Detection of IL-1β and TNF-α levels in serum samples of mice 48 h post-infection.

<p>Detection of IL-1β and TNF-α levels in serum samples of mice 48 h post-infection.</p

Histopathological changes observed in mouse mammary tissue.

<p>Control mouse showing absence of inflammatory response (Level 0) in mammary tissue (A) to inoculation of sterile normal saline, H&E x100, bar, 200 μm (Fig 1a); Level 1 inflammatory response induced in the mouse teat by inoculation of <i>S</i>. <i>aureus</i> via the mammary duct (A), characterized by acute neutrophil rich response in the intraductal exudate, H&E x400, bar, 50 μm (Fig 1b); Level 2 inflammation of the mammary glands (A) Infiltrate of acute inflammatory cells, predominantly neutrophils, in supporting connective tissue, with intraluminal organisms, H&E x200, bar, 100 μm (Fig 1b); Level 2 inflammation of the mammary tissue post-inoculation of mammary gland with <i>S aureus</i>, characterized by infiltration of acute inflammatory cells, predominantly neutrophils (A), in supporting connective tissue and intraluminal space, H&E x200, bar, 100 μm (Fig 1c); Level 3 inflammation of mammary tissue post-inoculation of mammary gland with <i>S</i>. <i>aureus</i>, characterized by marked acute neutrophil rich infiltrate (A) with tissue necrosis (B), H&E x200, bar, 100 μm (Fig 1c); Level 3 inflammation of the mammary tissue post-inoculation of mammary gland with <i>S</i>. <i>aureus</i>, characterized by marked acute neutrophil-rich infiltrate (A) with tissue necrosis (B), H&E x200, bar, 100 μm (Fig 1d); Level 3 inflammation of the mammary tissue post-inoculation of mammary gland with <i>S</i>. <i>aureus</i>, characterized by neutrophil-rich inflammatory exudate, H&E x1000, bar, 20 μm (Fig 1e); Level 3 inflammation of the mammary tissue post-inoculation of mammary gland with <i>S</i>. <i>aureus</i>, characterized by presence of Gram-positive bacteria and neutrophil-rich inflammatory exudate, Gram Twort x400, bar, 50 μm (Fig 1f).</p

Phenotypic and genotypic characteristics of <i>S</i>. <i>aureus</i> strains used in this study.

<p>Phenotypic and genotypic characteristics of <i>S</i>. <i>aureus</i> strains used in this study.</p

Clinical signs observed in mice infected with strong versus weak-biofilm forming <i>S</i>. <i>aureus</i> strains by intra-mammary route (observations up to 48 hours post inoculum).

<p>Clinical signs observed in mice infected with strong versus weak-biofilm forming <i>S</i>. <i>aureus</i> strains by intra-mammary route (observations up to 48 hours post inoculum).</p