Question

Microbiology: Where are/aren’t normal flora found in the body? (male vs. female)

How do we acquire them? (birth and afterward

Why might the populations fluctuate? (naturally, antibiotics)

Answer 1

1. ANS: Normal flora found in the body: (male vs. female)

Normal flora can be found in many sites of the human body including the skin (especially in moist areas), respiratory tract (nose), urinary tract, and the digestive tract (primarily the mouth and the colon).

nose skin mouth lungs small intestine stomach colon urinary/ vaginal tract(s) rectum

2. ANS: Normal flora acquiring:

Birth: During the process of birth, the infant is exposed to vaginal flora. Within a few hours of birth oral and nasopharyngeal flora develops and in a day or two resident flora of the lower intestine appears

Afterward: The normal flora in humans usually develops in an orderly sequence, or succession, after birth, leading to the stable populations of bacteria that make up the normal adult flora.

3. ANS: Populations fluctuate:

Transient fluctuations in the stability of the oral ecosystem may be induced by the frequency and type of food ingested, periods of antibiotic therapy, and variations in the composition and rate of flow of saliva.

Ex: 1. When antibiotics given for other infections cause collateral damage to the normal intestinal flora.

      2. A side-effect of medication can be a reduction in saliva flow, and this can predispose a site to caries.