Eminently Adaptable Harry smiled at his favorite nurse. He was back in hospital being treated for a chronic lung infection caused by Pseudomonas aeruginosa. Four years ago, shortly before his first birthday, Harry had been diagnosed with cystic fibrosis (CF). This recessive hereditary disease causes several systemic problems, including breathing difficulties precipated by abnormally viscous mucus in the lungs. Normally, dust and potential pathogens are swept out of the respiratory passages by the mucociliary elevator, but in patients with CF , this mechanism is impaired by the thick mucus which instead promotes bacterial growth. In fact, most CF patients eventually die from complications caused by long-term P . aeruginosa colonization of the bronchial passages. While P , aeruginosa is also abundant in the environment and a common opportunistic pathogen in hospitals, CF-associated strains seem particularly suited to persistence in the lungs. As one example, CF-associated P . aeruginosa strains are commonly observed to produce large slimy colonies, although the trait is rare in environmental isolates. The mucoid phenotype is due to the overproduction of alginate-the exopolysaccharide normally associated with biofilm formation. 1st attempt Part 1 (1 point) The mucoid phenotype promotes P . aeruginosa persistence in the lungs because of alginate's ability to do which? Choose one: A. protect cells from antibiotics B. stimulate cell division C. facilitate movement through the biofilm D. promote nutrient uptake Part 2 (1 point) The mucoid phenotype can result from one or more alterations in certain genes that encode regulatory proteins involved in alginate production. What is the likely mechanism by which cells in the biofilm acquire this ability? Choose one: A. conjugation B. mutation C. transformation D. transduction Part 3 (1 point) In addition to the mucoid phenotype, CF-associated P . aeruginosa may rapidly diversify during a persistent infection to produce mutants with cell envelope modifications, nutritional dependencies, and/or acquired resistance to various antibiotics. This phenomenom would be consistent with an inoperative cellular.

1. Eminently Adaptable Harry smiled at his favorite nurse. He was back in hospital being treated
for a chronic lung infection caused by Pseudomonas aeruginosa. Four years ago, shortly before
his first birthday, Harry had been diagnosed with cystic fibrosis (CF). This recessive hereditary
disease causes several systemic problems, including breathing difficulties precipated by
abnormally viscous mucus in the lungs. Normally, dust and potential pathogens are swept out of
the respiratory passages by the mucociliary elevator, but in patients with CF , this mechanism is
impaired by the thick mucus which instead promotes bacterial growth. In fact, most CF patients
eventually die from complications caused by long-term P . aeruginosa colonization of the
bronchial passages. While P , aeruginosa is also abundant in the environment and a common
opportunistic pathogen in hospitals, CF-associated strains seem particularly suited to persistence
in the lungs. As one example, CF-associated P . aeruginosa strains are commonly observed to
produce large slimy colonies, although the trait is rare in environmental isolates. The mucoid
phenotype is due to the overproduction of alginate-the exopolysaccharide normally associated
with biofilm formation. 1st attempt Part 1 (1 point) The mucoid phenotype promotes P .
aeruginosa persistence in the lungs because of alginate's ability to do which? Choose one: A.
protect cells from antibiotics B. stimulate cell division C. facilitate movement through the
biofilm D. promote nutrient uptake Part 2 (1 point) The mucoid phenotype can result from one or
more alterations in certain genes that encode regulatory proteins involved in alginate production.
What is the likely mechanism by which cells in the biofilm acquire this ability? Choose one: A.
conjugation B. mutation C. transformation D. transduction Part 3 (1 point) In addition to the
mucoid phenotype, CF-associated P . aeruginosa may rapidly diversify during a persistent
infection to produce mutants with cell envelope modifications, nutritional dependencies, and/or
acquired resistance to various antibiotics. This phenomenom would be consistent with an
inoperative cellular