Chp 19, Lect 2

Bacteria diseases of the skin and wounds folliculitis

infection of hair follicle

Furuncle

A large painful raised nodular extensions of folliculitis result in spread of infection surrounding tissues

When furuncles join together they make carbuncle

Most common cause of folliculitis and associated functions is staphylococcus

Gram-Positive anaerobic bacteria where the spherical cells are clustered in grap arrangements

Staphylococcus

Epidermidis

Major member of microbiome accounting for 90% of bacteria on skin

Aureus

virulent pathogen grows nasal passages and produces a wide variety of disease conditions and symptoms

Staohylococci

3 categories of virulence factors allow them to make disease

Enzymes

virlence strains of S. Aureus

Coagulase clots blood which hide the bacterium from phagocytosis

Stapylokinase

Dissolves blood clots which allows staph to spread to new locations

Lipases

Presents in S. epidermidis digest lipids providing pathogen with food on surface of skin, hair follicles, and in sebaceous glands

B- Lactamase

Gives resistance to many beta-lactam antimicrobial drugs like PCN and cephalosporin

Both of these avoid bodies defense by creating loosely organized polysaccharide slime layers stop chemotaxis pf phagocytosis by leukocytes

Cytolytic toxins

Disrupt the cells membrane

This is transmitted via direct contact or by fomites

Can spread into hypodermis to form furuncle or into other hair follicles to form carbuncle. Can spread into blood