Elevated glucose increases methicillin-resistant Staphylococcus aureus antibiotic tolerance in a cystic fibrosis airway epithelial cell infection model.

Background: In a healthy lung, the airway epithelium regulates glucose transport to maintain low glucose concentrations in the airway surface liquid (ASL). However, hyperglycemia and chronic lung diseases, such as cystic fibrosis (CF), can result in increased glucose in bronchial aspirates. People with CF are also at increased risk of lung infections caused by bacterial pathogens, including methicillin-resistant Methods: To model the CF airways, we cultured immortalized CF (CFBE41o-) and non-CF (16HBE) human bronchial epithelial cells at air liquid interface (ALI). Glucose concentrations in the basolateral media were maintained at 5.5 mM or 12.5 mM, to mimic a normal and hyperglycemic milieu respectively. 2-deoxyglucose was added to high glucose culture media to restrict glucose availability. We collected ASL, basolateral media, and RNA from ALI cultures to assess the effects of elevated glucose. We also inoculated Results: We found that glucose concentrations in the ASL of ALI cultures maintained in normal or high glucose mimicked levels measured in breath condensate assays from people with CF and hyperglycemia. Additionally, we found hyperglycemia increased Conclusions: These data indicate hyperglycemia alters