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A Mouse Model to Assess Innate Immune Response to Staphylococcus aureus Infection
Published on: February 28, 2019
Recovery and virulence factors of sublethally injured Staphylococcus aureus after ohmic heating
Lele Shao1, Yijie Zhao1, Bo Zou1
1College of Food Science and Nutritional Engineering, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing, 100083, PR China; Beijing Higher Institution Engineering Research Center of Animal Product, China Agricultural University, No. 17 Qinghua East Road, Haidian District, Beijing, 100083, PR China.
Abstract:
Ohmic heating (OH) is an alternative thermal processing technique, which is widely used to pasteurize or sterilize food. However, sublethally injured Staphylococcus aureus induced by OH is a great concern to food safety. The recovery of injured S. aureus by OH and virulence factor changes during recovery were investigated in this study. The liquid media (phosphate-buffered saline, buffered peptone water and nutrient broth (NB)), temperature (4, 25 and 37 °C) and pH (6.0, 7.2 and 8.0) influenced the recovery rate and the injured cells completely repaired in NB at 37 °C, pH 7.2 with the shortest time of 2 h. The biofilm formation ability, mannitol fermentation, hemolysis, and coagulase activities decreased in injured S. aureus and recovered during repair process. Quantitative real-time PCR showed the expression of sek, clfB and lukH involved in virulence factors increased during recovery. The results indicated that the virulence factors of injured S. aureus recovered after repair.
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