SECRETORY IGA DOES NOT ENHANCE THE BACTERIOSTATIC EFFECTS OF IRON-BINDING OR VITAMIN-B12-BINDING PROTEINS IN HUMAN COLOSTRUM

  • 1 January 1979
    • journal article
    • research article
    • Vol. 38  (2) , 367-373
Abstract
Human milk contains an unsaturated iron-binding protein (lactoferrin) and an unsaturated vitamin B12-binding protein. Lactoferrin has bacteriostatic properties, and a bacteriostatic role for the B12-binding protein was postulated. The bacteriostatic effect of lactoferrin was confirmed for strains of Escherichia coli, Pseudomonas and Proteus. Growth inhibition attributable to the unsaturated B12-binding protein could be demonstrated only with a known vitamin B12-dependent E. coli. The bacteriostatic effect of lactoferrin is potentiated by horse Ig[immunoglobulin]G antibody [Ab] and a similar potentiating effect of secretory IgA Ab in colostrum and milk would have obvious importance. Secretory IgA Ab does not enhance the growth-inhibiting effects of lactoferrin or the vitamin B12-binding protein.