|Cystic fibrosis lung microbiome|
Cystic fibrosis (CF), the most common lethal autosomal recessive disorder in Caucasians populations, is caused by mutations in the CFTR gene, located on chromosome 7, which encodes the CF transmembrane conductance regulator (CFTR). It is characterized by severe pulmonary and intestinal symptoms, in particular chronic pulmonary inflammation, microbial lung infections, intestinal obstruction and pancreatic insufficiency. CFTR regulates chloride and bicarbonate transport across the epithelial cells. The mutations in this gene provoke an abnormal chloride transport, which ends with the dehydration of the mucus layer located around the epithelial cells (Figure). This thick mucus provides a favorable environment for colonization and growth of several opportunistic bacterial pathogens causing inflammatory responses and infections in CF patients. For this reason, a better understanding of community profile is needed as well as the identification of the nucleotide variants in the main pathogens or antibiotic resistance genes.
Already is known that during the first years of CF patients' life, Staphylococcus aureus and Hemophilus influenzae are the most common bacteria isolated from the sputum, but in the second and third decade of life, the opportunistic pathogen Pseudomonas aeruginosa is the prevalent bacterium. Other opportunists include nosocomial pathogens such as Stenotrophomonas maltophilia and Achromobacter xylosoxidans and other species like the Burkholderia cepacia complex. Chronic infection by these pathogens lead to inflammation that gradually degrades lung function, resulting in morbidity and early mortality.
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