Antibiotic-resistant Pseudomonas aeruginosa infection in patients with bronchiectasis: prevalence, risk factors and prognostic implications

Abstract

Background and aims

Pseudomonas aeruginosa (PA) is the most common pathogen in bronchiectasis and frequently develops resistance to multiple classes of antibiotics, but little is known about the clinical impacts of PA-resistant (PA-R) isolates on bronchiectasis. We, therefore, investigated the prevalence, risk factors and prognostic implications of PA-R isolates in hospitalized bronchiectasis patients.

Patients and methods

Between June 2011 and July 2016, data from adult bronchiectasis patients isolated with PA at the First Affiliated Hospital of Zhengzhou University were retrospectively analyzed. PA was classified as PA-R in case antibiogram demonstrated resistance on at least one occasion.

Results

Seven hundred forty-seven bronchiectasis patients were assessed. Of these, 147 (19.7%) had PA isolate in the sputum or bronchoscopic culture. PA-R and PA-sensitive accounted for 88 (59.9%) and 59 (31.1%) patients, respectively. In multivariate model, factors associated with PA-R isolate in bronchiectasis included prior exposure to antibiotics (odds ratio [OR] =6.18), three or more exacerbations in the previous year (OR =2.81), higher modified Medical Research Council dyspnea scores (OR =1.93) and greater radiologic severity (OR =1.15). During follow-up (median: 26 months; interquartile range: 6–59 months), 36 patients died, of whom 24 (66.7%) had PA-R isolate at baseline. However, PA-R isolate was not associated with greater all-cause mortality in bronchiectasis.

Conclusion

PA-R infection is common among bronchiectasis patients, mainly determined by prior exposure to antibiotics, frequent exacerbations, more pronounced dyspnea and more severe radiologic involvement. However, PA-R isolate is not an independent risk factor for all-cause mortality in bronchiectasis.

Keywords:

• bronchiectasis
• antibiotic resistance
• Pseudomonas aeruginosa
• risk factors
• mortality

Supplementary materials

Table S1 MIC interpretive standards of the disk diffusion methodologies for PA according to the CLSI

Table S2 Antibiotic resistance profile of 147 Pseudomonas aeruginosa isolates

Table S3 Baseline and clinical characteristics of bronchiectasis patients with PA-R in non-MDR and MDR groups in sputum

Table S4 Factors associated with the presence of MDR-PA in patients with bronchiectasis in a logistic regression model

Acknowledgments

Y-HG declared that he has received the National Natural Science Foundation No 81500006 and the Open Project of State Key Laboratory of Respiratory Disease No SKLRD2016OP013. W-JG declared that he has received the National Natural Science Foundation No 81400010, Pearl River S&T Nova Program of Guangzhou No 201710010097, and Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2017.

Author contributions

Y-HG and W-JG drafted the manuscript; Y-NZ, R-CC and G-JZ were responsible for data collection; Y-HG performed statistical analyses; Y-HG, W-JG, R-CC and G-JZ contributed to study conception; R-CC and G-JZ provided critical review of the manuscript and approved the final submission. All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.