Untreated and Enzyme-Modified Bovine Whey Products Reduce Association of Salmonella Typhimurium, Escherichia coli O157:H7 and Cronobacter malonaticus (formerly Enterobacter sakazakii) to CaCo-2 Cells

Adhesion of a micro-organism to a cell surface is often considered to be the first step in pathogenesis. Inhibiting this process may have therapeutic effects in vivo. This study investigates the inhibitory effects of various bovine whey products on the association of Salm. Typhimurium, E. coli O157:H7 and C. malonaticus (formerly Enterobacter sakazakii) to the human CaCo-2 cell line. Invasion of CaCo-2 cells by Salm. Typhimurium and C. malonaticus was also examined

The Effect of Untreated and Enzyme-Treated Commercial Dairy Powders on the Growth and Adhesion of Streptococcus mutans

Dental caries is a common bacterial infection, but the progression of this disease can be delayed by preventing initial attachment of cariogenic bacteria such as Streptococcus mutans to tooth surfaces. This study firstly compares the effect of untreated (UT) and enzyme-treated (ET) dairy powders on the adherence of S. mutans to hydroxylapatite (HA), an analogue of tooth enamel. A fluorescence-based method was used to quantify adherence of S. mutans to HA both in the presence (S-HA) and absence (PBS-HA) of saliva. Secondly, binding of proteins present in the test materials to HA was quantified using bicinchonic acid assays and SDS-PAGE. In addition, the effect of UT and ET dairy powders on growth of S. mutans was examined using an optical-density based assay. UT acid whey protein concentrate (WPC) 80, sweet WPC80, buttermilk powder (BMP) and cream powder (CP) significantly (P < 0.05) inhibited adhesion of S. mutans at ≥31.25 μg mL−1 in the presence and absence of saliva. ET dairy powders were less effective inhibitors of adhesion, but ET sweet WPC80 significantly (P < 0.05) inhibited growth of S. mutans at ≥0.6 mg mL−1. Therefore, due to their adherence- and growth-inhibitory properties, dairy powders may be beneficial in the treatment of dental caries

Determination of the Effect of Dairy Powders on Adherence of Streptococcus sobrinus and Streptococcus salivarius to Hydroxylapatite and Growth of these Bacteria

Dental caries is a highly prevalent disease caused by colonisation of tooth surfaces by cariogenic bacteria, such as Streptococcus sobrinus and Streptococcus salivarius. Reducing initial adherence of such bacteria to teeth may delay onset of caries. Many foods, such as milk, can inhibit microbial adherence. In this investigation, the effect of untreated (UT) and enzyme-treated (ET) dairy powders on adherence of S. sobrinus and S. salivarius to hydroxylapatite (HA), an analogue of tooth enamel, was examined. Untreated (UT) acid whey protein concentrate (AWPC) 80 inhibited streptococcal adherence to phosphate-buffered saline-coated HA (PBS-HA) and saliva-coated HA (S-HA) by >80% at ⩾31.25 μg mL−1. UT sweet WPC80, buttermilk powder and cream powder also significantly reduced adherence (P < 0.05). Enzyme-treatment of all dairy powders reduced their anti-adhesion activity. However, ET sweet WPC80 significantly inhibited growth of these streptococci (P < 0.05) at ⩾0.6 mg mL−1. Therefore, dairy powders may reduce progression of dental caries by their anti-adhesion and/or antibacterial activity