Staphylococcus spp.

• Gram positive cocci

Staphylococcus hyicus

• Pigs - greasy pig disease
• Exudative epidermitis due to Staphylococcus hyicus is a worldwide problem in piglets.
• The organism can often be isolated from the mucosa and skin of healthy adult pigs, and can persist in the environment for long periods.
• Disease occurs only in young piglets up to about 35 days of age.
• Passive transfer of antibodies from immune sows and development of immunity with age appear to adequately protect against disease.
• Piglets from non-immune sows are predisposed.
• Skin trauma, such as due to fighting, allowing entry of infective organisms is also considered a risk factor in this disease.

Pathology

Pathogenesis

• Staphylococcus hyicus produces an exfoliative toxin of approximately 30 kDa that causes separation of cells in the upper stratum spinosum resulting in rapid intraepidermal spread of organisms.
• Death of affected piglets is common and is attributed to dehydration, septicemia, or both.
• This porcine disorder has been likened to “scalded skin syndrome” in human neonates, due to skin infection by exfoliative toxin-producing Staphylococcus aureus.

Differential diagnosis

• mange (Sarcoptes scabiei var. suis)
• swine parakeratosis (zinc and essential fatty acid deficiency)
• porcine juvenile pustular psoriasiform dermatitis (collarettes or rings typically on the ventrum of young pigs)
• dermatosis vegetans (associated with a giant cell pneumonia)
• dermatophytosis (most commonly Microsporum nanum)