title: Incubation of Streptococcus uberis with extracellular matrix proteins enhances adherence to and internalization into bovine mammary epithelial cells.
abstract: Two strains of Streptococcus uberis (UT 888 and UT 366) isolated from cows with clinical mastitis were co-cultured with bovine mammary epithelial cells (MAC-T) with and without laminin, fibrinogen, fibronectin or collagen. Incubation of S. uberis with extracellular matrix proteins (ECMPs) increased adherence to and internalization into MAC-T cells. Both strains of S. uberis exhibited greater adherence when co-cultured in the presence of collagen than with any other ECMP. However, adherence was always higher when strains were co-cultured with ECMP than in medium alone. S. uberis UT 888 adhered better to MAC-T cells than S. uberis UT 366. The influence of ECMPs on bacterial internalization into MAC-T cells was similar to adherence, however, differences among ECMPs were less noticeable. S. uberis UT 888 had a higher internalization index than S. uberis UT 366. It is possible that ECMPs induce or up-regulate proteins that selectively adhere to ECMPs which could serve as a bridge between the eukaryotic cell and the bacterial pathogen that leads to internalization of the ECMP-bound pathogen into the mammary epithelial cell.
authors.affiliation: Department of Animal Science, University of Tennessee, Knoxville 37996, USA. soliver@utk.edu
authors.forename: R A
authors.initials: RA
authors.lastname: Almeida
authors.forename: D A
authors.initials: DA
authors.lastname: Luther
authors.forename: S P
authors.initials: SP
authors.lastname: Oliver
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000187:drug effects*; D002417:Cattle; D002460:Cell Line / Q000382:microbiology; D003094:Collagen / Q000494:pharmacology; D004847:Epithelial Cells / Q000382:microbiology; D016326:Extracellular Matrix Proteins / Q000494:pharmacology*; D005260:Female; D005340:Fibrinogen / Q000494:pharmacology; D005353:Fibronectins / Q000494:pharmacology; D007797:Laminin / Q000494:pharmacology; D008321:Mammary Glands, Animal / Q000382:microbiology; D008413:Mastitis / Q000382:microbiology; D013291:Streptococcus / Q000187:drug effects* / Q000472:pathogenicity / Q000502:physiology
chemical_list: D016326:Extracellular Matrix Proteins; D005353:Fibronectins; D007797:Laminin; D005340:Fibrinogen; D003094:Collagen