All of the following statements about staphylococcus aureus are true, EXCEPT:

Carriers of staphylococcus aureus are the primary source for cross infection to individuals who do not normally have this bacterium in their commensal microflora. Individuals normally free from s.aureus may have less immunity against the lethal consequence of S.aureus infection compared with those who are persistent carrier of the species and suffer from endogenous infection. Most individuals who develop staphylococcus aureus infections are infected with their own colonizing strains. However, S. aureus may also be acquired from other people or from environmental exposures. Ref: Jawetz, Melnick and Adelberg's Medical Microbiology, 23rd Edition, Pages 224 - 228; Staphylococci in Human Disease By Kent B. Crossley, Page 265; Microbiology and Immunology By Monica Gandhi, Page 4; Harrison's Principles of Internal Medicine, 17th edition, Pages 873 - 879.