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The burden of diarrhoeal disease and the progressive increase in antibiotic resistance to enteric pathogens is a critical area of concern that necessitates exploration of alternative therapeutic approaches. Free secretory component (FSC), derived from human milk, has been shown to inhibit adhesion and invasion of pathogenic bacteria. Cows' milk also contains FSC, but its activity has not yet been characterised. FSC was purified from non-pasteurised and pasteurised bovine milk. The binding properties of purified bovine FSC were investigated against enteropathogenic Escherichia coli (EPEC). Bovine FSC bound to EPEC and facilitated aggregation of the bacteria. FSC also attenuated binding of EPEC to Caco-2 cells. Pasteurisation of milk before extraction of FSC did not affect activity of the FSC. These activities of FSC are consistent with a role in suppressing colonisation of EPEC. Milk extracts enriched for bovine FSC have potential as an alternative to antibiotic therapy for protection against diarrhoeal disease.

Skimmed milk powder (SMP) and whey protein concentrate (WPC) were manufactured from fresh milk collected from cows producing high or low Immunoglobulin (Ig) A levels in their milk. In addition commercial products were purchased for use as diluent or control treatments. A murine enteric disease model (Citrobacter rodentium) was used to assess whether delivery of selected bioactive molecules (IgA, IgG, Lactoferrin (Lf)) or formulation delivery matrix (SMP, WPC) affected faecal shedding of bacteria in C. rodentium infected mice. In trial one, faecal pellets collected from mice fed SMP containing IgA (0.007–0.35 mg/mL), IgG (0.28–0.58 mg/mL) and Lf (0.03–0.1 mg/mL) contained fewer C. rodentium (cfu) compared to control mice fed water (day 8, p < 0.04, analysis of variance (ANOVA) followed by Fisher’s unprotected least significant difference (ULSD)). In trial two, WPC containing IgA (0.35–1.66 mg/mL), IgG (0.58–2.36 mg/mL) and Lf (0.02–0.45 mg/mL) did not affect C. rodentium shedding, but SMP again reduced faecal C. rodentium levels (day 12, p < 0.04, ANOVA followed by Fisher’s ULSD). No C. rodentium was detected in sham phosphate-buffered saline inoculated mice. Mice fed a commercial WPC shed significantly greater numbers of C. rodentium over 4 consecutive days (Fishers ULSD test), compared to control mice fed water. These data indicate that SMP, but not WPC, modulates faecal shedding in C. rodentium-infected mice and may impact progression of C. rodentium infection independently of selected bioactive concentration. This suggests that food matrix can impact biological effects of foods.

Two members of the ribonucleaseA (RNaseA) family were identified in cows' milk. RNase5, already known to be present, was found at concentrations between 3 and 19 μg mL−1. RNase4, which was not previously known to be in milk, was found at concentrations between 1 and 4 μg mL−1. These proteins were purified from milk. Purified RNase5 suppressed the growth of Candida albicans, particularly its hyphal form, but not any other microbes tested. The concentrations required to suppress growth were higher than those found in milk. RNase4 had no growth suppression activity. Both RNases reduced the number of viable C. albicans cells, with RNase5 being the more potent. This activity was abrogated by physiological concentrations of NaCl. Although both RNases bound to C. albicans cell membrane, their mode of action was not through membrane lysis or permeabilization. Together, these results suggest that the bovine milk RNases do not have intrinsic anti-microbial activity in milk.

The serum amyloid A protein is one of the major reactants in the acute-phase response. Using representational difference analysis comparing RNA from normal and involuting quarters of a dairy cow mammary gland, we found an mRNA encoding the SAA3 protein (M-SAA3). The M-SAA3 mRNA was localized to restricted populations of bovine mammary epithelial cells (MECs). It was expressed at a moderate level in late pregnancy, at a low level through lactation, was induced early in milk stasis, and expressed at high levels in most MECs during mid to late involution and inflammation/mastitis. The mature M-SAA3 peptide was expressed in Escherichia coli, antibodies made, and shown to have antibacterial activity against E. coli, Streptococcus uberis and Pseudomonas aeruginosa. These results suggest that the mammary SAA3 may have a role in protection of the mammary gland during remodelling and infection and possibly in the neonate gastrointestinal tract.

Results from large multicentre epidemiological studies suggest an association between the consumption of raw milk and a reduced incidence of allergy and asthma in children. Although the underlying mechanisms for this association are yet to be confirmed, researchers have investigated whether bacteria or bacterial components that naturally occur in cow’s milk are responsible for modulating the immune system to reduce the risk of allergic diseases. Previous research in human and mice suggests that bacterial components derived from the maternal intestine are transported to breast milk through the bloodstream. The aim of our study was to assess whether a similar mechanism of bacterial trafficking could occur in the cow. Through the application of culture-independent methodology, we investigated the microbial composition and diversity of milk, blood and feces of healthy lactating cows. We found that a small number of bacterial OTUs belonging to the genera Ruminococcus and Bifidobacterium, and the Peptostreptococcaceae family were present in all three samples from the same individual animals. Although these results do not confirm the hypothesis that trafficking of intestinal bacteria into mammary secretions does occur in the cow, they support the existence of an endogenous entero-mammary pathway for some bacterial components during lactation in the cow. Further research is required to define the specific mechanisms by which gut bacteria are transported into the mammary gland of the cow, and the health implications of such bacteria being present in milk.

A ruminant mammary cell culture that accurately reproduces mammary function in vitro would be a valuable tool in studies of ruminant lactation. With this in mind, we have examined milk protein synthesis and secretion, milk protein mRNA abundance, and hormonal responsiveness in primary cultures of mammary acini from lactating sheep. alpha- and beta-casein protein synthesis, beta-lactoglobulin synthesis, and alpha-casein, beta-casein, and beta-lactoglobulin secretion are maintained at high levels for 8 h in culture, but then decline to approximately 25% of maximal rates between 8 and 24 h in culture, whereas synthesis of other proteins remains unaltered. The relative abundance of alpha-S1-casein, beta-lactoglobulin, and alpha-lactalbumin mRNAs similarly decline between 8 and 24 h in culture. Extracellular labeled alpha-casein is increased fourfold in the presence of fetal calf serum (FCS). In total, FCS alters the abundance of 47 of 68 secreted proteins detected by two-dimensional electrophoresis. However, FCS and lactogenic/galactopoietic hormones had no effect on the rate of decline of mammary function and did not promote any regaining of function when present for up to 9 days in culture. These results suggest that providing its limitations are recognized, this primary cell culture system may be useful in studying some aspects of ruminant mammary function in vitro.

The family of BPI-like proteins are thought to play a role in innate immunity of the airways and oral cavity. They have similarities with bactericidal/permeability-increasing protein (BPI), an important host defence molecule in mammals, in the nucleotide sequence of their mRNAs, organisation of exons and their predicted protein structure. We compared the expression and function of 2 of the 13 known bovine BPI-like proteins, BSP30a and b, which together constitute 30% of the total protein in bovine saliva. Despite their recent divergence, we found that the two proteins have unique expression patterns, considerable inter- and intra-animal variation in abundance and differ in their glycosylation status. Recombinant and native BSP30a and b exhibited growth suppression activity against Pseudomonas aeruginosa and Streptococcus pneumoniae. Native BSP30a and b had no significant lipopolysaccharide-binding activity. These data provide functional evidence supporting a role for the BPI-like proteins in host defence and suggest that BSP30a and b contribute to the growth suppression function of bovine saliva through a mechanism independent of LPS opsonisation.

This volume represents a wide range of disciplines—English, anthropology, history, Irish and European studies, sociology, and geography—and deals with both Ireland and Northern Ireland, stretching from the late eighteenth century to the present. Editors Marilyn Cohen and Nancy J. Curtin define their project as a theoretical analysis of gender, an approach that results in compelling revisions of Irish studies, as well as contributions to gender and feminist theory relevant beyond the geographical focus of the book. For an indication of the range of topics addressed, consider articles by Cohen, Jane Gray, and Gordon Bigelow, which demonstrate how attention to gender can offer insights into migration, industrialization, and domestic economy.