Factors influencing the fate of Salmonella in the plant and soil environment

von Eva Fornefeld

196 Seiten, Taschenbuch

Kurzbeschreibung des Verlags

Fresh fruits and vegetables are increasingly recognized as part of a healthy diet. However, disease outbreaks caused by Salmonella linked to fresh produce indicate that raw fruits and vegetables could be a vector for human pathogens. Contamination of fresh produce with Salmonella can occur along the whole production chain and one possible source is
contaminated soil. Soil, rhizosphere and phyllosphere are heterogenous habitats where conditions can change quickly and survival of human pathogens in this environment is influenced by various biotic and abiotic factors. So far, the ecology of Salmonella in the environment is largely unknown and this thesis aimed at extending the knowledge of factors influencing the persistence of Salmonella in the soil-plant environment.
In this thesis, microcosm and greenhouse experiments were conducted to analyze factors influencing the fate of Salmonella under defined conditions. Lettuce (Lactuca sativa cv. Tizian) was used as a model plant and Salmonella enterica serovar Typhimurium strain LT2 as a model human pathogen. 5. Typhimurium LT2 was inoculated into soil and its fate was monitored using cultivation-dependent and -independent methods.
Among the factors investigated in this thesis, the influence of preadaptation, meaning the conditions which the bacteria encounter before their introduction into the analyzed environment, on the survival of 5. Typhimurium LT2 was investigated in soil microcosms. It was found that numbers of cultivable 5. Typhimurium LT2 cells were significantly higher in the treatment with preadaptation than in the respective treatmment without preadaptation, showing that preadaptation can prolong survival of this strain in soil. These results indicate that the medium used to pre-grow Salmonella before inoculation
into soil influenced the ability to survive in soil in a strain-specific manner. Therefore, conditions which bacteria encounter before their introduction into the environment might have a major influence on their survival and should be considered also with respect to comparability between studies.

• Reihe: Dissertationen aus dem Julius Kühn-Institut
• ISBN: 9783955470456
• Sprache: Englisch
• Erscheinungsdatum: 08.02.2019
• Genre: Biologie/Landwirtschaft, Gartenbau, Forstwirtschaft, Fischerei, Ernährung
• Verlag: Bundesforschungsinstitut für Kulturpflanzen (JKI)