Biofilms in cystic fibrosisDownloads

A 4-year-old boy is brought by his parents to his pediatrician’s office. His mother mentions that the child has been producing an increased number of foul stools recently. His mother says that over the past year, he has had 1 or 2 foul-smelling stools per month. Lately, however, the stools are looser, more frequent, and have a distinct odor. Over the past several years, he has been admitted 4 times with episodes of pneumonia. Genetic studies reveal a mutation on a specific chromosome that has led to a 3 base-pair deletion for the amino acid phenylalanine. Which of the following chromosomes is the defective gene responsible for this boy’s clinical condition?

A 20-year-old woman presents for a follow-up visit with her physician. She has a history of cystic fibrosis and is currently under treatment. She has recently been struggling with recurrent bouts of cough and foul-smelling, mucopurulent sputum over the past year. Each episode lasts for about a week or so and then subsides. She does not have a fever or chills during these episodes. She has been hospitalized several times for pneumonia as a child and continues to struggle with diarrhea. Physically she appears to be underweight and in distress. Auscultation reveals reduced breath sounds on the lower lung fields with prominent rhonchi. Which of the following infectious agents is most likely associated with the recurrent symptoms this patient is experiencing?