oropharyngeal normal flora

Question 1

Name the microbiota of the oropharyngeal tract

Answer 1

viridans streptococci, β-hemolytic streptococci, Staphylococcus aureus, Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, many anaerobic bacteria including Fusobacterium spp. and Actinomyces israelii, and yeast including Candida albicans.

Question 2

Why does the normal microbiota of patients that have been in the hospital for long and are very sick switch from predominantly gram positive (streptococci) to gram negative (Enterobactericiae and Pseudomonas spp.)?

Answer 2

May have less fibronectin expressed on surface of cells leading to loss of binding of gram positives.