All are TRUE about S.aureus, EXCEPT:
S. aureus is a pa of the normal human flora; 25-50% of healthy persons are usually colonized. The rate of colonization is higher in 1. Insulin-dependent diabetics, 2. HIV-infected patients, 3. Patients undergoing hemodialysis, 4. Individuals with skin damage. MUST KNOW: Frequent site of colonization: 1. Anterior nares are a frequent site of human colonization, 2. Skin (especially when damaged), 3. Vagina, axilla, perineum 4. Oropharynx may also be colonized Injectable insulin with the possibility of impaired leukocyte function increases the risk of colonization. Group of patients with increased risk of colonization: 1. Neutropenic patients (e.g., those receiving chemotherapeutic agents) 2. Chronic granulomatous disease 3. Job's or Chediak-Higashi syndrome. ALSO KNOW: It is the most common cause of surgical wound infections. Most individuals who develop S. aureus infections are infected with their own colonizing strains. Numerous outbreaks of community-based infection caused by methicillin-resistant S. aureus (MRSA) in individuals with no prior medical exposure have been repoed recently. Ref: Harrison, Edition-18, Page-1160.
25-50% of healthy persons are colonized
Injectable insulin users are at increased risk of colonization
It is the most common cause of surgical wound inf
Methicillin resistant S.aureus will not develop in persons not exposed to antibiotics previously