where is staphylococcus aureus found in the human body
Staphylococcus aureus Staphylococcus aureus is a Gram-positive, round-shaped bacterium that is a member of the Firmicutes, and it is a member of the normal flora of the body, frequently found in the nose, respiratory tract, and on the skin. It is often positive for catalase and nitrate reduction and is a facultative anaerobe that can grow without the need for oxygen.[1] Although S. aureus is not always pathogenic (and can commonly be found existing as a commensal), it is a common cause of skin infections including abscesses, respiratory infections such as sinusitis, and food poisoning. Pathogenic strains often promote infections by producing virulence factors such as potent protein toxins, and the expression of a cell-surface protein that binds and inactivates antibodies. The emergence of antibiotic-resistant strains of S. aureus such as methicillin-resistant S. aureus (MRSA) is a worldwide problem in clinical medicine. Despite much research and development, no vaccine for S. aureus has been approved.
Streptococcal pharyngitis Strep throat is caused by group A beta-hemolytic streptococcus (GAS or S. pyogenes).[11] Other bacteria such as non–group A beta-hemolytic streptococci and fusobacterium may also cause pharyngitis.[8][10] It is spread by direct, close contact with an infected person; thus crowding, as may be found in the military and schools, increases the rate of transmission.[10][12] Dried bacteria in dust are not infectious, although moist bacteria on toothbrushes or similar items can persist for up to fifteen days.[10] Contaminated food can result in outbreaks, but this is rare.[10] Of children with no signs or symptoms, 12% carry GAS in their pharynx,[5] and, after treatment, approximately 15% of those remain positive, and are true "carriers".[13]