Possible involvement of selenium inStaphylococcus aureusinhibition in cow's whey

Abstract

Previous investigations have shown that selenium supplementation inhibits growth of mastitis pathogens in cow's milk. The present study was performed to clarify the role of selenium in defence mechanisms of mammary gland. We have examined the effects of selenium supplementation on Staphylococcus aureus growth inhibiting activity in whey. Six selenium-supplemented and six non-supplemented Estonian dairy cows were used for this study. Selenium-supplemented cows received 4 mg organic selenium in the form of selenium yeast in their daily diet for 8-week period. Cows from non-supplemented group received the same amount of yeast free of selenium in their diet. All cows had initially low blood glutathione peroxidase (GPx) activity (<or=1.02 microkat/g Hb). During the 8-week experiment these cows had low somatic cell count (<300,000 cells/ml) and negative bacteriological findings in their quarter milk samples. Bacterial growth inhibitory activity in specific whey fractions was clearly evident in 3 out of 6 cows supplemented with selenium. The inhibitory effect was more profound if the cow's blood GPx activity exceeded 4 microkat/g Hb, whereas in non-supplemented cows the inhibition of S. aureus growth was not observed. This study confirms the presence of selenium-dependent antibacterial activity in cow's milk.

The effect of selenium sources and supplementation on neutrophil functions in dairy cows

“…Our findings are in agreement with several authors who demonstrated that neutrophils from cows with supplemental Se (inorganic) increased intracellular kill of bacteria, enhanced viability and reduced extracellular hydrogen peroxide concentration as compared to non supplemented cows (Gyang et al, 1984;Grasso et al, 1990;Hogan et al, 1990). Malbe et al (2006) also demonstrated possible involvement of organic Se supplementation (4 mg/day) with Staphylococcus aureus inhibition in cow's whey. In our study, these effects were more pronounced with organic Se at both levels of supplementation.…”

Bacterial Diversity of Breast Milk in Healthy Spanish Women: Evolution from Birth to Five Years Postpartum

“…This fact may be linked to the inhibitory effects of this mineral on staphylococci growth, as previously demonstrated by in vitro studies with S. aureus and Se nanoparticles [ 66 ]. Additionally, it has been observed that supplementation of dairy cattle with Se inhibits the growth of S. aureus in bovine milk, in comparison with control cows [ 67 ]. Similarly, a recent in vivo study has demonstrated that organic Se ameliorates S. aureus induced mastitis in rats [ 68 ].…”

The role of dietary selenium in bovine mammary gland health and immune function

“…Sodium selenite SCC; GSH-Px d SCC decreased significantly (P <0.05) from 2961•10 3 to 630• 10 3 in buffaloes screened positive for intra mammary infections, whereas GSH-Px activity increased significantly. Malbe et al (2006) C 4 mg day À1 in diet (8 weeks)…”

“…In an experiment described by Hemingway (1999), 14 of 36 cows receiving intramammary antibiotic infusions at drying off needed extra treatment in the subsequent lactation, whereas only 5 of 36 cows which received additionally 4 mg Se at drying off needed such treatment. Udder health benefits have been attributed to antibacterial activities against S. aureus in milk whey protein (Ali-Vehmas et al , 1997; Malbe et al , 2006). The underlying mechanism of this antibacterial activity is not well understood.…”

“…Neutrophils from the Se-yeast fed group exhibited a little higher value than did neutrophils from the group fed sodium selenite (Weiss and Hogan, 2005). Unspecified antibacterial activity against Staphylococcus aureus has been reported in milk whey from cows fed 4 mg supplemental Se as Se-yeast in their daily rations (Malbe et al , 2006).…”