Journal
FEMS MICROBIOLOGY LETTERS
Volume 193, Issue 1, Pages 57-62Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0378-1097(00)00455-9
Keywords
mastitis; internalization; invasion; Staphylococcus aureus
Categories
Ask authors/readers for more resources
Numerous in vitro studies have demonstrated that Staphylococcus aureus may be internalized and survive in a bovine mammary epithelial cell line. We report here the presence of internalized and living S. aureus in alveolar cells and macrophages in milk samples of bovine mastitis. We used fluorochrome labeled monoclonal antibodies, specifically recognizing surface cell markers of bovine alveolar cells and macrophages, to isolate these two types of cells using fluorescence activated cell sorting. Extracellular bacteria and DNA were previously eliminated to exclude possible contamination, In order to detect intracellular bacterial DNA inside the isolated cells, we used PCR amplification of bacterial DNA and the PCR products were analyzed by Southern blot with a specific probe for Staphylococcus. The results showed the presence of Staphylococcus DNA inside the two isolated populations of cells, confirming that S. aureus could penetrate alveolar cells and macrophages. The demonstration of the presence of intracellular living S. aureus was determined by bacteriological culture of positive samples plated onto blood agar plates and by its further identification. Our results showed for the first time that living S. aureus and its DNA are present in both alveolar cells and macrophages in chronically infected cow milk. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available