(P-430) Chronic Obstructive Pulmonary Disease and Drug-resistant Pseudomonas in Patients Hospitalized with Community-acquired Bacterial Pneumonia

Background: Patients with chronic obstructive pulmonary disease (COPD) are at risk for hospitalization due to pneumonia with drug-resistant pathogens including pseudomonal species. Pneumonia caused by these pathogens is associated with increased mortality. Understanding relevant risk factors for drug-resistant pseudomonas acquisition has implications for antimicrobial stewardship.

Objectives: To identify factors associated with drug-resistant pseudomonas in patients with COPD hospitalized for the first time with community-acquired bacterial pneumonia.

Methods: We used ICD-9/10 codes to query the electronic medical record (EMR) of the University of Alabama at Birmingham Healthcare System to identify a clinical cohort of patients hospitalized for community-acquired bacterial pneumonia with pseudomonas positive culture from a respiratory sample (sputum, bronchoalveolar lavage, bronchial wash, or tracheal aspirate) between 01/01/2013–12/31/2019; only first hospitalization for bacterial pneumonia during the study period was included, and antimicrobial resistance patterns were recorded. COPD diagnosis of patients before hospitalization was determined. Multivariable logistic regression models were used to examine associations between COPD diagnosis and pseudomonas resistant to specific antipseudomonal agents, adjusted for age, race, and smoking status.

Results: There were 415 adults hospitalized with community-acquired bacterial pneumonia with pseudomonas isolates during the study period. The cohort had a median age of 58 years (IQR:47–69), were 61% male (253), 61% white (251), 92% (379) non-Hispanics, 64% (255) ever-smokers, and 51% (212) had COPD. Also, 97% (402) of the pseudomonal isolates were Pseudomonas aeruginosa. Within the cohort, 42% (175) had pseudomonas isolates resistant to at least 1 antipseudomonal agent. COPD was independently associated with pseudomonas isolates with ciprofloxacin resistance (adjusted odds ratio [aOR] 1.89; 95%CI 1.08-3.31; p=0.03) and levofloxacin resistance (aOR 2.23; 95%CI 1.24-4.00; p=0.007). There were no significant associations between COPD and pseudomonas resistance to piperacillin-tazobactam, ceftazidime, cefepime, imipenem, meropenem, tobramycin, amikacin, or gentamicin.

Conclusions: We observed increased pseudomonas resistance to two fluoroquinolones in COPD patients hospitalized for the first time with community-acquired bacterial pneumonia, possibly reflecting outpatient fluoroquinolone use among this patient population.