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28 results on '"Dorn-In, Samart"'

6. Symbiotic Husbandry of Chickens and Pigs Does Not Increase Pathogen Transmission Risk

Author

Kaeder, Emma, Schwaiger, Karin, Dorn-In, Samart, and Gareis, Manfred

Subjects
Health (social science), Campylobacter spp, E. coli, free-range rearing system, MALDI-TOF MS, FT-IR, animal welfare, Plant Science, Health Professions (miscellaneous), Microbiology, Escherichia-Coli, Free-Range, Campylobacter-Jejuni, Animal-Welfare, Prevalence, Cattle, Time, Identification, Strains, Food Science
Abstract

A symbiotic or mixed animal husbandry (e.g., pigs and chickens) is considered to have a positive effect for animal welfare and sustainable agriculture. On the other hand, a risk of infection and transmission of microorganisms, especially of zoonotic pathogens, between animal species may potentially occur and thus might increase the risk of foodborne illnesses for consumers. To prove these assumptions, two groups of animals and their environmental (soil) samples were investigated in this study. Animals were kept in a free-range system. In the first group, pigs and chickens were reared together (pasture 1), while the other group contained only pigs (pasture 2). During a one-year study, fecal swab samples of 240 pigs and 120 chickens, as well as 120 ground samples, were investigated for the presence of Campylobacter spp., Salmonella spp. and E. coli. Altogether, 438 E. coli and 201 Campylobacter spp. strains were isolated and identified by MALDI-TOF MS. Salmonella spp. was not isolated from any of the sample types. The prevalences of Campylobacter coli and C. jejuni in pigs were 26.7% and 3.3% in pasture 1 and 30.0% and 6.7% in pasture 2, while the prevalences of C. coli and C. jejuni in chickens from pasture 1 were 9.2% and 78.3%, respectively. No correlation between the rearing type (mixed vs. pigs alone) and the prevalence of Campylobacter spp. was observed. All swab samples were positive for E. coli, while the average prevalences in soil samples were 78.3% and 51.7% in pasture 1 and 2, respectively. Results of similarity analysis of the MALDI-TOF MS spectra (for C. coli, C. jejuni and E. coli) and FT-IR spectra (for E. coli) of the same bacterial species showed no recognizable correlations, no matter if strains were isolated from chickens, pig or soil samples or isolated at different sampling periods. The results of the study indicate that the symbiotic husbandry of pigs and chickens neither results in an increased risk of a transmission of Campylobacter spp. or E. coli, nor in a risk of bacterial alteration, as shown by MALDI-TOF MS and FT-IR spectra. In conclusion, the benefits of keeping pigs and chickens together are not diminished by the possible transmission of pathogens.

Published
2022
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19. Antimicrobial Effects of Plant Extracts against Clostridium perfringenswith Respect to Food-Relevant Influencing Factors

Author

Friedlein, Ulrike, Dorn-In, Samart, and Schwaiger, Karin

Abstract

The application of plant extracts (PEs) could be a promising option to satisfy consumers' demand for natural additives to inhibit growth of variable pathogenic bacteria. Thus, the aim of this study was to develop a standardized microdilution method to examine the antimicrobial effects of 10 hydrophilic PEs against two strains of Clostridium perfringensfacing various food-relevant influencing factors. Because of the high opacity of PEs, resazurin was used as an indicator for bacterial growth instead of pellet formation. The highest value of the MIC of the replications of each PE was defined as effective plant extract concentration (EPC), whereas the next concentration beneath the lowest MIC was defined as the ineffective plant extract concentration (IEPC). The EPCs of seven PEs, allspice, cardamom, cinnamon, clove, coriander, ginger, and mace, were between 0.625 and 10 g/kg, whereas extracts of caraway, nutmeg, and thyme showed no antimicrobial activity up to the maximum concentration tested (10 g/kg) against C. perfringensin vitro. Two intrinsic factors, sodium chloride (NaCl) and sodium nitrite (NaNO2), displayed either synergistic or additive effects or no interaction with most PEs. By combination with PEs at their IEPC (0.08 to 1.25 g/kg), MIC of NaCl and NaNO2decreased from between 25 and 50 g/kg to between 6 and 25 g/kg and from more than 200 mg/kg to between 0.2 and 100 mg/kg, respectively. In contrast, lipid (sunflower oil) at a low concentration inhibited the antimicrobial effects of all tested PEs. For extrinsic factors, only allspice, ginger, and coriander could maintain their antimicrobial effects after being heated to 78°C for 30 min. The synergistic effect between PEs and pH values (5.0 and 5.5) was also found for all PEs. The established screening method with resazurin and defining EPC and IEPC values allows the verification of antimicrobial effects of PEs under various food-relevant influencing factors in a fast and reproducible way.

Published
2021
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20. Viable Campylobacter jejunion Eggshells and Its Potential to Cross-contaminate Egg White and Yolk When Using a Manual Separation Technique, Determined by Culture and Propidium Monoazide (PMA) qPCR

Author

Dorn-In, Samart, Daldrup, Eva, Mang, Sirkka, Esteban-Cuesta, Irene, Gareis, Manfred, and Schwaiger, Karin

Abstract

•A total of 22 specific pathogen-free eggs were contaminated with C. jejuni3.1 ± 0.6 log cfu/g.•Separating egg white from yolk using the eggshell results in cross-contamination.•68% egg white and 14% yolk samples were cross-contaminated with C. jejuni.•PMA-qPCR was developed to quantify only viable C. jejunicells on eggshells.•23% of egg packs from retail were positive for dead and 3% for viable C. jejuni.

Published
2024
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21. Shedding of Mycobacterium caprae by wild red deer (Cervus elaphus) in the Bavarian alpine regions, Germany.

Author

Dorn‐In, Samart, Körner, Thomas, Büttner, Mathias, Hafner‐Marx, Angela, Müller, Matthias, Heurich, Marco, Varadharajan, Ashok, Blum, Helmut, Gareis, Manfred, and Schwaiger, Karin

Subjects
*RED deer, *ALPINE regions, *MYCOBACTERIUM, *NATURAL numbers, *MYCOBACTERIUM tuberculosis, *SALIVA
Abstract

The number of natural infections with Mycobacterium caprae in wildlife and in cattle in the Bavarian and Austrian alpine regions has increased over the last decade. Red deer (Cervus elaphus) have been recognized as maintenance reservoir; however, the transmission routes of M. caprae among and from naturally infected red deer are unknown. The unexpected high prevalence in some hot spot regions might suggest an effective indirect transmission of infection. Therefore, this study was undertaken to diagnose the occurrence of M. caprae in faeces and secretions of red deer in their natural habitat. A total of 2,806 red deer hunted in this region during 2014–2016 were included in this study. After pathological examination, organs (lymph nodes, lung, heart), excretions and secretions (faeces, urine, saliva and tonsil swabs) were further investigated by qPCR specific for Mycobacterium tuberculosis complex (MTC), M. bovis and M. caprae. Samples tested positive by qPCR were processed for culturing of mycobacteria. In total, 55 (2.0%) animals were confirmed positive for M. caprae by pathological examination, PCR and culturing of the affected organ material. With the exception of one sample, all of the secretion and excretion samples were negative for mycobacteria of the Mycobacterium tuberculosis complex (MTC). From one red deer, M. caprae could be isolated from the heart sac as well as from the faeces. Whole‐genome sequencing confirmed that both strains were clonally related. This is the first confirmation that M. caprae can be shed with the faeces of a naturally infected red deer. However, further studies focusing on a higher number of infected animals, sample standardization and coordinated multiple sampling are necessary to improve the understanding of transmission routes under natural conditions. [ABSTRACT FROM AUTHOR]

Published
2020
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