Nonspecific Antibacterial Factors in Milk from Cows Immunized with Human Oral Bacterial Pathogens

¹ Department of Oral Sciences, Clinical Research Center for Periodontal Diseases, School of Dentistry, University of Minnesota, Minneapolis 55455
² Procor Technologies, Inc. and Land O'Lakes, Inc. Arden Hills, MN 55112

Both the immunoglobulins and non-specific antibacterial factors in milk from cows immunized with pathogenic oral bacteria have the potential to influence the oral microflora during passive immunization studies. The first six milks after calving were collected from 2 cows immunized with adjuvant and from 14 cows immunized with adjuvant and heat-killed strains of periodontopathic Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Analysis of the products from the first to the sixth milks revealed that the protein and lysozyme content decreased approximately 66 and 72%, respectively; the mean specific activity of the enzyme remained relatively constant. In contrast, the mean lactoperoxidase activity increased 2.3-fold in the second milking and increased further in the fourth and sixth milkings. The mean iron-binding activity increased 1.2-fold from the first to the second milkings and then decreased 3.6-fold through the sixth milking. Cows immunized with adjuvant alone showed similar responses. Per unit volume, the milk contained approximately 150 times less lysozyme than whole human saliva obtained from six subjects but higher concentrations of lactoperoxidase and iron-binding components. Purified bovine nonspecific factors prevented the growth of the bacteria used for immunization when bacteria were tested at concentrations similar to those found in saliva and milk. Because bovine nonspecific antibacterial factors could influence both the pathogenic target bacteria and the indigenous microflora in oral passive immunization studies with bovine immunoglobulins, the presence of these proteins should be considered.

Key Words: antibacterial factors • bovine milk • oral bacteria

Submitted on December 2, 1991
Accepted on March 10, 1992

This article has been cited by other articles:

				T. Oho, Y. Shimazaki, M. Mitoma, M. Yoshimura, Y. Yamashita, K. Okano, Y. Nakano, H. Kawagoe, M. Fukuyama, N. Fujihara, et al. Bovine Milk Antibodies against Cell Surface Protein Antigen PAc-Glucosyltransferase Fusion Protein Suppress Cell Adhesion and Alter Glucan Synthesis of Streptococcus mutans J. Nutr., October 1, 1999; 129(10): 1836 - 1841. [Abstract] [Full Text]