Sequential changes in serum albumin, immunoglobulin (IgG1, IgG2, IgM) and lactoferrin concentrations in milk following infusion of Escherichia coli into the udder of immunised and unimmunised cows.
Two immunised and three unimmunised cows were infected in a single mammary gland with 10(4) CFU of the vaccine Escherichia coli strain. Immunisation comprised systemic (subcutaneous) injection of killed bacteria at drying-off and one intramammary infusion five weeks later. Immunoglobulin (Ig) G1, IgG2, lgM, serum albumin (BSA) and lactoferrin concentrations were monitored by sampling the inoculated glands at 2 h-intervals during the first 16 h post-inoculation, then at each milking for four days. Whether immunised or not, mammary glands started to react at 10 h post-inoculation. During the early acute phase, IgG1 and IgG2 permeated from blood into milk at a rate similar to BSA. Later on, IgM (and at a lower degree IgG1) concentrations were higher than expected on the basis of passive transfer. Marked protein exudation was seen in all of the cows but one. Nevertheless, this cow (immunised) showed an intense cellular reaction like the other animals. Lactoferrin concentrations rose from 24-32 h post-inoculation and remained elevated to the end of the observed period in inoculated quarters in unimmunised cows. By contrast, in immunised cows lactoferrin concentrations remained low. Heat-labile bactericidal activity against a serum-sensitive E. coli strain appeared concomitantly with rise in BSA concentration. Heat-resistant bactericidal activity of cell-free milk was detected one or two days later in three of the cows. Bacteriological cure of quarters occurred without therapy in all cases.
D000818:Animals; D001428:Bacterial Vaccines / Q000008:administration & dosage; D002417:Cattle; D004927:Escherichia coli Infections / Q000276:immunology*; D005260:Female; D007114:Immunization / Q000662:veterinary; D007074:Immunoglobulin G / Q000032:analysis*; D007075:Immunoglobulin M / Q000032:analysis*; D007781:Lactoferrin / Q000032:analysis*; D007782:Lactoglobulins / Q000032:analysis*; D008321:Mammary Glands, Animal / Q000382:microbiology*; D008414:Mastitis, Bovine / Q000276:immunology*; D008892:Milk / Q000276:immunology*; D008894:Milk Proteins / Q000032:analysis; D012710:Serum Albumin, Bovine / Q000032:analysis*; D013997:Time Factors
D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D007782:Lactoglobulins; D008894:Milk Proteins; D012710:Serum Albumin, Bovine; D007781:Lactoferrin