title: Milk protein profiles in response to Streptococcus agalactiae subclinical mastitis in dairy cows.
abstract: The objective of this study was to investigate the milk protein profiles of normal milk and those of milk during the course of subclinical mastitis, caused by natural Streptococcus agalactiae infection. Two-dimensional gel electrophoresis and liquid chromatography mass spectrometry were used to assess protein profiles and to identify the proteins. The results showed that S. agalactiae subclinical mastitis altered the protein profiles of milk. Following Mascot database matching, 11 and 12 protein types were identified in the milk collected from healthy and S. agalactiae subclinical mastitic udders, respectively. The distinct presence of the antibacterial protein cathelicidin-1 was detected in infected milk samples, which in turn was highly correlated to the severity of subclinical mastitis as represented by the milk somatic cell count (r = 0.616), but not the bacterial count. The protein profile of milk reveals changes in the host response to S. agalactiae intramammary infection; cathelicidin-1 could therefore serve as a biomarker for the detection of subclinical mastitis in dairy cows.
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.|Agricultural Biotechnology Research Center for Sustainable Economy, Khon Kaen University, Khon Kaen, Thailand.|Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok, Thailand.
authors.forename: Pongphol
authors.initials: P
authors.lastname: Pongthaisong
authors.affiliation: Department of Animal Science, Faculty of Agriculture, Khon Kaen University, Khon Kaen, Thailand.|Agricultural Biotechnology Research Center for Sustainable Economy, Khon Kaen University, Khon Kaen, Thailand.|Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok, Thailand.
authors.forename: Suporn
authors.initials: S
authors.lastname: Katawatin
authors.affiliation: Department of Medicine, Faculty of Veterinary Medicine and Research Group of Preventive Technology in Livestock, Khon Kaen University, Khon Kaen, Thailand.
authors.forename: Chaiyapas
authors.initials: C
authors.lastname: Thamrongyoswittayakul
authors.affiliation: National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathumthani, Thailand.
authors.forename: Sittiruk
authors.initials: S
authors.lastname: Roytrakul
mesh_terms: D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000032:analysis; D015415:Biomarkers / Q000032:analysis; D002417:Cattle; D002853:Chromatography, Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D013058:Mass Spectrometry; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000378:metabolism* / Q000382:microbiology*; D008892:Milk / Q000737:chemistry* / Q000166:cytology; D008894:Milk Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D012720:Severity of Illness Index; D013290:Streptococcal Infections; D013292:Streptococcus agalactiae; D054804:Cathelicidins
chemical_list: D023181:Antimicrobial Cationic Peptides; D015415:Biomarkers; D008894:Milk Proteins; D054804:Cathelicidins
keywords: 2D-PAGE; antimicrobial protein; bovine; mammary gland; proteomics