Inhibition of adhesion of S‐fimbriated E. coli to buccal epithelial cells by human skim milk is predominantly mediated by mucins and depends on the period of lactation

Abstract

Expression of S-fimbriae is frequent in Escherichia coli strains causing sepsis and meningitis in the newborn period. We analysed the ability of human skim milk to inhibit adhesion of S-fimbriated E. coli to human buccal epithelia. Adhesion was inhibited by up to 90% using colostrum (5%) and up to 50% with mature milk (5%), indicating that this anti-infective mechanism depends on the period of lactation. Elimination of up to 99% of immunoglobulins and 91% of lactoferrin by affinity chromatography had no effect on the inhibition of adhesion. After separation of high- (> 10 kD) and low-molecular-weight fractions of skim milk, only the fraction > 10 kD was found to be able to inhibit bacterial adhesion. In order to further characterize receptor molecules for bacteria, we investigated binding of isolated S-fimbriae to glycoprotein bands on Western blot strips. Fimbriae mainly bound to a high-molecular-weight band (> 200 kD). According to molecular weight and staining behaviour, this band most likely represents mucins. We conclude that carbohydrate residues on secreted mucins of human skim milk are able to inhibit bacterial adhesion to mucosal surfaces. This could provide protection against neonatal sepsis and meningitis caused by E. coli.

Expression and localization of Muc4/sialomucin complex (SMC) in the adult and developing rat intestine: Implications for Muc4/SMC function

“…It has been suggested that milk mucins provide protection to newborns against microbes (Schroten et al, 1992;Patton et al, 1995). Colonic goblet cells synthesize and secrete mucins that provide a physical and chemical barrier that protects the epithelium from agents such as bacteria, bacterial and environmental toxins, and some dietary components (Specian and Oliver, 1991).…”

Glycoproteins of the Human Milk Fat Globule in the Protection of the Breast-Fed Infant against Infections

“…In addition, the mucin fractions from meconium and from feces from human milk-fed infants were also found to have inhibitory activity, while mucin from feces from formula-fed infants was less effective [21]. Skim milk was also found to have inhibitory activity, the greatest being in colostrum compared to mature milk, and the activity was associated with high molecular weight material (1200 kD) characteristic of mucins [22]. Although whether or not MUC-1, MUC-X, or other mucins are involved in this inhibi- tory activity has not been determined, it is important to note that large fragments of MUC-1 milk mucin have been detected in feces of breast-fed infants.…”

Aptamer‐based Biosensor Developed to Monitor MUC1 Released by Prostate Cancer Cells

“…Its primary function is to protect the cells from mechanical damage, harmful chemicals and pathogens through epithelia lubrication and hydration. Moreover, its extracellular domain has adhesive and antiadhesive features that can help decreasing the immune response . Despite its regular physiological functions, MUC1 plays a key role in boosting many malignant tumor types, including breast, colon, lung, gastric, pancreatic and prostate carcinomas.…”