Symptoms And Treatment Of Patients

2043 Words Dec 4th, 2014 9 Pages
Patient A
Paronychia is an infection of the nail that occurs when bacteria enter the tissue surrounding the nail following trauma to the surrounding skin or cuticle. (Rigopoulos et al, 2008)
S. aureus forms part of the nasal flora of approximately 30% - 40% of the population, and can also be found transiently on the skin and in other areas e.g. mucous membranes, vagina. S. aureus produce lipases and glycerol ester hydrolases which break down lipids in the skin and can also grow in high salt concentrations. These factors facilitate colonisation of the skin.
When the skin barrier is broken, S. aureus is able to penetrate the tissue below. S. aureus produces microbial surface components recognising adhesive matrix molecules (MSCRAMMs) that bind to collagen (CNAs), fibrinogen (clumping factors A and B), and fibronectin (FnbpA, and FnbpB). These MSCRAMMs enable the bacteria to adhere to and infiltrate wounds and tissues.
Once S. aureus has invaded the tissues and multiplied, a combination of the bacteria’s virulence factors and the host immune response causes the formation of an abscess.
Around 90% of S. aureus species produce a capsule that helps the bacterium evade phagocytosis.
Protein A in the cell wall of S. aureus binds to the Fc portion of IgG inhibiting the opsonisation of the organism. Peptidoglycan in the bacterial cell wall activates complement and an inflammatory response. Lipoteichoic acid in the peptidoglycan associates with toll-like receptors on…
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