Listeria monocytogenes efficiently invades caco-2 cells after low-temperature storage in broth and on deli meat
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Listeria monocytogenes efficiently invades caco-2 cells after low-temperature storage in broth and on deli meat. / Larsen, Marianne Halberg; Koch, Anette Granly; Ingmer, Hanne.
I: Foodborne Pathogens and Diseases, Bind 7, Nr. 9, 2010, s. 1013-1018.Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
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T1 - Listeria monocytogenes efficiently invades caco-2 cells after low-temperature storage in broth and on deli meat
AU - Larsen, Marianne Halberg
AU - Koch, Anette Granly
AU - Ingmer, Hanne
PY - 2010
Y1 - 2010
N2 - The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p < 0.05) than the strains isolated from meat and food-processing environments (3008, 3126, and 4140) after grown in BHI at 30 degrees C. This attenuation could not be ascribed to a defective Internalin A as all strains encoded an intact inlA gene. To determine the influence of food products on virulence, the ability of L. monocytogenes to invade Caco-2 cells was compared after growth on a fermented sausage and on cured cooked ham to that of bacteria grown in BHI broth supplemented with salt. Samples were stored under chilling conditions for up to 4 weeks. The results showed no difference (p > 0.05) in invasiveness after 7 days at 10 degrees C in BHI broth or on sausage, whereas a slight increase (p < 0.05) was observed after incubation on ham for 2 and 4 weeks compared to that in BHI broth. Most importantly, our results show that L. monocytogenes efficiently invade Caco-2 cells even after 4 weeks of storage at chilled temperature. This is highly relevant for safety assessment of this organism in food as these conditions reflect storage of ready-to-eat food products in domestic refrigerators. Udgivelsesdato: sep 2010
AB - The objective of this study was to investigate how various growth conditions influence the virulence of Listeria monocytogenes monitored by its ability to invade the epithelial cell lines Caco-2 and INT-407. The growth conditions examined were modified atmosphere-packaged deli meat and brain heart infusion broth (BHI) with and without salt. Five strains of L. monocytogenes were selected to investigate their invasiveness and all strains invaded Caco-2 cells at higher levels than INT-407 cells. Further, the clinical strains (3443 and 3734) were more invasive (p < 0.05) than the strains isolated from meat and food-processing environments (3008, 3126, and 4140) after grown in BHI at 30 degrees C. This attenuation could not be ascribed to a defective Internalin A as all strains encoded an intact inlA gene. To determine the influence of food products on virulence, the ability of L. monocytogenes to invade Caco-2 cells was compared after growth on a fermented sausage and on cured cooked ham to that of bacteria grown in BHI broth supplemented with salt. Samples were stored under chilling conditions for up to 4 weeks. The results showed no difference (p > 0.05) in invasiveness after 7 days at 10 degrees C in BHI broth or on sausage, whereas a slight increase (p < 0.05) was observed after incubation on ham for 2 and 4 weeks compared to that in BHI broth. Most importantly, our results show that L. monocytogenes efficiently invade Caco-2 cells even after 4 weeks of storage at chilled temperature. This is highly relevant for safety assessment of this organism in food as these conditions reflect storage of ready-to-eat food products in domestic refrigerators. Udgivelsesdato: sep 2010
U2 - 10.1089/fpd.2009.0470
DO - 10.1089/fpd.2009.0470
M3 - Journal article
C2 - 20443727
VL - 7
SP - 1013
EP - 1018
JO - Foodborne Pathogens and Disease
JF - Foodborne Pathogens and Disease
SN - 1535-3141
IS - 9
ER -
ID: 22150275