Clinical Features and Antimicrobial Susceptibility of Pseudomonas aeruginosa and Acinetobacter baumannii Complex Isolates in Intensive Care Patients with Chronic Obstructive Pulmonary Disease and Community-Acquired Pneumonia in Taiwan

Purpose: Little is known about the features and implications of Pseudomonas aeruginosa (PA) and Acinetobacter baumannii complex (ABC) isolates discovered in patients with chronic obstructive pulmonary disease (COPD) and community-acquired pneumonia (CAP) requiring invasive mechanical ventilation and admission to an intensive care unit. Thus, our study aimed to investigate the clinical characteristics and antimicrobial susceptibilities of PA and ABC isolates cultured from endotracheal aspirates (EAs) in such population. Patients and Methods: In this retrospective, cross-sectional study, clinical data from medical records were reviewed and collected for analysis. Results: Of the 262 participants, 17.2% (45/262), 11.5% (30/262), and 27.1% (71/262) had PA, ABC, and any of the two isolates discovered from EA cultures, respectively. Patients with PA isolates were associated with poorer lung function (the Global Initiative for Chronic Obstructive Lung Disease (GOLD) III+IV versus GOLD I+II, odds ratio (OR)=2.39, p= 0.022) and a lower body mass index (per increase of 1 kg/m(2), OR= 0.93, p= 0.106) while the former was an independent predictor. Moreover, both subjects with ABC isolates and those with any of these two microorganisms were independently associated with a lower serum albumin level (per increase of 1 g/dL, OR= 0.44, p=0.009 and OR= 0.59, p=0.023, respectively). Participants with PA isolates were more likely to have failed weaning (62.2% versus 44.7%, p= 0.048) and death (28.9% versus 12.4%, p= 0.010) than those without PA isolates. The majority of the PA and ABC isolates were susceptible and resistant to all the tested antimicrobials, respectively, except that tigecycline had a reliable activity against ABC. Conclusion: Our findings provide important information to help intensivists make better treatment decisions in critically ill patients with COPD and CAP.