Staphylococcus aureus lipotechoic acid induces differential expression of bovine serum amyloid A3 (SAA3) by mammary epithelial cells: Implications for early diagnosis of mastitis

Annika Weber, Allen T. Weber, Thomas L. McDonald, Marilynn A. Larson

Research output: Contribution to journalArticle

32 Scopus citations


Mastitis is one of the most costly diseases of agriculturally important animals and is a common problem for lactating cows. Current methods used to detect clinical and especially subclinical mastitis are either inadequate or problematic. Pathogens such as the gram-positive bacterium Staphylococcus aureus or the gram-negative bacterium Escherichia coli typically cause mastitis. E. coli induces clinical mastitis, whereas, S. aureus causes a subclinical, chronic infection of the mammary gland. In this study we report the differential expression and secretion of mammary-derived serum amyloid A3 (SAA3) by bovine mammary epithelial cells following stimulation with the S. aureus cell wall component, lipotechoic acid (LTA). Two-dimensional immunoblot analyses confirmed that bovine SAA3 is the predominant SAA isoform produced by LTA stimulated mammary epithelial cells. Our previous study showed that bovine SAA3 is also differentially expressed in response to the gram-negative bacterial endotoxin lipopolysaccharide. Collectively, these data indicate that the local production of SAA3 by mammary epithelial cells in response to either gram-positive or gram-negative bacterial components may provide a sensitive indicator for early detection and treatment of mastitis in vivo, minimizing chronic cases of infection, the spread of mastitis to other animals, and economic losses.

Original languageEnglish (US)
Pages (from-to)79-83
Number of pages5
JournalVeterinary Immunology and Immunopathology
Issue number1-2
Publication statusPublished - Jan 15 2006



  • Bovine serum amyloid A3
  • Lipotechoic acid
  • Mammary gland
  • Mastitis diagnostic marker
  • Staphylococcus aureus

ASJC Scopus subject areas

  • Immunology
  • veterinary(all)

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