Open Access Research article

Aspirin enhances opsonophagocytosis and is associated to a lower risk for Klebsiella pneumoniae invasive syndrome

Chen-Hsiang Lee12, Lin-Hui Su34, Jien-Wei Liu12, Chia-Chi Chang1, Rong-Fu Chen5 and Kuender-D Yang5*

Author Affiliations

1 Division of Infectious Diseases, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan

2 Chang Gung University College of Medicine, Kaohsiung, Taiwan

3 Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taiwan

4 Chang Gung University, College of Medicine, Kweishan, Taoyuan, Taiwan

5 Department of Medical Research, Show Chwan Memorial Hospital, 6 Lukong Road, Lugang, Changhua 505, Taiwan

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BMC Infectious Diseases 2014, 14:47  doi:10.1186/1471-2334-14-47

Published: 30 January 2014



Klebsiella pneumoniae (KP) expressing hypermucoviscosity phenotype (HV-KP) has abundant capsular polysaccharide (CPS) and is capable of causing invasive syndrome. Sodium salicylate (SAL) reduces the production of CPS. The study was aimed to investigate the relationship between aspirin usage and KP-mediated invasive syndrome and the effect of SAL on HV-KP.


Patients with community-acquired KP bacteraemia were prospectively enrolled. KP-M1, a serotype-K1 HV-KP clinical isolate, was used in the following experiments: CPS production, HV-KP phenotype, and the effect of SAL on neutrophils phagocytosis. The effect of oral aspirin intake on the leukocyte bactericidal activity was evaluated.


Patients infected by HV-KP and diabetic patients with poor glycemic control were at an increased risk for invasive syndrome (p < 0.01); those who had recent use of aspirin (p = 0.02) were at a lower risk. CPS production was significantly reduced in the presence of SAL. The HV-KP phenotype and resistance to neutrophil phagocytosis were both significantly reduced in the KP-M1 after incubation with SAL (p < 0.01). Aspirin treatment significantly enhanced the killing of KP-M1 by leukocytes (p < 0.01).


Treatment with SAL significantly reduces CPS production in HV-KP, thereby contributing to leukocyte phagocytosis and bactericidal activity against this pathogen.

Salicylate; K. pneumoniae; Hypermucoviscosity; Phagocytosis; Invasive syndrome