It is true regarding the normal microbial flora present on the skin and mucous membranes that ?

Ans is 'a' i.e., It cannot be eradicated by antimicrobial agents . The normal microbial flora are more or less constant for each species and are broadly divided into residents and transients. The former constitute a constant population which cannot be completely removed permanently. - Ananthanarayan 7'''/e 599 . Because of low pH of stomach, it is viually sterile except soon after eating - Ananthanarayan 71/4 601 . With in 4-24 hours of bih an intestinal flora is established - Ananthanarayan r/e 600 . In the pharynx and trachea, flora is similar to that of mouth, while smaller bronchi and alveoli are normally sterile - Ananthanarayan 7th/e 600