Expression of lymphocyte homing and adhesion molecules during intramammary infection of cows with Serratia marcescens or Streptococcus uberis: Correlation with bacterial colonization and clinical signs

摘要: We wished to determine the expression of trafficking/adhesion molecules on surface lymphocytes isolated from infected mammary glands cows challenged with either Serratia marcescens or Staphylococcus uberis. Healthy Holstein in mid lactation were by intramammary infusion S. Following infection, milk samples collected at various time points. Body temperatures taken, and was analyzed for colony forming units (CFU) bacteria somatic cell counts (SCC). Leukocytes flow cytometry. Percentages types determined as well CD62L, CD11a, LPAM-1 CD44 these cells. found that percentage expressing CD62L CD11a showed a marked increase 12 h post infection (PI) not seen Conversely, increased uberis PI, but marcescens. Expression low all points both groups cows. became elevated cows, peaking 24 PI marcescens-infected dropping thereafter. In contrast, uberis-infected continued rise still 96 PI. CFU dropped precipitously high levels SCC began falling 48 Thus, greater had phenotype consistent recruitment peripheral pool following than Concurrent increases percentages this lymphocyte phenotype, clinical signs lessened