Dagmar Schoder

Prof. Dr. Dagmar Schoder


Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 May 2019 in Viruses
Verified
Journal Article
Open access
PDF file
JSJulia SOMMER
Julia SOMMER
CTChristoph Trautner
Christoph Trautner
AWAnna Kristina Witte
Anna Kristina Witte
SFSusanne Fister
Susanne Fister
DSDagmar Schoder
Dagmar Schoder
PMPatrick Mester
Patrick Mester
In recent years, a new potential measure against foodborne pathogenic bacteria was rediscovered—bacteriophages. However, despite all their advantages, in connection to their widespread application in the food industry, negative consequences such as an uncontrolled phage spread as well as a development of phage resistant bacteria can occur. These problems are mostly a result of long-term persistence of phages in the food production environment. As this topic has been neglected so far, this article reviews the current knowledge regarding the effectiveness of disinfectant strategies for phage inactivation and removal. For this purpose, the main commercial phage products, as well as their application fields are first discussed in terms of applicable inactivation strategies and legal regulations. Secondly, an overview of the effectiveness of disinfectants for bacteriophage inactivation in general and commercial phages in particular is given. Finally, this review outlines a possible strategy for users of commercial phage products in order to improve the effectiveness of phage inactivation and removal after application.

1 November 2022 in Foods
Verified
Journal Article
Open access
PDF file
DSDagmar Schoder
Dagmar Schoder
CGClaudia Guldimann
Claudia Guldimann
EMErwin Märtlbauer
Erwin Märtlbauer
Humans and animals can become asymptomatic carriers of Listeria monocytogenes and introduce the pathogen into their environment with their feces. In turn, this environmental contamination can become the source of food- and feed-borne illnesses in humans and animals, with the food production chain representing a continuum between the farm environment and human populations that are susceptible to listeriosis. Here, we update a review from 2012 and summarize the current knowledge on the asymptomatic carrier statuses in humans and animals. The data on fecal shedding by species with an impact on the food chain are summarized, and the ways by which asymptomatic carriers contribute to the risk of listeriosis in humans and animals are reviewed.

1 June 2011 in Journal of Food Protection
Verified
Journal Article
Closed access
DSDagmar Schoder
Dagmar Schoder
DMDaniela Melzner
Daniela Melzner
Alois W. SchmalwieserAlois W. Schmalwieser
Alois W. Schmalwieser
AZAbdoulla Zangana
Abdoulla Zangana
PWPetra Winter
Petra Winter
MWMartin Wagner
Martin Wagner
The aim of this study was to determine the transmission routs of Listeria spp. in dairy farms manufacturing fresh cheese made from ovine and caprine raw milk and to evaluate the impact of Listeria monocytogenes mastitis on raw milk contamination. Overall, 5,799 samples, including 835 environmental samples, 230 milk and milk product samples, and 4,734 aseptic half-udder foremilk samples were collected from 53 dairy farms in the dairy intensive area of Lower Austria. Farms were selected for the study because raw milk was processed to cheese that was sold directly to consumers. A total of 153 samples were positive for Listeria spp., yielding an overall prevalence of 2.6%; L. monocytogenes was found in 0.9% of the samples. Bulk tank milk, cheese, and half-udder samples were negative for Listeria spp. Because none of the sheep and goats tested positive from udder samples, L. monocytogenes mastitis was excluded as a significant source of raw milk contamination. L. monocytogenes was detected at 30.2% of all insp...

1 September 2015 in International Journal of Food Microbiology
Verified
Journal Article
Closed access
DSDagmar Schoder
Dagmar Schoder
ASAnja Strauß
Anja Strauß
KSKati Szakmary-Brändle
Kati Szakmary-Brändle
Beatrix StesslBeatrix Stessl
Beatrix Stessl
SSSabine Schlager
Sabine Schlager
MWMartin Wagner
Martin Wagner

1 November 2013 in Journal of Food Protection
Verified
Journal Article
Closed access
DSDagmar Schoder
Dagmar Schoder
AMAndreas Maichin
Andreas Maichin
BLBenedict Lema
Benedict Lema
JLJohn Laffa
John Laffa
In Tanzania, pastoralists such as the Maasai and small urban farmers are responsible for the country's milk production, and 95% of the national milk supply is sold without regulation. This study was conducted using hygiene checklists and milk sampling to investigate milk quality and safety at various steps throughout the milk production chain. In regions of Dar es Salaam and Lake Victoria, 196 milk samples were collected: 109 samples of raw milk, 41 samples of packed or open served heat-treated products, and 46 samples of fermented products. Samples were taken from (i) the production level (pastoralists and urban farmers), (ii) the collection level (middlemen and depots), (iii) processors (dairies), and (iv) retailers (kiosks). Samples were analyzed for hygiene criteria (total bacteria, total coliforms, Escherichia coli, and coagulase-positive staphylococci) and foodborne pathogens such as Salmonella, enterohemorrhagic E. coli O157:H7, and Listeria monocytogenes. Adequate heating of milk for drinking was determined via heat labile alkaline phosphatase and lactoperoxidase analysis. Total bacterial counts indicated that only 67% (73 of 109) of raw milk samples and 46% (19 of 41) of heat-treated samples met national Tanzanian standards. Bulk milk samples taken from the traditional milking vessels of Maasai pastoralists had the lowest total bacterial counts: ≥ 1 × 10(2) CFU/ml. Foodborne pathogens such as E. coli O157:H7 and Salmonella were isolated from 10.1% (11 of 109) of raw milk samples but were not detected in heat-treated or fermented products, and 83% of heat-treated milk samples were lactoperoxidase negative, indicating overpasteurization. Coliforms were detected in 41% (17 of 41) of processed milk samples, thus indicating a high rate of recontamination. A progressive decrease in microbial quality along the milk production chain was attributed to departures from traditional methods, inadequate milk containers, long transport distances, lack of cooling, and lack of a basic understanding of hygiene.