title: Effect of dietary vitamin A on resistance to experimental Staphylococcus mastitis in mice.
abstract: Weanling mice (118) were fed a purified diet free of vitamin A for 3 wk and subsequently assigned to diets containing 10, 100 (4000 IU vitamin A/kg diet), or 300% of National Research Council recommended vitamin A. After 3 wk on the treatment diet all mice were bred and allowed to complete gestation. At 24 h postpartum, the left fourth abdominal mammary gland of each mouse was inoculated with Staphylococcus aureus (10(8) cells in .1 ml of saline/gland), and mammary gland infection was observed daily for 6 consecutive days. Liver vitamin A content was lowest in mice for 10% and highest for 300%. However, mice fed 10% showed normal growth and reproduction by small treatment differences in body weight changes, litter size at birth, and average pup weight. Mice fed 10 and 100% vitamin A showed more severe mammary gland inflammation after intramammary inoculation as opposed to mice fed 300%. Severity of mastitis in mice fed 100% vitamin A was similar to 10%. The number of mice classified as mastitic was also similar between 10 and 100% on days 1 and 2 postinoculation; however, on day 3 postinoculation mice fed 100% had a lower incidence of mastitis as opposed to 10%. Severity of mammary inflammation on days 4 through 6 were similar to those on day 3. Results showed a protective effect of dietary vitamin A supplementation against experimental Staphylococcus aureus mastitis in mice.
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D005260:Female; D005527:Food, Fortified; D008099:Liver / Q000378:metabolism; D008413:Mastitis / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D011247:Pregnancy; D011645:Puerperal Infection / Q000276:immunology* / Q000378:metabolism; D013203:Staphylococcal Infections / Q000276:immunology* / Q000378:metabolism; D013211:Staphylococcus aureus / Q000276:immunology; D014801:Vitamin A / Q000378:metabolism / Q000494:pharmacology*; D014886:Weaning
chemical_list: D014801:Vitamin A