Significance of Stenotrophomonas maltophilia When Detected in Sputum of Ambulatory Patients with COPD

Abstract

Introduction:Stenotrophomonas maltophilia is an emerging Gram-negative MDR bacteria. In patients with chronic obstructive pulmonary disease (COPD), it is mostly found in those with severe exacerbation of COPD requiring mechanical ventilation. The significance of S. maltophilia when detected in the sputum of ambulatory patients with COPD is uncertain. Objective: To access the prevalence and the risk factors of the presence of S. maltophilia in the sputum of ambulatory patients with COPD and to determine whether it was associated with prognosis. Methods: All consecutive unselected ambulatory patients with GOLD 2-4 COPD were recruited between January 2017 and September 2019 from the COPD clinic of a tertiary care hospital. Presence of S. maltophilia was defined by a positive sputum culture for S. maltophilia. Demographics, COPD characteristics, comorbidities and known predisposing risk factors associated with S. maltophilia were collected from medical records. Results: S. maltophilia was detected in the sputum of 41/393 (10%) of study participants. Comorbidities, exacerbation, use of oral steroids and carbapenems in the previous year were risk factors for the presence of S. maltophilia. After adjusting on confounding factors associated with mortality including age, Charlson comorbidity index and FEV 1 , S. maltophilia was significantly associated with mortality (adjusted hazard ratio 2.3; 95% CI 1.1-4.9). Conclusion:In the current study, we found that 10% of ambulatory patients with GOLD 2-4 COPD had S. maltophilia detected in their sputum. In addition, S. maltophilia may represent a marker of overall morbidity in patients with COPD.

Inhaled corticosteroids andStenotrophomonas maltophiliain outpatients with chronic obstructive pulmonary disease: a retrospective cohort study

“… 18 In a Canadian population of outpatients with COPD, S. maltophilia was detected in 10% of patients and associated with a twofold increase in mortality. 19 In a recent study from our group, S. maltophilia in the lower respiratory tract was associated with a threefold increased risk of both hospitalisation-requiring exacerbation of COPD and death. 20 …”

“…The evidence on COPD and the role of S. maltophilia is sparse, and even slimmer when considering ICS use in patients with COPD. A single study has found an association between ICS and infection with S. maltophilia , but not differentiated by ICS doses 19. A meta-analysis covering eight studies on S. maltophilia in intensive care units shows an association between COPD and S. maltophilia pneumonia 29…”

“…The role of S. maltophilia in patients with COPD is poorly understood, and it is debated whether it should be considered a marker of disease progression or regarded as a pathogen in chronic lung diseases such as cystic fibrosis 18. In a Canadian population of outpatients with COPD, S. maltophilia was detected in 10% of patients and associated with a twofold increase in mortality 19. In a recent study from our group, S. maltophilia in the lower respiratory tract was associated with a threefold increased risk of both hospitalisation-requiring exacerbation of COPD and death 20…”

Current viewpoint on the epidemiology of nonfermenting Gram-negative bacterial strains

“…The clinical epidemiology of the emerging NFGNB from recent studies is summarized in Table 1[45,46,61,70,72–97].…”

Mortality and exacerbations associated with Stenotrophomonas maltophilia in chronic obstructive pulmonary disease. A regional cohort study of 22,689 outpatients

“…In a Canadian population of COPD outpatients, S. maltophilia was found in 10% of patients, and associated with a 2-fold increase in mortality [ 6 ]. However, the sample size was small (n = 397), and the prevalence was notably higher than earlier findings of 0.5% in stable COPD patients [ 7 ].…”