Phenotypic and Genotypic Characteristics of Pseudomonas aeruginosa Causing Bloodstream Infection from Six Tertiary Hospitals in Beijing, China

Abstract

Background: Pseudomonas aeruginosa is one of the most prevalent pathogens in China. However, little is known about the prevalence of clinical P. aeruginosa isolates causing bloodstream infections (BSIs) in China. Methods: BSI-causing P. aeruginosa (BSI-PA) was collected from six tertiary-care hospitals in Beijing. Genetic relatedness was analyzed by pulsed-field gel electrophoresis (PFGE); Antimicrobial susceptibility testing was performed by agar dilution method, and sequence types (STs) were evaluated by multilocus sequence typing (MLST).Results: A total of 80 non-duplicated BSI-PA isolates were collected from December 2013 to December 2014 and categorized into 69 types (strains) using unique PFGE patterns. Among the 69 BSI-PA strains, 41 STs were identified. Overall, the primary STs were ST244, ST274, ST260 and ST1052 (n = 18), followed by ST270, ST235, ST1295 (n = 3), and ST242, ST275, ST316, ST357 (n = 2). There were 25 STs that only contained a single strain. Approximately 31.9% (22/69) of the strains exhibited carbapenem-resistant phenotype, and most of them carried bla VIM . Conclusion:The majority of BSI-PA strains exhibited high genetic diversity and low resistance to commonly used antimicrobials.