title: Invasion of bovine mammary epithelial cells by Streptococcus dysgalactiae.
abstract: Two strains of Streptococcus dysgalactiae, isolated from cows with mastitis, were assayed for their ability to invade, multiply, and induce damage to a bovine mammary epithelial cell line, MAC-T. Invasion of S. dysgalactiae into MAC-T cells was time-dependent, and invasion was inhibited in a dose-dependent manner by cytochalasin B and D, but not by colchicine. The invasion process did not appear to affect viability of mammary epithelial cells, but cellular damage was induced, as indicated by a time-dependent release of increasing amounts of lactate dehydrogenase. No net intracellular bacterial growth was observed, but S. dysgalactiae survived inside MAC-T cells. These results indicated that S. dysgalactiae invaded epithelial cells, induced cellular damage, and was capable of persisting inside bovine mammary epithelial cells.
authors.affiliation: Department of Animal Science, University of Tennessee, Knoxville 37901-1071, USA.
authors.forename: R A
authors.initials: RA
authors.lastname: Almeida
authors.forename: S P
authors.initials: SP
authors.lastname: Oliver
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D002470:Cell Survival; D003078:Colchicine / Q000494:pharmacology; D003571:Cytochalasin B / Q000494:pharmacology; D015638:Cytochalasin D / Q000494:pharmacology; D004848:Epithelium / Q000382:microbiology / Q000648:ultrastructure; D005260:Female; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008321:Mammary Glands, Animal / Q000382:microbiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D013291:Streptococcus / Q000187:drug effects / Q000254:growth & development* / Q000302:isolation & purification
chemical_list: D015638:Cytochalasin D; D003571:Cytochalasin B; D007770:L-Lactate Dehydrogenase; D003078:Colchicine