Staphylococcus aureus can cause lung infections and is often present in the mucus and sputum of children with cystic fibrosis. When S. aureus -- including the antibiotic-resistant form, MRSA -- is found in people with CF, it is treated with antibiotics, but exactly how S. aureus affects the lungs in people with this condition is unknown. Previous research models have often looked at S. aureus in the lungs of mice, however when S. aureus is infected into mouse lungs, abscesses form and abscess are extremely rare in people with CF. In the paper 'An ex vivo cystic fibrosis model recapitulates key clinical aspects of chronic Staphylococcus aureus infection', published in the journal Microbiology, researchers from the School of Life Sciences at the University of Warwick, have found that using left over pig lungs from a butcher, and synthetic mucus that mimics CF lung secretions, that S. aureus tends to aggregate in mucus, not invade the lung tissue as it does in mice. To see if they could find a better way to mimic human CF lungs, and decrease the use of animal testing, the researchers used pig lungs from a butcher, and adding synthetic CF mucus. They then introduced the S. aureus and found that it tended to aggregate in the mucus, rather than invading the lung tissue as would happen with an abscess. Get the full story at sciencedaily.com.