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


METHODS
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.


RESULTS
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).


CONCLUSIONS
Treatment with SAL significantly reduces CPS production in HV-KP, thereby contributing to leukocyte phagocytosis and bactericidal activity against this pathogen.
Chen-Hsiang
CH
Lee
Lin-Hui
LH
Su
Jien-Wei
JW
Liu
Chia-Chi
CC
Chang
Rong-Fu
RF
Chen
Department of Medical Research, Show Chwan Memorial Hospital, 6 Lukong Road, Lugang, Changhua 505, Taiwan. yangkd.yeh@hotmail.com.
Kuender-D
KD
Yang
D000368:Aged; D001241:Aspirin / Q000008:administration & dosage*; D016470:Bacteremia / Q000188:drug therapy* / Q000276:immunology; D016667:Bacterial Capsules / Q000187:drug effects; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000276:immunology; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000188:drug therapy* / Q000276:immunology; D007711:Klebsiella pneumoniae / Q000235:genetics / Q000502:physiology*; D007962:Leukocytes / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects*; D011446:Prospective Studies; D012307:Risk Factors
D001241:Aspirin