Comparison of the ability of adhesion, invasion and enterotoxin production among strains of Staphylococcus aureus isolated from milk of cows with subclinical mastitis and milk from a human milk bank

• Grant number: 13/01359-2
• Support Opportunities: Scholarships in Brazil - Master
• Start date: May 01, 2013
• End date: February 28, 2015
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Vera Lúcia Mores Rall
• Grantee: Mirella Rossitto Zanutto
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil

Abstract

The bovine mastites is defined as an inflammation of the mammary glands of cows, mainly caused by bacteria, and can be identified in the milk samples due to the increase in somatic cell count (SCC). This disease is a major concern of the dairy industry throughout the world, causing severe economic losses. Several micro-organisms may cause mastitis, however, Staphylococcus aureus are among the main pathogens involved in this framework, due to virulence factors they possess. In humans, S. aureus is the etiologic agent of mastitis in women also infants, affecting 20-30% of the mothers. Despite the many advantages of breast milk, this has no physical protection against secondary contaminants coming from the environment, utensils, donors and practitioners of Human Milk Bank. This specie can invade bovine mammary epithelial cells, which starts with the adhesion to the surface of these cells - the first step towards the establishment of mastitis - leaving the bacterium free from host defense mechanisms and the action of antibiotics and with a nutrient source guaranteed. Biofilms are formed by adhesion of bacteria on solid surfaces with bacterial multiplication and development of a polysaccharide matrix involving the multilayered cells. Several genes are involved in its formation, as the cluster ica and bap gene. Studies have shown the biofilm production by strains isolated from mastitis, but this expression is always tested in vitro in abiotic surfaces such stainless steel, polystyrene, plastic, etc. Therefore, the objective of this study is to assess the invasive and adherence potential of Staphylococcus aureus isolated from milk of cows with subclinical mastitis and human milk from milk bank, in cultures of bovine mammary epithelial cells (BMEC) on this substrate. Also, the strains of S. aureus will be tested for the genes involved in enterotoxins formation by PCR. The culture of bovine mammary epithelial cells will be developed from the raw milk. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ZANUTTO, Mirella Rossitto. Capacidade de adesão, invasão e produção de enterotoxinas de Staphylococcus aureus isolados de leite de vacas com mastite subclínica e leite humano de um banco de leite. 2015. Master's Dissertation - Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu Botucatu.