Jung IY, et al. - Researchers sought to determine the predictive factors for mortality and the impact of mucA gene mutation in chronic obstructive pulmonary disease (COPD) patients with P. aeruginosa pneumonia. For COPD patients with P. aeruginosa pneumonia at two university hospitals, they gathered clinical and laboratory data and analyzed the P. aeruginosa isolates for the presence of mucA gene mutations. They found that the presence of mucoid P. aeruginosa was related to poor prognosis. They also observed that MucA gene mutation mediated the mucoid conversion of P. aeruginosa. Overall, to identify poor prognosis in COPD patients with P. aeruginosa pneumonia, CA ratio and mucA gene mutation of P. aeruginosa could be used as predictors.