Streptococcus uberis is one of the most prevalent environmental pathogens of bovine mastitis. Biofilm growth ability by S. uberis looks to depend first upon the adherence of cells to a surface. The S. uberis ability to adhere to mammary gland epithelia might provide an advantage to colonize the lactating mammary gland. The objectives of this study were (a) to select S.uberis strains according to their ability to form biofilm, (b) to determine adherence to and internalization into MAC-T cells and (c) to investigate the expression profile adherence genes in these S. uberis strains. For the assays, the MAC-T bovine mammary epithelial cell line was used. Relative expression of genes acdA, lmb, scpA, sua, fbp and lbp was quantified by RT-qPCR. We observed that the RC38 strain from clinical bovine mastitis showed in the six genes higher values than control in both conditions. While the strain with greater ability to adhere, from clinical mastitis and biofilm producer (RC29) evidenced higher values in group 1 (G₁) (bacteria after the initial contact with MAC-T cells) and decrease in group 2 (G₂) (both adhered and internalized bacteria) than control. Strains with a moderate or strong capacity for biofilm production showed significantly lower relative expression values in the G₂. In all adherence associated genes, strain RC19 showed relative expression values incremented in G_1, while in G₂ decreased expression. In conclusion, we did not find a single profile of relative expression because the relative expression levels of each gene differed depending on the strain and the co-culture stage of S. uberis cells from which RNA was obtained.

乳房链球菌是牛乳腺炎最流行的环境病原体之一。乳房链球菌的生物膜生长能力看起来首先取决于细胞对表面的粘附。在乳房链球菌附着能力乳腺上皮细胞可能会提供一个优势定居于哺乳期乳腺。这项研究的目的是（a）根据其形成生物膜的能力选择乳房链球菌菌株，（b）确定对MAC-T细胞的粘附和内在化，以及（c）研究这些菌株中的表达谱粘附基因乳房链球菌菌株。对于测定，使用了MAC-T牛乳腺上皮细胞系。基因的相对表达ACDA，LMB，SCPA，SUA，FBP和LBP通过RT-qPCR定量。我们观察到，在两种情况下，来自临床牛乳腺炎的RC38菌株在六个基因中均显示出比对照更高的值。而具有更大的能力，以附着，从临床乳腺炎和生物膜生产者（RC29）菌株在第1组（G证明较高的值₁）（与MAC-T细胞中的初始接触后菌）和第2组（G减少₂）（黏附细菌和内在细菌）。具有中等或较强生物膜生产能力的菌株在G _2中显示出相对较低的相对表达值。在所有与粘附相关的基因中，菌株RC19在G _1中显示相对表达值增加_，而在G _2中表达降低。总之，我们没有发现单一的相对表达谱，因为每种基因的相对表达水平取决于从其获得RNA的乳房链球菌细胞的菌株和共培养阶段而不同。