BioDefender™

		Facts About Microbes Resident Normal Flora
Normal Skin Flora The skin becomes colonized by normal flora from birth. Colonization of the skin by normal skin flora is related to different factors: Age In infants and children Micrococci are more prominent than in adult's skin. In adults Propionibacterium are more due to the increased skin lipids. In old age streptococci and enterococci become residents of skin especially in moist areas. Sex Males carry higher numbers of bacteria than females. Race Blacks have less nasal carriage of Staphylococci than Caucasians. Type of colonizing strains Colonization of one area of skin by one strain of Staphylococci interferes with colonization by another species. Skin Conditions The skin provides a dry, mechanical barrier from which contaminating organisms on the surface are constantly removed by desquamation. Resident normal skin flora are found more on moist areas containing abundant sebaceous glands, while dry skin has less resident normal flora. Huge number of harmless normal bacterial flora colonizes the normal skin. These may be resident on the skin and its appendages or transient flora. When the immune condition is impaired or the skin is irritated or injured, non-pathogenic organisms may change their behavior and become pathogenic. The mechanism of pathogenicity and even the same strain virulence and ability to cause inflammation depend mainly on: The state of the skin epithelium and its secretions. The cellular and humoral factors. Interaction between the commensal organisms and other organisms. Permanent eradication of carriage of Staph. Aureus is not possible, but temporary elimination may be by oral or topical antibiotics but soon there will be recolonization after stopping the antibiotics.

back