Immune components present in mammary secretions are reviewed. In swine, the histological structure of the placenta prevents in utero transfer of immunoglobulins and mammary secretions are the sole source of maternal antibody for the neonate. In addition to immunoglobulins, porcine mammary secretions contain significant numbers of maternal cells of various types that may contribute to neonatal immunity, including phagocytes (neutrophils and macrophages), lymphocytes (B and T cells), and epithelial cells. Immunomodulating and/or antimicrobial substances, including lactoferrin, lysozyme, lactoperoxidase, and cytokines, are also present in mammary secretions and may contribute to the protection of the neonate. While the role of immunoglobulins in mammary secretions is well understood, the contribution of cellular components and non-specific immune factors to neonatal immunity remains to be defined.

Outbreak features were consistent with Pontiac fever. Respiratory symptoms, which are atypical for Pontiac fever, could be attributed to a high exposure dose of L. pneumophila from confined-space aerosolization or to endotoxin exposure. This outbreak demonstrates the potential occupational hazards for those performing high-pressure cleaning in confined spaces.

Salmonella is a foodborne pathogenic bacterium that causes human illnesses and morbidity and mortality in swine. Bacteriophages are viruses that prey on bacteria and are naturally found in many microbial environments, including the gut of food animals, and have been suggested as a potential intervention strategy to reduce Salmonella levels in the live animal. The present study was designed to determine if anti-Salmonella phages isolated from the feces of commercial finishing swine could reduce gastrointestinal populations of the foodborne pathogen Salmonella Typhimurium in artificially inoculated swine. Weaned pigs (n = 48) were randomly assigned to two treatment groups (control or phage-treated). Each pig was inoculated with Salmonella Typhimurium (2 × 10(10) colony forming units/pig) via oral gavage at 0 h and fecal samples were collected every 24 h. Swine were inoculated with a phage cocktail via oral gavage (3 × 10(9) plaque forming units) at 24 and 48 h. Pigs were humanely killed at 96 h, and cecal and rectal intestinal contents were collected for quantitative and qualitative analysis. Fecal Salmonella populations in phage-treated pigs were lower (p < 0.09) than controls after 48 h. Phage treatment reduced intestinal populations of inoculated Salmonella Typhimurium in pigs compared to controls at necropsy. Cecal populations were reduced (p = 0.07) by phage treatment >1.4 log(10) colony forming units/g digesta, and rectal populations were numerically reduced. The number of pigs that contained inoculated Salmonella Typhimurium was reduced by phage treatment, but a significant (p < 0.05) reduction was only observed in the rectum. We conclude that phages can be a viable tool to reduce Salmonella in swine. Further research needs to be performed to determine the most efficacious dosing regimens and the most effective combinations of phages targeting the diverse Salmonella population found in swine before they can enter the food supply.

Naïve sows inoculated late in gestation shed PRRS virus in mammary secretions. Previous vaccination appeared to prevent shedding during the subsequent lactation. Results for samples obtained from sows in commercial herds suggested that virus shedding in mammary gland secretions of such sows is uncommon.

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