title: Role of several Staphylococcus aureus virulence factors on the inflammatory response in bovine mammary gland.
abstract: Staphylococcus aureus causes many serious diseases in humans and animals, and it is the most common aetiologic agent of contagious bovine mastitis. The bacteria produce several virulence factors and the importance of evaluating the combination of these virulence factors has been recently emphasized. In study, the combination of several virulence factors: coagulase gene (coa), protein A gene (spa), collagen-binding protein gene (cna), fibrinogen-binding protein gene (efb), Panton-Valentin leukocydin gene (pvl) and enterotoxins (sea,seb, sec, sed, see, seg, seh, sei, sej) was considered. The analysis of the relationship between presence/absence of the different genes and the udder inflammatory response measured by milk somatic cell counts was performed by general linear models and logistic regression. The classification of isolates in clusters by virulence genes combinations showed that at least one cluster induced a higher inflammatory response. Moreover, the analysis of the association between virulence genes and the presence of a subclinical mastitis showed the role of spa and sej gene as risk factors. These results support that the development of subclinical mastitis could be related to strains characteristics and to the expression of specific combinations of the virulence factors.
authors.affiliation: Department Animal Pathology, Hygiene and Public Health. Università degli Studi di Milano, Via Celoria 10, 20133 Milano, Italy. alfonso.zecconi@unimi.it
authors.forename: Alfonso
authors.initials: A
authors.lastname: Zecconi
authors.forename: Lorenza
authors.initials: L
authors.lastname: Cesaris
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Liandris
authors.forename: Valentina
authors.initials: V
authors.lastname: Daprà
authors.forename: Renata
authors.initials: R
authors.lastname: Piccinini
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002452:Cell Count; D005260:Female; D007249:Inflammation / Q000276:immunology* / Q000382:microbiology; D016015:Logistic Models; D008321:Mammary Glands, Animal / Q000276:immunology* / Q000382:microbiology; D008414:Mastitis, Bovine / Q000276:immunology* / Q000382:microbiology / Q000503:physiopathology; D008892:Milk / Q000166:cytology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors