of plants by Escherichia coli and Salmonella enterica
Funder: Federal Ministry of Food and Agriculture
Period: 2015-2018
Detailed description:
In recent years, the number of food-born human diseases that are caused by the consumption of vegetables contaminated with human pathogenic bacteria, such as Salmonella and Escherichia coli, is steadily increasing worldwide. The importance of the soil type and its chemical properties for the colonization of the crop plants are currently only poorly understood. Similarly unexplained, remains the role of organic manure or other sources of bacteria, like irrigation water or incorporation of contaminated plant debris into the soil. Furthermore, the knowledge about the activation of crop plants’ defense mechanisms after an infection with human pathogens is missing. Due to the existing threat for the consumer, we will study the influence of these factors on the colonization of lettuce and corn salad with Salmonella enterica and the enterohemorrhagic Escherichia coli (EHEC). The goals of this research program are divided into three groups: i) establishment of methods for the specific detection of human pathogenic bacteria in plant tissues and in the soil; ii) investigation of factors, which influence the colonization of crop plants; and iii) risk assessment. Studies with S. enterica and EHEC will be performed separately and compared subsequently. The project structures into four work packages: 1. Validation of specific detection methods for Salmonella and EHEC in plants and soil. Adaptation of international methods such as e.g. the DIN CEN ISO / TS 13136 method for EHEC. 2. Impact of organic fertilizers on the abundance and uptake of Salmonella and EHEC into crop plants. 3. Analysis of the distribution of bacteria in the plant by means of microscopy, DNA-based techniques and cultivation-based methods. 4. Risk assessment for the consumer and intervention strategies based on the results. In addition we will perform a comprehensive literature evaluation, which will be published as review articles. In this part of the project we will study the impact of cultivation conditions on the reaction of lettuce and corn salad to infections with EHEC and Salmonella. Moreover, we will investigate the distribution of the bacteria and made an assessment of the health risk to consumers. In two steps we will determine how lettuce and corn salad that has grown in different soil/fertilizer combinations, respond to infection by EHEC and S. Typhimurium. First, the expression of selected genes will be determined, and then the global change in gene expression. Subsequently, the efficiency of the defense mechanisms is examined. The distribution of bacteria in lettuce and corn salad will be determined with the help of wild-type strains expressing gfp or DsRed genes and confocal microscopy. To assess the health risk to consumers, we will use the quantified number of bacteria in plant tissues, the known infectious dose of Salmonella and EHEC, and the already known virulence of Salmonella from plant tissue.
In recent years, the number of food-born human diseases that are caused by the consumption of vegetables contaminated with human pathogenic bacteria, such as Salmonella and Escherichia coli, is steadily increasing worldwide. The importance of the soil type and its chemical properties for the colonization of the crop plants are currently only poorly understood. Similarly unexplained, remains the role of organic manure or other sources of bacteria, like irrigation water or incorporation of contaminated plant debris into the soil. Furthermore, the knowledge about the activation of crop plants’ defense mechanisms after an infection with human pathogens is missing. Due to the existing threat for the consumer, we will study the influence of these factors on the colonization of lettuce and corn salad with Salmonella enterica and the enterohemorrhagic Escherichia coli (EHEC). The goals of this research program are divided into three groups: i) establishment of methods for the specific detection of human pathogenic bacteria in plant tissues and in the soil; ii) investigation of factors, which influence the colonization of crop plants; and iii) risk assessment. Studies with S. enterica and EHEC will be performed separately and compared subsequently. The project structures into four work packages: 1. Validation of specific detection methods for Salmonella and EHEC in plants and soil. Adaptation of international methods such as e.g. the DIN CEN ISO / TS 13136 method for EHEC. 2. Impact of organic fertilizers on the abundance and uptake of Salmonella and EHEC into crop plants. 3. Analysis of the distribution of bacteria in the plant by means of microscopy, DNA-based techniques and cultivation-based methods. 4. Risk assessment for the consumer and intervention strategies based on the results. In addition we will perform a comprehensive literature evaluation, which will be published as review articles. In this part of the project we will study the impact of cultivation conditions on the reaction of lettuce and corn salad to infections with EHEC and Salmonella. Moreover, we will investigate the distribution of the bacteria and made an assessment of the health risk to consumers. In two steps we will determine how lettuce and corn salad that has grown in different soil/fertilizer combinations, respond to infection by EHEC and S. Typhimurium. First, the expression of selected genes will be determined, and then the global change in gene expression. Subsequently, the efficiency of the defense mechanisms is examined. The distribution of bacteria in lettuce and corn salad will be determined with the help of wild-type strains expressing gfp or DsRed genes and confocal microscopy. To assess the health risk to consumers, we will use the quantified number of bacteria in plant tissues, the known infectious dose of Salmonella and EHEC, and the already known virulence of Salmonella from plant tissue.
Coordinating organisation / Consortium Leader
- Julius Kühn-Institut - Bundesforschungsinstitut für Kulturpflanzen
Cooperation partners with funding
- University of Giessen
- University of Hohenheim
- Osnabrück University
- Leibniz Institute of Vegetable and Ornamental Crops
