Figure 11
From: Local immunization impacts the response of dairy cows to Escherichia coli mastitis
Assessment of the bactericidal activity of whole milk and of the opsonic activity of milk and serum. (a) Survival of bacteria (EcP4) after 1 h of incubation under agitation in whole milk drawn from infected glands at 12, 16 or 32 hpi. (b) Opsonic activity of milk assessed through the survival of bacteria incubated with blood granulocytes for 90 min under agitation in the presence of 20% milk drawn from glands immediately before challenge (H0). (c) Opsonic activity of serum before immunisation (I0) and 2 weeks after the booster immunization (R14), assessed through the survival of bacteria (EcP4) incubated with blood granulocytes for 90 min under agitation in the presence of 0.25% serum. (d) Opsonic activity of immune serum (R14) used at 1% in the phagocytic mixture. *p < 0.05, Friedman test and post hoc Dunn’s multiple comparison test.
